Constraining fundamental physics with future CMB experiments
Galli, Silvia; Martinelli, Matteo; Melchiorri, Alessandro; Pagano, Luca; Sherwin, Blake D.; Spergel, David N.
2010-12-01
The Planck experiment will soon provide a very accurate measurement of cosmic microwave background anisotropies. This will let cosmologists determine most of the cosmological parameters with unprecedented accuracy. Future experiments will improve and complement the Planck data with better angular resolution and better polarization sensitivity. This unexplored region of the CMB power spectrum contains information on many parameters of interest, including neutrino mass, the number of relativistic particles at recombination, the primordial helium abundance, and the injection of additional ionizing photons by dark matter self-annihilation. We review the imprint of each parameter on the CMB and forecast the constraints achievable by future experiments by performing a Monte Carlo analysis on synthetic realizations of simulated data. We find that next generation satellite missions such as CMBPol could provide valuable constraints with a precision close to that expected in current and near future laboratory experiments. Finally, we discuss the implications of this intersection between cosmology and fundamental physics.
Optimal scan strategies for future CMB satellite experiments
Wallis, Christopher G R; Battye, Richard A; Delabrouille, Jacques
2016-01-01
The B-mode polarisation power spectrum in the Cosmic Microwave Background (CMB) is about four orders of magnitude fainter than the CMB temperature power spectrum. Any instrumental imperfections that couple temperature fluctuations to B-mode polarisation must therefore be carefully controlled and/or removed. We investigate the role that a scan strategy can have in mitigating certain common systematics by averaging systematic errors down with many crossing angles. We present approximate analytic forms for the error on the recovered B-mode power spectrum that would result from differential gain, differential pointing and differential ellipticity for the case where two detector pairs are used in a polarisation experiment. We use these analytic predictions to search the parameter space of common satellite scan strategies in order to identify those features of a scan strategy that have most impact in mitigating systematic effects. As an example we go on to identify a scan strategy suitable for the CMB satellite pro...
A Guide to Designing Future Ground-based CMB Experiments
Energy Technology Data Exchange (ETDEWEB)
Wu, W. L.K. [Stanford Univ., CA (United States); Kavli Inst. for Particle Astrophysics and Cosmology, Menlo, Park, CA (United States); Errard, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Dvorkin, C. [Inst. for Advanced Study, Princeton, NJ (United States); Kuo, C. L. [Stanford Univ., CA (United States); Kavli Inst. for Particle Astrophysics and Cosmology, Menlo, Park, CA (United States); Lee, A. T. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McDonald, P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Slosar, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zahn, O. [Univ. of California, Berkeley and Lawrence Berkeley National Lab. (LBNL), CA (United States)
2014-02-18
In this follow-up work to the High Energy Physics Community Summer Study 2013 (HEP CSS 2013, a.k.a. Snowmass), we explore the scientific capabilities of a future Stage-IV Cosmic Microwave Background polarization experiment (CMB-S4) under various assumptions on detector count, resolution, and sky coverage. We use the Fisher matrix technique to calculate the expected uncertainties in cosmological parameters in vΛCDM that are especially relevant to the physics of fundamental interactions, including neutrino masses, effective number of relativistic species, dark-energy equation of state, dark-matter annihilation, and inflationary parameters. To further chart the landscape of future cosmology probes, we include forecasted results from the Baryon Acoustic Oscillation (BAO) signal as measured by DESI to constrain parameters that would benefit from low redshift information. We find the following best 1-σ constraints: σ(M_{v} ) = 15 meV, σ(N_{eff } ) = 0.0156, Dark energy Figure of Merit = 303, σ(p_{ann}) = 0.00588 x 3 x 10^{-26} cm^{3}/s/GeV, σ( Ω_{K}) = 0.00074, σ(n_{s}) = 0.00110, σ( α_{s}) = 0.00145, and σ(r) = 0.00009. We also detail the dependences of the parameter constraints on detector count, resolution, and sky coverage.
Optimal scan strategies for future CMB satellite experiments
Wallis, Christopher G. R.; Brown, Michael L.; Battye, Richard A.; Delabrouille, Jacques
2017-04-01
The B-mode polarization power spectrum in the cosmic microwave background (CMB) is about four orders of magnitude fainter than the CMB temperature power spectrum. Any instrumental imperfections that couple temperature fluctuations to B-mode polarization must therefore be carefully controlled and/or removed. We investigate the role that a scan strategy can have in mitigating certain common systematics by averaging systematic errors down with many crossing angles. We present approximate analytic forms for the error on the recovered B-mode power spectrum that would result from differential gain, differential pointing and differential ellipticity for the case where two detector pairs are used in a polarization experiment. We use these analytic predictions to search the parameter space of common satellite scan strategies in order to identify those features of a scan strategy that have most impact in mitigating systematic effects. As an example, we go on to identify a scan strategy suitable for the CMB satellite proposed for the European Space Agency M5 call, considering the practical considerations of fuel requirement, data rate and the relative orientation of the telescope to the earth. Having chosen a scan strategy we then go on to investigate the suitability of the scan strategy.
Parameterization of temperature and spectral distortions in future CMB experiments
Energy Technology Data Exchange (ETDEWEB)
Pitrou, Cyril; Stebbins, Albert
2014-10-15
CMB spectral distortions are induced by Compton collisions with electrons. We review the various schemes to characterize the anisotropic CMB with a non-Planckian spectrum. We advocate using logarithmically averaged temperature moments as the preferred language to describe these spectral distortions, both for theoretical modeling and observations. Numerical modeling is simpler, the moments are frame-independent, and in terms of scattering the mode truncation is exact.
The Quintessential CMB, Past & Future
Bond, J R; Prunet, S; Sigurdson, K; Ade, P; Balbi, A; Bock, J J; Borrill, J; Boscaleri, A; Coble, K; Crill, B P; De Bernardis, P; Farese, P; Ferreira, P; Ganga, K; Giacometti, M; Hanany, S; Hivon, E; Hristov, V V; Iacoangeli, A; Jaffe, A; Lange, A; Lee, A; Martinis, L; Masi, S; Mauskopf, P D; Melchiorri, A; Montroy, T; Netterfield, C B; Oh, S; Pascale, E; Piacentini, F; Rabii, B; Rao, S; Richards, P; Romeo, G; Ruhl, J E; Scaramuzzi, F; Sforza, D M; Smoot, G F; Stompor, R; Winant, C; Wu, P
2000-01-01
The past, present and future of cosmic microwave background (CMB) anisotropy research is discussed, with emphasis on the Boomerang and Maxima balloon experiments. These data are combined with large scale structure (LSS) information and high redshift supernova (SN1) observations to explore the inflation-based cosmic structure formation paradigm. Here we primarily focus on a simplified inflation parameter set, {omega_b,omega_{cdm},Omega_{tot}, Omega_Q,w_Q, n_s,tau_C, sigma_8}. After marginalizing over the other cosmic and experimental variables, we find the current CMB+LSS+SN1 data gives Omega_{tot}=1.04\\pm 0.05, consistent with (non-baroque) inflation theory. Restricting to Omega_{tot}=1, we find a nearly scale invariant spectrum, n_s =1.03 \\pm 0.07. The CDM density, omega_{cdm}=0.17\\pm 0.02, is in the expected range, but the baryon density, omega_b=0.030\\pm 0.004, is slightly larger than the current nucleosynthesis estimate. Substantial dark energy is inferred, Omega_Q\\approx 0.68\\pm 0.05, and CMB+LSS Omega_Q...
Rubiño-Martín, J. A.; Rebolo, R.; Tucci, M.; Génova-Santos, R.; Hildebrandt, S. R.; Hoyland, R.; Herreros, J. M.; Gómez-Reñasco, F.; Caraballo, C. López; Martínez-González, E.; Vielva, P.; Herranz, D.; Casas, F. J.; Artal, E.; Aja, B.; Fuente, L. dela; Cano, J. L.; Villa, E.; Mediavilla, A.; Pascual, J. P.; Piccirillo, L.; Maffei, B.; Pisano, G.; Watson, R. A.; Davis, R.; Davies, R.; Battye, R.; Saunders, R.; Grainge, K.; Scott, P.; Hobson, M.; Lasenby, A.; Murga, G.; Gómez, C.; Gómez, A.; Ariño, J.; Sanquirce, R.; Pan, J.; Vizcargüenaga, A.; Etxeita, B.
We present the current status of the QUIJOTE (Q-U-I JOint TEnerife) CMB Experiment, a new instrument which will start operations early in 2009 at Teide Observatory with the aim of characterizing the polarization of the CMB and other processes of galactic and extragalactic emission in the frequency range 10-30GHz and at large angular scales. QUIJOTE will be a valuable complement at low frequencies for the PLANCK mission, and will have the required sensitivity to detect a primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r = 0.05.
Rubiño-Martín, J A; Tucci, M; Genova-Santos, R; Hildebrandt, S R; Hoyland, R; Herreros, J M; Gomez-Renasco, F; Caraballo, C Lopez; Martínez-González, E; Vielva, P; Herranz, D; Casas, F J; Artal, E; Aja, B; de la Fuente, L; Cano, J L; Villa, E; Mediavilla, A; Pascual, J P; Piccirillo, L; Maffei, B; Pisano, G; Watson, R A; Davis, R; Davies, R; Battye, R; Saunders, R; Grainge, K; Scott, P; Hobson, M; Lasenby, A; Murga, G; Gómez, C; Gómez, A; Arino, J; Sanquirce, R; Pan, J; Vizcarguenaga, A; Etxeita, B
2008-01-01
We present the current status of the QUIJOTE (Q-U-I JOint TEnerife) CMB Experiment, a new instrument which will start operations early 2009 at Teide Observatory, with the aim of characterizing the polarization of the CMB and other processes of galactic and extragalactic emission in the frequency range 10-30 GHz and at large angular scales. QUIJOTE will be a valuable complement at low frequencies for the PLANCK mission, and will have the required sensitivity to detect a primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r=0.05.
Karkare, Kirit S.; BICEP/Keck Array Collaboration
2017-01-01
The BICEP/Keck Array cosmic microwave background (CMB) polarization experiments located at the South Pole are a series of small-aperture refracting telescopes focused on the degree-scale B-mode signature of inflationary gravitational waves. These highly-targeted experiments have produced the world's deepest maps of CMB polarization, leading to the most stringent constraints on the tensor-to-scalar ratio to date: sigma(r) = 0.024 and r current instrument and analysis technology will scale with detector count.
The QUIJOTE-CMB Experiment: Progress Report
Génova-Santos, Ricardo; Rebolo, R.; Rubiño-Martín, J. A.; Aguiar, M.; Gómez-Reñasco, F.; Herreros, J. M.; Hildebrandt, S.; Hoyland, R.; López-Caraballo, C.; Rodríguez, R.; Tucci, M.; Martínez-González, E.; Barreiro, R. B.; Casas, F. J.; Fernández-Cobos, R.; Herranz, D.; López-Caniego, M.; Vielva, P.; Artal, E.; Aja, B.; Cano, J. L.; de La Fuente, L.; Mediavilla, A.; Pascual, J. P.; Villa, E.; Piccirillo, L.; Battye, R.; Davies, R.; Davis, R.; Dickinson, C.; Maffei, B.; Pisano, G.; Watson, R. A.; Brown, M.; Challinor, A.; Grainge, K.; Hobson, M.; Lasenby, A.; Saunders, R.; Scott, P.; Ariño, J.; Etxeita, B.; Gómez, A.; Gómez, C.; Murga, G.; Pan, J.; Sanquirce, R.; Vizcargüenaga, A.
We briefly discuss the scientific objectives of the QUIJOTE (Q-U-I JOint TEnerife) CMB experiment, and present the current status and future scheduling of this project. QUIJOTE is a new project to study the polarization of the Cosmic Microwave Background (CMB) and of the Galactic and extragalactic emission in the frequency range 10-30 GHz and with an angular resolution of 1°. It will start operations in summer 2010 from the Teide Observatory. The scientific goal of this experiment is twofold: i) to characterize at low frequencies the polarization of the synchrotron and anomalous emissions, making then possible the correction of these CMB contaminants in the data of similar experiments operating at higher frequencies; and ii) to detect (or to constrain) the imprint of the primordial gravitational-wave background in the polarization pattern of the CMB if the tensor-to-scalar ratio is larger (lower) than r = 0:05.
Impact of modelling foreground uncertainties on future CMB polarization satellite experiments
Hervías-Caimapo, Carlos; Bonaldi, Anna; Brown, Michael L.
2017-07-01
We present an analysis of errors on the tensor-to-scalar ratio due to residual diffuse foregrounds. We use simulated observations of a cosmic microwave background (CMB) polarization satellite, the Cosmic Origins Explorer (COrE), using the specifications of the version proposed to ESA in 2010. We construct a full pipeline from microwave sky maps to r likelihood, using two models of diffuse Galactic foregrounds with different complexity and assuming component separation with varying degrees of accuracy. Our pipeline uses a linear mixture (generalized least squares) solution for component separation, and a hybrid approach for power spectrum estimation, with a quadratic maximum likelihood estimator at low ℓs and a pseudo-Cℓ deconvolution at high ℓs. In the likelihood for r, we explore modelling foreground residuals as nuisance parameters. Our analysis aims at measuring the bias introduced in r by mismodelling the foregrounds and to determine what error is tolerable while still successfully detecting r. We find that r = 0.01 can be measured successfully even for a complex sky model and in the presence of foreground parameters error. However, the detection of r = 0.001 is a lot more challenging, as inaccurate modelling of the foreground spectral properties may result in a biased measurement of r. Once biases are eliminated, the total error on r allows setting an upper limit rather than a detection, unless the uncertainties on the foreground spectral indices are very small, i.e. equal or better than 0.5 per cent error for both dust and synchrotron. This emphasizes the need for pursuing research on component separation and foreground characterization in view of next-generation CMB polarization experiments.
Raghunathan, Srinivasan; Patil, Sanjaykumar; Baxter, Eric J.; Bianchini, Federico; Bleem, Lindsey E.; Crawford, Thomas M.; Holder, Gilbert P.; Manzotti, Alessandro; Reichardt, Christian L.
2017-08-01
We develop a Maximum Likelihood estimator (MLE) to measure the masses of galaxy clusters through the impact of gravitational lensing on the temperature and polarization anisotropies of the cosmic microwave background (CMB). We show that, at low noise levels in temperature, this optimal estimator outperforms the standard quadratic estimator by a factor of two. For polarization, we show that the Stokes Q/U maps can be used instead of the traditional E- and B-mode maps without losing information. We test and quantify the bias in the recovered lensing mass for a comprehensive list of potential systematic errors. Using realistic simulations, we examine the cluster mass uncertainties from CMB-cluster lensing as a function of an experiment's beam size and noise level. We predict the cluster mass uncertainties will be 3 - 6% for SPT-3G, AdvACT, and Simons Array experiments with 10,000 clusters and less than 1% for the CMB-S4 experiment with a sample containing 100,000 clusters. The mass constraints from CMB polarization are very sensitive to the experimental beam size and map noise level: for a factor of three reduction in either the beam size or noise level, the lensing signal-to-noise improves by roughly a factor of two.
Can CMB Experiments Find Planet Nine?
Kohler, Susanna
2016-04-01
Recent studies have identified signs of an unseen, distant ninth planet in our solar system. How might we find the elusive Planet Nine? A team of scientists suggests the key might be cosmology experiments.AHypothetical PlanetOrbits of six distant Kuiper-belt objects. Their clustered perihelia and orbital orientations suggest they may have been shepherded by a massive object, hypothesized to be Planet Nine. [Caltech/Robert Hurt]Early this year, a study was published that demonstrated that the clustered orbits of distant Kuiper belt objects (and several other features of our solar system) can be explained by the gravitational tug of a yet-undiscovered planet. This hypothetical Planet Nine is predicted to be a giant planet similar to Neptune or Uranus, with a mass of more than ~10 Earthmasses, currently orbiting ~700 AU away.In a recent study, a team of scientists led by Nicolas Cowan (McGill University in Canada) has estimated the blackbody emission expected from Planet Nine. The team proposes how we might be able to search for this distant body using its heat signature.Heat from an Icy WorldCowan and collaborators first estimate Planet Nines effective temperature, based on the solar flux received at ~700 AU and assuming its internal heating is similar to Uranus or Neptune. They find that Planet Nines effective temperature would likely be an icy ~3050 K, corresponding to a blackbody peak at 50100 micrometers.Search space for Planet Nine. Based on its millimeter flux and annual parallax motion, several current and future cosmology experiments may be able to detect it. Experiments resolution ranges are shown with blue boxes. [Cowan et al. 2016]How can we detect an object withemission that peaks in this range? Intriguingly, cosmology experiments monitoring the cosmic microwave background (CMB) radiation are optimized for millimeter flux. At a wavelength of 1mm, Cowan and collaborators estimate that Planet Nine would have a very detectable flux level of ~30 mJy. The
Rayleigh scattering: blue sky thinking for future CMB observations
Lewis, Antony
2013-01-01
Rayleigh scattering from neutral hydrogen during and shortly after recombination causes the CMB anisotropies to be significantly frequency dependent at high frequencies. This may be detectable with Planck, and would be a strong signal at in any future space-based CMB missions. The later peak of the Rayleigh visibility compared to Thomson scattering gives an increased large-scale CMB polarization signal that is a greater than 4% effect for observed frequencies greater than 500GHz. There is a similar magnitude suppression on small scales from additional damping. Due to strong correlation between the Rayleigh and primary signal, measurement of the Rayleigh component is limited by noise and foregrounds, not cosmic variance of the primary CMB, and should observable over a wide range of angular scales at frequencies between roughly 200GHz and 800GHz. I give new numerical calculations of the temperature and polarization power spectra, and show that future CMB missions could measure the temperature Rayleigh cross-spe...
Trappe, N.; Bucher, M.; De Bernardis, P.; Delabrouille, J.; Deo, P.; DePetris, M.; Doherty, S.; Ghribi, A.; Gradziel, M.; Kuzmin, L.; Maffei, B.; Mahashabde, S.; Masi, S.; Murphy, J. A.; Noviello, F.; O'Sullivan, C.; Pagano, L.; Piacentini, F.; Piat, M.; Pisano, G.; Robinson, M.; Stompor, R.; Tartari, A.; van der Vorst, M.; Verhoeve, P.
2016-07-01
The main objective of this activity is to develop new focal plane coupling array concepts and technologies that optimise the coupling from reflector optics to the large number of detectors for next generation sub millimetre wave telescopes particularly targeting measurement of the polarization of the cosmic microwave background (CMB). In this 18 month TRP programme the consortium are tasked with developing, manufacturing and experimentally verifying a prototype multichroic pixel which would be suitable for the large focal plane arrays which will be demanded to reach the required sensitivity of future CMB polarization missions. One major development was to have multichroic operation to potentially reduce the required focal plane size of a CMB mission. After research in the optimum telescope design and definition of requirements based on a stringent science case review, a number of compact focal plane architecture concepts were investigated before a pixel demonstrator consisting of a planar mesh lens feeding a backend Resonant Cold Electron Bolometer RCEB for filtering and detection of the dual frequency signal was planned for manufacture and test. In this demonstrator the frequencies of the channels was chosen to be 75 and 105 GHz in the w band close to the peak CMB signal. In the next year the prototype breadboards will be developed to test the beams produced by the manufactured flat lenses fed by a variety of antenna configurations and the spectral response of the RCEBs will also be verified.
QUIJOTE-CMB experiment: a technical overview
Pérez-de-Taoro, M. R.; Aguiar-González, M.; Génova-Santos, R.; Gómez-Reñasco, F.; Hoyland, R.; López-Caraballo, C.; Peláez-Santos, A.; Poidevin, F.; Tramonte, D.; Rebolo-López, R.; Rubiño-Martín, J. A.; Sánchez-de la Rosa, V.; Vega-Moreno, A.; Viera-Curbelo, T.; Vignaga, R.; Martínez-Gonzalez, E.; Aja, B.; Artal, E.; Cagigas, J.; Cano-de-Diego, J. L.; Cuerno, E. M.; de-la-Fuente, L.; Pérez, A.; Terán, J. V.; Villa, E.; Piccirillo, L.; Lasenby, A.
2014-07-01
The QUIJOTE-CMB experiment (Q-U-I JOint TEnerife CMB experiment) is an ambitious project to obtain polarization measurements of the sky microwave emission in the 10 to 47 GHz range. With this aim, a pair of 2,5μm telescopes and three instruments are being sited at the Teide Observatory, in Tenerife (Canary Islands, Spain). The first telescope and the first instrument (the MFI: Multi Frequency Instrument) are both already operating in the band from 10 to 20 GHz, since November 2012. The second telescope and the second instrument (TGI: Thirty GHz instrument) is planned to be in commissioning by the end of summer 2014, covering the range of 26 to 36 GHz. After that, a third instrument named FGI (Forty GHz instrument) will be designed and manufactured to complete the sky survey in the frequency range from 37 to 47 GHz. In this paper we present an overview of the whole project current status, from the technical point of view.
The bolometric focal plane array of the Polarbear CMB experiment
Arnold, K; Anthony, A E; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Dobbs, M A; Errard, J; Fabbian, G; Flanigan, D; Fuller, G; Ghribi, A; Grainger, W; Halverson, N; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Howard, J; Hyland, P; Jaffe, A; Keating, B; Kermish, Z; Kisner, T; Jeune, M Le; Lee, A T; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Miller, N J; Meng, X; Morii, H; Moyerman, S; Myers, M J; Nishino, H; Paar, H; Quealy, E; Reichardt, C; Richards, P L; Ross, C; Shimizu, A; Shimmin, C; Shimon, M; Sholl, M; Siritanasak, P; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Tomaru, T; Tucker, C; Zahn, O
2012-01-01
The Polarbear Cosmic Microwave Background (CMB) polarization experiment is currently observing from the Atacama Desert in Northern Chile. It will characterize the expected B-mode polarization due to gravitational lensing of the CMB, and search for the possible B-mode signature of inflationary gravitational waves. Its 250 mK focal plane detector array consists of 1,274 polarization-sensitive antenna-coupled bolometers, each with an associated lithographed band-defining filter. Each detector's planar antenna structure is coupled to the telescope's optical system through a contacting dielectric lenslet, an architecture unique in current CMB experiments. We present the initial characterization of this focal plane.
External priors for the next generation of CMB experiments
Energy Technology Data Exchange (ETDEWEB)
Manzotti, Alessandro [Chicago U., KICP; Dodelson, Scott [Chicago U., KICP; Park, Youngsoo [Arizona U.
2015-12-08
Planned cosmic microwave background (CMB) experiments can dramatically improve what we know about neutrino physics, inflation, and dark energy. The low level of noise, together with improved angular resolution, will increase the signal to noise of the CMB polarized signal as well as the reconstructed lensing potential of high redshift large scale structure. Projected constraints on cosmological parameters are extremely tight, but these can be improved even further with information from external experiments. Here, we examine quantitatively the extent to which external priors can lead to improvement in projected constraints from a CMB-Stage IV (S4) experiment on neutrino and dark energy properties. We find that CMB S4 constraints on neutrino mass could be strongly enhanced by external constraints on the cold dark matter density $\\Omega_{c}h^{2}$ and the Hubble constant $H_{0}$. If polarization on the largest scales ($\\ell<50$) will not be measured, an external prior on the primordial amplitude $A_{s}$ or the optical depth $\\tau$ will also be important. A CMB constraint on the number of relativistic degrees of freedom, $N_{\\rm eff}$, will benefit from an external prior on the spectral index $n_{s}$ and the baryon energy density $\\Omega_{b}h^{2}$. Finally, an external prior on $H_{0}$ will help constrain the dark energy equation of state ($w$).
External priors for the next generation of CMB experiments
Energy Technology Data Exchange (ETDEWEB)
Manzotti, Alessandro; Dodelson, Scott; Park, Youngsoo
2016-03-01
Planned cosmic microwave background (CMB) experiments can dramatically improve what we know about neutrino physics, inflation, and dark energy. The low level of noise, together with improved angular resolution, will increase the signal to noise of the CMB polarized signal as well as the reconstructed lensing potential of high redshift large scale structure. Projected constraints on cosmological parameters are extremely tight, but these can be improved even further with information from external experiments. Here, we examine quantitatively the extent to which external priors can lead to improvement in projected constraints from a CMB-Stage IV (S4) experiment on neutrino and dark energy properties. We find that CMB S4 constraints on neutrino mass could be strongly enhanced by external constraints on the cold dark matter density $\\Omega_{c}h^{2}$ and the Hubble constant $H_{0}$. If polarization on the largest scales ($\\ell<50$) will not be measured, an external prior on the primordial amplitude $A_{s}$ or the optical depth $\\tau$ will also be important. A CMB constraint on the number of relativistic degrees of freedom, $N_{\\rm eff}$, will benefit from an external prior on the spectral index $n_{s}$ and the baryon energy density $\\Omega_{b}h^{2}$. Finally, an external prior on $H_{0}$ will help constrain the dark energy equation of state ($w$).
Future CMB tests of dark matter: ultra-light axions and massive neutrinos
Hložek, Renée; Grin, Daniel; Allison, Rupert; Dunkley, Jo; Calabrese, Erminia
2016-01-01
Measurements of cosmic microwave background (CMB) anisotropies provide strong evidence for the existence of dark matter and dark energy. They can also test its composition, probing the energy density and particle mass of different dark-matter and dark-energy components. CMB data have already shown that ultra-light axions (ULAs) with mass in the range $10^{-32}~{\\rm eV} \\to 10^{-26}~{\\rm eV}$ compose a fraction $< 0.01$ of the cosmological critical density. Here, the sensitivity of a proposed CMB-Stage IV (CMB-S4) experiment (assuming a 1 arcmin beam and $< 1~\\mu K{\\rm-arcmin}$ noise levels over a sky fraction of 0.4) to the density of ULAs and other dark-sector components is assessed. CMB-S4 data should be $\\sim 10$ times more sensitive to the ULA energy-density than Planck data alone, across a wide range of ULA masses $10^{-32}< m_{a}< 10^{-23}~{\\rm eV}$, and will probe axion decay constants of $f_{a}\\approx 10^{16}~{\\rm GeV}$, at the grand unified scale. CMB-S4 could improve the CMB lower bound ...
A template of atmospheric O2 circularly polarized emission for CMB experiments
Spinelli, Sebastiano; Tartari, Andrea; Zannoni, Mario; Gervasi, Massimo
2011-01-01
We compute the circularly polarized signal from atmospheric molecular oxygen. Polarization of O2 rotational lines is caused by Zeeman effect in the Earth magnetic field. We evaluate the circularly polarized emission for various sites suitable for CMB measurements: South Pole and Dome C (Antarctica), Atacama (Chile) and Testa Grigia (Italy). An analysis of the polarized signal is presented and discussed in the framework of future CMB polarization experiments. We find a typical circularly polarized signal (V Stokes parameter) of ~ 50 - 300 {\\mu}K at 90 GHz looking at the zenith. Among the other sites Atacama shows the lower polarized signal at the zenith. We present maps of this signal for the various sites and show typical elevation and azimuth scans. We find that Dome C presents the lowest gradient in polarized temperature: ~ 0.3 {\\mu}K/\\circ at 90 GHz. We also study the frequency bands of observation: around {\
Future CMB tests of dark matter: Ultralight axions and massive neutrinos
Hložek, Renée; Marsh, David J. E.; Grin, Daniel; Allison, Rupert; Dunkley, Jo; Calabrese, Erminia
2017-06-01
Measurements of cosmic microwave background (CMB) anisotropies provide strong evidence for the existence of dark matter and dark energy. They can also test its composition, probing the energy density and particle mass of different dark-matter and dark-energy components. CMB data have already shown that ultralight axions (ULAs) with mass in the range 10-32 eV →10-26 eV compose a fraction ≲0.01 of the cosmological critical density. The next Stage-IV CMB experiment (CMB-S4) (assuming a 1 arcmin beam and ˜1 μ K -arcmin noise levels over a sky fraction of 0.4) to the density of ULAs and other dark-sector components is assessed. CMB-S4 data should be ˜10 times more sensitive to the ULA energy density than Planck data alone, across a wide range of ULA masses 10-32≲ma≲10-23 eV , and will probe axion decay constants of fa≈1 016 GeV , at the grand unified scale. CMB-S4 could improve the CMB lower bound on the ULA mass from ˜10-25 eV to 10-23 eV , nearing the mass range probed by dwarf galaxy abundances and dark-matter halo density profiles. These improvements will allow for a multi-σ detection of percent-level departures from CDM over a wide range of masses. Much of this improvement is driven by the effects of weak gravitational lensing on the CMB, which breaks degeneracies between ULAs and neutrinos. We also find that the addition of ULA parameters does not significantly degrade the sensitivity of the CMB to neutrino masses. These results were obtained using the axionCAMB code (a modification to the CAMB Boltzmann code), presented here for public use.
The CMB - Contemporary Measurements and Cosmology
Miller, A. D.
2002-09-01
Since the discovery of the Cosmic Microwave Background (CMB) in 1965, characterization of the CMB anisotropy angular power spectrum has become somewhat of a holy grail for experimental cosmology. Because CMB anisotropy measurements are difficult, the full potential of the CMB is only now being realized. Improvements in experimental techniques and detector technology have yielded an explosion of progress in the past couple of years resulting in the ability to use measurements of the CMB to place meaningful constraints on cosmological parameters. In this review, I discuss the theory behind the CMB but focus primarily on the experiments, reviewing briefly the history of CMB anisotropy measurements and focusing on the recent experiments that have revolutionized this field. Results from these modern experiments are reviewed and the cosmological implications discussed. I conclude with brief comments about the future of CMB physics.
Primordial magnetism in CMB polarization
Pogosian, Levon
2014-03-01
A large scale B-mode signal in the CMB polarization would constitute a smoking gun of Inflation and is the main target of several ongoing and upcoming experiments. In this contribution, I consider distinguishing features of another potential source of primordial B-modes - magnetic fields. In particular, the Faraday Rotation of CMB polarization provides a distinctive signature of cosmic magnetic fields through the characteristic frequency dependence and the mode-coupling correlations of the CMB variables. I discuss constraints on primordial magnetism that can be expected from future CMB experiments, taking into account the obstruction caused by the magnetic field of the Milky Way.
Constraints on hidden photons from current and future observations of CMB spectral distortions
Kunze, Kerstin E
2015-01-01
A variety of beyond the standard model scenarios contain very light hidden sector U(1) gauge bosons undergoing kinetic mixing with the photon. The resulting oscillation between ordinary and hidden photons leads to spectral distortions of the cosmic microwave background. We update the bounds on the mixing parameter $\\chi_0$ and the mass of the hidden photon $m_{\\gamma'}$ for future experiments measuring CMB spectral distortions, such as PIXIE and PRISM/COrE. For $10^{-14}\\;{\\rm eV}\\lesssim m_{\\gamma'}\\lesssim 10^{-13}\\;{\\rm eV}$, we find the kinetic mixing angle $\\chi_0$ has to be less than $10^{-8}$ at 95\\% CL. These bounds are more than an order of magnitude stronger than those derived from the COBE/FIRAS data.
A 200-GHz telescope unit for the QUIJOTE CMB Experiment
Sanquirce, Rubén.; Etxeita, Borja; Murga, Gaizka; Fernandez, Esther; Sainz, Iñaki; Sánchez, Vicente; Viera-Curbelo, Teodora A.; Gómez, María. F.; Aguiar-Gonzalez, Marta; Hoyland, Roger J.; Pérez de Taoro, Ángeles R.; Vega, Afrodisio; Rebolo-López, Rafael; Rubiño, Jose Alberto
2014-07-01
Experiment QUIJOTE (Q-U-I JOint TEnerife) is a scientific collaboration, leaded by the Instituto de Astrofísica de Canarias (IAC), which can measure the polarization of the Cosmic Microwave Background (CMB) in the range of frequency up to 200 GHz, at angular scales of 1°. The project is composed of 2 telescopes and 3 instruments, located in Teide Observatory (Tenerife, Spain). After the successful delivery of the first telescope (operative since 2012), Idom is currently involved on the turn key supply of the second telescope (phase II). The work started in June 2013 and it will be completed in a challenging period of 12 months (operative at the beginning of July 2014), including design, factory assembly and testing, transport and final commissioning on site. This second unit will improve the opto-mechanical performance and maintainability. The telescope will have an unlimited rotation capacity in azimuth axis and a range of movement between 25°-95° in elevation axis. An integrated rotary joint will transmit fluid, power and signal to the rotary elements. The pointing and tracking accuracy will be significantly below to specification: 1.76 arcmin and 44 arcsec, respectively. This project completes Idoḿs contribution during phase I, which also comprises the integration and functional tests for the 5 polarimeters of the first instrument in Bilbao headquarters, and the design and supervision of the building which protects both telescopes, including the installation and commissioning of the mechanism for shutters aperture.
EBEX: A balloon-borne CMB polarization experiment
Reichborn-Kjennerud, Britt; Ade, Peter; Aubin, Françcois; Baccigalupi, Carlo; Bao, Chaoyun; Borrill, Julian; Cantalupo, Christopher; Chapman, Daniel; Didier, Joy; Dobbs, Matt; Grain, Julien; Grainger, William; Hanany, Shaul; Hillbrand, Seth; Hubmayr, Johannes; Jaffe, Andrew; Johnson, Bradley; Jones, Terry; Kisner, Theodore; Klein, Jeff; Korotkov, Andrei; Leach, Sam; Lee, Adrian; Levinson, Lorne; Limon, Michele; MacDermid, Kevin; Matsumura, Tomotake; Meng, Xiaofan; Miller, Amber; Milligan, Michael; Pascale, Enzo; Polsgrove, Daniel; Ponthieu, Nicolas; Raach, Kate; Sagiv, Ilan; Smecher, Graeme; Stivoli, Federico; Stompor, Radek; Tran, Huan; Tristram, Matthieu; Tucker, Gregory S; Vinokurov, Yury; Yadav, Amit; Zaldarriaga, Matias; Zilic, Kyle
2010-01-01
EBEX is a NASA-funded balloon-borne experiment designed to measure the polarization of the cosmic microwave background (CMB). Observations will be made using 1432 transition edge sensor (TES) bolometric detectors read out with frequency multiplexed SQuIDs. EBEX will observe in three frequency bands centered at 150, 250, and 410 GHz, with 768, 384, and 280 detectors in each band, respectively. This broad frequency coverage is designed to provide valuable information about polarized foreground signals from dust. The polarized sky signals will be modulated with an achromatic half wave plate (AHWP) rotating on a superconducting magnetic bearing (SMB) and analyzed with a fixed wire grid polarizer. EBEX will observe a patch covering ~1% of the sky with 8' resolution, allowing for observation of the angular power spectrum from \\ell = 20 to 1000. This will allow EBEX to search for both the primordial B-mode signal predicted by inflation and the anticipated lensing B-mode signal. Calculations to predict EBEX constrain...
MAPCUMBA : a fast iterative multi-grid map-making algorithm for CMB experiments
Doré, O; Teyssier, R.; Bouchet, F. R.; Vibert, D.; Prunet, S.
2001-01-01
The data analysis of current Cosmic Microwave Background (CMB) experiments like BOOMERanG or MAXIMA poses severe challenges which already stretch the limits of current (super-) computer capabilities, if brute force methods are used. In this paper we present a practical solution to the optimal map making problem which can be used directly for next generation CMB experiments like ARCHEOPS and TopHat, and can probably be extended relatively easily to the full PLANCK case. This solution is based ...
Complementing the ground-based CMB Stage-4 experiment on large scales with the PIXIE satellite
Calabrese, Erminia; Dunkley, Jo
2016-01-01
We present forecasts for cosmological parameters from future Cosmic Microwave Background (CMB) data measured by the Stage-4 (S4) generation of ground-based experiments in combination with large-scale anisotropy data from the PIXIE satellite. We demonstrate the complementarity of the two experiments and focus on science targets that benefit from their combination. We show that a cosmic-variance-limited measurement of the optical depth to reionization provided by PIXIE, with error $\\sigma(\\tau)=0.002$, is vital for enabling a 5$\\sigma$ detection of the sum of the neutrino masses when combined with a CMB-S4 lensing measurement, and with lower-redshift constraints on the growth of structure and the distance-redshift relation. Parameters characterizing the epoch of reionization will also be tightly constrained; PIXIE's $\\tau$ constraint converts into $\\sigma(\\rm{z_{re}})=0.2$ for the mean time of reionization, and a kinematic Sunyaev-Zel'dovich measurement from S4 gives $\\sigma(\\Delta \\rm{z_{re}})=0.03$ for the du...
Cosmological parameter estimation with QUaD CMB polarization and temperature experiment
Memari, Yasin
2009-01-01
In this thesis we examine the theoretical origin and statistical features of the Cosmic Microwave Background radiation. We particularly focus on the CMB power spectra and cosmological parameter estimation from QUaD CMB experiment data in order to derive implications for the concordance cosmological model. In chapter 4 we present a detailed parameter estimation analysis of the combined polarization and temperature power spectra from the second and third season observations of...
MADAM- a map-making method for CMB experiments
Keihänen, E.; Kurki-Suonio, H.; Poutanen, T.
2005-06-01
We present a new map-making method for cosmic microwave background (CMB) measurements. The method is based on the destriping technique, but it also utilizes information about the noise spectrum. The low-frequency component of the instrument noise stream is modelled as a superposition of a set of simple base functions, whose amplitudes are determined by means of maximum-likelihood analysis, involving the covariance matrix of the amplitudes. We present simulation results with 1/f noise and show a reduction in the residual noise with respect to ordinary destriping. This study is related to Planck Low Frequency Instrument (LFI) activities.
Madam - a map-making method for CMB experiments
Keihanen, E; Poutanen, T
2004-01-01
We present a new map-making method for CMB measurements. The method is based on the destriping technique, but it also utilizes information about the noise spectrum. The low-frequency component of the instrument noise stream is modelled as a superposition of a set of simple base functions, whose amplitudes are determined by means of maximum-likelihood analysis, involving the covariance matrix of the amplitudes. We present simulation results with $1/f$ noise and show a reduction in the residual noise with respect to ordinary destriping. This study is related to \\Planck LFI activities.
Rubiño-Martín, J. A.; Rebolo, R.; Aguiar, M.; Génova-Santos, R.; Gómez-Reñasco, F.; Herreros, J. M.; Hoyland, R. J.; López-Caraballo, C.; Pelaez Santos, A. E.; Sanchez de la Rosa, V.; Vega-Moreno, A.; Viera-Curbelo, T.; Martínez-Gonzalez, E.; Barreiro, R. B.; Casas, F. J.; Diego, J. M.; Fernández-Cobos, R.; Herranz, D.; López-Caniego, M.; Ortiz, D.; Vielva, P.; Artal, E.; Aja, B.; Cagigas, J.; Cano, J. L.; de la Fuente, L.; Mediavilla, A.; Terán, J. V.; Villa, E.; Piccirillo, L.; Battye, R.; Blackhurst, E.; Brown, M.; Davies, R. D.; Davis, R. J.; Dickinson, C.; Harper, S.; Maffei, B.; McCulloch, M.; Melhuish, S.; Pisano, G.; Watson, R. A.; Hobson, M.; Grainge, K.; Lasenby, A.; Saunders, R.; Scott, P.
2012-09-01
The QUIJOTE (Q-U-I JOint Tenerife) CMB Experiment will operate at the Teide Observatory with the aim of characterizing the polarisation of the CMB and other processes of Galactic and extragalactic emission in the frequency range of 10-40GHz and at large and medium angular scales. The first of the two QUIJOTE telescopes and the first multi-frequency (10-30GHz) instrument are already built and have been tested in the laboratory. QUIJOTE-CMB will be a valuable complement at low frequencies for the Planck mission, and will have the required sensitivity to detect a primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r = 0.05.
Burigana, C
2003-01-01
We analyse the implications of future observations of the CMB absolute temperature at centimeter and decimeter wavelengths, necessary to complement the accurate COBE/FIRAS data. Our analysis shows that forthcoming ground and balloon measures will allow a better understanding of free-free distortions but will not be able to significantly improve the constraints already provided by the FIRAS data on the possible energy exchanges in the primeval plasma. The same holds even improving the sensitivity up to ~10 times. Thus, we have studied the impact of very high quality data, such those in principle achievable with a space experiment like DIMES planned to measure the CMB absolute temperature at 0.5 - 15 cm with a sensitivity of ~0.1 mK, close to that of FIRAS. Such high quality data would improve by a factor ~50 the FIRAS results on the fractional energy exchanges associated to dissipation processes possibly occurred in a wide range of cosmic epochs, at intermediate and high redshifts (y_h > 1). The energy dissipa...
On the excess of power in high resolution CMB experiments
Diego-Rodriguez, J M; Martinez-Gonalez, E; Silk, J
2004-01-01
We revisit the possibility that an excess in the CMB power spectrum at small angular scales (CBI, ACBAR) can be due to galaxy clusters (or compact sources in general). We perform a Gaussian analysis of ACBAR-like simulated data based on wavelets. We show how models with a significant excess should show a clear non-Gaussian signal in the wavelet space. In particular, a value of the normalization sigma_8 = 1 would imply a highly significant skewness and kurtosis in the wavelet coefficients at scales around 3 arcmin. Models with a more moderate excess also show a non-Gaussian signal in the simulated data. We conclude that current data (ACBAR) should show this signature if the excess is to be due to the SZ effect. Otherwise, the reason for that excess should be explained by some systematic effect. The significance of the non-Gaussian signal depends on the cluster model but it grows with the surveyed area. Non-Gaussianity test performed on incoming data sets should reveal the presence of a cluster population even ...
Burigana, C
2003-01-01
We have studied the implications of the new generation of CMB spectrum space experiments for our knowledge of the thermal history of the Universe. The combination of two experiments with the sensitivity and the frequency coverage jointly forseen for DIMES and FIRAS II will be able to greatly change our vision of the capability of the CMB spectrum information to constrain physical processes at different cosmic ages. The limits on the energy dissipations at the all cosmic times accessible to CMB spectrum investigations (z < z_therm) could be improved by about two order of magnitudes and even dissipation processes with DE/E ~ 10^-6 could be detected and possibly accurately studied. These results are possible because such levels of accuracy on a so wide frequency range allow to remove the approximate degeneracy both between free-free and Bose-Einstein (BE) like distortions and between Comptonization and BE-like distortions. Finally, we discussed the different signatures imprinted on the CMB spectrum by some la...
Krauss, Lawrence M.
1995-01-01
The Table of Contents for the book is as follows: * Preface * I. The Experimental Situation Two Years After COBE: Anisotropies, and the CMB Power Spectrum * COBE DMR Data, Signal and Noise: Color Plates * CMB Two Years After the COBE Discovery of Anisotropies * Comparison of Spectral Index Determinations * Two-Point Correlations in the COBE-DMR Two-Year Anisotropy Maps * A Preliminary Analysis of UCSB's South Pole 1993-94 Results * CMB Anisotropy Measurements During the Fourth Flight of MAX * Observations of the Anisotropy in the Cosmic Microwave Background by the Firs, SK93, and MSAM-I Experiments * The Python Microwave Background Anisotropy Experiment * II. Theoretical Implications and Cosmology: The Early Universe, Large Scale Structure and Dark Matter * Testing Inflationary Cosmology and Measuring Cosmological Parameters Using the Cosmic Microwave Background * Inflation Confronts the CMB: An Analysis Including the Effects of Foreground * Testing Inflation with MSAM, MAX Tenerife and COBE * CMBR Anisotropy Due to Gravitational Radiation in Inflationary Cosmologies * Black Holes From Blue Spectra * Cosmic Microwave Background Anisotropies and the Geometry of the Universe * Ω and Cosmic Microwave Background Anisotropies * CDM Cosmogony in an Open Universe * Cosmic Microwave Background Radiation Anisotropy Induced by Cosmic Strings * Temperature Anisotropies in a Universe with Global Defects * The Nature Versus Nurture of Anisotropies * The Existence of Baryons at z = 1000 * Polarization-Temperature Correlations in the Microwave Background * III. Related Issues: BBN Limits on ΩB, and Comparing Theoretical Predictions and Observations * Big Bang Nucleosynthesis and ΩB: A Guide for CMB Interpreters * Quoting Experimental Information
Cosmological Parameters From the Quad Cmb Polarization Experiment
Castro, P.G. (Patricia Garrido); Ade, P.; Bock, J.; Bowden, M.; Brown, M L; Cahill, G.; Church, S.; Culverhouse, T.; Friedman, R. B.; Ganga, K.; Gear, W.K.; S. Gupta; Hinderks, J.; Kovac, John M.; Lange, A. E.
2009-01-01
In this paper, we present a parameter estimation analysis of the polarization and temperature power spectra from the second and third season of observations with the QUaD experiment. QUaD has for the first time detected multiple acoustic peaks in the E-mode polarization spectrum with high significance. Although QUaD-only parameter constraints are not competitive with previous results for the standard six-parameter ΛCDM cosmology, they do allow meaningful polarization-only parameter analyses f...
Measuring CMB polarization from ISS: the SPOrt experiment
Energy Technology Data Exchange (ETDEWEB)
Colombo, L.P.L. [Physics Dep. ' G. Occhialini' , Universita di Milano-Bicocca and INFN sezione di Milano-Bicocca, Piazza della Scienza, 3 I-20126 Milan (Italy)
2004-09-01
The SPOrt (Sky Polarization Observatory) experiment aims to measure CMBP (cosmic microwave background polarization) on about 80% of the sky from space. Selected by ESA to fly on board the ISS in 2006, it is funded by the Italian Space Agency (ASI). As shown also by the recent WMAP release, CMBP data, besides of removing various degeneracies among cosmological parameters, provided new and important information on the cosmic opacity {tau} and, therefore, on very early cosmic objects which reionized the world at z {approx} 15. Most such information is obtained from low-l spectral components, that SPOrt, with its HPBW resolution of 7 degrees will explore with a high level of sensitivity. The 4 polarimeters of SPOrt work at 22, 32 and (2x) 90 GHz. At lower frequencies they will provide a (nearly) all-sky survey of Galactic synchrotron polarized emission, while data at the higher frequency will measure the CMBP signal. Correlating SPOrt with anisotropy data, by other experiments, shall therefore provide significant cosmological information. We performed a number of simulations of SPOrt performance, aimed to determine how far {tau} and/or other parameter(s) concerning reionization are constrained by the expected data. We also considered a possible interplay between reionization histories and Dark Energy nature. Besides of information on technological developments for systematics reduction, long term stability and observing time efficiency, we report here recent outputs on the expected SPOrt performance in constraining cosmological models.
Cosmological Parameters from the QUaD CMB polarization experiment
Ade, P; Bowden, M; Brown, M L; Cahill, G; Church, S; Culverhouse, T; Friedman, R B; Ganga, K; Gear, W K; Gupta, S; Hinderks, J; Kovac, J; Lange, A E; Leitch, E; Melhuish, S J; Memari, Y; Murphy, J A; Orlando, A; Pryke, C; Schwarz, R; O'Sullivan, C; Piccirillo, L; Rajguru, N; Rusholme, B; Taylor, A N; Thompson, K L; Turner, A H; Wu, E Y S; Zemcov, M
2009-01-01
In this paper we present a parameter estimation analysis of the polarization and temperature power spectra from the second and third season of observations with the QUaD experiment. QUaD has for the first time detected multiple acoustic peaks in the E-mode polarization spectrum with high significance. Although QUaD-only parameter constraints are not competitive with previous results for the standard 6-parameter LCDM cosmology, they do allow meaningful polarization-only parameter analyses for the first time. In a standard 6-parameter LCDM analysis we find the QUaD TT power spectrum to be in good agreement with previous results. However, the QUaD polarization data shows some tension with LCDM. The origin of this 1 to 2 sigma tension remains unclear, and may point to new physics, residual systematics or simple random chance. We also combine QUaD with the five-year WMAP data set and the SDSS Luminous Red Galaxies 4th data release power spectrum, and extend our analysis to constrain individual isocurvature mode fr...
Precision epoch of reionization studies with next-generation CMB experiments
Energy Technology Data Exchange (ETDEWEB)
Calabrese, Erminia; Louis, Thibaut [Sub-department of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom); Hložek, Renée; Hil, J. Colin [Department of Astrophysical Science, Peyton Hall, 4 Ivy Lane, Princeton, NJ, 08544 (United States); Battaglia, Nick [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213 (United States); Bond, J. Richard; Hajian, Amir [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St George Street, Toronto, ON, M5S 3H8 Canada (Canada); De Bernardis, Francesco; Henderson, Shawn; Niemack, Michael D. [Department of Physics, Cornell University, 109 Clark Hall, Ithaca, NY, 14853 (United States); Devlin, Mark J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA, 19104 (United States); Kosowsky, Arthur [Department of Physics and Astronomy, University of Pittsburgh, 315 Allen Hall, Pittsburgh, PA, 15260 (United States); McMahon, Jeff [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI, 48109 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4041 South Africa (South Africa); Newburgh, Laura [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George St., Toronto, ON, M5S 3H4 Canada (Canada); Page, Lyman A. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Washington Road, Princeton, NJ, 08544 (United States); Partridge, Bruce [Department of Physics and Astronomy, Haverford College, 370 Lancaster Avenue, Haverford, PA, 19041 (United States); Sehgal, Neelima, E-mail: erminia.calabrese@astro.ox.ac.uk, E-mail: rhlozek@astro.princeton.edu [Physics and Astronomy Department, Stony Brook University, Stony Brook, NY, 11794 (United States); and others
2014-08-01
Future arcminute resolution polarization data from ground-based Cosmic Microwave Background (CMB) observations can be used to estimate the contribution to the temperature power spectrum from the primary anisotropies and to uncover the signature of reionization near ℓ=1500 in the small angular-scale temperature measurements. Our projections are based on combining expected small-scale E-mode polarization measurements from Advanced ACTPol in the range 300<ℓ<3000 with simulated temperature data from the full Planck mission in the low and intermediate ℓ region, 2<ℓ<2000. We show that the six basic cosmological parameters determined from this combination of data will predict the underlying primordial temperature spectrum at high multipoles to better than 1% accuracy. Assuming an efficient cleaning from multi-frequency channels of most foregrounds in the temperature data, we investigate the sensitivity to the only residual secondary component, the kinematic Sunyaev-Zel'dovich (kSZ) term. The CMB polarization is used to break degeneracies between primordial and secondary terms present in temperature and, in effect, to remove from the temperature data all but the residual kSZ term. We estimate a 15σ detection of the diffuse homogeneous kSZ signal from expected AdvACT temperature data at ℓ>1500, leading to a measurement of the amplitude of matter density fluctuations, σ{sub 8}, at 1% precision. Alternatively, by exploring the reionization signal encoded in the patchy kSZ measurements, we bound the time and duration of the reionization with σ(z{sub re})=1.1 and σ(Δz{sub re})=0.2. We find that these constraints degrade rapidly with large beam sizes, which highlights the importance of arcminute-scale resolution for future CMB surveys.
Future Solar Neutrino Experiments
Energy Technology Data Exchange (ETDEWEB)
Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida-shi, Gifu, Japan, 506-1205 (Japan)]. E-mail: nakahata@suketto.icrr.u-tokyo.ac.jp
2005-08-15
The value of future solar neutrino experiments is discussed from particle physics and astrophysics points of view based on current understanding of solar neutrino oscillations. R and D statuses of future experiments are also discussed.
Detecting patchy reionization in the CMB
Smith, Kendrick M
2016-01-01
Upcoming cosmic microwave background (CMB) experiments will measure temperature fluctuations on small angular scales with unprecedented precision. Small-scale CMB fluctuations are a mixture of late-time effects: gravitational lensing, Doppler shifting of CMB photons by moving electrons (the kSZ effect), and residual foregrounds. We propose a new statistic which separates the kSZ signal from the others, and also allows the kSZ signal to be decomposed in redshift bins. The decomposition extends to high redshift, and does not require external datasets such as galaxy surveys. In particular, the high-redshift signal from patchy reionization can be cleanly isolated, enabling future CMB experiments to make high-significance and qualitatively new measurements of the reionization era.
MAPCUMBA a fast iterative multi-grid map-making algorithm for CMB experiments
Doré, O; Bouchet, F R; Vibert, D; Prunet, S
2001-01-01
The data analysis of current Cosmic Microwave Background (CMB) experiments like BOOMERanG or MAXIMA poses severe challenges which already stretch the limits of current (super-) computer capabilities, if brute force methods are used. In this paper we present a practical solution to the optimal map making problem which can be used directly for next generation CMB experiments like ARCHEOPS and TopHat, and can probably be extended relatively easily to the full PLANCK case. This solution is based on an iterative multi-grid Jacobi algorithm which is both fast and memory sparing. Indeed, if there are N_tod data points along the one dimensional timeline to analyse, the number of operations is O(N_tod ln N_tod) and the memory requirement is O(N_tod). Timing and accuracy issues have been analysed on simulated ARCHEOPS and TopHat data, and we discuss as well the issue of the joint evaluation of the signal and noise statistical properties.
Complementing the ground-based CMB-S4 experiment on large scales with the PIXIE satellite
Calabrese, Erminia; Alonso, David; Dunkley, Jo
2017-03-01
We present forecasts for cosmological parameters from future cosmic microwave background (CMB) data measured by the stage-4 (S4) generation of ground-based experiments in combination with large-scale anisotropy data from the PIXIE satellite. We demonstrate the complementarity of the two experiments and focus on science targets that benefit from their combination. We show that a cosmic-variance-limited measurement of the optical depth to reionization provided by PIXIE, with error σ (τ )=0.002 , is vital for enabling a 5 σ detection of the sum of the neutrino masses when combined with a CMB-S4 lensing measurement and with lower-redshift constraints on the growth of structure and the distance-redshift relation. Parameters characterizing the epoch of reionization will also be tightly constrained; PIXIE's τ constraint converts into σ (zre)=0.2 for the mean time of reionization, and a kinematic Sunyaev-Zel'dovich measurement from S4 gives σ (Δ zre)=0.03 for the duration of reionization. Both PIXIE and S4 will put strong constraints on primordial tensor fluctuations, vital for testing early-Universe models, and will do so at distinct angular scales. We forecast σ (r )≈5 ×10-4 for a signal with a tensor-to-scalar ratio r =10-3, after accounting for diffuse foreground removal and delensing. The wide and dense frequency coverage of PIXIE results in an expected foreground-degradation factor on r of only ≈25 %. By measuring large and small scales PIXIE and S4 will together better limit the energy injection at recombination from dark matter annihilation, with pannmeasured from the damping tail with S4 will be best constrained by polarization, which has the advantage of minimal contamination from extragalactic emission.
Future Solar Neutrino Experiments
Energy Technology Data Exchange (ETDEWEB)
Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida-city, 506-1205 (Japan)]. E-mail: suzuki@suketto.icrr.u-tokyo.ac.jp
2005-06-15
The purpose of the future solar neutrino experiments is briefly reviewed. The future experimental programs which aim to measure the low energy solar neutrinos are described. We do not cover all the projects. Experiments using noble gases are promising for the pp-neutrino measurements.
Constraints on parity violation from ACTpol and forecasts for forthcoming CMB experiments
Molinari, Diego; Gruppuso, Alessandro; Natoli, Paolo
2016-12-01
We use the ACTpol published cosmic microwave background (CMB) polarization data to constrain cosmological birefringence, a tracer of parity violation beyond the standard model of particle physics. To this purpose, we employ all the polarized ACTpol spectra, including the cross-correlations between temperature anisotropy and B mode polarization (TB) and between E mode and B mode (EB), which are most sensitive to the effect. We build specific, so-called D-estimators for birefringence and assess their performances and error budgets by using realistic Monte Carlo simulations based on the experimental characteristics provided by the ACTpol collaboration. We determine the optimal multipole range for our analysis to be 250 < ℓ < 3025 over which we find a null result for the uniform birefringence angle α = 0.29 ° ± 0.28 ° (stat.) ± 0.5 ° (syst.), the latter uncertainty being the estimate published by the ACTpol team on their global systematic error budget. We show that this result holds consistently when other multipole ranges are considered. Finally, we forecast the capability of several forthcoming ground based, balloon and space borne CMB experiments to constrain the birefringence angle, showing, e.g., that the proposed post-Planck COrE satellite mission could in principle constrain α at a level of 10 arcsec, provided that all systematics are under control. Under the same circumstances, we find the COrE constraints to be at least 2 or 3 times better than what could ideally be achieved by the other experiments considered.
Bond, J R; Crittenden, Robert G.
2001-01-01
We describe the subject of Cosmic Microwave Background (CMB) analysis - its past, present and future. The theory of Gaussian primary anisotropies, those arising from linear physics operating in the early Universe, is in reasonably good shape so the focus has shifted to the statistical pipeline which confronts the data with the theory: mapping, filtering, comparing, cleaning, compressing, forecasting, estimating. There have been many algorithmic advances in the analysis pipeline in recent years, but still more are needed for the forecasts of high precision cosmic parameter estimation to be realized. For secondary anisotropies, those arising once nonlinearity develops, the computational state of the art currently needs effort in all the areas: the Sunyaev-Zeldovich effect, inhomogeneous reionization, gravitational lensing, the Rees-Sciama effect, dusty galaxies. We use the Sunyaev-Zeldovich example to illustrate the issues. The direct interface with observations for these non-Gaussian signals is much more compl...
A new model of the microwave polarized sky for CMB experiments
Hervías-Caimapo, Carlos; Brown, Michael L
2016-01-01
We present a new model of the microwave sky in polarization that can be used to simulate data from CMB polarization experiments. We exploit the most recent results from the Planck satellite to provide an accurate description of the diffuse polarized foreground synchrotron and thermal dust emission. Our model can include the two mentioned foregrounds, and also a constructed template of Anomalous Microwave Emission (AME). Several options for the frequency dependence of the foregrounds can be easily selected, to reflect our uncertainties and to test the impact of different assumptions. Small angular scale features can be added to the foreground templates to simulate high-resolution observations. We present tests of the model outputs to show the excellent agreement with Planck and WMAP data. We determine the range within which the foreground spectral indices can be varied to be consistent with the current data. We also show forecasts for a high-sensitivity, high-resolution full-sky experiment such as the Cosmic O...
He, Miao
2013-01-01
The measurement of the neutrino mixing angle $\\theta_{13}$ opens a gateway for the next generation experiments to measure the neutrino mass hierarchy and the leptonic CP-violating phase. Future reactor experiments will focus on mass hierarchy determination and the precision measurement of mixing parameters. Mass hierarchy can be determined from the disappearance of reactor electron antineutrinos based on the interference effect of two separated oscillation modes. Relative and absolute measure...
The QUIJOTE CMB Experiment: status and first results with the multi-frequency instrument
López-Caniego, M; Aguiar, M; Génova-Santos, R; Gómez-Reñasco, F; Gutierrez, C; Herreros, J M; Hoyland, R J; López-Caraballo, C; Santos, A E Pelaez; Poidevin, F; Rubiño-Martín, J A; de la Rosa, V Sanchez; Tramonte, D; Vega-Moreno, A; Viera-Curbelo, T; Vignaga, R; Martínez-González, E; Barreiro, R B; Casaponsa, B; Casas, F J; Diego, J M; Fernández-Cobos, R; Herranz, D; Ortiz, D; Vielva, P; Artal, E; Aja, B; Cagigas, J; Cano, J L; de la Fuente, L; Mediavilla, A; Terán, J V; Villa, E; Piccirillo, L; Battye, R; Blackhurst, E; Brown, M; Davies, R D; Davis, R J; Dickinson, C; Grainge, K; Harper, S; Maffei, B; McCulloch, M; Melhuish, S; Pisano, G; Watson, R A; Hobson, M; Lasenby, A; Saunders, R; Scott, P
2014-01-01
The QUIJOTE (Q-U-I JOint Tenerife) CMB Experiment is designed to observe the polarization of the Cosmic Microwave Background and other Galactic and extragalactic signals at medium and large angular scales in the frequency range of 10-40 GHz. The first of the two QUIJOTE telescopes and the multi-frequency (10-20 GHz) instrument have been in operation since November 2012. In 2014 a second telescope and a new instrument at 30GHz will be ready for commissioning, and an additional instrument at 40 GHz is in its final design stages. After three years of effective observations, the data obtained by these telescopes and instruments will have the required sensitivity to detect a primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r = 0.05. At the moment, we have completed half of the wide Galactic survey with the multi-frequency instrument covering 18 000 square degrees of the Northern hemisphere. When we finish this survey in early 2014, we shall have reached approximately 14{\\mu}K pe...
Predicted Constraints on Cosmic String Tension from Planck and Future CMB Polarization Measurements
Foreman, Simon; Scott, Douglas
2011-01-01
We perform a Fisher matrix calculation of the predicted uncertainties on estimates of the cosmic string tension Gmu from upcoming observational data (namely, cosmic microwave background power spectra from the Planck satellite and an idealized future polarization experiment). We employ simulations that are more general than others commonly used in the literature, leaving the mean velocity of strings, correlation length of the string network, and "wiggliness" (which parametrizes smaller-scale structure along the strings) as free parameters that can be observationally measured. In a new code, StringFast, we implement a method for efficient computation of the C_l spectra induced by a network of strings, which is fast enough to be used in Markov Chain Monte Carlo analyses of future data. Performing a calculation with the string parameters left free results in projected constraints on Gmu that are larger than those obtained by fixing their values a priori, typically by a factor of ~2-7. We also find that if Gmu is ...
Future flavour physics experiments
2015-01-01
The current status of flavour physics and the prospects for present and future experiments will be reviewed. Measurements in B‐physics, in which sensitive probes of new physics are the CKM angle γ, the Bs mixing phase ϕs, and the branching ratios of the rare decays B(s)0→μ+μ− , will be highlighted. Topics in charm and kaon physics, in which the measurements of ACP and the branching ratios of the rare decays K→πνν¯ are key measurements, will be discussed. Finally the complementarity of the future heavy flavour experiments, the LHCb upgrade and Belle‐II, will be summarised. PMID:26877543
Forecasting performance of CMB experiments in the presence of complex foreground contaminations
Stompor, Radek; Poletti, Davide
2016-01-01
We present a new, semi-analytic framework for estimating the level of residuals present in CMB maps derived from multi-frequency Cosmic Microwave Background (CMB) data and forecasting their impact on cosmological parameters. The data are assumed to contain non-negligible signals of astrophysical and/or Galactic origin, which we clean using parametric component separation technique. We account for discrepancies between the foreground model assumed during the separation procedure and the true one, allowing for differences in scaling laws and/or their spatial variations. Our estimates and their uncertainties include both systematic and statistical effects and are averaged over the instrumental noise and CMB signal realizations. The framework can be further extended to account self-consistently for existing uncertainties in the foreground models. We demonstrate and validate the framework on simple study cases which aim at estimating the tensor-to-scalar ratio, r. The proposed approach is computationally efficient...
CMB foregrounds - A brief review
Dickinson, Clive
2016-01-01
CMB foregrounds consist of all radiation between the surface of last scattering and the detectors, which can interfere with the cosmological interpretation of CMB data. Fortunately, in temperature (intensity), even though the foregrounds are complex they can relatively easily be mitigated. However, in polarization, diffuse Galactic radiation (synchrotron and thermal dust) can be polarized at a level of >10 % making it more of a challenge. In particular, CMB B-modes, which are a smoking-gun signature of inflation, will be dominated by foregrounds. Component separation will therefore be critical for future CMB polarization missions, requiring many channels covering a wide range of frequencies, to ensure that foreground modelling errors are minimised.
Future of neutrino experiments
Indian Academy of Sciences (India)
Takaaki Kajita
2009-01-01
Atmospheric, solar, reactor and accelerator neutrino oscillation experiments have measured $ m_{12}^{2}$, sin2 12, $| m_{23}^{2} |$ and sin2 223. The next stage of the oscillation studies should be the observation of a finite sin2 213. If a non-zero sin2 213 is observed, the subsequent goals should be the observation of the CP violation and the determination sign of $ m_{23}^{2}$. Possible future neutrino oscillation experiments that could assess these questions are discussed.
The Theoretical Agenda in CMB Research
Bond, J R
1996-01-01
The terrain that theorists cover in this CMB golden age is described. We ponder early universe physics in quest of the fluctuation generator. We extoll the virtues of inflation and defects. We transport fields, matter and radiation into the linear (primary anisotropies) and nonlinear (secondary anisotropies) regimes. We validate our linear codes to deliver accurate predictions for experimentalists to shoot at. We struggle at the computing edge to push our nonlinear simulations from only illustrative to fully predictive. We are now phenomenologists, optimizing statistical techniques for extracting truths and their errors from current and future experiments. We begin to clean foregrounds. We join CMB experimental teams. We combine the CMB with large scale structure, galaxy and other cosmological observations in search of current concordance. The brave use all topical data. Others carefully craft their prior probabilities to downweight data sets. We are always unbiased. We declare theories sick, dead, ugly. Some...
Final acceptance of the 200 GHz telescope unit for the QUIJOTE CMB experiment
Sanquirce-García, R.; Sainz-Pardo, I.; Etxeita-Arriaga, B.; Murga-Llano, Gaizka; Fernandez-Santos, E.; Sánchez-de-la-Rosa, V.; Viera-Curbelo, T. A.; Gómez-Reñasco, F.; Aguiar-González, M.; Pérez de Taoro, M. R.; Rubiño-Martín, J. A.
2016-07-01
The QUIJOTE (Q-U-I JOint TEnerife) experiment is a scientific collaboration, led by the Instituto de Astrofísica de Canarias (IAC), with the aim of measuring the polarization of the Cosmic Microwave Background (CMB) in the frequency range 10-40 GHz and at large angular scales (around 1°). The project is composed of 2 telescopes and 3 instruments, located in Teide Observatory (Tenerife, Spain). Idoḿs contribution for this project is divided in two phases. Phase I consisted on the design, assembly and factory testing of the first telescope (2008), the integration and functional tests for the 5 polarimeters of the first instrument (2009), and the design and construction supervision of the building which protects both telescopes (2009), including the installation and commissioning of the mechanism for domes apertures. Phase II comprised the design, factory assembly and testing, transport and final commissioning on site of the second telescope, which finished in January 2015. The optical design of both telescopes should allow them to reach up to 200 GHz. The required opto-mechanical performance was checked under nominal conditions, reaching a pointing and tracking accuracy lower than 5 arcsec in both axes, 8 times better than specified. Particular inspections and tests were carried out for critical systems, as the rotary joint that transmits fluid, power and signal to the rotary elements, or for the safety system to ensure personnel and hardware protection under emergency conditions. This paper contains a comprehensive description of the power electronics and acquisition/control design required for safely operation under nominal and emergency conditions, as well as a detailed description of the factory and observatory tests required for the final acceptance of the telescope
Bolometeric detector arrays for CMB polarimetry
Kuo, C. L.; Bock, J. J.; Day, P.; Goldin, A.; Golwala, S.; Holmes, W.; Irwin, K.; Kenyon, M.; Lange, A. E.; LeDuc, H. G.; Rossinot, P.; Sterb, J.; Vayonakis, A.; Wang, G.; Yun, M.; Zmuidzinas, J.
2005-01-01
We describe the development of antenna coupled bolometers for CMB polarization experiments. The necessary components of a bolometric CMB polarimeter - a beam forming element, a band defining filter, and detectors - are all fabricated on a silicon chip with photolithography.
Hill, Charles A.; Beckman, Shawn; Chinone, Yuji; Goeckner-Wald, Neil; Hazumi, Masashi; Keating, Brian; Kusaka, Akito; Lee, Adrian T.; Matsuda, Frederick; Plambeck, Richard; Suzuki, Aritoki; Takakura, Satoru
2016-07-01
We describe the development of an ambient-temperature continuously-rotating half-wave plate (HWP) for study of the Cosmic Microwave Background (CMB) polarization by the POLARBEAR-2 (PB2) experiment. Rapid polarization modulation suppresses 1/f noise due to unpolarized atmospheric turbulence and improves sensitivity to degree-angular-scale CMB fluctuations where the inflationary gravitational wave signal is thought to exist. A HWP modulator rotates the input polarization signal and therefore allows a single polarimeter to measure both linear polarization states, eliminating systematic errors associated with differencing of orthogonal detectors. PB2 projects a 365-mm-diameter focal plane of 7,588 dichroic, 95/150 GHz transition-edge-sensor bolometers onto a 4-degree field of view that scans the sky at 1 degree per second. We find that a 500-mm-diameter ambient-temperature sapphire achromatic HWP rotating at 2 Hz is a suitable polarization modulator for PB2. We present the design considerations for the PB2 HWP, the construction of the HWP optical stack and rotation mechanism, and the performance of the fully-assembled HWP instrument. We conclude with a discussion of HWP polarization modulation for future Simons Array receivers.
5,120 Superconducting Bolometers for the PIPER Balloon-Borne CMB Polarization Experiment
Benford, Dominic J.; Chuss, David T.; Hilton, Gene C.; Irwin, Kent D.; Jethava, Nikhil S.; Jhabvala, Christine A.; Kogut, Alan J.; Miller, Timothy M.; Mirel, Paul; Moseley, S. Harvey; Rostem, Karwan; Sharp, Elmer H.; Staguhn, Johannes G.; Stiehl, gregory M.; Voellmer, George M.; Wollack, Edward J.
2010-01-01
We are constructing the Primordial Inflation Polarization Explorer (PIPER) to measure the polarization o[ the cosmic microwave background (CMB) and search for the imprint of gravity waves produced during an inflationary epoch in the early universe. The signal is faint and lies behind confusing foregrounds, both astrophysical and cosmological, and so many detectors are required to complete the measurement in a limited time. We will use four of our matured 1,280 pixel, high-filling-factor backshort-under-grid bolometer arrays for efficient operation at the PIPER CMB wavelengths. All four arrays observe at a common wavelength set by passband filters in the optical path. PIPER will fly four times to observe at wavelengths of 1500, 1100, 850, and 500 microns in order to separate CMB from foreground emission. The arrays employ leg-isolated superconducting transition edge sensor bolometers operated at 128mK; tuned resonant backshorts for efficient optical coupling; and a second-generation superconducting quantum interference device (SQUID) multiplexer readout. We describe the design, development, and performance of PIPER bo|ometer array technology to achieve background-limited sensitivity for a cryogenic balloon-borne telescope.
5,120 Superconducting Bolometers for the PIPER Balloon-Borne CMB Polarization Experiment
Benford, Dominic J.; Chuss, David T.; Hilton, Gene C.; Irwin, Kent D.; Jethava, Nikhil S.; Jhabvala, Christine A.; Kogut, Alan J.; Miller, Timothy M.; Mirel, Paul; Moseley, S. Harvey;
2010-01-01
We are constructing the Primordial Inflation Polarization Explorer (PIPER) to measure the polarization o[ the cosmic microwave background (CMB) and search for the imprint of gravity waves produced during an inflationary epoch in the early universe. The signal is faint and lies behind confusing foregrounds, both astrophysical and cosmological, and so many detectors are required to complete the measurement in a limited time. We will use four of our matured 1,280 pixel, high-filling-factor backshort-under-grid bolometer arrays for efficient operation at the PIPER CMB wavelengths. All four arrays observe at a common wavelength set by passband filters in the optical path. PIPER will fly four times to observe at wavelengths of 1500, 1100, 850, and 500 microns in order to separate CMB from foreground emission. The arrays employ leg-isolated superconducting transition edge sensor bolometers operated at 128mK; tuned resonant backshorts for efficient optical coupling; and a second-generation superconducting quantum interference device (SQUID) multiplexer readout. We describe the design, development, and performance of PIPER bo|ometer array technology to achieve background-limited sensitivity for a cryogenic balloon-borne telescope.
CMB anisotropy science: a review
Challinor, Anthony
2012-01-01
The cosmic microwave background (CMB) provides us with our most direct observational window to the early universe. Observations of the temperature and polarization anisotropies in the CMB have played a critical role in defining the now-standard cosmological model. In this contribution we review some of the basics of CMB science, highlighting the role of observations made with ground-based and balloon-borne Antarctic telescopes. Most of the ingredients of the standard cosmological model are poorly understood in terms of fundamental physics. We discuss how current and future CMB observations can address some of these issues, focusing on two directly relevant for Antarctic programmes: searching for gravitational waves from inflation via B-mode polarization, and mapping dark matter through CMB lensing.
Introduction and Overview CMB Sessions
Smoot, G F
1998-01-01
This is a very exciting time for the CMB field. It is widely recognized that precision measurements of the CMB can provide a definitive test of cosmological models and determine their parameters accurately. At present observations give us the first rough results but ongoing experiments promise new and improved results soon and eventually satellite missions (MAP and COBRAS/SAMBA now named Planck) are expected to provide the requisite precision measurements. Other areas such as observations of the spectrum and Sunyaev-Zeldovich effect are also making significant progress. There has long been anticipation that cosmic microwave background (CMB) radiation would provide significant information about the early Universe due to its early central role and its general lack of interaction in the later epochs. Though there have been many observations of the CMB since its discovery by Penzias and Wilson in 1964, the Cosmic Background Explorer satellite, COBE, provided two watershed observations: (1) the CMB is extremely we...
Energy Technology Data Exchange (ETDEWEB)
Suzuki, Yoichiro [Kamioka, Observatory, Institute for Cosmic Ray Research, University of Tokyo, and Institute for the Physics and Mathematics of the Universe, University of Tokyo. 456 Higashi-Mozumi, Kamioka, Hida-city, Gifu, 506-1205 Japan (Japan)], E-mail: suzuki@suketto.icrr.u-tokyo.ac.jp
2008-11-01
The personal view for the next to the next neutrino detector, the ultimate experiment, is discussed. Considering the size, cost and head winds against the basic science, the ultimate experiment will be the only experiment in the world. Here two such experiments one for the neutrino oscillation and the other for the double beta decay were discussed. The ultimate experiment needs to include a bread and butter science and to have a discovery potential for an unexpected phenomenon. There are many technical challenges and international co-operations are absolutely necessary.
A template of atmospheric molecular oxygen circularly polarized emission for CMB experiments
Fabbian, Giulio; Gervasi, Massimo; Tartari, Andrea; Zannoni, Mario
2012-01-01
We compute the polarized signal from atmospheric molecular oxygen due to Zeeman effect in the Earth magnetic field for various sites suitable for CMB measurements such as South Pole, Dome C (Antarctica) and Atacama desert (Chile). We present maps of this signal for those sites and show their typical elevation and azimuth dependencies. We find a typical circularly polarized signal (V Stokes parameter) level of 50 - 300 \\mu K at 90 GHz when looking at the zenith; Atacama site shows the lowest emission while Dome C site presents the lowest gradient in polarized brightness temperature (0.3 \\mu K/deg at 90 GHz). The accuracy and robustness of the template are tested with respect to actual knowledge of the Earth magnetic field, its variability and atmospheric parameters.
True CMB Power Spectrum Estimation
Paykari, P; Fadili, M J
2012-01-01
The cosmic microwave background (CMB) power spectrum is a powerful cosmological probe as it entails almost all the statistical information of the CMB perturbations. Having access to only one sky, the CMB power spectrum measured by our experiments is only a realization of the true underlying angular power spectrum. In this paper we aim to recover the true underlying CMB power spectrum from the one realization that we have without a need to know the cosmological parameters. The sparsity of the CMB power spectrum is first investigated in two dictionaries; Discrete Cosine Transform (DCT) and Wavelet Transform (WT). The CMB power spectrum can be recovered with only a few percentage of the coefficients in both of these dictionaries and hence is very compressible in these dictionaries. We study the performance of these dictionaries in smoothing a set of simulated power spectra. Based on this, we develop a technique that estimates the true underlying CMB power spectrum from data, i.e. without a need to know the cosmo...
Cooray, A R
2002-01-01
We discuss several opportunities involving cosmic microwave background (CMB) observations during the post-MAP era. The curl-modes of CMB polarization allow a direct detection of inflationary gravitational waves and a measurement of the energy scale of inflation. While a significant source of confusion is expected from cosmic shear conversion of polarization related to density perturbations, higher resolution observations of CMB anisotropies can be used for a lensing reconstruction and to separate gravitational-wave polarization signature from that of lensing. With perfect all-sky maps, separations based on current lensing reconstruction techniques allow the possibility to probe inflationary energy scales down to 10^15 GeV, well below that of grand unified theories. Another aspect of future CMB studies will be related to large scale structure, such as wide-field imaging of Sunyaev-Zel'dovich (SZ) effect in galaxy clusters. Here, we comment on a potentially interesting and unique application of the SZ effect in...
Constraints on parity violation from ACTpol and forecasts for forthcoming CMB experiments
Molinari, Diego; Natoli, Paolo
2016-01-01
We use the ACTpol published cosmic microwave background (CMB) polarization data to constrain cosmological birefringence, a tracer of parity violation beyond the standard model of particle physics. To this purpose, we employ all the polarized ACTpol spectra, including the cross-correlations between temperature anisotropy and B mode polarization (TB) and between E mode and B mode (EB), which are most sensitive to the effect. We build specific, so-called D-estimators for birefringence and assess their performances and error budgets by using realistic Monte Carlo simulations based on the experimental characteristics provided by the ACTpol collaboration. We determine the optimal multipole range for our analysis to be $250 < \\ell < 3025$ over which we find a null result for the birefringence angle $\\alpha = 0.29^\\circ \\pm 0.28^\\circ$ (stat.) $\\pm 0.5^\\circ$ (syst.), the latter uncertainty being the estimate published by the ACTpol team on their global systematic error budget. We show that this result holds co...
Cosmic Bandits: Exploration versus Exploitation in CMB B-Mode Experiments
Kovetz, Ely D
2016-01-01
A preferred method to detect the curl-component, or B-mode, signature of inflationary gravitational waves (IGWs) in the cosmic microwave background (CMB) polarization, in the absence of foregrounds and lensing, is a prolonged integration over a single patch of sky of a few square degrees. In practice, however, foregrounds abound and the sensitivity to B modes can be improved considerably by finding the region of sky cleanest of foregrounds. The best strategy to detect B modes thus involves a tradeoff between exploration (to find lower-foreground patches) and exploitation (through prolonged integration). This problem is akin to the multi-armed bandit (MAB) problem in probability theory, wherein a bandit faces a series of slot machines with unknown winning odds and must develop a strategy to maximize his/her winnings with some finite number of pulls. While the optimal MAB strategy remains to be determined, a number of algorithms have been developed in an effort to maximize the winnings. Here, we formulate the s...
Violation of the Rotational Invariance in the CMB Bispectrum
Shiraishi, Maresuke
2011-01-01
We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field. We find a new configurations in the multipole space of the CMB bispectrum given by $\\ell_1 = \\ell_2 + \\ell_3 + 2, |\\ell_2 - \\ell_3| - 2$ and their permutations, which violate the rotational invariance, such as an off-diagonal configuration in the CMB power spectrum. We also find that in a model presented by Yokoyama and Soda (2008), the amplitude of the statistically anisotropic bispectrum in the above configurations becomes as large as that in other configuration such as $\\ell_1 = \\ell_2 + \\ell_3$. As a result, it might be possible to detect these contributions in the future experiments and then it would give us novel information about the physics of the early Universe.
CMBPol Mission Concept Study: Probing Inflation with CMB Polarization
Baumann, Daniel; Adshead, Peter; Amblard, Alexandre; Ashoorioon, Amjad; Bartolo, Nicola; Bean, Rachel; Beltran, Maria; de Bernardis, Francesco; Bird, Simeon; Chen, Xingang; Chung, Daniel Jun Hun; Colombo, Loris; Cooray, Asantha R.; Creminelli, Paolo; Dodelson, Scott; Dunkley, Joanna; Dvorkin, Cora; Easther, Richard; Finelli, Fabio; Flauger, Raphael; Hertzberg, Mark P.; Jones-Smith, Katherine; Kachru, Shamit; Kadota, Kenji; Khoury, Justin; Kinney, William H.; Komatsu, Eiichiro; Krauss, Lawrence M.; Lesgourgues, Julien; Liddle, Andrew R.; Liguori, Michele; Lim, Eugene A.; Linde, Andrei D.; Matarrese, Sabino; Mathur, Harsh; McAllister, Liam; Melchiorri, Alessandro; Nicolis, Alberto; Pagano, Luca; Peiris, Hiranya V.; Peloso, Marco; Pogosian, Levon; Pierpaoli, Elena; Riotto, Antonio; Seljak, Uros; Senatore, Leonardo; Shandera, Sarah E.; Silverstein, Eva; Smith, Tristan; Vaudrevange, Pascal M.; Verde, Licia; Wandelt, Ben; Wands, David; Watson, Scott; Wyman, Mark; Yadav, Amit; Valkenburg, Wessel; Zaldarriaga, Matias
2009-01-01
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high energy scale, and that the inflaton traversed a super-Planckian distance in field space. We explain how such a detection or constraint would illuminate aspects of physics at the Planck scale. Moreover, CMB measurements can constrain the scale-dependence and non-Gaussianity of the primordial fluctuations and limit the possibility of a significant isocurvature contribution. Each such limit provides crucial information on the underlying inflationary dynamics. Finally, we quantify these considerations by presenting forecasts for the sensitivities of a future satellite experiment to the inflationary parameters.
Probing polarization states of primordial gravitational waves with CMB anisotropies
Saito, Shun; Taruya, Atsushi
2007-01-01
We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or M-theory generically yield parity violating terms, which may produce a circularly polarized gravitational wave background (GWB) during inflation. In contrast to the standard prediction of inflation with un-polarized GWB, circularly polarized GWB generates non-vanishing TB and EB-mode power spectra of CMB anisotropies. We evaluate the TB and EB-mode power spectra taking into account the secondary effects and investigate the dependence of cosmological parameters. We then discuss current constraints on the circularly polarized GWB from large angular scales (l < 16) of the three year WMAP data. Prospects for future CMB experiments are also investigated based on a Monte Carlo analysis of parameter estimation, showing that the circular polarization degree, varepsilon, which is the asymmetry of the tensor power spectra betwe...
Precision of future experiments measuring primordial tensor fluctuation
Wang, Yi
2014-01-01
Recently the second phase of Background Imaging of Cosmic Extragalactic Polarization (BICEP2) claimed a detection of the tensor-to-scalar ratio ($r$) of primordial fluctuation at $5\\sigma$ confidence level. If it is true, this large and measurable amplitude ($r \\simeq 0.2$) of B-mode polarization indicates that it is possible to measure the shape of CMB B-mode polarization with future experiments. Given the current understanding of the experimental noise and foreground contamination, we forecast the precision of $r$ and the tensor spectral index $n_{\\rm t}$ measurements from Planck, Spider and POLARBEAR with $n_{\\rm t}$ as a free parameter. We quantitatively determine the signal-to-noise of the measurement in $r$-$n_{\\rm t}$ parameter space for the three experiments. The forecasted signal-to-noise ratio of the B-mode polarization somewhat depends on $n_{\\rm t}$, but strongly depends on the true value of $r$.
Constraints on the Cosmological Parameters using CMB observations
Rocha, Graca
1999-01-01
This paper covers several techniques of intercomparison of Cosmic Microwave Background (CMB) anisotropy experiments and models of structure formation. It presents the constraints on several cosmological parameters using current CMB observations.
Gomez-Cadenas, J J; Vidal, J Muñoz; Peña-Garay, C
2013-01-01
The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, mnu = 0.32+-0.11 eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass involved in neutrinoless double beta decay (bb0nu) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based bb0nu experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg year, could already have a sizable opportunity to observe bb0nu events, and their combined discovery potential is quite large. The next generation, with an exposure in the rang...
Liu, Jia; Sherwin, Blake D; Petri, Andrea; Böhm, Vanessa; Haiman, Zoltán
2016-01-01
Unprecedentedly precise cosmic microwave background (CMB) data are expected from ongoing and near-future CMB Stage-III and IV surveys, which will yield reconstructed CMB lensing maps with effective resolution approaching several arcminutes. The small-scale CMB lensing fluctuations receive non-negligible contributions from nonlinear structure in the late-time density field. These fluctuations are not fully characterized by traditional two-point statistics, such as the power spectrum. Here, we use $N$-body ray-tracing simulations of CMB lensing maps to examine two higher-order statistics: the lensing convergence one-point probability distribution function (PDF) and peak counts. We show that these statistics contain significant information not captured by the two-point function, and provide specific forecasts for the ongoing Stage-III Advanced Atacama Cosmology Telescope (AdvACT) experiment. Considering only the temperature-based reconstruction estimator, we forecast 30$\\sigma$ (PDF) and 10$\\sigma$ (peaks) detec...
Power spectrum sensitivity of raster-scanned CMB experiments in the presence of 1/f noise
Crawford, Tom
2007-09-01
We investigate the effects of 1/f noise on the ability of a particular class of cosmic microwave background experiments to measure the angular power spectrum of temperature anisotropy. We concentrate on experiments that operate primarily in raster-scan mode and develop formalism that allows us to calculate analytically the effect of 1/f noise on power-spectrum sensitivity for this class of experiments and determine the benefits of raster-scanning at different angles relative to the sky field versus scanning at only a single angle (cross-linking versus not cross-linking). We find that the sensitivity of such experiments in the presence of 1/f noise is not significantly degraded at moderate spatial scales (ℓ˜100) for reasonable values of scan speed and 1/f knee. We further find that the difference between cross-linked and non-cross-linked experiments is small in all cases and that the non-cross-linked experiments are preferred from a raw sensitivity standpoint in the noise-dominated regime—i.e., in experiments in which the instrument noise is greater than the sample variance of the target power spectrum at the scales of interest. This analysis does not take into account systematic effects.
Science with CMB spectral distortions
Chluba, Jens
2014-01-01
The measurements of COBE/FIRAS have shown that the CMB spectrum is extremely close to a perfect blackbody. There are, however, a number of processes in the early Universe that should create spectral distortions at a level which is within reach of present day technology. In this talk, I will give a brief overview of recent theoretical and experimental developments, explaining why future measurements of the CMB spectrum will open up an unexplored window to early-universe and particle physics with possible non-standard surprises but also several guaranteed signals awaiting us.
Limits Due to Instrumental Polarisation in CMB Experiments at Microwave Wavelengths
Carretti, E; Cortiglioni, S; Monari, J; Orsini, M
2001-01-01
An extended analysis of some instrumental polarisation sources has been done, as a consequence of the renewed interest in extremely sensitive polarisation measurements stimulated by Cosmic Microwave Background experiments. The case of correlation polarimeters, being them more suitable than other configurations, has been studied in detail and the algorithm has been derived to calculate their intrinsic sensitivity limit due to device characteristics as well as to the operating environment. The atmosphere emission, even though totally unpolarised, has been recognized to be the most important source of sensitivity degradation for ground based experiments. This happens through receiver component losses (mainly in the OMT), which generate instrumental polarisation in genuinely uncorrelated signals. The relevant result is that, also in best conditions (cfr. Antarctica), integration times longer than ~40s are not allowed on ground without modulation techniques. Finally, basic rules to estimate the maximum modulation ...
Large-scale CMB temperature and polarization cross-spectra likelihoods
Mangilli, A; Tristram, M
2015-01-01
One of the main challenges left for the present and future Cosmic Microwave Background (CMB) experiments is the high precision measurement of the CMB polarization anisotropies at large angular scales. The reionization bump in the CMB polarization power spectra encodes unique informations about the reionization history of the Universe and the inflationary epoch. Such valuable information can be accessed only with an unprecedented accuracy and care on each step of the data analysis and its interpretation. In this paper we present a cross-spectra based approach for the analysis of the CMB data at large angular scales to constrain the reionization optical depth, the tensor to scalar ratio and the amplitude of the primordial scalar perturbations. Using cross-spectra has the advantage to eliminate spurious noise bias and to give a better handle of residual systematics with respect to the pixel-based approach used so far, allowing to efficiently combine the cosmological information encoded in cross-frequency or cros...
Energy Technology Data Exchange (ETDEWEB)
Gómez-Cadenas, J.J.; Martín-Albo, J.; Vidal, J. Muñoz; Peña-Garay, C., E-mail: gomez@mail.cern.ch, E-mail: jmalbos@ific.uv.es, E-mail: jmunoz@ific.uv.es, E-mail: penya@ific.uv.es [Instituto de Física Corpuscular (IFIC), CSIC and Universitat de Valencia Calle Catedrático José Beltrán, 2, 46090 Paterna, Valencia (Spain)
2013-03-01
The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with Σm{sub ν} = (0.32±0.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m{sub ββ} involved in neutrinoless double beta decay (ββ0ν) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ββ0ν experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg·year, could already have a sizeable opportunity to observe ββ0ν events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 ton·year, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely.
A new model of the microwave polarized sky for CMB experiments
Hervías-Caimapo, Carlos; Bonaldi, Anna; Brown, Michael L.
2016-10-01
We present a new model of the microwave sky in polarization that can be used to simulate data from cosmic microwave background polarization experiments. We exploit the most recent results from the Planck satellite to provide an accurate description of the diffuse polarized foreground synchrotron and thermal dust emission. Our model can include the two mentioned foregrounds, and also a constructed template of Anomalous Microwave Emission. Several options for the frequency dependence of the foregrounds can be easily selected, to reflect our uncertainties and to test the impact of different assumptions. Small angular scale features can be added to the foreground templates to simulate high-resolution observations. We present tests of the model outputs to show the excellent agreement with Planck and Wilkinson Microwave Anisotropy Probe (WMAP) data. We determine the range within which the foreground spectral indices can be varied to be consistent with the current data. We also show forecasts for a high-sensitivity, high-resolution full-sky experiment such as the Cosmic ORigin Explorer. Our model is released as a PYTHON script that is quick and easy to use, available at http://www.jb.man.ac.uk/chervias.
Cosmologists in Search of Planet Nine: the Case for CMB Experiments
Cowan, Nicolas B; Kaib, Nathan A
2016-01-01
Cosmology experiments at mm-wavelengths may be able to detect Planet Nine if it is the size of Neptune, has an effective temperature of 40 K, and is 700 AU from the Sun. It would appear as a ~30 mJy source at 1 mm (or ~8 mJy at 150 GHz) with a parallax of ~5 arcmin. The challenge will be to distinguish it from the ~4000 foreground asteroids brighter than 30 mJy. Fortunately, asteroids can by identified by looking for sources that move across a resolution element in a matter of hours, orders of magnitude faster than Planet Nine. If Planet Nine is smaller, colder, and/or more distant than expected, then it could be as faint as 1 mJy at 1 mm. There are approximately 1E6 asteroids this bright, making many cosmology experiments confusion limited for moving sources. Nonetheless, it may still be possible to find the proverbial needle in the haystack using a matched filter. This would require mm telescopes with high angular resolution and high sensitivity in order to alleviate confusion and to enable the identificati...
Sensitivity and foreground modelling for large-scale CMB B-mode polarization satellite missions
Remazeilles, M; Eriksen, H K K; Wehus, I K
2015-01-01
Measurements of large-scale B-mode polarization in the cosmic microwave background (CMB) are a fundamental goal of current and future CMB experiments. However, because of the much higher instrumental sensitivity, CMB experiments will be more sensitive to any imperfect modelling of the Galactic foreground polarization in the estimation of the primordial B-mode signal. We compare the sensitivity to B-modes for different concepts of CMB satellite missions (LiteBIRD, COrE, COrE+, PRISM, EPIC, PIXIE) in the presence of Galactic foregrounds that are either correctly or incorrectly modelled. We quantify the impact on the tensor-to-scalar parameter of imperfect foreground modelling in the component separation process. Using Bayesian parametric fitting and Gibbs sampling, we perform the separation of the CMB and the Galactic foreground B-mode polarization. The resulting CMB B-mode power spectrum is used to compute the likelihood distribution of the tensor-to-scalar ratio. We focus the analysis to the very large angula...
Bias to CMB lensing measurements from the bispectrum of large-scale structure
Böhm, Vanessa; Schmittfull, Marcel; Sherwin, Blake D.
2016-08-01
The rapidly improving precision of measurements of gravitational lensing of the cosmic microwave background (CMB) also requires a corresponding increase in the precision of theoretical modeling. A commonly made approximation is to model the CMB deflection angle or lensing potential as a Gaussian random field. In this paper, however, we analytically quantify the influence of the non-Gaussianity of large-scale structure (LSS) lenses, arising from nonlinear structure formation, on CMB lensing measurements. In particular, evaluating the impact of the nonzero bispectrum of large-scale structure on the relevant CMB four-point correlation functions, we find that there is a bias to estimates of the CMB lensing power spectrum. For temperature-based lensing reconstruction with CMB stage III and stage IV experiments, we find that this lensing power spectrum bias is negative and is of order 1% of the signal. This corresponds to a shift of multiple standard deviations for these upcoming experiments. We caution, however, that our numerical calculation only evaluates two of the largest bias terms and, thus, only provides an approximate estimate of the full bias. We conclude that further investigation into lensing biases from nonlinear structure formation is required and that these biases should be accounted for in future lensing analyses.
A CMB/Dark Energy Cosmic Duality
Enqvist, K; Enqvist, Kari; Sloth, Martin S.
2004-01-01
We investigate a possible connection between the suppression of the power at low multipoles in the CMB spectrum and the late time acceleration. We show that, assuming a cosmic IR/UV duality between the UV cutoff and a global infrared cutoff given by the size of the future event horizon, the equation of state of the dark energy can be related to the apparent cutoff in the CMB spectrum. The present limits on the equation of state of dark energy are shown to imply an IR cutoff in the CMB multipole interval of 9>l>8.5.
A CMB/Dark Energy Cosmic Duality
DEFF Research Database (Denmark)
Enqvist, Kari; Sloth, Martin Snoager
2004-01-01
We investigate a possible connection between the suppression of the power at low multipoles in the CMB spectrum and the late time acceleration. We show that, assuming a cosmic IR/UV duality between the UV cutoff and a global infrared cutoff given by the size of the future event horizon, the equat......We investigate a possible connection between the suppression of the power at low multipoles in the CMB spectrum and the late time acceleration. We show that, assuming a cosmic IR/UV duality between the UV cutoff and a global infrared cutoff given by the size of the future event horizon......, the equation of state of the dark energy can be related to the apparent cutoff in the CMB spectrum. The present limits on the equation of state of dark energy are shown to imply an IR cutoff in the CMB multipole interval of 9>l>8.5....
Full covariance of CMB and lensing reconstruction power spectra
Peloton, Julien; Lewis, Antony; Carron, Julien; Zahn, Oliver
2016-01-01
CMB and lensing reconstruction power spectra are powerful probes of cosmology. However they are correlated, since the CMB power spectra are lensed and the lensing reconstruction is constructed using CMB multipoles. We perform a full analysis of the auto- and cross-covariances, including polarization power spectra and minimum variance lensing estimators, and compare with simulations of idealized future CMB-S4 observations. Covariances sourced by fluctuations in the unlensed CMB and instrumental noise can largely be removed by using a realization-dependent subtraction of lensing reconstruction noise, leaving a relatively simple covariance model that is dominated by lensing-induced terms and well described by a small number of principal components. The correlations between the CMB and lensing power spectra will be detectable at the level of $\\sim 5\\sigma$ for a CMB-S4 mission, and neglecting those could underestimate some parameter error bars by several tens of percent. However we found that the inclusion of ext...
Sparse component separation for accurate CMB map estimation
Bobin, J; Sureau, F; Basak, S
2012-01-01
The Cosmological Microwave Background (CMB) is of premier importance for the cosmologists to study the birth of our universe. Unfortunately, most CMB experiments such as COBE, WMAP or Planck do not provide a direct measure of the cosmological signal; CMB is mixed up with galactic foregrounds and point sources. For the sake of scientific exploitation, measuring the CMB requires extracting several different astrophysical components (CMB, Sunyaev-Zel'dovich clusters, galactic dust) form multi-wavelength observations. Mathematically speaking, the problem of disentangling the CMB map from the galactic foregrounds amounts to a component or source separation problem. In the field of CMB studies, a very large range of source separation methods have been applied which all differ from each other in the way they model the data and the criteria they rely on to separate components. Two main difficulties are i) the instrument's beam varies across frequencies and ii) the emission laws of most astrophysical components vary a...
Probing the Supersymmetric Inflaton and Dark Matter link via the CMB, LHC and XENON1T experiments
hm, Céline Bœ; Mazumdar, Anupam; Pukartas, Ernestas
2012-01-01
The primordial inflation dilutes all matter except the quantum fluctuations which we see in the cosmic microwave background (CMB) radiation. Therefore the last phases of inflation must be embedded within a beyond the Standard Model (SM) sector where the inflaton can directly excite the SM quarks and leptons. In this paper we consider two inflaton candidates LLe and udd whose decay can naturally excite all the relevant degrees of freedom besides thermalizing the lightest supersymmetric particle (LSP) during and after reheating. In particular, we present the regions of the parameter space which can yield successful inflation with the right temperature anisotropy in the CMB, the observed relic density for the neutralino LSP, and the recent Higgs mass constraints from LHC within the MSSM with non-universal Higgs masses -- referred to as the NUHM2 model. We found that in most scenarios, the LSP seems strongly mass degenerated with the next to lightest LSP (NLSP) and the branching ratio B_s -> mu^+ mu^- very close ...
Advanced Antenna-Coupled Superconducting Detector Arrays for CMB Polarimetry
Bock, James
2014-01-01
We are developing high-sensitivity millimeter-wave detector arrays for measuring the polarization of the cosmic microwave background (CMB). This development is directed to advance the technology readiness of the Inflation Probe mission in NASA's Physics of the Cosmos program. The Inflation Probe is a fourth-generation CMB satellite that will measure the polarization of the CMB to astrophysical limits, characterizing the inflationary polarization signal, mapping large-scale structure based on polarization induced by gravitational lensing, and mapping Galactic magnetic fields through measurements of polarized dust emission. The inflationary polarization signal is produced by a background of gravitational waves from the epoch of inflation, an exponential expansion of space-time in the early universe, with an amplitude that depends on the physical mechanism producing inflation. The inflationary polarization signal may be distinguished by its unique 'B-mode' vector properties from polarization from the density variations that predominantly source CMB temperature anisotropy. Mission concepts for the Inflation Probe are being developed in the US, Europe and Japan. The arrays are based on planar antennas that provide integral beam collimation, polarization analysis, and spectral band definition in a compact lithographed format that eliminates discrete fore-optics such as lenses and feedhorns. The antennas are coupled to transition-edge superconducting bolometers, read out with multiplexed SQUID current amplifiers. The superconducting sensors and readouts developed in this program share common technologies with NASA X-ray and FIR detector applications. Our program targets developments required for space observations, and we discuss our technical progress over the past two years and plans for future development. We are incorporating arrays into active sub-orbital and ground-based experiments, which advance technology readiness while producing state of the art CMB
Hill, Charles A; Chinone, Yuji; Goeckner-Wald, Neil; Hazumi, Masashi; Keating, Brian; Kusaka, Akito; Lee, Adrian T; Matsuda, Frederick; Plambeck, Richard; Suzuki, Aritoki; Takakura, Satoru
2016-01-01
We describe the development of an ambient-temperature continuously-rotating half-wave plate (HWP) for study of the Cosmic Microwave Background (CMB) polarization by the POLARBEAR-2 (PB2) experiment. Rapid polarization modulation suppresses 1/f noise due to unpolarized atmospheric turbulence and improves sensitivity to degree-angular-scale CMB fluctuations where the inflationary gravitational wave signal is thought to exist. A HWP modulator rotates the input polarization signal and therefore allows a single polarimeter to measure both linear polarization states, eliminating systematic errors associated with differencing of orthogonal detectors. PB2 projects a 365-mm-diameter focal plane of 7,588 dichroic, 95/150 GHz transition-edge-sensor bolometers onto a 4-degree field of view that scans the sky at $\\sim$ 1 degree per second. We find that a 500-mm-diameter ambient-temperature sapphire achromatic HWP rotating at 2 Hz is a suitable polarization modulator for PB2. We present the design considerations for the PB...
Antenna-coupled TES bolometer arrays for CMB polarimetry
Kuo, C L; Bonetti, J A; Brevik, J; Chattopadhyay, G; Day, P K; Golwala, S; Kenyon, M; Lange, A E; LeDuc, H G; Nguyen, H; Ogburn, R W; Orlando, A; Trangsrud, A; Turner, A; Wang, G; Zmuidzinas, J; 10.1117/12.788588
2009-01-01
We describe the design and performance of polarization selective antenna-coupled TES arrays that will be used in several upcoming Cosmic Microwave Background (CMB) experiments: SPIDER, BICEP-2/SPUD. The fully lithographic polarimeter arrays utilize planar phased-antennas for collimation (F/4 beam) and microstrip filters for band definition (25% bandwidth). These devices demonstrate high optical efficiency, excellent beam shapes, and well-defined spectral bands. The dual-polarization antennas provide well-matched beams and low cross polarization response, both important for high-fidelity polarization measurements. These devices have so far been developed for the 100 GHz and 150 GHz bands, two premier millimeter-wave atmospheric windows for CMB observations. In the near future, the flexible microstrip-coupled architecture can provide photon noise-limited detection for the entire frequency range of the CMBPOL mission. This paper is a summary of the progress we have made since the 2006 SPIE meeting in Orlando, FL...
Future double beta decay experiments
Energy Technology Data Exchange (ETDEWEB)
Piquemal, F. [Laboratoire Souterrain de Modane, Modane (France); Centre d' Etudes Nucleaire, Bordeaux-Gradignan (France)
2013-02-15
The search of neutrinoless double beta decay is very challenging because of the expected half-life of the process and the backgrounds from the natural radioactivity. Many projects exist to try to reach a sensitivity of ∼50 meV on the effective neutrino mass corresponding to a mass of isotopes of ∼100 kg. In this article some of the futur projects are presented.
Non-Gaussianity of Large-Scale CMB Anisotropies beyond Perturbation Theory
Bartolo, N; Riotto, Antonio
2005-01-01
We compute the fully non-linear Cosmic Microwave Background (CMB) anisotropies on scales larger than the horizon at last-scattering in terms of only the curvature perturbation, providing a generalization of the linear Sachs-Wolfe effect at any order in perturbation theory. We show how to compute the $n$-point connected correlation functions of the large-scale CMB anisotropies for generic primordial seeds provided by standard slow-roll inflation as well as the curvaton and other scenarios for the generation of cosmological perturbations. As an application of our formalism, we compute the three- and four-point connected correlation functions whose detection in future CMB experiments might be used to assess the level of primordial non-Gaussianity, giving the theoretical predictions for the parameters of quadratic and cubic non-linearities f_NL and g_NL.
Cooray, A R
2005-01-01
The curl-modes of Cosmic Microwave Background (CMB) polarization probe horizon-scale primordial gravitational waves related to inflation. A significant source of confusion is expected from a lensing conversion of polarization related to density perturbations to the curl mode, during the propagation of photons through the large scale structure. Either high resolution CMB anisotropy observations or 21 cm fluctuations at redshifts 30 and higher can be used to delens polarization data and to separate gravitational-wave polarization signature from that of cosmic-shear related signal. Separations based on proposed lensing reconstruction techniques for reasonable future experiments allow the possibility to probe inflationary energy scales down to 10^15 GeV. Beyond CMB polarization, at frequencies between 0.01 Hz to 1 Hz, space-based laser interferometers can also be used to probe the inflationary gravitational wave background. The confusion here is related to the removal of merging neutron star binaries at cosmologi...
Probing the statistical properties of CMB B-mode polarization through Minkowski functionals
Santos, Larissa; Wang, Kai; Zhao, Wen
2016-07-01
The detection of the magnetic type B-mode polarization is the main goal of future cosmic microwave background (CMB) experiments. In the standard model, the B-mode map is a strong non-gaussian field due to the CMB lensing component. Besides the two-point correlation function, the other statistics are also very important to dig the information of the polarization map. In this paper, we employ the Minkowski functionals to study the morphological properties of the lensed B-mode maps. We find that the deviations from Gaussianity are very significant for both full and partial-sky surveys. As an application of the analysis, we investigate the morphological imprints of the foreground residuals in the B-mode map. We find that even for very tiny foreground residuals, the effects on the map can be detected by the Minkowski functional analysis. Therefore, it provides a complementary way to investigate the foreground contaminations in the CMB studies.
The Future of Social Experimenting
Helbing, Dirk; 10.1073/pnas.1000140107
2010-01-01
Recent lab experiments by Traulsen et al. for the spatial prisoner's dilemma suggest that exploratory behavior of human subjects prevents cooperation through neighborhood interactions over experimentally accessible time spans. This indicates that new theoretical and experimental efforts are needed to explore the mechanisms underlying a number of famous puzzles in the social sciences.
Robust Signatures of the Relic Neutrinos in CMB
Bashinsky, S V
2004-01-01
When the perturbations forming the acoustic peaks of the cosmic microwave background (CMB) reentered the horizon and interacted gravitationally with all the matter, neutrinos presumably comprised 41% of the universe energy. CMB experiments have reached a capacity to probe this background of relic neutrinos. I review the neutrino imprints on CMB anisotropy and polarization at the onset of the acoustic oscillations. The discussion addresses the underlying physics, robustness or degeneracy of the imprints with changes of free cosmological parameters, and non-minimal models for the unseen radiation sector with detectable signatures in CMB.
Spin-SILC: CMB polarisation component separation with spin wavelets
Rogers, Keir K.; Peiris, Hiranya V.; Leistedt, Boris; McEwen, Jason D.; Pontzen, Andrew
2016-08-01
We present Spin-SILC, a new foreground component separation method that accurately extracts the cosmic microwave background (CMB) polarisation E and B modes from raw multifrequency Stokes Q and U measurements of the microwave sky. Spin-SILC is an internal linear combination method that uses spin wavelets to analyse the spin-2 polarisation signal P = Q + iU. The wavelets are additionally directional (non-axisymmetric). This allows different morphologies of signals to be separated and therefore the cleaning algorithm is localised using an additional domain of information. The advantage of spin wavelets over standard scalar wavelets is to simultaneously and self-consistently probe scales and directions in the polarisation signal P = Q + iU and in the underlying E and B modes, therefore providing the ability to perform component separation and E-B decomposition concurrently for the first time. We test Spin-SILC on full-mission Planck simulations and data and show the capacity to correctly recover the underlying cosmological E and B modes. We also demonstrate a strong consistency of our CMB maps with those derived from existing component separation methods. Spin-SILC can be combined with the pseudo- and pure E-B spin wavelet estimators presented in a companion paper to reliably extract the cosmological signal in the presence of complicated sky cuts and noise. Therefore, it will provide a computationally-efficient method to accurately extract the CMB E and B modes for future polarisation experiments.
CMB Distortions from Superconducting Cosmic Strings
Tashiro, Hiroyuki; Vachaspati, Tanmay
2012-01-01
We reconsider the effect of electromagnetic radiation from superconducting strings on cosmic microwave background (CMB) mu- and y-distortions and derive present (COBE-FIRAS) and future (PIXIE) constraints on the string tension, mu_s, and electric current, I. We show that absence of distortions of the CMB in PIXIE will impose strong constraints on mu_s and I, leaving the possibility of light strings (G mu_s < 10^{-18}) or relatively weak currents (I < 10 TeV).
Cosmological parameter estimation: impact of CMB aberration
Catena, Riccardo
2012-01-01
The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, i.e. aberration, and a shift in their frequency, i.e. Doppler effect. Both effects distort the temperature multipoles a_lm's via a mixing matrix at any l. The common lore when performing a CMB based cosmological parameter estimation is to consider that Doppler affects only the l=1 multipole, and neglect any other corrections. In this paper we reconsider the validity of this assumption, showing that it is actually not robust when sky cuts are included to model CMB foreground contaminations. Assuming a simple fiducial cosmological model with five parameters, we simulated CMB temperature maps of the sky in a WMAP-like and in a Planck-like experiment and added aberration and Doppler effects to the maps. We then analyzed with a MCMC in a Bayesian framework the maps with and without aberration and Doppler effects in order to assess the ability of reconstructing the parameters of the fidu...
Oyama, Yoshihiko
2015-01-01
Observations of the 21 cm line radiation coming from the epoch of reionization have a great capacity to study the cosmological growth of the Universe. Also, CMB polarization produced by gravitational lensing has a large amount of information about the growth of matter fluctuations at late time. In this thesis, we investigate their sensitivities to the impact of neutrino property on the growth of density fluctuations, such as the total neutrino mass, the neutrino mass hierarchy, the effective number of neutrino species (extra radiation), and the lepton asymmetry of our Universe. We will show that by combining the precise CMB polarization observations with Square Kilometer Array (SKA) we can measure the impact of non-zero neutrino mass on the growth of density fluctuation, and determine the neutrino mass hierarchy at 2 sigma level if the total neutrino mass is smaller than 0.1 eV. Additionally, we will show that by using these combinations we can constrain the lepton asymmetry better than big-bang nucleosynthes...
Hu, W; Hu, Wayne; Okamoto, Takemi
2004-01-01
We study the physical limitations placed on CMB temperature and polarization measurements of the initial power spectrum by geometric projection, acoustic physics, gravitational lensing and the joint fitting of cosmological parameters. Detailed information on the spectrum is greatly assisted by polarization information and localized to the acoustic regime k = 0.02-0.2 Mpc^{-1} with a fundamental resolution of Delta k/k>0.05. From this study we construct principal component based statistics, which are orthogonal to cosmological parameters including the initial amplitude and tilt of the spectrum, that best probe deviations from scale-free initial conditions. These statistics resemble Fourier modes confined to the acoustic regime and ultimately can yield ~50 independent measurements of the power spectrum features to percent level precision. They are straightforwardly related to more traditional parameterizations such as the the running of the tilt and in the future can provide many statistically independent measu...
Liu, Jia; Hill, J. Colin; Sherwin, Blake D.; Petri, Andrea; Böhm, Vanessa; Haiman, Zoltán
2016-11-01
Unprecedentedly precise cosmic microwave background (CMB) data are expected from ongoing and near-future CMB stage III and IV surveys, which will yield reconstructed CMB lensing maps with effective resolution approaching several arcminutes. The small-scale CMB lensing fluctuations receive non-negligible contributions from nonlinear structure in the late-time density field. These fluctuations are not fully characterized by traditional two-point statistics, such as the power spectrum. Here, we use N -body ray-tracing simulations of CMB lensing maps to examine two higher-order statistics: the lensing convergence one-point probability distribution function (PDF) and peak counts. We show that these statistics contain significant information not captured by the two-point function and provide specific forecasts for the ongoing stage III Advanced Atacama Cosmology Telescope (AdvACT) experiment. Considering only the temperature-based reconstruction estimator, we forecast 9 σ (PDF) and 6 σ (peaks) detections of these statistics with AdvACT. Our simulation pipeline fully accounts for the non-Gaussianity of the lensing reconstruction noise, which is significant and cannot be neglected. Combining the power spectrum, PDF, and peak counts for AdvACT will tighten cosmological constraints in the Ωm-σ8 plane by ≈30 %, compared to using the power spectrum alone.
Full covariance of CMB and lensing reconstruction power spectra
Peloton, Julien; Schmittfull, Marcel; Lewis, Antony; Carron, Julien; Zahn, Oliver
2017-02-01
CMB and lensing reconstruction power spectra are powerful probes of cosmology. However, they are correlated, since the CMB power spectra are lensed, and the lensing reconstruction is constructed using CMB multipoles. We perform a full analysis of the auto- and cross-covariances, including polarization power spectra and minimum-variance lensing estimators, and compare with simulations of idealized future CMB-S4 observations. Covariances sourced by fluctuations in the unlensed CMB and instrumental noise can largely be removed by using a realization-dependent subtraction of lensing reconstruction noise, leaving a relatively simple covariance model that is dominated by lensing-induced terms and well described by a small number of principal components. The correlations between the CMB and lensing power spectra will be detectable at the level of ˜5 σ for a CMB-S4 mission, and neglecting them could underestimate some parameter error bars by several tens of percent. However, we found that the inclusion of external priors or data sets to estimate parameter error bars can make the impact of the correlations almost negligible.
CMB Observations with the South Pole Telescope
Keisler, Ryan
2013-04-01
I will describe a program of cosmological research centered on using measurements of the cosmic microwave background (CMB) to address questions relevant to physics: What is the absolute mass scale of neutrinos? How many species of neutrino-like particles were present in the early Universe? How does gravity behave on cosmological scales? Did inflation occur, and, if so, at what energy scale? A new generation of CMB experiments is targeting these questions, and I will focus on recent results from the South Pole Telescope (SPT). The SPT is a ground-based mm-wave observatory located at the geographic south pole in Antarctica, and in 2011 finished its initial, 2500 square-degree ``SPT-SZ'' survey. The data from this survey provided an unprecedented combination of resolution, area, and sensitivity, and has been used to make ground-breaking measurements of the CMB anisotropy and the gravitational lensing of the CMB. These measurements have, in conjunction with data from the WMAP satellite, led to strong constraints on the number of neutrino-like particle species present in the early universe and the shape of the power spectrum of primordial density fluctuations. The SPT-SZ data overlaps with the ongoing Dark Energy Survey (DES) footprint, and the joint dataset will provide new probes of large-scale structure, such as the relative velocities of massive galaxy clusters. In 2012, a new polarization-sensitive camera, SPTpol, was installed on the SPT, and I will summarize its performance and prospects for detecting the B-mode CMB polarization pattern. Finally, I will touch on what will be possible with a third-generation camera, SPT-3G. The leap in sensitivity provided by this camera will yield, for example, a constraint on the sum of the neutrino masses relevant for exploring the neutrino mass hierarchy.
POLARBEAR-2: an instrument for CMB polarization measurements
Inoue, Y; Akiba, Y; Aleman, C; Arnold, K; Baccigalupi, C; Barch, B; Barron, D; Bender, A; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Cukierman, A; de Haan, T; Dobbs, M A; Ducout, A; Dunner, R; Elleflot, T; Errard, J; Fabbian, G; Feeney, S; Feng, C; Fuller, G; Gilbert, A J; Goeckner-Wald, N; Groh, J; Hall, G; Halverson, N; Hamada, T; Hasegawa, M; Hattori, K; Hazumi, M; Hill, C; Holzapfel, W L; Hori, Y; Howe, L; Irie, F; Jaehnig, G; Jaffe, A; Jeongh, O; Katayama, N; Kaufman, J P; Kazemzadeh, K; Keating, B G; Kermish, Z; Keskital, R; Kisner, T; Kusaka, A; Jeune, M Le; Lee, A T; Leon, D; Linder, E V; Lowry, L; Matsuda, F; Matsumura, T; Miller, N; Mizukami, K; Montgomery, J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Poletti, D; Puglisi, G; Raum, C R; Rebeiz, G M; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K M; Segaw, Y; Sherwin, B D; Shirley, I; Siritanasak, P; Stebor, N; Suzuki, R Stompor A; Tajima, O; Takada, S; Takatori, S; Teply, G P; Tikhomirol, A; Tomaru, T; Whitehorn, N; Zahn, A; Zahn, O
2016-01-01
POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization experiment that will be located in the Atacama highland in Chile at an altitude of 5200 m. Its science goals are to measure the CMB polarization signals originating from both primordial gravitational waves and weak lensing. PB-2 is designed to measure the tensor to scalar ratio, r, with precision {\\sigma}(r) < 0.01, and the sum of neutrino masses, {\\Sigma}m{\
CMB-S4 Science Book, First Edition
Abazajian, Kevork N.; Adshead, Peter; Ahmed, Zeeshan; Allen, Steven W.; Alonso, David; Arnold, Kam S.; Baccigalupi, Carlo; Bartlett, James G.; Battaglia, Nicholas; Benson, Bradford A.; Bischoff, Colin A.; Borrill, Julian; Buza, Victor; Calabrese, Erminia; Caldwell, Robert
2016-01-01
This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves...
Endovascular Neurosurgery: Personal Experience and Future Perspectives.
Raymond, Jean
2016-09-01
From Luessenhop's early clinical experience until the present day, experimental methods have been introduced to make progress in endovascular neurosurgery. A personal historical narrative, spanning the 1980s to 2010s, with a review of past opportunities, current problems, and future perspectives. Although the technology has significantly improved, our clinical culture remains a barrier to methodologically sound and safe innovative care and progress. We must learn how to safely practice endovascular neurosurgery in the presence of uncertainty and verify patient outcomes in real time. Copyright © 2016 Elsevier Inc. All rights reserved.
Current and Future Constraints on Primordial Magnetic Fields
Sutton, Dylan R.; Feng, Chang; Reichardt, Christian L.
2017-09-01
We present new limits on the amplitude of potential primordial magnetic fields (PMFs) using temperature and polarization measurements of the cosmic microwave background (CMB) from Planck, the BICEP2/Keck Array, Polarbear, and SPTpol. We reduce twofold the 95% confidence upper limit on the CMB anisotropy power due to a nearly scale-invariant PMF, with an allowed B-mode power at ℓ = 1500 of {D}{\\ell =1500}{BB}< 0.071 μ {K}2 for Planck versus {D}{\\ell =1500}{BB}< 0.034 μ {K}2 for the combined data set. We also forecast the expected limits from soon-to-deploy CMB experiments (like SPT-3G, Adv. ACTpol, or the Simons Array) and the proposed CMB-S4 experiment. Future CMB experiments should dramatically reduce the current uncertainties by one order of magnitude for the near-term experiments and two orders of magnitude for the CMB-S4 experiment. The constraints from CMB-S4 have the potential to rule out much of the parameter space for PMFs.
CMB-S4 and the Hemispherical Variance Anomaly
O'Dwyer, Marcio; Knox, Lloyd; Starkman, Glenn D
2016-01-01
Cosmic Microwave Background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the northern and southern Ecliptic hemispheres. In this context, the northern hemisphere displays an anomalously low variance while the southern hemisphere appears unremarkable (consistent with expectations from the best-fitting theory, $\\Lambda$CDM). While this is a well established result in temperature, the low signal-to-noise ratio in current polarization data prevents a similar comparison. This will change with a proposed ground-based CMB experiment, CMB-S4. With that in mind, we generate realizations of polarization maps constrained by the temperature data and predict the distribution of the hemispherical variance in polarization considering two different sky coverage scenarios possible in CMB-S4: full Ecliptic north coverage and just the portion of the North that can be observed from a ground ba...
Probing the statistical properties of CMB $B$-mode polarization through Minkowski Functionals
Zhao, W
2015-01-01
The detection of the magnetic type $B$-mode polarization is the main goal of future cosmic microwave background (CMB) experiments. In the standard model, the $B$-mode map is a strongly non-gaussian field due to the lensed component. Besides the two-point correlation function, the other statistics are also very important to dig the information of the polarization map. In this paper, we employ the Minkowski functionals to study the morphological properties of the lensed $B$-mode maps. We find that the deviations from Gaussianity are very significant for both full and partial-sky surveys. As an application of the analysis, we investigate the morphological imprints of the foreground residuals in the $B$-mode map. We find that even for very tiny foreground residuals, the effects on the map can be detected by the Minkowski functional analysis. Therefore, it provides a complementary way to investigate the foreground contaminations in the CMB studies.
Calibrating Cluster Number Counts with CMB lensing
Louis, Thibaut
2016-01-01
CMB Stage-4 experiments will reduce the uncertainties on the gravitational lensing potential by an order of magnitude compared to current measurements, and will also produce a Sunyaev-Zel'dovich (SZ) cluster catalog containing $\\sim10^{5}$ objects, two orders of magnitudes higher than what is currently available. In this paper we propose to combine these two observables and show that it is possible to calibrate the masses of the full Stage-4 cluster catalog internally owing to the high signal to noise measurement of the CMB lensing convergence field. We find that a CMB Stage-4 experiment will constrain the hydrostatic bias parameter to sub-percent accuracy. We also show constraints on a non parametric $Y-M$ relationship which could be used to study its evolution with mass and redshift. Finally we present a joint likelihood for thermal SZ (tSZ) flux and mass measurements, and show that it could lead to a $\\sim5\\sigma$ detection of the lower limit on the sum of the neutrino masses in the normal hierarchy ($\\sum...
Cosmology from CMB polarization with POLARBEAR and the Simons Array
Barron, Darcy; POLARBEAR Collaboration
2016-01-01
POLARBEAR is a cosmic microwave background (CMB) polarization experiment located in the Atacama desert in Chile. The science goals of the POLARBEAR project are to do a deep search for CMB B-mode polarization created by inflationary gravitational waves, as well as characterize the CMB B-mode signal from gravitational lensing. POLARBEAR-1 started observations in 2012. The POLARBEAR team has published results from its first season of observations on a small fraction of the sky, including a measurement of a non-zero B-mode polarization angular power spectrum at sub-degree scales, where the dominant signal is gravitational lensing of the CMB. Improving these measurements requires precision characterization of the CMB polarization signal over large fractions of the sky, at multiple frequencies. To achieve these goals, POLARBEAR has begun expanding to include an additional two 3.5 meter telescopes with multi-chroic receivers, known as the Simons Array. With high sensitivity and large sky coverage, the Simons Array will create a detailed survey of B-mode polarization, and its spectral information will be used to extract the CMB signal from astrophysical foregrounds. The Simons Array data will place strong constraints on the sum of the neutrino masses, when combined with data from the next generation of baryon acoustic oscillation measurements. We present the status of this funded instrument and its expected capabilities.
Constraining dark photon model with dark matter from CMB spectral distortions
Directory of Open Access Journals (Sweden)
Ki-Young Choi
2017-08-01
Full Text Available Many extensions of Standard Model (SM include a dark sector which can interact with the SM sector via a light mediator. We explore the possibilities to probe such a dark sector by studying the distortion of the CMB spectrum from the blackbody shape due to the elastic scatterings between the dark matter and baryons through a hidden light mediator. We in particular focus on the model where the dark sector gauge boson kinetically mixes with the SM and present the future experimental prospect for a PIXIE-like experiment along with its comparison to the existing bounds from complementary terrestrial experiments.
Schwarz, Dominik J.; Copi, Craig J.; Huterer, Dragan; Starkman, Glenn D.
2016-09-01
Several unexpected features have been observed in the microwave sky at large angular scales, both by WMAP and by Planck. Among those features is a lack of both variance and correlation on the largest angular scales, alignment of the lowest multipole moments with one another and with the motion and geometry of the solar system, a hemispherical power asymmetry or dipolar power modulation, a preference for odd parity modes and an unexpectedly large cold spot in the Southern hemisphere. The individual p-values of the significance of these features are in the per mille to per cent level, when compared to the expectations of the best-fit inflationary ΛCDM model. Some pairs of those features are demonstrably uncorrelated, increasing their combined statistical significance and indicating a significant detection of CMB features at angular scales larger than a few degrees on top of the standard model. Despite numerous detailed investigations, we still lack a clear understanding of these large-scale features, which seem to imply a violation of statistical isotropy and scale invariance of inflationary perturbations. In this contribution we present a critical analysis of our current understanding and discuss several ideas of how to make further progress.
Schwarz, Dominik J; Huterer, Dragan; Starkman, Glenn D
2015-01-01
Several unexpected features have been observed in the microwave sky at large angular scales, both by WMAP an by Planck. Among those features is a lack of both variance and correlation on the largest angular scales, alignment of the lowest multipole moments with one another and with the motion and geometry of the Solar System, a hemispherical power asymmetry or dipolar power modulation, a preference for odd parity modes and an unexpectedly large cold spot in the Southern hemisphere. The individual p-values of the significance of these features are in the per mille to per cent level, when compared to the expectations of the best-fit inflationary $\\Lambda$CDM model. Some pairs of those features are demonstrably uncorrelated, increasing their combined statistical significance and indicating a significant detection of CMB features at angular scales larger than a few degrees on top of the standard model. Despite numerous detailed investigations, we still lack a clear understanding of these large-scale features, whi...
Measuring Distance Ratios with CMB-Galaxy Lensing Cross-correlations
Das, Sudeep; 10.1103/PhysRevD.79.043509
2009-01-01
We propose a method for cosmographic measurements by combining gravitational lensing of the cosmic microwave background (CMB) with cosmic shear surveys. We cross-correlate the galaxy counts in the lens plane with two different source planes: the CMB at $z \\sim 1100$ and galaxies at an intermediate redshift. The ratio of the galaxy count/CMB lensing cross-correlation to the galaxy count/galaxy lensing cross correlation is shown to be a purely geometric quantity, depending only on the distribution function of the source galaxies. By combining Planck, ADEPT and LSST the ratio can be measured to $\\sim 4%$ accuracy, whereas a future polarization based experiment like CMBPOL can make a more precise ($\\sim 1%$) measurement. For cosmological models where the curvature and the equation of state parameter are allowed to vary, the direction of degeneracy defined by the measurement of this ratio is different from that traced out by Baryon Acoustic Oscillation (BAO) measurements. Combining this method with the stacked clu...
Environmental futures research: experiences, approaches, and opportunities
David N., comp. Bengston
2012-01-01
These papers, presented in a special session at the International Symposium on Society and Resource Management in June 2011, explore the transdisciplinary field of futures research and its application to long-range environmental analysis, planning, and policy. Futures research began in the post-World War II era and has emerged as a mature research field. Although the...
CMB Polarization with BICEP2 and Keck-Array
Pryke, Clement; BICEP2 and Keck-Array Collaborations
2013-01-01
BICEP2 is an evolution from the highly successful BICEP CMB polarization experiment. In turn Keck-Array is an array of BICEP2 like receivers to achieve an additional increase in sensitivity. All these experiments are located at the South Pole in Antarctica and target the CMB B-mode polarization signal which is predicted to exist in many simpler models of Inflation at angular scales of several degrees. The design and performance of BICEP2 and Keck-Array is described and some preliminary polarization maps are presented.
CMB lensing from SPT+Planck and cross-correlations
Omori, Yuuki; SPT Collaboration; DES Collaboration
2017-01-01
The South Pole Telescope (SPT) SZ survey has observed 2500 square degrees of the Cosmic Microwave Background (CMB) to high accuracy down to 1 arcminute resolution at 150GHz. The Planck satellite has also observed the same patch of the CMB sky at 143GHz, but the two experiments were designed to measure temperature anisotropies optimally at different angular scales. By combining data from these two experiments, we are able to produce a temperature map that has an improved signal-to-noise ratio at all scales. This combined temperature map is used to produce a CMB weak lensing map, which we use for cosmological parameter and cross-correlation analyses. In particular, the SPT footprint has significant overlap with the Dark Energy Survey (DES) observing region, which allows us to cross-correlate the CMB lensing map with galaxy density and galaxy shear measurements obtained by DES. In this talk, I will present the SPT+Planck combining procedure, the CMB lensing reconstruction pipeline, tests performed to verify the lensing map, and finally the cross-correlation measurements.
Wavelets Applied to CMB Maps a Multiresolution Analysis for Denoising
Sanz, J L; Cayon, L; Martínez-González, E; Barriero, R B; Toffolatti, L
1999-01-01
Analysis and denoising of Cosmic Microwave Background (CMB) maps are performed using wavelet multiresolution techniques. The method is tested on $12^{\\circ}.8\\times 12^{\\circ}.8$ maps with resolution resembling the experimental one expected for future high resolution space observations. Semianalytic formulae of the variance of wavelet coefficients are given for the Haar and Mexican Hat wavelet bases. Results are presented for the standard Cold Dark Matter (CDM) model. Denoising of simulated maps is carried out by removal of wavelet coefficients dominated by instrumental noise. CMB maps with a signal-to-noise, $S/N \\sim 1$, are denoised with an error improvement factor between 3 and 5. Moreover we have also tested how well the CMB temperature power spectrum is recovered after denoising. We are able to reconstruct the $C_{\\ell}$'s up to $l\\sim 1500$ with errors always below $20% $ in cases with $S/N \\ge 1$.
Working Group Report: Dark Energy and CMB
Energy Technology Data Exchange (ETDEWEB)
Dodelson, S.; Honscheid, K.; Abazajian, K.; Carlstrom, J.; Huterer, D.; Jain, B.; Kim, A.; Kirkby, D.; Lee, A.; Padmanabhan, N.; Rhodes, J.; Weinberg, D.
2013-09-20
The American Physical Society's Division of Particles and Fields initiated a long-term planning exercise over 2012-13, with the goal of developing the community's long term aspirations. The sub-group "Dark Energy and CMB" prepared a series of papers explaining and highlighting the physics that will be studied with large galaxy surveys and cosmic microwave background experiments. This paper summarizes the findings of the other papers, all of which have been submitted jointly to the arXiv.
Primordial gravitational waves measurements and anisotropies of CMB polarization rotation
Directory of Open Access Journals (Sweden)
Si-Yu Li
2015-12-01
Full Text Available Searching for the signal of primordial gravitational waves in the B-modes (BB power spectrum is one of the key scientific aims of the cosmic microwave background (CMB polarization experiments. However, this could be easily contaminated by several foreground issues, such as the interstellar dust grains and the galactic cyclotron electrons. In this paper we study another mechanism, the cosmic birefringence, which can be introduced by a CPT-violating interaction between CMB photons and an external scalar field. Such kind of interaction could give rise to the rotation of the linear polarization state of CMB photons, and consequently induce the CMB BB power spectrum, which could mimic the signal of primordial gravitational waves at large scales. With the recently released polarization data of BICEP2 and the joint analysis data of BICEP2/Keck Array and Planck, we perform a global fitting analysis on constraining the tensor-to-scalar ratio r by considering the polarization rotation angle [α(nˆ] which can be separated into a background isotropic part [α¯] and a small anisotropic part [Δα(nˆ]. Since the data of BICEP2 and Keck Array experiments have already been corrected by using the “self-calibration” method, here we mainly focus on the effects from the anisotropies of CMB polarization rotation angle. We find that including Δα(nˆ in the analysis could slightly weaken the constraints on the tensor-to-scalar ratio r, when using current CMB polarization measurements. We also simulate the mock CMB data with the BICEP3-like sensitivity. Very interestingly, we find that if the effects of the anisotropic polarization rotation angle could not be taken into account properly in the analysis, the constraints on r will be dramatically biased. This implies that we need to break the degeneracy between the anisotropies of the CMB polarization rotation angle and the CMB primordial tensor perturbations, in order to measure the signal of primordial
CMB statistical anisotropy from noncommutative gravitational waves
Energy Technology Data Exchange (ETDEWEB)
Shiraishi, Maresuke; Ricciardone, Angelo [Dipartimento di Fisica e Astronomia ' ' G. Galilei' ' , Università degli Studi di Padova, via Marzolo 8, I-35131, Padova (Italy); Mota, David F. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Arroja, Frederico, E-mail: maresuke.shiraishi@pd.infn.it, E-mail: d.f.mota@astro.uio.no, E-mail: angelo.ricciardone@pd.infn.it, E-mail: arroja@pd.infn.it [INFN, Sezione di Padova, via Marzolo 8, I-35131, Padova (Italy)
2014-07-01
Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from anisotropic gravitational waves, parametrised by P{sub h}(k) = P{sub h}{sup (0)}(k) [ 1 + ∑{sub LM} f{sub L}(k) g{sub LM} Y{sub LM} ( k-circumflex )], where P{sub h}{sup (0)}(k) is the usual scale-invariant power spectrum. Such anisotropic tensor fluctuations may arise from an inflationary model with noncommutativity of fields. It is verified that in this model, an isotropic component and a quadrupole asymmetry with f{sub 0}(k) = f{sub 2}(k) ∝ k{sup -2} are created and hence highly red-tilted off-diagonal components arise in the CMB power spectra, namely ℓ{sub 2} = ℓ{sub 1} ± 2 in TT, TE, EE and BB, and ℓ{sub 2} = ℓ{sub 1} ± 1 in TB and EB. We find that B-mode polarisation is more sensitive to such signals than temperature and E-mode polarisation due to the smallness of large-scale cosmic variance and we can potentially measure g{sub 00} = 30 and g{sub 2M} = 58 at 68% CL in a cosmic-variance-limited experiment. Such a level of signal may be measured in a PRISM like experiment, while the instrumental noise contaminates it in the Planck experiment. These results imply that it is impossible to measure the noncommutative parameter if it is small enough for the perturbative treatment to be valid. Our formalism and methodology for dealing with the CMB tensor statistical anisotropy are general and straightforwardly applicable to other early Universe models.
Solar neutrino experiments: now and future
Nakahata, M
2003-01-01
The deficit of the solar neutrino event rate (so called 'solar neutrino problem') was initially presented by Davis since 1960s. It was established as a deficit of the solar neutrino flux by Kamiokande led by Koshiba. In the recent two years, it was found that the solar neutrino problem is due to neutrino oscillations by the results from Super-Kamiokande and SNO experiments. Combining with other solar neutrino experiments, most probable solution of the neutrino oscillation parameters was the Large Mixing Angle (LMA) solution. In December 2002, the reactor long baseline experiment, KamLAND, confirmed that the LMA is the correct solution. (author)
CMB radiation in an inhomogeneous spherical space
Aurich, R; Lustig, S
2011-01-01
We analyse the CMB radiation in spherical 3-spaces with non-trivial topology. The focus is put on an inhomogeneous space which possesses observer dependent CMB properties. The suppression of the CMB anisotropies on large angular scales is analysed with respect to the position of the CMB observer. The equivalence of a lens space with a Platonic cubic space is shown and used for the harmonic analysis. We give the transformation of the CMB multipole radiation amplitude as a function of the position of the observer. General sum rules are obtained in terms of the squares of the expansion coefficients for invariant polynomials on the 3-sphere.
Power filtration of CMB observational data
DEFF Research Database (Denmark)
Novikov, D.I.; Naselsky, P.; Jørgensen, H.E.
2001-01-01
We propose a power filter Cp for linear reconstruction of the CMB signal from one-dimensional scans of observational maps. This Gp filter preserves the power spectrum of the CMB signal in contrast to the Wiener filter which diminishes the power spectrum of the reconstructed CMB signal. We...... demonstrate how peak statistics and a cluster analysis can be used to estimate the probability of the presence of a CMB signal in observational records. The efficiency of the G, filter is demonstrated on a toy model of an observational record consisting of a CMB signal and noise in the form of foreground...
CMB polarimetry with BICEP: instrument characterization, calibration, and performance
Takahashi, Yuki D; Battle, John O; Bierman, Evan M; Bock, James J; Chiang, H Cynthia; Dowell, C Darren; Hivon, Eric F; Holzapfel, William L; Hristov, Viktor V; Jones, William C; Kaufman, J P; Keating, Brian G; Kovac, John M; Kuo, Chao-Lin; Lange, Andrew E; Leitch, Erik M; Mason, Peter V; Matsumura, Tomotake; Nguyen, Hien T; Ponthieu, Nicolas; Rocha, Graca M; Yoon, Ki Won; Ade, P; Duband, L
2008-01-01
BICEP is a ground-based millimeter-wave bolometric array designed to target the primordial gravity wave signature on the polarization of the cosmic microwave background (CMB) at degree angular scales. Currently in its third year of operation at the South Pole, BICEP is measuring the CMB polarization with unprecedented sensitivity at 100 and 150 GHz in the cleanest available 2% of the sky, as well as deriving independent constraints on the diffuse polarized foregrounds with select observations on and off the Galactic plane. Instrument calibrations are discussed in the context of rigorous control of systematic errors, and the performance during the first two years of the experiment is reviewed.
Antenna-Coupled TES Bolometers for CMB Polarimetry
Kuo, C L; Chattopadhyay, G; Goldin, A; Golwala, S; Holmes, W; Irwin, K; Kenyon, M; Lange, A E; Le Duc, H G; Rossinot, P; Vayonakis, A; Wang, G; Yun, M; Zmuidzinas, J
2006-01-01
We have developed a completely lithographic antenna-coupled bolometer for CMB polarimetry. The necessary components of a millimeter wave radiometer -- a beam forming element, a band defining filter, and the TES detectors -- are fabricated on a silicon chip with photolithography. The densely populated antennas allow a very efficient use of the focal plane area. We have fabricated and characterized a series of prototype devices. We find that their properties, including the frequency and angular responses, are in good agreement with the theoretical expectations. The devices are undergoing optimization for upcoming CMB experiments.
Phenomenology of future neutrino oscillation experiments
Schwetz, Thomas
2010-01-01
give a brief overview of the phenomenology related to the measurements of the last unknown lepton mixing angle !13, CP violation (CPV) in neutrino os- cillations, and the neutrino mass hierarchy (MH). Sensitivities of upcoming reactor and accelerator experiments to !13 are discussed, showing that within a few years values of sin2 2!13 ! 10−2 will be probed, while CPV andMH mea- surements will be very difÞcult with that generation of experiments. I make some selected remarks on CPV andMH determinations with a subsequent gen- eration of experiment consisting of a high precision/high luminosity oscillation facility. In particular, I emphasize the possibility to explore synergies of such an advanced accelerator facility with a huge multi-purpose detector.
Electroweak effective couplings for future precision experiments
Energy Technology Data Exchange (ETDEWEB)
Jegerlehner, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik
2011-07-15
The leading hadronic effects in electroweak theory derive from vacuum polarization which are non-perturbative hadronic contributions to the running of the gauge couplings, the electromagnetic {alpha}{sub em}(s) and the SU(2){sub L} coupling {alpha}{sub 2}(s). I report on my recent package alphaQED [1], which besides the effective fine structure constant {alpha}{sub em}(s) also allows for a fairly precise calculation of the SU(2){sub L} gauge coupling {alpha}{sub 2}(s). I will briefly review the role, future requirements and possibilities. Applied together with the Rhad package by Harlander and Steinhauser [2], the package allows to calculate all SM running couplings as well as running sin{sup 2} {theta} versions with state-of-the-art accuracy. (orig.)
Diamond sensors for future high energy experiments
Energy Technology Data Exchange (ETDEWEB)
Bachmair, Felix, E-mail: bachmair@phys.ethz.ch
2016-09-21
With the planned upgrade of the LHC to High-Luminosity-LHC [1], the general purpose experiments ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation tolerant technologies. Chemical Vapor Deposition CVD diamond is one such technology. CVD diamond sensors are an established technology as beam condition monitors in the highest radiation areas of all LHC experiments. The RD42-collaboration at CERN is leading the effort to use CVD diamond as a material for tracking detectors operating in extreme radiation environments. An overview of the latest developments from RD42 is presented including the present status of diamond sensor production, a study of pulse height dependencies on incident particle flux and the development of 3D diamond sensors.
Diamond sensors for future high energy experiments
Bachmair, Felix
2016-09-01
With the planned upgrade of the LHC to High-Luminosity-LHC [1], the general purpose experiments ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation tolerant technologies. Chemical Vapor Deposition CVD diamond is one such technology. CVD diamond sensors are an established technology as beam condition monitors in the highest radiation areas of all LHC experiments. The RD42-collaboration at CERN is leading the effort to use CVD diamond as a material for tracking detectors operating in extreme radiation environments. An overview of the latest developments from RD42 is presented including the present status of diamond sensor production, a study of pulse height dependencies on incident particle flux and the development of 3D diamond sensors.
Experimenting with Alternative Futures in Cairo
DEFF Research Database (Denmark)
Sparre, Sara Cathrine Lei
2017-01-01
. Focusing mainly on two young volunteers, I show how their Resala experiences within specific socio-political circumstances paved the way for personal hopes to develop into utopian aspirations. Demonstrating the dynamic relationship between the formation of political subjectivities and how utopias emerge......This article investigates young, middle-class Egyptians’ engagement with the religious and national visions of Resala, Egypt’s largest Muslim youth NGO, and how they come to rethink themselves existentially and politically through this commitment and with the 2011 uprising and its aftermath...
Ruiz-Granados, Beatriz; Battaner, Eduardo; Florido, Estrella
2016-10-01
WMAP CMB polarization maps have been used to detect a low signal of Faraday Rotation (FR). If this detection is not interpreted as simple noise, it could be produced: at the last scattering surface (LSS) (z=1100), being primordial, at Reionization (z=10), in the Milky Way. The second interpretation is favoured here. In this case magnetic fields at Reionization with peak values of the order of 10-8 G should produce this observational FR.
CMB all-scale blackbody distortions induced by linearizing temperature
Notari, Alessio; Quartin, Miguel
2016-08-01
Cosmic microwave background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a linearized formula for relating them to the temperature blackbody fluctuations. However, this procedure also generates a signal in the maps in the form of y -type distortions which is degenerate with the thermal Sunyaev Zel'dovich (tSZ) effect. These are small effects that arise at second order in the temperature fluctuations not from primordial physics but from such a limitation of the map-making procedure. They constitute a contaminant for measurements of our peculiar velocity, the tSZ and primordial y -distortions. They can nevertheless be well modeled and accounted for. We show that the distortions arise from a leakage of the CMB dipole into the y -channel which couples to all multipoles, mostly affecting the range ℓ≲400 . This should be visible in Planck's y -maps with an estimated signal-to-noise ratio of about 12. We note however that such frequency-dependent terms carry no new information on the nature of the CMB dipole. This implies that the real significance of Planck's Doppler coupling measurements is actually lower than reported by the collaboration. Finally, we quantify the level of contamination in tSZ and primordial y -type distortions and show that it is above the sensitivity of proposed next-generation CMB experiments.
Righi, M.; Hernández-Monteagudo, C.; Sunyaev, R. A.
2008-02-01
Context: Future observations of CMB anisotropies will be able to probe high multipole regions of the angular power spectrum, corresponding to a resolution of a few arcminutes. Dust emission from merging haloes is one of the foregrounds that will affect such very small scales. Aims: We estimate the contribution to CMB angular fluctuations from objects that are bright in the sub-millimeter band due to intense star formation bursts following merging episodes. Methods: We base our approach on the Lacey-Cole merger model and on the Kennicutt relation which connects the star formation rate in galaxies with their infrared luminosity. We set the free parameters of the model in order to not exceed the SCUBA source counts, the Madau plot of star formation rate in the universe and COBE/FIRAS data on the intensity of the sub-millimeter cosmic background radiation. Results: We show that the angular power spectrum arising from the distribution of such star-forming haloes will be one of the most significant foregrounds in the high frequency channels of future CMB experiments, such as PLANCK, ACT and SPT. The correlation term, due to the clustering of multiple haloes at redshift z ~ 2-6, is dominant in the broad range of angular scales 200 ⪉ l ⪉ 3000. Poisson fluctuations due to bright sub-millimeter sources are more important at higher l, but since they are generated from the bright sources, such contribution could be strongly reduced if bright sources are excised from the sky maps. The contribution of the correlation term to the angular power spectrum depends strongly on the redshift evolution of the escape fraction of UV photons and the resulting temperature of the dust. The measurement of this signal will therefore give important information about the sub-millimeter emission and the escape fraction of UV photons from galaxies, in the early stage of their evolution.
CMB Cluster Lensing: Cosmography with the Longest Lever Arm
Hu, Wayne; Vale, Chris
2007-01-01
We discuss combining gravitational lensing of galaxies and the cosmic microwave background (CMB) by clusters to measure cosmographic distance ratios, and hence dark energy parameters. Advantages to using the CMB as the second source plane, instead of galaxies, include: a well-determined source distance, a longer lever arm for distance ratios, typically up to an order of magnitude higher sensitivity to dark energy parameters, and a decreased sensitivity to photometric redshift accuracy of the lens and galaxy sources. Disadvantages include: higher statistical errors, potential systematic errors, and the need for disparate surveys that overlap on the sky. Ongoing and planned surveys, such as the South Pol Telescope in conjunction with the Dark Energy Survey, can potentially reach the statistical sensitivity to make interesting consistency tests of the standard cosmological constant model. Future measurements that reach 1% or better precision in the convergences can provide sharp tests for future supernovae dista...
Delensing the CMB with the Cosmic Infrared Background
Sherwin, Blake D
2015-01-01
As confusion with lensing B-modes begins to limit experiments that search for primordial B-mode polarization, robust methods for delensing the CMB polarization sky are becoming increasingly important. We investigate in detail the possibility of delensing the CMB with the cosmic infrared background (CIB), emission from dusty star-forming galaxies that is an excellent tracer of the CMB lensing signal, in order to improve constraints on the tensor-to-scalar ratio $r$. We find that the maps of the CIB, such as current Planck satellite maps at 545 GHz, can be used to remove more than half of the lensing B-mode power. Calculating optimal combinations of different large-scale-structure tracers for delensing, we find that co-adding CIB data and external arcminute-resolution CMB lensing reconstruction can lead to significant additional improvements in delensing performance. We investigate whether measurement uncertainty in the CIB spectra will degrade the delensing performance if no model of the CIB spectra is assumed...
A New Limit on CMB Circular Polarization from SPIDER
Energy Technology Data Exchange (ETDEWEB)
Nagy, J.M.; et al.
2017-04-01
We present a new upper limit on CMB circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for $B$-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the non-zero circular-to-linear polarization coupling of the HWP polarization modulators, data from SPIDER's 2015 Antarctic flight provides a constraint on Stokes $V$ at 95 and 150 GHz from $33<\\ell<307$. No other limits exist over this full range of angular scales, and SPIDER improves upon the previous limit by several orders of magnitude, providing 95% C.L. constraints on $\\ell (\\ell+1)C_{\\ell}^{VV}/(2\\pi)$ ranging from 141 $\\mu K ^2$ to 203 $\\mu K ^2$ at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain stronger constraints on circular polarization.
A New Limit on CMB Circular Polarization from SPIDER
Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, A. J.; Eriksen, H. K.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, A. E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, L.; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, B.; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, T. M.; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; Van Der List, J. F.; Weber, A. C.; Wehus, I. K.; Wiebe, D. V.; Young, E. Y.
2017-08-01
We present a new upper limit on cosmic microwave background (CMB) circular polarization from the 2015 flight of Spider, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the nonzero circular-to-linear polarization coupling of the half-wave plate polarization modulators, data from Spider's 2015 Antarctic flight provide a constraint on Stokes V at 95 and 150 GHz in the range 33Spider improves on the previous limit by several orders of magnitude, providing 95% C.L. constraints on {\\ell }({\\ell }+1){C}{\\ell }{VV}/(2π ) ranging from 141 to 255 μK2 at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain even stronger constraints on circular polarization.
Determination of {theta}{sup 12} in future experiments
Energy Technology Data Exchange (ETDEWEB)
Choubey, Sandhya [INFN and SISSA, Trieste (Italy)
2005-08-15
We discuss the possibility of high precision measurement of solar mixing angle in future reactor and solar neutrino experiments. Reactor experiments tuned to Survival Probability MINima (SPMIN) can measure sin{sup 2}{theta}{sub 12} to within 2%(6%) at l{sigma}(3{sigma})
Real Space Approach to CMB deboosting
Yoho, Amanda; Starkman, Glenn D.; Pereira, Thiago S.
2013-01-01
The effect of our Galaxy's motion through the Cosmic Microwave Background rest frame, which aberrates and Doppler shifts incoming photons measured by current CMB experiments, has been shown to produce mode-mixing in the multipole space temperature coefficients. However, multipole space determinations are subject to many difficulties, and a real-space analysis can provide a straightforward alternative. In this work we describe a numerical method for removing Lorentz- boost effects from real-space temperature maps. We show that to deboost a map so that one can accurately extract the temperature power spectrum requires calculating the boost kernel at a finer pixelization than one might naively expect. In idealized cases that allow for easy comparison to analytic results, we have confirmed that there is indeed mode mixing among the spherical harmonic coefficients of the temperature. We find that using a boost kernel calculated at Nside=8192 leads to a 1% bias in the binned boosted power spectrum at l~2000, while ...
Oscillations in the CMB from Axion Monodromy Inflation
Energy Technology Data Exchange (ETDEWEB)
Flauger, Raphael; /Texas U.; McAllister, Liam; Pajer, Enrico; /Cornell U., Phys. Dept.; Westphal, Alexander; /SLAC /Stanford U., Phys. Dept.; Xu, Gang; /Cornell U., Phys. Dept.
2011-12-01
We study the CMB observables in axion monodromy inflation. These well-motivated scenarios for inflation in string theory have monomial potentials over super-Planckian field ranges, with superimposed sinusoidal modulations from instanton effects. Such periodic modulations of the potential can drive resonant enhancements of the correlation functions of cosmological perturbations, with characteristic modulations of the amplitude as a function of wavenumber. We give an analytical result for the scalar power spectrum in this class of models, and we determine the limits that present data places on the amplitude and frequency of modulations. Then, incorporating an improved understanding of the realization of axion monodromy inflation in string theory, we perform a careful study of microphysical constraints in this scenario. We find that detectable modulations of the scalar power spectrum are commonplace in well-controlled examples, while resonant contributions to the bispectrum are undetectable in some classes of examples and detectable in others. We conclude that resonant contributions to the spectrum and bispectrum are a characteristic signature of axion monodromy inflation that, in favorable cases, could be detected in near-future experiments.
CMBACT: CMB from ACTive sources
Pogosian, Levon; Vachaspati, Tanmay
2011-06-01
This code is based on the cosmic string model described in this paper by Pogosian and Vachaspati, as well as on the CMBFAST code created by Uros Seljak and Matias Zaldarriaga. It contains an integrator for the vector contribution to the CMB temperature and polarization. The code is reconfigured to make it easier to use with or without active sources. To produce inflationary CMB spectra one simply sets the string tension to zero (gmu=0.0d0). For a non-zero value of tension only the string contribution is calculated. An option is added to randomize the directions of velocities of consolidated segments as they evolve in time. In the original segment model, which is still the default version (irandomv=0), each segment is given a random velocity initially, but then continues to move in a straight line for the rest of its life. The new option (irandomv=1) allows to additionally randomize velocities of each segment at roughly each Hubble time. However, the merits of this new option are still under investigation. The default version (irandomv=0) is strongly recommended, since it actually gives reasonable unequal time correlators. For each Fourier mode, k, the string stress-energy components are now evaluated on a time grid sufficiently fine for that k.
Dark Synergy Gravitational Lensing and the CMB
Hu, W
2002-01-01
Power spectra and cross-correlation measurements from the weak gravitational lensing of the cosmic microwave background (CMB) and the cosmic shearing of faint galaxies images will help shed light on quantities hidden from the CMB temperature anisotropies: the dark energy, the end of the dark ages, and the inflationary gravitational wave amplitude. Even with modest surveys, both types of lensing power spectra break CMB degeneracies and they can ultimately improve constraints on the dark energy equation of state w by over an order of magnitude. In its cross correlation with the integrated Sachs-Wolfe effect, CMB lensing offers a unique opportunity for a more direct detection of the dark energy and enables study of its clustering properties. By obtaining source redshifts and cross-correlations with CMB lensing, cosmic shear surveys provide tomographic handles on the evolution of clustering correspondingly better precision on the dark energy equation of state and density. Both can indirectly provide detections of...
Reconstructing the primordial power spectrum from the CMB
Energy Technology Data Exchange (ETDEWEB)
Gauthier, Christopher; Bucher, Martin, E-mail: cgauthie@apc.univ-paris7.fr, E-mail: bucher@apc.univ-paris7.fr [Laboratoire APC, Université Paris Diderot, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)
2012-10-01
We propose a straightforward and model independent methodology for characterizing the sensitivity of CMB and other experiments to wiggles, irregularities, and features in the primordial power spectrum. Assuming that the primordial cosmological perturbations are adiabatic, we present a function space generalization of the usual Fisher matrix formalism applied to a CMB experiment resembling Planck with and without ancillary data. This work is closely related to other work on recovering the inflationary potential and exploring specific models of non-minimal, or perhaps baroque, primordial power spectra. The approach adopted here, however, most directly expresses what the data is really telling us. We explore in detail the structure of the available information and quantify exactly what features can be reconstructed and at what statistical significance.
Reconstructing the primordial power spectrum from the CMB
Gauthier, Christopher
2012-01-01
We propose a straightforward and model independent methodology for characterizing the sensitivity of CMB and other experiments to wiggles, irregularities, and features in the primordial power spectrum. Assuming that the primordial cosmological perturbations are adiabatic, we present a function space generalization of the usual Fisher matrix formalism, applied to a CMB experiment resembling Planck with and without ancillary data. This work is closely related to other work on recovering the inflationary potential and exploring specific models of non-minimal, or perhaps baroque, primordial power spectra. The approach adopted here, however, most directly expresses what the data is really telling us. We explore in detail the structure of the available information and quantify exactly what features can be reconstructed and at what statistical significance.
Urban Web Services—Experiences and Future Directions
DEFF Research Database (Denmark)
Hansen, Frank Allan; Grønbæk, Kaj
2008-01-01
This paper discusses experiences from implementing a mobile urban Web system using 2D visual barcodes as physical link anchors in the city and utilizing the users’ own mobile phones as interaction devices. We discuss the techniques and technologies used to create the system and the implemented...... services. Based on public use during the annual Aarhus Festival in September 2008, we evaluate the experiences and based on those we point to challenges and future developments....
Prospects for future experiments to search for nucleon decay
Energy Technology Data Exchange (ETDEWEB)
Ayres, D.S.; Heller, K.; LoSecco, J.; Mann, A.K.; Marciano, W.; Shrock, R.E.; Thornton, R.K.
1982-01-01
We review the status of theoretical expectations and experimental searches for nucleon decay, and predict the sensitivities which could be reached by future experiments. For the immediate future, we concur with the conclusions of the 1982 Summer Workshop on Proton Decay Experiments: all detectors now in operation or construction will be relatively insensitive to some potentially important decay modes. Next-generation experiments must therefore be designed to search for these modes, and should be undertaken whether or not present experiments detect nucleon decay in other modes. These future experiments should be designed to push the lifetime limits on all decay modes to the levels at which irreducible cosmic-ray neutrino-induced backgrounds become important. Since the technology for these next-generation experiments is available now, the timetable for starting work on them will be determined by funding constraints and not by the need for extensive development of detectors. Efforts to develop advanced detector techniques should also be pursued, in order to mount more sensitive searches than can be envisioned using current technology, or to provide the most precise measurements possible of the properties of the nucleon decay interaction if it should occur at a detectable rate.
Lenses in the forest: cross--correlation of the Lyman-alpha flux with CMB lensing
Energy Technology Data Exchange (ETDEWEB)
Vallinotto, Alberto; /Paris, Inst. Astrophys. /Fermilab; Das, Sudeep; /Princeton U. Observ. /Princeton U.; Spergel, David N.; /Princeton U. Observ. /APC, Paris; Viel, Matteo; /Trieste Observ. /INFN, Trieste
2009-03-01
We present a theoretical estimate for a new observable: the cross-correlation between the Lyman-{alpha}-flux fluctuations in quasar (QSO) spectra and the convergence of the cosmic microwave background (CMB) as measured along the same line-of-sight. As a first step toward the assessment of its detectability, we estimate the signal-to-noise ratio using linear theory. Although the signal-to-noise is small for a single line-of-sight and peaks at somewhat smaller redshifts than those probed by the Lyman-{alpha} forest, we estimate a total signal-to-noise of 9 for cross-correlating QSO spectra of SDSSIII with Planck and 20 for cross-correlating with a future polarization based CMB experiment. The detection of this effect would be a direct measure of the neutral hydrogen-matter cross-correlation and could provide important information on the growth of structures at large scales in a redshift range which is still poorly probed by observations.
Fundamental statistical limitations of future dark matter direct detection experiments
Strege, C.; Trotta, F.; Bertone, G.; Peter, A.H.G.; Scott, P.
2012-01-01
We discuss irreducible statistical limitations of future ton-scale dark matter direct detection experiments. We focus in particular on the coverage of confidence intervals, which quantifies the reliability of the statistical method used to reconstruct the dark matter parameters and the bias of the r
Novel calibration system with sparse wires for CMB polarization receivers
Energy Technology Data Exchange (ETDEWEB)
Tajima, O.; /KEK, Tsukuba /Chicago U., KICP; Nguyen, H.; /Fermilab; Bischoff, C.; /Chicago U., KICP /Harvard-Smithsonian Ctr. Astrophys.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP
2011-07-01
B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.
Novel calibration system with sparse wires for CMB polarization receivers
Energy Technology Data Exchange (ETDEWEB)
Tajima, O.; /KEK, Tsukuba /Chicago U., KICP; Nguyen, H.; /Fermilab; Bischoff, C.; /Chicago U., KICP /Harvard-Smithsonian Ctr. Astrophys.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP
2011-07-01
B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.
Disformal transformations on the CMB
Burrage, Clare; Davis, Anne-Christine
2016-01-01
In this work we study the role of disformal transformation on cosmological backgrounds and its relation to the speed of sound for tensor modes. A speed different from one for tensor modes can arise in several contexts, such as Galileons theories or massive gravity, nevertheless the speed is very constrained to be one by observations of gravitational wave emission. It has been shown that in inflation a disformal trans- formation allows to set the speed for tensor modes to one without making changes to the curvature power spectrum. Here we show that this invariance does not hold when considering the CMB anisotropy power spectrum. It turns out that the after doing the transformation there is an imprint on the acoustic peaks and the diffusion damping. This has interesting consequences; here we explore quartic galileon theories which allow a modified speed for tensor modes. For these theories the transformation can be used to constraint the parameter space in different regimes.
Disformal transformations on the CMB
Burrage, Clare; Cespedes, Sebastian; Davis, Anne-Christine
2016-08-01
In this work we study the role of disformal transformation on cosmological backgrounds and its relation to the speed of sound for tensor modes. A speed different from one for tensor modes can arise in several contexts, such as Galileons theories or massive gravity, nevertheless the speed is very constrained to be one by observations of gravitational wave emission. It has been shown that in inflation a disformal transformation allows to set the speed for tensor modes to one without making changes to the curvature power spectrum. Here we show that this invariance does not hold when considering the CMB anisotropy power spectrum. It turns out that the after doing the transformation there is an imprint on the acoustic peaks and the diffusion damping. This has interesting consequences; here we explore quartic galileon theories which allow a modified speed for tensor modes. For these theories the transformation can be used to constraint the parameter space in different regimes.
Needlet estimation of cross-correlation between CMB lensing maps and LSS
Bianchini, Federico; Marinucci, Domenico
2016-01-01
In this paper we develop a novel needlet-based estimator to investigate the cross-correlation between cosmic microwave background (CMB) lensing maps and large-scale structure (LSS) data. We compare this estimator with its harmonic counterpart and, in particular, we analyze the bias effects of different forms of masking. In order to address this bias, we also implement a MASTER-like technique in the needlet case. The resulting estimator turns out to have an extremely good signal-to-noise performance. Our analysis aims at expanding and optimizing the operating domains in CMB-LSS cross-correlation studies, similarly to CMB needlet data analysis. It is motivated especially by next generation experiments (such as Euclid) which will allow us to derive much tighter constraints on cosmological and astrophysical parameters through cross-correlation measurements between CMB and LSS.
Parameter Estimation from Improved Measurements of the CMB from QUaD
Ade, P; Bowden, M; Brown, M L; Cahill, G; Castro, P G; Church, S; Culverhouse, T; Friedman, R B; Ganga, K; Gear, W K; Hinderks, J; Kovac, J; Lange, A E; Leitch, E; Melhuish, S J; Memari, Y; Murphy, J A; Orlando, A; O'Sullivan, C; Piccirillo, L; Pryke, C; Rajguru, N; Rusholme, B; Schwarz, R; Taylor, A N; Thompson, K L; Turner, A H; Wu, E Y S; Zemcov, M
2009-01-01
We evaluate the ability of cosmic microwave background (CMB) polarization spectra to constrain cosmological models by analyzing a multi-experiment CMB dataset including the final analysis of the QUaD experiment. We provide the best limits on parameters from combined polarization data and find that QUaD spectra combined with additional CMB datasets using the optimal pivot scale of k_p=0.013 Mpc-1 prefer standard LCDM parameters of {omch2, ombh2, H_0, A_s, n_s, tau}={0.113, 0.0224, 70.6, 2.29 times 10^-9, 0.960, 0.086}, with the confidence regions of ombh2, omch2 and H_0 tightened due to the presence of QUaD data. QUaD alone constrains cold dark matter and baryon densities and the acoustic scale very well. The temperature and polarization sub-sets each provide good limits on cosmological parameters which are consistent with values obtained from a combination of existing CMB data. We incorporate small-scale CMB data to provide the tightest constraint on tensor modes from CMB data alone.
A bias to CMB lensing measurements from the bispectrum of large-scale structure
Böhm, Vanessa; Sherwin, Blake D
2016-01-01
The rapidly improving precision of measurements of gravitational lensing of the Cosmic Microwave Background (CMB) also requires a corresponding increase in the precision of theoretical modeling. A commonly made approximation is to model the CMB deflection angle or lensing potential as a Gaussian random field. In this paper, however, we analytically quantify the influence of the non-Gaussianity of large-scale structure lenses, arising from nonlinear structure formation, on CMB lensing measurements. In particular, evaluating the impact of the non-zero bispectrum of large-scale structure on the relevant CMB four-point correlation functions, we find that there is a bias to estimates of the CMB lensing power spectrum. For temperature-based lensing reconstruction with CMB Stage-III and Stage-IV experiments, we find that this lensing power spectrum bias is negative and is of order one percent of the signal. This corresponds to a shift of multiple standard deviations for these upcoming experiments. We caution, howeve...
CMB-S4 Science Book, First Edition
Abazajian, Kevork N; Ahmed, Zeeshan; Allen, Steven W; Alonso, David; Arnold, Kam S; Baccigalupi, Carlo; Bartlett, James G; Battaglia, Nicholas; Benson, Bradford A; Bischoff, Colin A; Borrill, Julian; Buza, Victor; Calabrese, Erminia; Caldwell, Robert; Carlstrom, John E; Chang, Clarence L; Crawford, Thomas M; Cyr-Racine, Francis-Yan; De Bernardis, Francesco; de Haan, Tijmen; Alighieri, Sperello di Serego; Dunkley, Joanna; Dvorkin, Cora; Errard, Josquin; Fabbian, Giulio; Feeney, Stephen; Ferraro, Simone; Filippini, Jeffrey P; Flauger, Raphael; Fuller, George M; Gluscevic, Vera; Green, Daniel; Grin, Daniel; Grohs, Evan; Henning, Jason W; Hill, J Colin; Hlozek, Renee; Holder, Gilbert; Holzapfel, William; Hu, Wayne; Huffenberger, Kevin M; Keskitalo, Reijo; Knox, Lloyd; Kosowsky, Arthur; Kovac, John; Kovetz, Ely D; Kuo, Chao-Lin; Kusaka, Akito; Jeune, Maude Le; Lee, Adrian T; Lilley, Marc; Loverde, Marilena; Madhavacheril, Mathew S; Mantz, Adam; Marsh, David J E; McMahon, Jeffrey; Meerburg, Pieter Daniel; Meyers, Joel; Miller, Amber D; Munoz, Julian B; Nguyen, Ho Nam; Niemack, Michael D; Peloso, Marco; Peloton, Julien; Pogosian, Levon; Pryke, Clement; Raveri, Marco; Reichardt, Christian L; Rocha, Graca; Rotti, Aditya; Schaan, Emmanuel; Schmittfull, Marcel M; Scott, Douglas; Sehgal, Neelima; Shandera, Sarah; Sherwin, Blake D; Smith, Tristan L; Sorbo, Lorenzo; Starkman, Glenn D; Story, Kyle T; van Engelen, Alexander; Vieira, Joaquin D; Watson, Scott; Whitehorn, Nathan; Wu, W L Kimmy
2016-01-01
This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves, in the determination of the number and masses of the neutrinos, in the search for evidence of new light relics, in constraining the nature of dark energy, and in testing general relativity on large scales.
CMB Polarization B-mode Delensing with SPTpol and Herschel
Manzotti, A.; Story, K. T.; Wu, W. L. K.; Austermann, J. E.; Beall, J. A.; Bender, A. N.; Benson, B. A.; Bleem, L. E.; Bock, J. J.; Carlstrom, J. E.; Chang, C. L.; Chiang, H. C.; Cho, H.-M.; Citron, R.; Conley, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Dodelson, S.; Everett, W.; Gallicchio, J.; George, E. M.; Gilbert, A.; Halverson, N. W.; Harrington, N.; Henning, J. W.; Hilton, G. C.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hou, Z.; Hrubes, J. D.; Huang, N.; Hubmayr, J.; Irwin, K. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Li, D.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Natoli, T.; Nibarger, J. P.; Novosad, V.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Smecher, G.; Stark, A. A.; Vanderlinde, K.; Vieira, J. D.; Viero, M. P.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Zemcov, M.
2017-09-01
We present a demonstration of delensing the observed cosmic microwave background (CMB) B-mode polarization anisotropy. This process of reducing the gravitational-lensing-generated B-mode component will become increasingly important for improving searches for the B modes produced by primordial gravitational waves. In this work, we delens B-mode maps constructed from multi-frequency SPTpol observations of a 90 deg2 patch of sky by subtracting a B-mode template constructed from two inputs: SPTpol E-mode maps and a lensing potential map estimated from the Herschel 500 μm map of the cosmic infrared background. We find that our delensing procedure reduces the measured B-mode power spectrum by 28% in the multipole range 300importance of including realistic experimental non-idealities in the delensing forecasts used to inform instrument and survey-strategy planning of upcoming lower-noise experiments, such as CMB-S4.
CMB-S4 Science Book, First Edition
Energy Technology Data Exchange (ETDEWEB)
Abazajian, Kevork N. [Univ. of California, Irvine, CA (United States); et al.
2016-10-09
This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves, in the determination of the number and masses of the neutrinos, in the search for evidence of new light relics, in constraining the nature of dark energy, and in testing general relativity on large scales.
By Dawn's Early Light: CMB Polarization Impact on Cosmological Constraints
Das, Sudeep
2012-01-01
Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol significantly complement cosmological constraints from the Planck satellite, strengthening the CMB dark energy figure of merit and neutrino mass constraints by factors of 3-4. This changes the dark energy probe landscape. We evaluate the state of knowledge in 2017 from ongoing experiments including dark energy surveys (supernovae, weak lensing, galaxy clustering), fitting for dynamical dark energy, neutrino mass, and a modified gravitational growth index. Adding a modest strong lensing time delay survey improves those dark energy constraints by a further 32%, and an enhanced low redshift supernova program improves them by 26%.
Transverse Spin Effects in Future Drell-Yan Experiments
Directory of Open Access Journals (Sweden)
Peng Jen-Chieh
2015-01-01
Full Text Available We review the current status and future prospect for probing the transverse momentum dependent (TMD parton distributions using the Drell-Yan process. We focus on the Boer-Mulders and Sivers functions, which are expected to undergo a sign-change from semi-inclusive deep-inelastic scattering (SIDIS to Drell-Yan process. The constraints of existing Drell-Yan and SIDIS experiments on the signs of these functions are discussed. Future Drell-Yan measurements for the TMDs are also presented.
Reversed polarity patches at the CMB and geomagnetic field reversal
Institute of Scientific and Technical Information of China (English)
XU; Wenyao(徐文耀); WEI; Zigang(魏自刚)
2002-01-01
The International Geomagnetic Reference Field models (IGRF) for 1900-2000 are used to calculate the geomagnetic field distribution in the Earth' interior from the ground surface to the core-mantle boundary (CMB) under the assumption of insulated mantle. Four reversed polarity patches, as one of the most important features of the CMB field, are revealed. Two patches with +Z polarity (downward) at the southern African and the southern American regions stand out against the background of -Z polarity (upward) in the southern hemisphere, and two patches of -Z polarity at the North Polar and the northern Pacific regions stand out against the +Z background in the northern hemisphere. During the 1900-2000 period the southern African (SAF) patch has quickly drifted westward at a speed of 0.2-0.3°/a; meanwhile its area has expanded 5 times, and the magnetic flux crossing the area has intensified 30 times. On the other hand, other three patches show little if any change during this 100-year period. Extending upward, each of the reversed polarity patches at the CMB forms a chimney-shaped "reversed polarity column" in the mantle with the bottom at the CMB. The height of the SAF column has grown rapidly from 200km in 1900 to 900km in 2000. If the column grows steadily at the same rate in the future, its top will reach to the ground surface in 600-700 years. And then a reversed polarity patch will be observed at the Earth's surface, which will be an indicator of the beginning of a magnetic field reversal. On the basis of this study, one can describe the process of a geomagnetic polarity reversal, the polarity reversal may be observed firstly in one or several local regions; then the areas of these regions expand, and at the same time, other new reversed polarity regions may appear. Thus several poles may exist during a polarity reversal.
Measuring velocites using the CMB & LSS
Energy Technology Data Exchange (ETDEWEB)
Stebbins, Albert; /Fermilab /Paris, Inst. Astrophys.
2006-07-01
Here is discussed various ways by which the cosmic microwave background (CMB) radiation can be use to measure the velocities of matter in the universe. We include some new statistical techniques for using the kinetic Sunyaev-Zel'dovich (kSZ) effect and integrated Sachs-Wolfe (ISW) effect to determine velocities by correlating wide area CMB maps with overlapping large-scale structure (LSS) surveys.
Modeling CMB lensing cross correlations with CLEFT
Modi, Chirag; White, Martin; Vlah, Zvonimir
2017-08-01
A new generation of surveys will soon map large fractions of sky to ever greater depths and their science goals can be enhanced by exploiting cross correlations between them. In this paper we study cross correlations between the lensing of the CMB and biased tracers of large-scale structure at high z. We motivate the need for more sophisticated bias models for modeling increasingly biased tracers at these redshifts and propose the use of perturbation theories, specifically Convolution Lagrangian Effective Field Theory (CLEFT). Since such signals reside at large scales and redshifts, they can be well described by perturbative approaches. We compare our model with the current approach of using scale independent bias coupled with fitting functions for non-linear matter power spectra, showing that the latter will not be sufficient for upcoming surveys. We illustrate our ideas by estimating σ8 from the auto- and cross-spectra of mock surveys, finding that CLEFT returns accurate and unbiased results at high z. We discuss uncertainties due to the redshift distribution of the tracers, and several avenues for future development.
Beam dump experiment at future electron–positron colliders
Directory of Open Access Journals (Sweden)
Shinya Kanemura
2015-12-01
Full Text Available We propose a new beam dump experiment at future colliders with electron (e− and positron (e+ beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of e± beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at e+e− linear collider significantly enlarges the parameter region where the signal of the hidden particle can be discovered.
Neutrino Oscillation Parameter Sensitivity in Future Long-Baseline Experiments
Energy Technology Data Exchange (ETDEWEB)
Bass, Matthew [Colorado State Univ., Fort Collins, CO (United States)
2014-01-01
The study of neutrino interactions and propagation has produced evidence for physics beyond the standard model and promises to continue to shed light on rare phenomena. Since the discovery of neutrino oscillations in the late 1990s there have been rapid advances in establishing the three flavor paradigm of neutrino oscillations. The 2012 discovery of a large value for the last unmeasured missing angle has opened the way for future experiments to search for charge-parity symmetry violation in the lepton sector. This thesis presents an analysis of the future sensitivity to neutrino oscillations in the three flavor paradigm for the T2K, NO A, LBNE, and T2HK experiments. The theory of the three flavor paradigm is explained and the methods to use these theoretical predictions to design long baseline neutrino experiments are described. The sensitivity to the oscillation parameters for each experiment is presented with a particular focus on the search for CP violation and the measurement of the neutrino mass hierarchy. The variations of these sensitivities with statistical considerations and experimental design optimizations taken into account are explored. The effects of systematic uncertainties in the neutrino flux, interaction, and detection predictions are also considered by incorporating more advanced simulations inputs from the LBNE experiment.
Spectral distortions of the CMB dipole
Balashev, S A; Chluba, J; Ivanchik, A V; Varshalovich, D A
2015-01-01
We consider the distortions of the CMB dipole anisotropy related to the primordial recombination radiation (PRR) and primordial $y$- and $\\mu$-distortions. The signals arise due to our motion relative to the CMB restframe and appear as a frequency-dependent distortion of the CMB temperature dipole. To leading order, the expected relative distortion of CMB dipole does not depend on the particular observation directions and reaches the level of $10^{-6}$ for the PRR- and $\\mu$-distortions and $10^{-5}$ for the $y$-distortion in the frequency range 1 $-$ 700 GHz. The temperature differences arising from the dipole anisotropy of the relic CMB distortions depend on observation directions. For mutually opposite directions, collinear to the CMB dipole axis, the temperature differences because of the PRR- and $\\mu$-dipole anisotropy attain values $\\Delta T\\simeq 10\\,$nK in the considered range. The temperature difference arising from the $y$-dipole anisotropy may reach values up to $1\\,\\mu$K. The key features of the ...
Looking through the same lens: shear calibration for LSST, Euclid & WFIRST with stage 4 CMB lensing
Schaan, Emmanuel; Eifler, Tim; Doré, Olivier; Miyatake, Hironao; Rhodes, Jason; Spergel, David N
2016-01-01
The next generation weak lensing surveys (i.e., LSST, Euclid and WFIRST) will require exquisite control over systematic effects. In this paper, we address shear calibration and present the most realistic forecast to date for LSST/Euclid/WFIRST and CMB lensing from a stage 4 CMB experiment (CMB S4). We use the CosmoLike code to simulate a joint analysis of all the two-point functions of galaxy density, galaxy shear and CMB lensing convergence. We include the full Gaussian and non-Gaussian covariances and explore the resulting joint likelihood with Monte Carlo Markov Chains. We constrain shear calibration biases while simultaneously varying cosmological parameters, galaxy biases and photometric redshift uncertainties. We find that CMB lensing from CMB S4 enables the calibration of the shear biases down to 0.2% - 3% in 10 tomographic bins for LSST (below the ~0.5% requirements in most tomographic bins), down to 0.4% - 2.4% in 10 bins for Euclid and 0.6% - 3.2% in 10 bins for WFIRST. For a given lensing survey, t...
High Resolution Observations of the CMB Power Spectrum with ACBAR
Kuo, C L; Bock, J J; Cantalupo, C M; Daub, M D; Goldstein, J; Holzapfel, W L; Lange, A E; Lueker, M; Newcomb, M; Peterson, J B; Ruhl, J; Runyan, M C; Torbet, E
2004-01-01
We report the first measurements of anisotropy in the cosmic microwave background (CMB) radiation with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The instrument was installed on the 2.1m Viper telescope at the South Pole in January 2001; the data presented here are the product of observations up to and including July 2002. The two deep fields presented here, have had offsets removed by subtracting lead and trail observations and cover approximately 24 deg^2 of sky selected for low dust contrast. These results represent the highest signal to noise observations of CMB anisotropy to date; in the deepest 150GHz band map, we reached an RMS of 8.0\\mu K per 5' beam. The 3 degree extent of the maps, and small beamsize of the experiment allow the measurement of the CMB anisotropy power spectrum over the range \\ell = 150-3000 with resolution of \\Delta \\ell=150. The contributions of galactic dust and radio sources to the observed anisotropy are negligible and are removed in the analysis. The resulting pow...
Meerburg, P D; van Engelen, Alex; Ali-Haïmoud, Yacine
2016-01-01
We study the degree to which the cosmic microwave background (CMB) can be used to constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on the correlation of one $B$-mode polarization fluctuation with two temperature fluctuations. In the simplest models of inflation, the tensor-scalar-scalar primordial bispectrum is non-vanishing and is of the same order in slow-roll parameters as the scalar-scalar-scalar bispectrum. We calculate the $\\langle BTT\\rangle$ correlation arising from a primordial tensor-scalar-scalar bispectrum, and show that constraints from an experiment like CMB-Stage IV using this observable are more than an order of magnitude better than those on the same primordial coupling obtained from temperature measurements alone. We argue that $B$-mode non-Gaussianity opens up an as-yet-unexplored window into the early Universe, demonstrating that significant information on primordial physics remains to be harvested from CMB anisotropies.
CMB-S4 and the hemispherical variance anomaly
O'Dwyer, Márcio; Copi, Craig J.; Knox, Lloyd; Starkman, Glenn D.
2017-09-01
Cosmic microwave background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the Northern and Southern Ecliptic hemispheres, with the Northern hemisphere displaying an anomalously low variance while the Southern hemisphere appears unremarkable [consistent with expectations from the best-fitting theory, Lambda Cold Dark Matter (ΛCDM)]. While this is a well-established result in temperature, the low signal-to-noise ratio in current polarization data prevents a similar comparison. This will change with a proposed ground-based CMB experiment, CMB-S4. With that in mind, we generate realizations of polarization maps constrained by the temperature data and predict the distribution of the hemispherical variance in polarization considering two different sky coverage scenarios possible in CMB-S4: full Ecliptic north coverage and just the portion of the North that can be observed from a ground-based telescope at the high Chilean Atacama plateau. We find that even in the set of realizations constrained by the temperature data, the low Northern hemisphere variance observed in temperature is not expected in polarization. Therefore, observing an anomalously low variance in polarization would make the hypothesis that the temperature anomaly is simply a statistical fluke more unlikely and thus increase the motivation for physical explanations. We show, within ΛCDM, how variance measurements in both sky coverage scenarios are related. We find that the variance makes for a good statistic in cases where the sky coverage is limited, however, full northern coverage is still preferable.
Inflation, Renormalization, and CMB Anisotropies
Agullo, I; Olmo, Gonzalo J; Parker, Leonard
2010-01-01
In single-field, slow-roll inflationary models, scalar and tensorial (Gaussian) perturbations are both characterized by a zero mean and a non-zero variance. In position space, the corresponding variance of those fields diverges in the ultraviolet. The requirement of a finite variance in position space forces its regularization via quantum field renormalization in an expanding universe. This has an important impact on the predicted scalar and tensorial power spectra for wavelengths that today are at observable scales. In particular, we find a non-trivial change in the consistency condition that relates the tensor-to-scalar ratio "r" to the spectral indices. For instance, an exact scale-invariant tensorial power spectrum, n_t=0, is now compatible with a non-zero ratio r= 0.12 +/- 0.06, which is forbidden by the standard prediction (r=-8n_t). Forthcoming observations of the influence of relic gravitational waves on the CMB will offer a non-trivial test of the new predictions.
Searching for a holographic connection between dark energy and the low-l CMB multipoles
DEFF Research Database (Denmark)
Enqvist, Kari; Hannestad, Steen; Sloth, Martin Snoager
2004-01-01
We consider the angular power spectrum in a finite universe with different boundary conditions and perform a fit to the CMB, LSS and supernova data. A finite universe could be the consequence of a holographic constraint, giving rise to an effective IR cutoff at the future event horizon. In such a......We consider the angular power spectrum in a finite universe with different boundary conditions and perform a fit to the CMB, LSS and supernova data. A finite universe could be the consequence of a holographic constraint, giving rise to an effective IR cutoff at the future event horizon...... bubble that describes our universe. The best fit to the CMB and LSS data turns out to be better than in the standard Lambda-CDM model, but when combined with the supernova data, the holographic model becomes disfavored. We speculate on the possible implications....
Physics prospects of future neutrino oscillation experiments in Asia
Hagiwara, K
2004-01-01
The three neutrino model has 9 physical parameters, 3 neutrino masses, 3 mixing angles and 3 CP violating phases. Among them, neutrino oscillation experiments can probe 6 parameters: 2 mass squared differences, 3 mixing angles, and 1 CP phase. The experiments performed so far determined the magnitudes of the two mass squared differences, the sign of the smaller mass squared difference, the magnitudes of two of the three mixing angles, and the upper bound on the third mixing angle. The sign of the larger mass squared difference (the neutrino mass hierarchy pattern), the magnitude of the third mixing angle and the CP violating phase, and a two-fold ambiguity in the mixing angle that dictates the atmospheric neutrino oscillation should be determined by future oscillation experiments. In this talk, I introduce a few ideas of future long baseline neutrino oscillation experiments which make use of the super neutrino beams from J-PARC (Japan Proton Accelerator Research Complex) in Tokai village. We examine the poten...
CMB-lensing beyond the Born approximation
Marozzi, Giovanni; Fanizza, Giuseppe; Di Dio, Enea; Durrer, Ruth
2016-09-01
We investigate the weak lensing corrections to the cosmic microwave background temperature anisotropies considering effects beyond the Born approximation. To this aim, we use the small deflection angle approximation, to connect the lensed and unlensed power spectra, via expressions for the deflection angles up to third order in the gravitational potential. While the small deflection angle approximation has the drawback to be reliable only for multipoles l lesssim 2500, it allows us to consistently take into account the non-Gaussian nature of cosmological perturbation theory beyond the linear level. The contribution to the lensed temperature power spectrum coming from the non-Gaussian nature of the deflection angle at higher order is a new effect which has not been taken into account in the literature so far. It turns out to be the leading contribution among the post-Born lensing corrections. On the other hand, the effect is smaller than corrections coming from non-linearities in the matter power spectrum, and its imprint on CMB lensing is too small to be seen in present experiments.
Future perspectives of the alphasat TDP#5 Telecommunication Experiment
De Sanctis, M.; Rossi, T.; Mukherjee, S.; Ruggieri, M.
Future High throughput Satellite (HTS) systems, able to support hundreds of gigabit/s or terabit/s connectivity, will require a very large bandwidth availability; this pushes towards the exploitation of the so-called “ beyond Ka-band” systems. In particular the use of the Q/V frequency band is foreseen. This paper presents the most important features of the TDP#5 (Technology Demonstration Payload 5) scientific mission that will provide us the opportunity to perform, for the first time, a communication scientific experiment over a Q/V band satellite link.
Current status of the LHCf experiment and future plan
Directory of Open Access Journals (Sweden)
Tamura T.
2013-06-01
Full Text Available The Large Hadron Collider forward (= LHCf experiment has successfully finished the first phase of data taking at LHC √s = 0.9 and 7 TeV proton-proton collisions in 2010. As current status, we concentrate on analyzing the obtained data. As the first result, the energy spectra of photon measured by LHCf during = 7 TeV p-p collision has been published recently. Also the study of the upgraded version of LHCf detector for future = 14TeV run scenario is developed with the GSO scintillator. Another possible plan of p-A(nuclear collision in LHC is also studied. In this paper, as the current status of the experiment, analyses, and works for foreseen detector upgrade are summarized.
ABS: an Analytical method of Blind Separation of CMB B-mode from foregrounds
Zhang, Pengjie; Zhang, Le
2016-01-01
Extracting CMB B-mode polarization from complicated foregrounds is a challenging task in searching for inflationary gravitational waves. We propose an analytical solution to the B-mode power spectrum measurement directly from post-processing the cross bandpower between different frequency bands, without free parameters or fitting procedures, or any assumptions on foregrounds. Testing against a variety of foregrounds, survey frequency configurations and instrument noise, we verify its applicability and numerical stability. It also provides a clean diagnostic for future surveys to achieve unbiased B-mode measurement. Furthermore, it has applications beyond CMB and can even have profound impacts in totally different areas such as cosmic magnification.
Probing the origin of our universe through primordial gravitational waves by Ali CMB project
Cai, Yi-Fu
2016-01-01
This is a research highlight invited by SCIENCE CHINA Physics, Mechanics & Astronomy. In this article we report the Ali project of the cosmic microwave background (CMB) observation, which is under design in Tibet of China. The scientific goal of this project will help us to probe the origin of our universe by detecting the primordial B-mode of CMB polarization to falsify various theoretical models of the very early universe in the future. We also estimate the forecast for the observational ability of the Ali project.
Nonparametric Forecasts of the CMB Angular Power Spectra for the Planck Mission
Aghamousa, Amir; Souradeep, Tarun
2013-01-01
The Planck mission, designed for making measurements of the cosmic microwave background (CMB) radiation with unprecedented accuracy and angular resolution, is expected to release its first data set in the near future. For the first time in the CMB history, extensive measurements of the CMB polarization will be made available for the entire sky. Such precise and rich data are expected to contain a great wealth of information about the Universe. The information in the CMB data is conveniently represented in terms of angular power spectra for temperature and polarization. A proper estimation of these CMB power spectra from data is the first step in making inferences about the Universe and, in particular, cosmological parameters that govern the Universe. In this paper, we provide forecasts for the $TT$, $EE$, and $TE$ angular power spectra for the Planck mission. Our forecasts are made using synthetic data based on the best-fit $\\Lambda$CDM model while conforming to the characteristics and parameters of the Planc...
Extreme data compression for the CMB
Zablocki, Alan
2015-01-01
We apply the Karhunen-Lo\\'eve (KL) methods to cosmic microwave background (CMB) datasets, and show that we can recover the input cosmology and obtain the marginalized likelihoods in $\\Lambda$CDM cosmologies in under a minute, much faster than Markov Chain Monte Carlo (MCMC) methods. This is achieved by forming a linear combination of the power spectra at each multipole $l$, and solving a system of simultaneous equations such that the Fisher matrix is locally unchanged. Instead of carrying out a full likelihood evaluation over the whole parameter space, we need evaluate the likelihood only for the parameter of interest, with the data compression effectively marginalizing over all other parameters. The weighting vectors contain insight about the physical effects of the parameters on the cosmic microwave background (CMB) anisotropy power spectrum $C_l$. The shape and amplitude of these vectors give an intuitive feel for the physics of the CMB, the sensitivity of the observed spectrum to cosmological parameters, ...
CMB Cold Spot from Inflationary Feature Scattering
Wang, Yi
2015-01-01
We propose a "feature-scattering" mechanism to explain the cosmic microwave background cold spot seen from {\\it WMAP} and {\\it Planck} maps. If there are hidden features in the potential of multi-field inflation, the inflationary trajectory can be scattered by such features. The scattering is controlled by the amount of isocurvature fluctuations, and thus can be considered as a mechanism to convert isocurvature fluctuations into curvature fluctuations. This mechanism predicts localized cold spots (instead of hot ones) on the CMB. In addition, it may also bridge a connection between the cold spot and a dip on the CMB power spectrum at $\\ell \\sim 20$.
Experiences with OHP and Issues for the Future
DEFF Research Database (Denmark)
Bouvin, Niels Olof
2000-01-01
The OHSWG has by now moved from specifications to running code. This is an important step, not only because this is the only way of maturing the specifications, but also because it strengthens the credibility of the OHSWG. Showing that the ideas expressed by the OHSWG can be implemented is howeve...... are living in interesting times. Based on the experiences of developing the Arakne Environment, the author attempts to point out some worthwhile directions for future work within the OHSWG.......The OHSWG has by now moved from specifications to running code. This is an important step, not only because this is the only way of maturing the specifications, but also because it strengthens the credibility of the OHSWG. Showing that the ideas expressed by the OHSWG can be implemented is however...
CHARM 2010: Experiment summary and future charm facilities
Energy Technology Data Exchange (ETDEWEB)
Appel, Jeffrey A.; /Fermilab
2010-12-01
The CHARM 2010 meeting had over 30 presentations of experimental results, plus additional future facilities talks just before this summary talk. Since there is not enough time to even summarize all that has been shown from experiments and to recognize all the memorable plots and results - tempting as it is to reproduce the many clean signals and data vs theory figures, the quantum correlations plots, and the D-mixing plots before and after the latest CLEO-c data is added. So, this review will give only my personal observations, exposing my prejudices and my areas of ignorance, no doubt. This overview will be at a fairly high level of abstraction - no re-showing individual plots or results. I ask the forgiveness of those who will have been slighted in this way - meaning all the presents.
AFP: First Experience with Data and Future Plans
Gach, Grzegorz; The ATLAS collaboration
2017-01-01
The aim of the ATLAS Forward Proton (AFP) detector system is the measurement of protons scattered diffractively or electromagnetically at very small angles. The first arm of the system was installed last year and AFP took data in several commissioning and physics runs. The installation of the second arm is ongoing and will be completed in time for the 2017 data taking period. This will allow measurements of processes with two forward protons: central diffraction, exclusive production, and two-photon processes. During the presentation, the early results and experience from the first year of data taking will be presented together with the status of the second-arm installation and plans for the future.
Neutrino Astronomy – A Review of Future Experiments
Energy Technology Data Exchange (ETDEWEB)
Karle, Albrecht
2013-02-15
Current generation neutrino telescopes cover an energy range from about 10 GeV to beyond 10{sup 9} GeV. IceCube sets the scale for future experiments to make improvements. Strategies for future upgrades will be discussed in three energy ranges. At the low-energy end, an infill detector to IceCube's DeepCore would add sensitivity in the energy range from a few to a few tens of GeV with the primary goal of measuring the neutrino mass hierarchy. In the central energy range of classical optical neutrino telescopes, next generation detectors are being pursued in the Mediterranean and at Lake Baikal. The KM3NeT detector in its full scale would establish a substantial increase in sensitivity over IceCube. At the highest energies, radio detectors in ice are among the most promising and pursued technologies to increase exposure at 10{sup 9} GeV by more than an order of magnitude compared to IceCube.
Steerable wavelet analysis of CMB structures alignment
Vielva, P; Martínez-González, E; Vandergheynst, P
2006-01-01
This paper reviews the application of a novel methodology for analysing the isotropy of the universe by probing the alignment of local structures in the CMB. The strength of the proposed methodology relies on the steerable wavelet filtering of the CMB signal. One the one hand, the filter steerability renders the computation of the local orientation of the CMB features affordable in terms of computation time. On the other hand, the scale-space nature of the wavelet filtering allows to explore the alignment of the local structures at different scales, probing possible different phenomena. We present the WMAP first-year data analysis recently performed by the same authors (Wiaux et al.), where an extremely significant anisotropy was found. In particular, a preferred plane was detected, having a normal direction with a northern end position close to the northern end of the CMB dipole axis. In addition, a most preferred direction was found in that plane, with a northern end direction very close to the north eclipt...
Kovetz, Ely D; Itzhaki, Nissan
2010-01-01
We find a unique direction in the CMB sky around which giant rings have an anomalous mean temperature profile. This direction is in very close alignment with the afore measured anomalously large bulk flow direction. We argue that a cosmic defect seeded by a pre-inflationary particle could explain the giant rings, the large bulk flow and their alignment.
CMB (and other challenges to BBN
Directory of Open Access Journals (Sweden)
Gary Steigman
2002-01-01
Full Text Available La nucleos ntesis primordial proporciona una medida de la abundancia universal de bariones cuando el Universo ten a s olo unos minutos de edad. Las observaciones recientes de la anisotrop a en el fondo c osmico de radiaci on de microondas (CMB dan una medida de la abundancia de bariones cuando el Universo ten a varios cientos de miles de a~nos de edad. Las observaciones de supernovas tipo Ia y de c umulos de galaxias en el pasado muy reciente, cuando el Universo tiene una edad de varios miles de millones de a~nos y mayor, proporcionan una medida complementaria de la densidad de bariones en excelente concordancia con los valores del Universo temprano. La concordancia general entre las tres mediciones representa una notable con rmaci on del modelo est andar de la cosmolog a. Sin embargo, hay indicaciones de que las observaciones CMB pueden estar en desacuerdo con aquellas de nucleos ntesis de la Gran Explosi on (BBN. Si esta \\tensi on" persiste entre BBN y CMB, el modelo est andar de la cosmolog a pude requerir una modi caci on. Aq , en una contribuci on dedicada a Silvia Torres-Peimbert y Manuel Peimbert, describimos c omo una as metria entre neutrinos y antineutrinos (la \\degeneraci on de neutrinos" tiene el potencial para resolver este posible con icto entre BBN y CMB.
The SNO+ experiment. Current status and future prospects
Energy Technology Data Exchange (ETDEWEB)
Lozza, Valentina [Institut fuer Kern- und Teilchenphysik, Zellescher Weg 19, 01069 Dresden (Germany)
2016-07-01
SNO+ is a large liquid scintillator based experiment that reuses the Sudbury Neutrino Observatory detector. The detector, located 2 km underground in a mine near Sudbury, Canada, consists of a 12 m diameter acrylic vessel which will be filled with 780 tonnes of liquid scintillator. The main physics goal of SNO+ is to search for the neutrinoless double-beta (0νββ) decay of {sup 130}Te. During the double-beta phase, the liquid scintillator will be initially loaded with 0.3-0.5% natural tellurium. In 5 years of data taking, SNO+ expects to reach a sensitivity on the effective Majorana neutrino mass of 55-133 meV, just above the inverted neutrino mass hierarchy region. Recently, the possibility to deploy up to 10 times more natural tellurium has been investigated, by which SNO+ could explore deep into the parameter space for the inverted hierarchy in the near future. Designed as a general purpose neutrino experiment, SNO+ can additionally measure the reactor antineutrino oscillations, geo-neutrinos in a geologically-interesting location, watch supernova neutrinos and measure low-energy solar neutrinos. A first commissioning phase with the detector filled with water will begin soon. The scintillator phase is expected to start after few months of water data taking. The 0νββ decay phase is foreseen for the 2017. In this talk the current status and the broad physics program of SNO+ will be presented.
Current Status and Future Prospects of the SNO+ Experiment
Directory of Open Access Journals (Sweden)
S. Andringa
2016-01-01
Full Text Available SNO+ is a large liquid scintillator-based experiment located 2 km underground at SNOLAB, Sudbury, Canada. It reuses the Sudbury Neutrino Observatory detector, consisting of a 12 m diameter acrylic vessel which will be filled with about 780 tonnes of ultra-pure liquid scintillator. Designed as a multipurpose neutrino experiment, the primary goal of SNO+ is a search for the neutrinoless double-beta decay (0νββ of 130Te. In Phase I, the detector will be loaded with 0.3% natural tellurium, corresponding to nearly 800 kg of 130Te, with an expected effective Majorana neutrino mass sensitivity in the region of 55–133 meV, just above the inverted mass hierarchy. Recently, the possibility of deploying up to ten times more natural tellurium has been investigated, which would enable SNO+ to achieve sensitivity deep into the parameter space for the inverted neutrino mass hierarchy in the future. Additionally, SNO+ aims to measure reactor antineutrino oscillations, low energy solar neutrinos, and geoneutrinos, to be sensitive to supernova neutrinos, and to search for exotic physics. A first phase with the detector filled with water will begin soon, with the scintillator phase expected to start after a few months of water data taking. The 0νββ Phase I is foreseen for 2017.
Miniaturized Lab System for Future Cold Atom Experiments in Microgravity
Kulas, Sascha; Vogt, Christian; Resch, Andreas; Hartwig, Jonas; Ganske, Sven; Matthias, Jonas; Schlippert, Dennis; Wendrich, Thijs; Ertmer, Wolfgang; Maria Rasel, Ernst; Damjanic, Marcin; Weßels, Peter; Kohfeldt, Anja; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Grzeschik, Christoph; Krutzik, Markus; Wicht, Andreas; Peters, Achim; Herrmann, Sven; Lämmerzahl, Claus
2017-02-01
We present the technical realization of a compact system for performing experiments with cold 87Rb and 39K atoms in microgravity in the future. The whole system fits into a capsule to be used in the drop tower Bremen. One of the advantages of a microgravity environment is long time evolution of atomic clouds which yields higher sensitivities in atom interferometer measurements. We give a full description of the system containing an experimental chamber with ultra-high vacuum conditions, miniaturized laser systems, a high-power thulium-doped fiber laser, the electronics and the power management. In a two-stage magneto-optical trap atoms should be cooled to the low μK regime. The thulium-doped fiber laser will create an optical dipole trap which will allow further cooling to sub- μK temperatures. The presented system fulfills the demanding requirements on size and power management for cold atom experiments on a microgravity platform, especially with respect to the use of an optical dipole trap. A first test in microgravity, including the creation of a cold Rb ensemble, shows the functionality of the system.
Miniaturized Lab System for Future Cold Atom Experiments in Microgravity
Kulas, Sascha; Vogt, Christian; Resch, Andreas; Hartwig, Jonas; Ganske, Sven; Matthias, Jonas; Schlippert, Dennis; Wendrich, Thijs; Ertmer, Wolfgang; Maria Rasel, Ernst; Damjanic, Marcin; Weßels, Peter; Kohfeldt, Anja; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Grzeschik, Christoph; Krutzik, Markus; Wicht, Andreas; Peters, Achim; Herrmann, Sven; Lämmerzahl, Claus
2016-11-01
We present the technical realization of a compact system for performing experiments with cold 87Rb and 39K atoms in microgravity in the future. The whole system fits into a capsule to be used in the drop tower Bremen. One of the advantages of a microgravity environment is long time evolution of atomic clouds which yields higher sensitivities in atom interferometer measurements. We give a full description of the system containing an experimental chamber with ultra-high vacuum conditions, miniaturized laser systems, a high-power thulium-doped fiber laser, the electronics and the power management. In a two-stage magneto-optical trap atoms should be cooled to the low μK regime. The thulium-doped fiber laser will create an optical dipole trap which will allow further cooling to sub- μK temperatures. The presented system fulfills the demanding requirements on size and power management for cold atom experiments on a microgravity platform, especially with respect to the use of an optical dipole trap. A first test in microgravity, including the creation of a cold Rb ensemble, shows the functionality of the system.
The CMS High Level Trigger System: Experience and Future Development
Bauer, Gerry; Bowen, Matthew; Branson, James G; Bukowiec, Sebastian; Cittolin, Sergio; Coarasa, J A; Deldicque, Christian; Dobson, Marc; Dupont, Aymeric; Erhan, Samim; Flossdorf, Alexander; Gigi, Dominique; Glege, Frank; Gomez-Reino, R; Hartl, Christian; Hegeman, Jeroen; Holzner, André; Y L Hwong; Masetti, Lorenzo; Meijers, Frans; Meschi, Emilio; Mommsen, R K; O'Dell, Vivian; Orsini, Luciano; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Polese, Giovanni; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schwick, Christoph; Shpakov, Dennis; Simon, M; Spataru, A C; Sumorok, Konstanty
2012-01-01
The CMS experiment at the LHC features a two-level trigger system. Events accepted by the first level trigger, at a maximum rate of 100 kHz, are read out by the Data Acquisition system (DAQ), and subsequently assembled in memory in a farm of computers running a software high-level trigger (HLT), which selects interesting events for offline storage and analysis at a rate of order few hundred Hz. The HLT algorithms consist of sequences of offline-style reconstruction and filtering modules, executed on a farm of 0(10000) CPU cores built from commodity hardware. Experience from the operation of the HLT system in the collider run 2010/2011 is reported. The current architecture of the CMS HLT, its integration with the CMS reconstruction framework and the CMS DAQ, are discussed in the light of future development. The possible short- and medium-term evolution of the HLT software infrastructure to support extensions of the HLT computing power, and to address remaining performance and maintenance issues, are discussed.
Miniaturized lab system for future cold atom experiments in microgravity
Kulas, Sascha; Resch, Andreas; Hartwig, Jonas; Ganske, Sven; Matthias, Jonas; Schlippert, Dennis; Wendrich, Thijs; Ertmer, Wolfgang; Rasel, Ernst Maria; Damjanic, Marcin; Weßels, Peter; Kohfeldt, Anja; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Grzeschik, Christoph; Krutzik, Markus; Wicht, Andreas; Peters, Achim; Herrmann, Sven; Lämmerzahl, Claus
2016-01-01
We present the technical realization of a compact system for performing experiments with cold $^{87}{\\text{Rb}}$ and $^{39}{\\text{K}}$ atoms in microgravity in the future. The whole system fits into a capsule to be used in the drop tower Bremen. One of the advantages of a microgravity environment is long time evolution of atomic clouds which yields higher sensitivities in atom interferometer measurements. We give a full description of the system containing an experimental chamber with ultra-high vacuum conditions, miniaturized laser systems, a high-power thulium-doped fiber laser, the electronics and the power management. In a two-stage magneto-optical trap atoms should be cooled to the low $\\mu$K regime. The thulium-doped fiber laser will create an optical dipole trap which will allow further cooling to sub-$\\mu$K temperatures. The presented system fulfills the demanding requirements on size and power management for cold atom experiments on a microgravity platform, especially with respect to the use of an op...
Preparation to the CMB Planck analysis : contamination due to the polarized galactic emission
Fauvet, L
2010-01-01
The Planck satellite experiment, which was launched the 14th of may 2009, will give an accurate measurement of the anisotropies of the Cosmic Microwave Background (CMB) in temperature and polarization. This measurement is polluted by the presence of diffuse galactic polarized foreground emissions. In order to obtain the level of accuracy required for the Planck mission it is necessary to deal with these foregrounds. In order to do this, have develloped and implemented coherent 3D models of the two main galactic polarized emissions : the synchrotron and thermal dust emissions. We have optimized these models by comparing them to preexisting data : the K-band of the WMAP data, the ARCHEOPS data at 353 GHz and the 408 MHz all-sky continuum survey. By extrapolation of these models at the frequencies where the CMB is dominant, we are able to estimate the contamination to the CMB Planck signal due to these polarized galactic emissions.
van Engelen, A; Sehgal, N; Holder, G P; Zahn, O; Nagai, D
2013-01-01
The lensing power spectrum from cosmic microwave background (CMB) temperature maps will be measured with unprecedented precision with upcoming experiments, including upgrades to ACT and SPT. Achieving significant improvements in cosmological parameter constraints, such as percent level errors on sigma_8 and an uncertainty on the total neutrino mass of approximately 50 meV, requires percent level measurements of the CMB lensing power. This necessitates tight control of systematic biases. We study several types of biases to the temperature-based lensing reconstruction signal from foreground sources such as radio and infrared galaxies and the thermal Sunyaev-Zel'dovich effect from galaxy clusters. These foregrounds bias the CMB lensing signal due to their non-Gaussian nature. Using simulations as well as some analytical models we find that these sources can substantially impact the measured signal if left untreated. However, these biases can be brought to the percent level if one masks galaxies with fluxes at 15...
Westbrook, B.; Cukierman, A.; Lee, A.; Suzuki, A.; Raum, C.; Holzapfel, W.
2016-07-01
We present the development of the next generation of multi-chroic sinuous antenna-coupled transition edge sensor (TES) bolometers optimized for precision measurements of polarization of the cosmic microwave background (CMB) and cosmic foreground. These devices employ a polarization sensitive broadband self-complementary sinuous antenna to feed on-chip band defining filters before delivering the power to load resistors coupled to a TES on a released bolometer island. This technology was originally developed by UC Berkeley and will be deployed by POLARBEAR-2 and SPT-3G in the next year and half. In addition, it is a candidate detector for the LiteBIRD mission which will make all sky CMB and cosmic foreground polarization observations from a satellite platform in the early 2020's. This works focuses on expanding both the bandwidth and band count per pixel of this technology in order to meet the needs of future CMB missions. This work demonstrates that these devices are well suited for observations between 20 and 380 GHz. This proceeding describes the design, fabrication, and the characterization of three new pixel types: a low-frequency triplexing pixel (LFTP) with bands centered on 40, 60, and 90 GHz, a high-frequency triplexing pixel (HFTP) with bands centered on 220, 280, and 350 GHz, and a mid-frequency tetraplexing pixel with bands (MFTP) centered on 90, 150, 220, and 280 GHz. The average fractional bandwidth of these pixels designs was 36.7, 34.5, and 31.4 % respectively. In addition we found that the polarization modulation efficiency of each band was between 1 and 3 % which is consistent with the polarization efficiency of the wire grid used to take the measurement. Finally, we find that the beams have {˜ }1 % ellipticity for each pixel type. The thermal properties of the bolometers where tuned for characterization in our lab so we do not report on G and noise values as they would be unsuitable for modern CMB experiments.
Measuring the tensor to scalar ratio from CMB B-modes in presence of foregrounds
Betoule, Marc; Delabrouille, J; Jeune, M Le; Cardoso, Jean-François
2009-01-01
Abreg: We investigate the impact of polarized foreground emission on the performances of future CMB experiments in measuring the tensor-to-scalar ratio r. We design a component separation pipeline, based on the Smica method, aimed at estimating r and the foreground contamination from the data with no prior assumption on the frequency dependence or spatial distribution of the foregrounds. We derive error bars accounting for the uncertainty on foreground contribution. We use the current knowledge of galactic and extra-galactic foregrounds as implemented in the Planck Sky Model (PSM), to build simulations of the sky emission for various experimental setups. Our method, permits us to detect r = 0.1 at more than 3 sigma from B-modes only with Planck data, and r = 0.001 at 6 sigma for the most ambitious designs of the future EPIC probe. We find that all-sky experiments permit a proper measurement of the reionization bump despite the large scale foreground emission and are nearly insensitive to contamination from po...
N-body lensed CMB maps: lensing extraction and characterization
Antolini, Claudia; Martinelli, Matteo; Carbone, Carmelita; Baccigalupi, Carlo
2013-01-01
We reconstruct shear maps and angular power spectra from simulated weakly lensed total intensity (TT) and polarised (EB) maps of the Cosmic Microwave Background (CMB) anisotropies, obtained using Born approximated ray-tracing through the N-body simulated Cold Dark Matter (CDM) structures in the Millennium Simulations (MS). We compare the recovered signal with the ${\\Lambda}$CDM prediction, on the whole interval of angular scales which is allowed by the finite box size, extending from the degree scale to the arcminute, by applying a quadratic estimator in the flat sky limit; we consider PRISM-like instrumental specification for future generation CMB satellites, corresponding to arcminute angular resolution of 3.2' and sensitivity of 2.43 ${\\mu}$K-arcmin. The noise bias in the simulations closely follows the estimator prediction, becoming dominated by limits in the angular resolution for the EB signal, at l ${\\simeq}$ 1500. The de-biased signal shows no visible departure from predictions of the weak lensing pow...
Development of 1000 arrays MKID camera for the CMB observation
Karatsu, Kenichi; Naruse, Masato; Nitta, Tom; Sekine, Masakazu; Sekimoto, Yutaro; Noguchi, Takashi; Uzawa, Yoshinori; Matsuo, Hiroshi; Kiuchi, Hitoshi
2012-09-01
A precise measurement of the Cosmic Microwave Background (CMB) provides us a wealth of information about early universe. LiteBIRD is a future satellite mission lead by High Energy Accelerator Research Organization (KEK) and its scientific target is detection of the B-mode polarization of the CMB, which is a footprint of primordial gravitational waves generated during inflation era, but has not been successfully observed so far due to lack of sensitivity. Microwave Kinetic Inductance Detector (MKID) is one candidate of sensitive millimeterwave camera which will be able to detect the B-mode polarization. We have been developing MKID at National Astronomical Observatory of Japan (NAOJ) in cooperation with KEK and RIKEN for the focal plane detector of the LiteBIRD. The developed technologies are: fabrication process of MKIDs with epitaxially-formed aluminum (Al) on silicon (Si) wafer; optical system of the camera consisting of double-slot antenna with Si lens array; and readout circuit utilizing Fast Fourier Transform Spectrometer (FFTS). With these technologies, we designed a prototype MKIDs camera for the LiteBIRD.
The COMPASS experiment at CERN present and future
Bradamante, Franco
2006-01-01
COMPASS is a new fixed target experiment presently in operation at CERN. It consists of a modern two-stage magnetic spectrometer, with particle identification and calorimetry in both stages, which has started collecting physics data in 2002, and will run at the CERN SPS at least until 2010. First results obtained with a 160 GeV muon beam on a polarized deuteron target are presented for several physics channels under investigation: in the longitudinal target configuration, a very precise measurement of the structure function $g^{d}_{1}$ and the first precise measurement of $\\Delta G/G$, the gluon polarization in a polarized nucleon; in the transverse target mode, the first ever measurements of single spin asymmetries of the deuteron in DIS processes. An outline is also given of the physics programme of COMPASS with hadron beams, as well as the plans of the Collaboration for the near future. Topical to this workshop, are possible extensions of the presently approved COMPASS programme after 2010. A brief account...
Positive climate feedback under future climate implied by multifactor experiment
Beier, C.; van der Linden, L.; Ibrom, A.; Larsen, K. S.; Ambus, P.; Climaite Scientific Team
2011-12-01
Results after 2 years of a "full factor" climate change experiment in a semi natural shrubland ecosystem within the CLIMAITE project suggests that all three climate change factors warming, drought and elevated CO2 reduced the carbon sink strength of the ecosystem. In particular elevated CO2 stimulated the carbon loss from the ecosystem leading to a significant positive climate feedback. A fundamental question related to climate change concerns the overall biosphere-atmosphere feedback. Will terrestrial ecosystems mitigate climate change through increased plant derived uptake of CO2, or will they accelerate climate change through increased emission of CO2 from decomposition of organic matter? This fundamental question is key to understanding and predicting future climate change and the consequences for the globe. However, our knowledge in this field is still limited and experimental data is generally missing. The CLIMAITE experiment exposed a semi-natural Danish heathland ecosystem to elevated atmospheric carbon dioxide (CO2 - 510 ppm), warming (+1 oC), and extended summer drought (4-6 week precipitation removal) in all combinations to simulate a realistic climate scenario in Denmark in 2075. In total, the experiment provides a full-factorial design with 6 replicates of all eight combinations of D, T and CO2 and an untreated control for reference (A), i.e. N = 48. Details on the experimental setup are given by Mikkelsen et al. (2008). Generally, single factor treatments (i.e. CO2, warming or drought treatments alone) showed effects often in accordance with previous single factor studies, while, more interestingly, multifactor treatments often interacted generally leading to relatively small net effects of the full factor combined treatments relative to the control (Larsen et al., 2011). Warming and drought both reduced carbon uptake and stimulated carbon emissions slightly leading to a small and additive reduction in the carbon sink strength by these factors
General parity-odd CMB bispectrum estimation
Shiraishi, Maresuke; Fergusson, James R
2014-01-01
We develop a methodology for estimating parity-odd bispectra in the cosmic microwave background (CMB). This is achieved through the extension of the original separable modal methodology to parity-odd bispectrum domains ($\\ell_1 + \\ell_2 + \\ell_3 = {\\rm odd}$). Through numerical tests of the parity-odd modal decomposition with some theoretical bispectrum templates, we verify that the parity-odd modal methodology can successfully reproduce the CMB bispectrum, without numerical instabilities. We also present simulated non-Gaussian maps produced by modal-decomposed parity-odd bispectra, and show the consistency with the exact results. Our new methodology is applicable to all types of parity-odd temperature and polarization bispectra.
Polarized CMB recovery with sparse component separation
Bobin, Jerome; Starck, Jean-Luc
2015-01-01
The polarization modes of the cosmological microwave background are an invaluable source of information for cosmology, and a unique window to probe the energy scale of inflation. Extracting such information from microwave surveys requires disentangling between foreground emissions and the cosmological signal, which boils down to solving a component separation problem. Component separation techniques have been widely studied for the recovery of CMB temperature anisotropies but quite rarely for the polarization modes. In this case, most component separation techniques make use of second-order statistics to discriminate between the various components. More recent methods, which rather emphasize on the sparsity of the components in the wavelet domain, have been shown to provide low-foreground, full-sky estimate of the CMB temperature anisotropies. Building on sparsity, the present paper introduces a new component separation technique dubbed PolGMCA (Polarized Generalized Morphological Component Analysis), which r...
CMB anisotropies from primordial inhomogeneous magnetic fields
Lewis, A
2004-01-01
Primordial inhomogeneous magnetic fields of the right strength can leave a signature on the CMB temperature anisotropy and polarization. Potentially observable contributions to polarization B-modes are generated by vorticity and gravitational waves sourced by the magnetic anisotropic stress. We compute the corresponding CMB transfer functions in detail including the effect of neutrinos. The shear rapidly causes the neutrino anisotropic stress to cancel the stress from the magnetic field, suppressing the production of gravitational waves and vorticity on super-horizon scales after neutrino decoupling. A significant large scale signal from tensor modes can only be produced before neutrino decoupling, and the actual amplitude is somewhat uncertain. Plausible values suggest primordial nearly scale invariant fields of ~ 10^(-10)G today may be observable from their large scale tensor anisotropy. They can be distinguished from primordial gravitational waves by their non-Gaussianity. Vector mode vorticity sources B-m...
Geometry of weak lensing of CMB polarization
Challinor, A D; Challinor, Anthony; Chon, Gayoung
2002-01-01
Hu has presented a harmonic-space method for calculating the effects of weak gravitational lensing on the cosmic microwave background (CMB) over the full sky. Computing the lensed power spectra to first order in the deflection power requires one to formulate the lensing displacement beyond the tangent-space approximation. We point out that for CMB polarization this displacement must undergo geometric corrections on the spherical sky to maintain statistical isotropy of the lensed fields. Although not discussed by Hu, these geometric effects are implicit in his analysis. However, there they are hidden by an overly-compact notation that is both unconventional and rather confusing. Here we aim to ameliorate this deficiency by providing a rigorous derivation of the lensed spherical power spectra.
CMB Anisotropies Total Angular Momentum Method
Hu, W; Hu, Wayne; White, Martin
1997-01-01
A total angular momentum representation simplifies the radiation transport problem for temperature and polarization anisotropy in the CMB. Scattering terms couple only the quadrupole moments of the distributions and each moment corresponds directly to the observable angular pattern on the sky. We develop and employ these techniques to study the general properties of anisotropy generation from scalar, vector and tensor perturbations to the metric and the matter, both in the cosmological fluids and from any seed perturbations (e.g.~defects) that may be present. The simpler, more transparent form and derivation of the Boltzmann equations brings out the geometric and model-independent aspects of temperature and polarization anisotropy formation. Large angle scalar polarization provides a robust means to distinguish between isocurvature and adiabatic models for structure formation in principle. Vector modes have the unique property that the CMB polarization is dominated by magnetic type parity at small angles and ...
Status of CMB Observations in 2015
Bucher, Martin
2016-07-01
The 2.725 K cosmic microwave background has played a key role in the development of modern cosmology by providing a solid observational foundation for constraining possible theories of what happened at very large redshifts and theoretical speculation reaching back almost to the would-be big bang initial singularity. After recounting some of the lesser known history of this area, I summarize the current observational situation and also discuss some exciting challenges that lie ahead: the search for B modes, the precision mapping of the CMB gravitational lensing potential, and the ultra-precise characterization of the CMB frequency spectrum, which would allow the exploitation of spectral distortions to probe new physics.
CMB Delensing Beyond the B Modes
Green, Daniel; van Engelen, Alexander
2016-01-01
Gravitational lensing by large-scale structure significantly impacts observations of the cosmic microwave background (CMB): it smooths the acoustic peaks in temperature and $E$-mode polarization power spectra, correlating previously uncorrelated modes; and it converts $E$-mode polarization into $B$-mode polarization. The act of measuring and removing the effect of lensing from CMB maps, or delensing, has been well studied in the context of $B$ modes, but little attention has been given to the delensing of the temperature and $E$ modes. In this paper, we model the expected delensed $T$ and $E$ power spectra to all orders in the lensing potential, demonstrating the sharpening of the acoustic peaks and a significant reduction in lens-induced power spectrum covariances. We then perform cosmological forecasts, demonstrating that delensing will yield improved sensitivity to parameters with upcoming surveys. We highlight the breaking of the degeneracy between the effective number of neutrino species and primordial h...
Status of CMB observations in 2015
Bucher, Martin
2016-01-01
The 2.725 K cosmic microwave background has played a key role in the development of modern cosmology by providing a solid observational foundation for constraining possible theories of what happened at very large redshifts and theoretical speculation reaching back almost to the would-be big bang initial singularity. After recounting some of the lesser known history of this area, I summarize the current observational situation and also discuss some exciting challenges that lie ahead: the search for B modes, the precision mapping of the CMB gravitational lensing potential, and the ultra-precise characterization of the CMB frequency spectrum, which would allow the exploitation of spectral distortions to probe new physics.
Establishing the origin of CMB B-mode polarization
Sheere, Connor; Meerburg, P Daniel; Meyers, Joel
2016-01-01
Primordial gravitational waves leave a characteristic imprint on the cosmic microwave background (CMB) in the form of $B$-mode polarization. Photons are also deflected by large scale gravitational waves which intervene between the source screen and our telescopes, resulting in curl-type gravitational lensing. Gravitational waves present at the epoch of reionization contribute to both effects, thereby leading to a non-vanishing cross-correlation between $B$-mode polarization and curl lensing of the CMB. Observing such a cross correlation would be very strong evidence that an observation of $B$-mode polarization was due to the presence of large scale gravitational waves, as opposed to astrophysical foregrounds or experimental systematic effects. We study the cross-correlation across a wide range of source redshifts and show that a post-SKA experiment aimed to map out the 21-cm sky between $15 \\leq z \\leq 30$ could rule out non-zero cross-correlation at high significance for $r \\geq 0.01$.
CMB likelihood approximation by a Gaussianized Blackwell-Rao estimator
Rudjord, Ø; Eriksen, H K; Huey, Greg; Górski, K M; Jewell, J B
2008-01-01
We introduce a new CMB temperature likelihood approximation called the Gaussianized Blackwell-Rao (GBR) estimator. This estimator is derived by transforming the observed marginal power spectrum distributions obtained by the CMB Gibbs sampler into standard univariate Gaussians, and then approximate their joint transformed distribution by a multivariate Gaussian. The method is exact for full-sky coverage and uniform noise, and an excellent approximation for sky cuts and scanning patterns relevant for modern satellite experiments such as WMAP and Planck. A single evaluation of this estimator between l=2 and 200 takes ~0.2 CPU milliseconds, while for comparison, a single pixel space likelihood evaluation between l=2 and 30 for a map with ~2500 pixels requires ~20 seconds. We apply this tool to the 5-year WMAP temperature data, and re-estimate the angular temperature power spectrum, $C_{\\ell}$, and likelihood, L(C_l), for l<=200, and derive new cosmological parameters for the standard six-parameter LambdaCDM mo...
Effect of noncircularity of experimental beam on CMB parameter estimation
Das, Santanu; Paulson, Sonu Tabitha
2015-01-01
Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological models and parameters. However, precision can only be meaningful when all major systematic effects are taken into account. Non-circular beams in CMB experiments can cause large systematic deviation in the angular power spectrum, not only by modifying the measurement at a given multipole, but also introducing coupling between different multipoles through a deterministic bias matrix. Here we add a mechanism for emulating the effect of a full bias matrix to the Planck likelihood code through the parameter estimation code SCoPE. We show that if the angular power spectrum was measured with a non-circular beam, the assumption of circular Gaussian beam or considering only the diagonal part of the bias matrix can lead to huge error in parameter estimation. We demonstrate that, at least for elliptical Gaussian beams, use of scalar beam window fun...
Effect of noncircularity of experimental beam on CMB parameter estimation
Das, Santanu; Mitra, Sanjit; Tabitha Paulson, Sonu
2015-03-01
Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological models and parameters. However, precision can only be meaningful when all major systematic effects are taken into account. Non-circular beams in CMB experiments can cause large systematic deviation in the angular power spectrum, not only by modifying the measurement at a given multipole, but also introducing coupling between different multipoles through a deterministic bias matrix. Here we add a mechanism for emulating the effect of a full bias matrix to the PLANCK likelihood code through the parameter estimation code SCoPE. We show that if the angular power spectrum was measured with a non-circular beam, the assumption of circular Gaussian beam or considering only the diagonal part of the bias matrix can lead to huge error in parameter estimation. We demonstrate that, at least for elliptical Gaussian beams, use of scalar beam window functions obtained via Monte Carlo simulations starting from a fiducial spectrum, as implemented in PLANCK analyses for example, leads to only few percent of sigma deviation of the best-fit parameters. However, we notice more significant differences in the posterior distributions for some of the parameters, which would in turn lead to incorrect errorbars. These differences can be reduced, so that the errorbars match within few percent, by adding an iterative reanalysis step, where the beam window function would be recomputed using the best-fit spectrum estimated in the first step.
CMB Polarization B-mode Delensing with SPTpol and Herschel
Energy Technology Data Exchange (ETDEWEB)
Manzotti, A.; et al.
2017-01-16
We present a demonstration of delensing the observed cosmic microwave background (CMB) B-mode polarization anisotropy. This process of reducing the gravitational-lensing generated B-mode component will become increasingly important for improving searches for the B modes produced by primordial gravitational waves. In this work, we delens B-mode maps constructed from multi-frequency SPTpol observations of a 90 deg$^2$ patch of sky by subtracting a B-mode template constructed from two inputs: SPTpol E-mode maps and a lensing potential map estimated from the $\\textit{Herschel}$ $500\\,\\mu m$ map of the CIB. We find that our delensing procedure reduces the measured B-mode power spectrum by 28% in the multipole range $300 < \\ell < 2300$; this is shown to be consistent with expectations from theory and simulations and to be robust against systematics. The null hypothesis of no delensing is rejected at $6.9 \\sigma$. Furthermore, we build and use a suite of realistic simulations to study the general properties of the delensing process and find that the delensing efficiency achieved in this work is limited primarily by the noise in the lensing potential map. We demonstrate the importance of including realistic experimental non-idealities in the delensing forecasts used to inform instrument and survey-strategy planning of upcoming lower-noise experiments, such as CMB-S4.
CMB all-scale blackbody distortions induced by linearizing temperature
Notari, Alessio
2016-01-01
Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a \\emph{linearized} formula for relating them to the temperature blackbody fluctuations. However such a procedure also generates a signal in the maps in the form of y-type distortions, and thus degenerate with the thermal SZ (tSZ) effect. These are small effects that arise at second-order in the temperature fluctuations not from primordial physics but from such a limitation of the map-making procedure. They constitute a contaminant for measurements of: our peculiar velocity, the tSZ and of primordial y-distortions, but they can nevertheless be well-modelled and accounted for. We show that the largest distortions arises at high ell from a leakage of the CMB dipole into the y-channel which couples to all multipoles, but mostly affects the range ell <~ 400. This should be visible in Planck's y-maps with an estimated signal-to-noise ratio of about 9. We note however that such frequency-de...
Fertility estimation: a review of past experience and future prospects.
Foote, Robert H
2003-01-15
Fertility has many components and stages which require that males and females be functionally capable of carrying out all critical stages if each generational reproductive cycle is to be completed. To accomplish this, the male must produce and ejaculate normal fertile sperm. The female must produce, store and ovulate normal fertilizable oocytes. Furthermore, the female must provide a reproductive system compatible with sperm transport, capacitation, and fertilization of the oocytes, embryo and fetal development, and finally birth of healthy young. Reproductive success or failure at several of these points can be estimated quantitatively on a population basis, and in a few situations on an individual basis. It is important that fertility estimates be determined accurately and with precision to be most useful to researchers and managers of animal enterprises. Many studies have underestimated the biological relationship of fertility to other traits because the estimates lacked precision. Many in vitro manipulations of sperm in artificial insemination, of gametes in various assisted reproductive technologies, and of embryos in embryo transfer are utilized in animal breeding programs. Accurate estimation of reproductive efficiency of these in vitro procedures also is important. Conditions surrounding different sets of fertility estimates almost certainly will be different. These conditions should be described as precisely as possible, and appropriate controls included in all experiments. When possible, experiments should be replicated over time and place to determine the repeatability of the various criteria used to estimate fertility and reproductive efficiency. Advances in genomic information and molecular biology should facilitate characterizing more fully inherent potential fertility of animals at birth. In vitro tests will improve, and automated techniques will facilitate making multiple determinations possible on a large scale. Reliability of fertility estimates
Anomalous CMB polarization and gravitational chirality
Contaldi, Carlo R.; Magueijo, Joao; Smolin, Lee
2008-01-01
We consider the possibility that gravity breaks parity, with left and right handed gravitons coupling to matter with a different Newton's constant and show that this would affect their zero-point vacuum fluctuations during inflation. Should there be a cosmic background of gravity waves, the effect would translate into anomalous CMB polarization. Non-vanishing TB (and EB) polarization components emerge, revealing interesting experimental targets. Indeed if reasonable chirality is present a TB ...
CMB statistical anisotropy from noncommutative gravitational waves
Shiraishi, Maresuke; Ricciardone, Angelo; Arroja, Frederico
2014-01-01
Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from anisotropic gravitational waves, parametrised by $P_h({\\bf k}) = P_h^{(0)}(k) [ 1 + \\sum_{LM} f_L(k) g_{LM} Y_{LM} (\\hat{\\bf k}) ]$, where $P_h^{(0)}(k)$ is the usual scale-invariant power spectrum. Such anisotropic tensor fluctuations may arise from an inflationary model with noncommutativity of fields. It is verified that in this model, an isotropic component and a quadrupole asymmetry with $f_0(k) = f_2(k) \\propto k^{-2}$ are created and hence highly red-tilted off-diagonal components arise in the CMB power spectra, namely $\\ell_2 = \\ell_1 \\pm 2$ in $TT$, $TE$, $EE$ and $BB$, and $\\ell_2 = \\ell_1 \\pm 1$ in $TB$ and $EB$. We find that B-mode polarisation is more sensitive to such signals than temperature and E-mode polarisation due to the smallness of large-scale cosmic varian...
CMB lens sample covariance and consistency relations
Motloch, Pavel; Hu, Wayne; Benoit-Lévy, Aurélien
2017-02-01
Gravitational lensing information from the two and higher point statistics of the cosmic microwave background (CMB) temperature and polarization fields are intrinsically correlated because they are lensed by the same realization of structure between last scattering and observation. Using an analytic model for lens sample covariance, we show that there is one mode, separately measurable in the lensed CMB power spectra and lensing reconstruction, that carries most of this correlation. Once these measurements become lens sample variance dominated, this mode should provide a useful consistency check between the observables that is largely free of sampling and cosmological parameter errors. Violations of consistency could indicate systematic errors in the data and lens reconstruction or new physics at last scattering, any of which could bias cosmological inferences and delensing for gravitational waves. A second mode provides a weaker consistency check for a spatially flat universe. Our analysis isolates the additional information supplied by lensing in a model-independent manner but is also useful for understanding and forecasting CMB cosmological parameter errors in the extended Λ cold dark matter parameter space of dark energy, curvature, and massive neutrinos. We introduce and test a simple but accurate forecasting technique for this purpose that neither double counts lensing information nor neglects lensing in the observables.
Testing CMB polarization data using position angles
Preece, Michael
2014-01-01
We consider a novel null test for contamination which can be applied to CMB polarization data that involves analysis of the statistics of the polarization position angles. Specifically, we will concentrate on using histograms of the measured position angles to illustrate the idea. Such a test has been used to identify systematics in the NVSS point source catalogue with an amplitude well below the noise level. We explore the statistical properties of polarization angles in CMB maps. If the polarization angle is not correlated between pixels, then the errors follow a simple $\\sqrt{N_{pix}}$ law. However this is typically not the case for CMB maps since these have correlations which result in an increase in the variance since the effective number of independent pixels is reduced. Then we illustrate how certain classes of systematic errors can result in very obvious patterns in these histograms, and thus that these errors could possibly be identified using this method. We discuss how this idea might be applied in...
Finding Futures: A Spatio-Visual Experiment In Participatory Engagement
DEFF Research Database (Denmark)
Davies, Sarah Rachael; Selin, Cynthia; Gano, Gretchen
2013-01-01
The Finding Futures Project explores innovative ways of deliberating the future of cities through an emphasis on embodied spatio-visual engagement with urban landscapes. The first instantiation of the project - which took place in Lisbon in 2011 - is reported through a discussion of the project...
Development of dual-polarization LEKIDs for CMB observations
McCarrick, Heather; Ade, Peter A R; Barry, Peter; Bryan, Sean; Che, George; Day, Peter; Doyle, Simon; Flanigan, Daniel; Johnson, Bradley R; Jones, Glenn; LeDuc, Henry G; Limon, Michele; Mauskopf, Philip; Miller, Amber; Tucker, Carole; Zmuidzinas, Jonas
2016-01-01
We discuss the design considerations and initial measurements from arrays of dual-polarization, lumped element kinetic inductance detectors (LEKIDs) nominally designed for cosmic microwave background (CMB) studies. The detectors are horn-coupled, and each array element contains two single-polarization LEKIDs, which are made from thin-film aluminum and optimized for a single spectral band centered on 150 GHz. We are developing two array architectures, one based on 160 micron thick silicon wafers and the other based on silicon-on-insulator (SOI) wafers with a 30 micron thick device layer. The 20-element test arrays (40 LEKIDs) are characterized with both a linearly-polarized electronic millimeter wave source and a thermal source. We present initial measurements including the noise spectra, noise-equivalent temperature, and responsivity. We discuss future testing and further design optimizations to be implemented.
Designs for a large-aperture telescope to map the CMB 10× faster.
Niemack, Michael D
2016-03-01
Current large-aperture cosmic microwave background (CMB) telescopes have nearly maximized the number of detectors that can be illuminated while maintaining diffraction-limited image quality. The polarization-sensitive detector arrays being deployed in these telescopes in the next few years will have roughly 10⁴ detectors. Increasing the mapping speed of future instruments by at least an order of magnitude is important to enable precise probes of the inflationary paradigm in the first fraction of a second after the big bang and provide strong constraints on cosmological parameters. The CMB community has begun planning a next generation "Stage IV" CMB project that will be comprised of multiple telescopes with between 10⁵-10⁶ detectors to pursue these goals. This paper introduces the new crossed Dragone telescope and receiver optics designs that increase the usable diffraction-limited field-of-view, and therefore the mapping speed, by an order of magnitude compared to the upcoming generation of large-aperture instruments. Polarization systematics and engineering considerations are presented, including a preliminary receiver model to demonstrate that these designs will enable high efficiency illumination of >10⁵ detectors in a next generation CMB telescope.
Weak Lensing and CMB: Parameter forecasts including a running spectral index
Ishak, M; McDonald, P; Seljak, U; Ishak, Mustapha; Hirata, Christopher M.; Donald, Patrick Mc; Seljak, Uros
2004-01-01
We use statistical inference theory to explore the constraints from future galaxy weak lensing (cosmic shear) surveys combined with the current CMB constraints on cosmological parameters, focusing particularly on the running of the spectral index of the primordial scalar power spectrum, $\\alpha_s$. Recent papers have drawn attention to the possibility of measuring $\\alpha_s$ by combining the CMB with galaxy clustering and/or the Lyman-$\\alpha$ forest. Weak lensing combined with the CMB provides an alternative probe of the primordial power spectrum. We run a series of simulations with variable runnings and compare them to semi-analytic non-linear mappings to test their validity for our calculations. We find that a ``Reference'' cosmic shear survey with $f_{sky}=0.01$ and $6.6\\times 10^8$ galaxies per steradian can reduce the uncertainty on $n_s$ and $\\alpha_s$ by roughly a factor of 2 relative to the CMB alone. We investigate the effect of shear calibration biases on lensing by including the calibration factor...
Atmospheric contamination for CMB ground-based observations
Errard, J; Akiba, Y; Arnold, K; Atlas, M; Baccigalupi, C; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Cukierman, A; Delabrouille, J; Dobbs, M; Ducout, A; Elleflot, T; Fabbian, G; Feng, C; Feeney, S; Gilbert, A; Goeckner-Wald, N; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Hill, C; Holzapfel, W L; Hori, Y; Inoue, Y; Jaehnig, G C; Jaffe, A H; Jeong, O; Katayama, N; Kaufman, J; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Jeune, M Le; Lee, A T; Leitch, E M; Leon, D; Linder, E; Matsuda, F; Matsumura, T; Miller, N J; Myers, M J; Navaroli, M; Nishino, H; Okamura, T; Paar, H; Peloton, J; Poletti, D; Puglisi, G; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K M; Schenck, D E; Sherwin, B D; Siritanasak, P; Smecher, G; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Tajima, O; Takakura, S; Tikhomirov, A; Tomaru, T; Whitehorn, N; Wilson, B; Yadav, A; Zahn, O
2015-01-01
Atmosphere is one of the most important noise sources for ground-based Cosmic Microwave Background (CMB) experiments. By increasing optical loading on the detectors, it amplifies their effective noise, while its fluctuations introduce spatial and temporal correlations between detected signals. We present a physically motivated 3d-model of the atmosphere total intensity emission in the millimeter and sub-millimeter wavelengths. We derive an analytical estimate for the correlation between detectors time-ordered data as a function of the instrument and survey design, as well as several atmospheric parameters such as wind, relative humidity, temperature and turbulence characteristics. Using numerical computation, we examine the effect of each physical parameter on the correlations in the time series of a given experiment. We then use a parametric-likelihood approach to validate the modeling and estimate atmosphere parameters from the POLARBEAR-I project first season data set. We compare our results to previous st...
Secondary anisotropies of the CMB
Aghanim, Nabila; Silk, Joseph
2007-01-01
The Cosmic Microwave Background fluctuations provide a powerful probe of the dark ages of the universe through the imprint of the secondary anisotropies associated with the reionisation of the universe and the growth of structure. We review the relation between the secondary anisotropies and and the primary anisotropies that are directly generated by quantum fluctuations in the very early universe. The physics of secondary fluctuations is described, with emphasis on the ionisation history and the evolution of structure. We discuss the different signatures arising from the secondary effects in terms of their induced temperature fluctuations, polarisation and statistics. The secondary anisotropies are being actively pursued at present, and we review the future and current observational status.
The isotropic blackbody CMB as evidence for a homogeneous universe
Clifton, Timothy; Bull, Philip
2011-01-01
The question of whether the Universe is spatially homogeneous and isotropic on the largest scales is of fundamental importance to cosmology, but has not yet been answered decisively. Surprisingly, neither an isotropic primary CMB nor combined observations of luminosity distances and galaxy number counts are sufficient to establish such a result. The inclusion of the Sunyaev-Zel'dovich effect in CMB observations, however, dramatically improves this situation. We show that even a solitary observer who sees an isotropic blackbody CMB can conclude that the universe is homogeneous and isotropic in their causal past when the Sunyaev-Zel'dovich effect is present. Critically, however, the CMB must either be viewed for an extended period of time, or CMB photons that have scattered more than once must be detected. This result provides a theoretical underpinning for testing the Cosmological Principle with observations of the CMB alone.
Kovac, John; Bicep/Keck Collaboration
2017-01-01
The BICEP/Keck Array cosmic microwave background (CMB) polarization experiments located at the South Pole are a series of small-aperture refracting telescopes designed to probe the degree-scale B-mode signature of primordial gravitational waves. These highly-targeted experiments have produced the world's deepest maps of CMB polarization, leading to the most stringent constraints on the tensor-to-scalar ratio to date: r r r < 0 . 01 and below within the next several years.
Searching for Cosmic Strings in CMB Anisotropy Maps using Wavelets and Curvelets
Hergt, Lukas; Brandenberger, Robert; Kacprzak, Tomasz; Refregier, Alexandre
2016-01-01
We use wavelet and curvelet transforms to extract signals of cosmic strings from cosmic microwave background (CMB) temperature anisotropy maps, and to study the limits on the cosmic string tension which various ongoing CMB temperature anisotropy experiments will be able to achieve. We construct sky maps with size and angular resolution corresponding to various experiments. These maps contain the signals of a scaling solution of long string segments with a given string tension $G \\mu$, the contribution of the dominant Gaussian primordial cosmological fluctuations, and pixel by pixel white noise with an amplitude corresponding to the instrumental noise of the various experiments. In the case that we include white noise, we find that the curvelets are more powerful than wavelets. For maps with Planck specification, we obtain bounds on the string tension comparable to what was obtained by the Planck collaboration. Experiments with better angular resolution such as the South Pole Telescope third generation (SPT-3G...
Designing a future Conditions Database based on LHC experience
AUTHOR|(INSPIRE)INSPIRE-00064378; Formica, Andrea; Gallas, Elizabeth; Lehmann Miotto, Giovanna; Pfeiffer, A.; Govi, G.
2015-01-01
We describe a proposal for a new Conditions Database infrastructure that ATLAS and CMS (or other) experiments could use starting on the timescale of Run 3. This proposal is based on the experience that both experiments accumulated during Run 1. We will present the identified relevant data flows for conditions data and underline the common use cases that lead to a joint effort for the development of a new system. Conditions data are needed in any scientific experiment. It includes any ancillary data associated with primary data taking such as detector configuration, state or calibration or the environment in which the detector is operating. In any non-trivial experiment, conditions data typically reside outside the primary data store for various reasons (size, complexity or availability) and are best accessed at the point of processing or analysis (including for Monte Carlo simulations). The ability of any experiment to produce correct and timely results depends on the complete and efficient availability of ne...
All sky CMB map from cosmic strings integrated Sachs-Wolfe effect
Ringeval, Christophe
2012-01-01
By actively distorting the Cosmic Microwave Background (CMB) over our past light cone, cosmic strings are unavoidable sources of non-Gaussianity. Developing optimal estimators able to disambiguate a string signal from the primordial type of non-Gaussianity requires calibration over synthetic full sky CMB maps, which till now had been numerically unachievable at the resolution of modern experiments. In this paper, we provide the first high resolution full sky CMB map of the temperature anisotropies induced by a network of cosmic strings since the recombination. The map has about 200 million sub-arcminute pixels in the healpix format which is the standard in use for CMB analyses (Nside=4096). This premiere required about 800,000 cpu hours; it has been generated by using a massively parallel ray tracing method piercing through a thousands of state of art Nambu-Goto cosmic string numerical simulations which pave the comoving volume between the observer and the last scattering surface. We explicitly show how this ...
Long baseline accelerator neutrino experiments present and future
Rubbia, André
2000-01-01
A nu /sub mu / disappearance effect has been seen in atmospheric neutrino experiments. This has led to the "evidence for neutrino oscillations". The next problem in neutrino physics is to perform the right experiment(s) to elucidate in a comprehensive way the pattern of neutrino masses and mixings. The long baseline experiments will play a fundamental role at settling definitively the question of flavor oscillation and at measuring with good precision the oscillation parameters. The CERN-NGS beam coupled with the proposed ICANOE and OPERA detectors is the only programme capable of sensitive tau and electron appearance searches. (14 refs).
First Release of Gauss-Legendre Sky Pixelization (GLESP) software package for CMB analysis
Doroshkevich, A G; Verkhodanov, O V; Novikov, D I; Turchaninov, V I; Novikov, I D; Christensen, P R; Chiang, L Y
2005-01-01
We report the release of the Gauss--Legendre Sky Pixelization (GLESP) software package version 1.0. In this report we present the main features and functions for processing and manipulation of sky signals. Features for CMB polarization is underway and to be incorporated in a future release. Interested readers can visit http://www.glesp.nbi.dk (www.glesp.nbi.dk) and register for receiving the package.
Intercultural Preparation for Future Mobile Students: A Pedagogical Experience
Beaven, Ana; Golubeva, Irina
2016-01-01
Higher education (HE) student mobility offers the opportunity to acquire, among other things, intercultural experience. Nevertheless, it is crucial to prepare students and give them the tools to reflect on their experiences before, during and after study abroad. In this pedagogical paper, we present and discuss "Perceptions of self and…
SPIDER: A Balloon-borne Large-scale CMB Polarimeter
Crill, B P; Battistelli, E S; Benton, S; Bihary, R; Bock, J J; Bond, J R; Brevik, J; Bryan, S; Contaldi, C R; Dore, O; Farhang, M; Fissel, L; Golwala, S R; Halpern, M; Hilton, G; Holmes, W; Hristov, V V; Irwin, K; Jones, W C; Kuo, C L; Lange, A E; Lawrie, C; MacTavish, C J; Martin, T G; Mason, P; Montroy, T E; Netterfield, C B; Pascale, E; Riley, D; Ruhl, J E; Runyan, M C; Trangsrud, A; Tucker, C; Turner, A; Viero, M; Wiebe, D
2008-01-01
Spider is a balloon-borne experiment that will measure the polarization of the Cosmic Microwave Background over a large fraction of a sky at 1 degree resolution. Six monochromatic refracting millimeter-wave telescopes with large arrays of antenna-coupled transition-edge superconducting bolometers will provide system sensitivities of 4.2 and 3.1 micro K_cmb rt s at 100 and 150 GHz, respectively. A rotating half-wave plate will modulate the polarization sensitivity of each telescope, controlling systematics. Bolometer arrays operating at 225 GHz and 275 GHz will allow removal of polarized galactic foregrounds. In a 2-6 day first flight from Alice Springs, Australia in 2010, Spider will map 50% of the sky to a depth necessary to improve our knowledge of the reionization optical depth by a large factor.
Making CMB temperature and polarization maps with Madam
Keihanen, E; Kurki-Suonio, H; Poutanen, T; Sirvio, A -S
2009-01-01
Madam is a CMB map-making code, designed to make temperature and polarization maps of time-ordered data of total power experiments like Planck. The algorithm is based on the destriping technique, but it also makes use of known noise properties in the form of a noise prior. The method in its early form was presented in an earlier work by Keihanen et al. (2005). In this paper we present an update of the method, extended to non-averaged data, and include polarization. In this method the baseline length is a freely adjustable parameter, and destriping can be performed at a different map resolution than that of the final maps. We show results obtained with simulated data. This study is related to Planck LFI activities.
CMB component separation in the pixel domain
Doroshkevich, A.; Verkhodanov, O.
2010-01-01
We show that the popular ILC approach is unstable in respect to the division of the sample of map pixels to the set of ``homogeneous'' subsamples. For suitable choice of such subsamples we can obtain the restored CMB signal with amplitudes ranged from zero to the amplitudes of the observed signal. We propose approach which allows us to obtain reasonable estimates of $C_\\ell$ at $\\ell\\leq 30$ and similar to WMAP $C_\\ell$ for larger $\\ell$. With this approach we reduce some anomalies of the WMA...
Anomalous CMB polarization and gravitational chirality
Contaldi, Carlo R; Smolin, Lee
2008-01-01
We consider the possibility that gravity breaks parity, with left and right handed gravitons coupling to matter with a different Newton's constant and show that this would affect their zero-point vacuum fluctuations during inflation. Should there be a cosmic background of gravity waves, the effect would translate into anomalous CMB polarization. Non-vanishing TB (and EB) polarization components emerge, revealing interesting experimental targets. Indeed if reasonable chirality is present a TB measurement would provide the easiest way to detect a gravitational wave background. We speculate on the theoretical implications of such an observation.
CMB Power Spectrum Likelihood with ILC
Dick, Jason; Delabrouille, Jacques
2012-01-01
We extend the ILC method in harmonic space to include the error in its CMB estimate. This allows parameter estimation routines to take into account the effect of the foregrounds as well as the errors in their subtraction in conjunction with the ILC method. Our method requires the use of a model of the foregrounds which we do not develop here. The reduction of the foreground level makes this method less sensitive to unaccounted for errors in the foreground model. Simulations are used to validate the calculations and approximations used in generating this likelihood function.
Imprints of Anisotropic Inflation on the CMB
Watanabe, Masa-aki; Soda, Jiro
2010-01-01
We study the imprints of anisotropic inflation on the CMB temperature fluctuations and polarizations. The statistical anisotropy stems not only from the direction dependence of curvature and tensor perturbations, but also from the cross correlation between curvature and tensor perturbations, and the linear polarization of tensor perturbations. We show that off-diagonal $TB$ and $EB$ spectrum as well as on- and off-diagonal $TT, EE, BB, TE$ spectrum are induced from anisotropic inflation. We emphasize that the off-diagonal spectrum induced by the cross correlation could be a characteristic signature of anisotropic inflation.
Deep-sea impact experiments and their future requirements
Digital Repository Service at National Institute of Oceanography (India)
Sharma, R.
In recent years, several experiments to assess the potential impacts due to deep-sea mining in the Pacific as well as the Indian Oceans have indicated the immediate changes and restoration patterns of environmental conditions in the marine ecosystem...
Designing a future Conditions Database based on LHC experience
Barberis, D; Gallas, E J; Govi, G; Miotto, G Lehman; Pfeiffer, A
2015-01-01
Starting from the experience collected by the ATLAS and CMS experiments in handling condition data during the first LHC run, we present a proposal for a new generation of condition databases, which could be implemented by 2020. We will present the identified relevant data flows for condition data and underline the common use cases that lead to a joint effort for the development of a new system.Condition data is needed in any scientific experiment. It includes any ancillary data associated with primary data taking such as detector configuration, state or calibration or the environment in which the detector is operating. Condition data typically reside outside the primary data store for various reasons (size, complexity or availability) and are best accessed at the point of processing or analysis (including for Monte Carlo simulations). The ability of any experiment to produce correct and timely results depends on the complete and efficient availability of needed conditions for each stage of data handling. Ther...
Current Status and Future Prospects of the SNO+ Experiment
:,; Arushanova, E; Asahi, S; Askins, M; Auty, D J; Back, A R; Barnard, Z; Barros, N; Beier, E W; Bialek, A; Biller, S D; Blucher, E; Bonventre, R; Braid, D; Caden, E; Caravaca, J; Carvalho, J; Cavalli, L; Chauhan, D; Chen, M; Chkvorets, O; Clark, K; Cleveland, B; Coulter, I T; Cressy, D; Dai, X; Darrach, C; Davis-Purcell, B; Deen, R; Depatie, M M; Descamps, F; Di Lodovico, F; Duhaime, N; Duncan, F; Dunger, J; Falk, E; Fatemighomi, N; Ford, R; Gorel, P; Grant, C; Grullon, S; Guillian, E; Hallin, A L; Hallman, D; Hans, S; Hartnell, J; Harvey, P; Hedayatipour, M; Heintzelman, W J; Helmer, R L; Howe, M; Hreljac, B; Hu, J; Iida, T; Jackson, C M; Jelley, N A; Jillings, C; Jones, C; Jones, P G; Kamdin, K; Kaptanoglu, T; Kaspar, J; Keener, P; Khaghani, P; Kippenbrock, L; Klein, J R; Knapik, R; Kofron, J N; Kormos, L L; Korte, S; Kraus, C; Krauss, C B; Labe, K; Lam, I; Lan, C; Land, B J; Langrock, S; LaTorre, A; Lawson, I; Lefeuvre, G M; Leming, E J; Lidgard, J; Liu, X; Liu, Y; Lozza, V; Maguire, S; Maio, A; Majumdar, K; Manecki, S; Maneira, J; Marzec, E; Mastbaum, A; McCauley, N; McDonald, A B; McMillan, J E; Mekarski, P; Miller, C; Mony, E; Mottram, M J; Novikov, V; O'Keeffe, H M; O'Sullivan, E; Gann, G D Orebi; Parnell, M J; Peeters, S J M; Pershing, T; Petriw, Z; Prior, G; Prouty, J C; Quirk, S; Reichold, A; Robertson, A; Rose, J; Rosero, R; Rost, P M; Rumleskie, J; Schumaker, M A; Schwendener, M H; Scislowski, D; Secrest, J; Seddighin, M; Segui, L; Seibert, S; Shantz, T; Shokair, T M; Sibley, L; Sinclair, J R; Singh, K; Skensved, P; Sonley, T; Stainforth, R; Strait, M; Stringer, M I; Svoboda, R; Soerensen, A; Tatar, J; Tian, L; Tolich, N; Tseng, J; Tseung, H W C; Van Berg, R; Virtue, C; von Krosigk, B; Vázquez-Jáuregui, E; Walker, J M G; Walker, M; Wasalski, O; Waterfield, J; White, R F; Wilkerson, J F; Wilson, J R; Winchester, T J; Wright, A; Yeh, M; Zhao, T; Zuber, K
2015-01-01
SNO+ is a large liquid scintillator-based experiment located 2km underground at SNOLAB, Sudbury, Canada. It reuses the Sudbury Neutrino Observatory detector, consisting of a 12m diameter acrylic vessel which will be filled with about 780 tonnes of ultra-pure liquid scintillator. Designed as a multi-purpose neutrino experiment, the primary goal of SNO+ is a search for the neutrinoless double-beta decay (0$\
Gravitational Lensing of the CMB: a Feynman Diagram Approach
Jenkins, A.E.; Manohar, A.V.; Waalewijn, W.J.; Yadav, A.P.S.
2014-01-01
We develop a Feynman diagram approach to calculating correlations of the Cosmic Microwave Background (CMB) in the presence of distortions. As one application, we focus on CMB distortions due to gravitational lensing by Large Scale Structure (LSS). We study the Hu-Okamoto quadratic estimator for extr
CMB anisotropies: Total angular momentum method
Hu, Wayne; White, Martin
1997-07-01
A total angular momentum representation simplifies the radiation transport problem for temperature and polarization anisotropy in the cosmic microwave background (CMB). Scattering terms couple only the quadrupole moments of the distributions and each moment corresponds directly to the observable angular pattern on the sky. We develop and employ these techniques to study the general properties of anisotropy generation from scalar, vector, and tensor perturbations to the metric and the matter, both in the cosmological fluids and from any seed perturbations (e.g., defects) that may be present. The simpler, more transparent form and derivation of the Boltzmann equations brings out the geometric and model-independent aspects of temperature and polarization anisotropy formation. Large angle scalar polarization provides a robust means to distinguish between isocurvature and adiabatic models for structure formation in principle. Vector modes have the unique property that the CMB polarization is dominated by magnetic-type parity at small angles (a factor of 6 in power compared with 0 for the scalars and 8/13 for the tensors) and hence potentially distinguishable independent of the model for the seed. The tensor modes produce a different sign from the scalars and vectors for the temperature-polarization correlations at large angles. We explore conditions under which one perturbation type may dominate over the others including a detailed treatment of the photon-baryon fluid before recombination.
Suppressing CMB low multipoles with ISW effect
Das, Santanu
2013-01-01
Recent results of Planck data reveal that the power in the low multipoles of the CMB angular power spectrum, approximately up to $l=30$, is significantly lower than the theoretically predicted in the best fit $\\Lambda$CDM model. In this paper we investigate the possibility of invoking the Integrated Sachs-Wolfe (ISW) effect to explain this power deficit at low multipoles. The ISW effect that originates from the late time expansion history of the universe is rich in possibilities given the limited understanding of the origin of dark energy (DE). It is a common understanding that the ISW effect adds to the power at the low multipoles of the CMB angular power spectrum. In this paper we carry out an analytic study to show that there are some expansion histories in which the ISW effect, instead of adding power, provides negative contribution to the power at low multipoles. Guided by the analytic study, we present examples of the features required in the late time expansion history of the universe that could explai...
Pre-Inflationary Relics in the CMB?
Gruppuso, A; Mandolesi, N; Natoli, P; Sagnotti, A
2015-01-01
String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an imprint in the CMB anisotropy, if it occurred at accessible wavelengths. We model the effect extending $\\Lambda$CDM with a scale $\\Delta$ related to the infrared depression and explore the constraints allowed by {\\sc Planck} data, employing also more conservative, wider Galactic masks in the low resolution CMB likelihood. In an extended mask with $f_{sky}=39\\%$, we thus find $\\Delta = (0.351 \\pm 0.114) \\times 10^{-3} \\, \\mbox{Mpc}^{-1}$, at $99.4\\%$ confidence level, to be compared with a nearby value at $88.5\\%$ with the standard $f_{sky}=94\\%$ mask. With about 64 $e$--folds of inflation, these values for $\\Delta$ would translate into primordial energy scales ${\\cal O}(10^{14})$ GeV.
Multiscale analysis of the CMB temperature derivatives
Marcos-Caballero, A.; Martínez-González, E.; Vielva, P.
2017-02-01
We study the Planck CMB temperature at different scales through its derivatives up to second order, which allows one to characterize the local shape and isotropy of the field. The problem of having an incomplete sky in the calculation and statistical characterization of the derivatives is addressed in the paper. The analysis confirms the existence of a low variance in the CMB at large scales, which is also noticeable in the derivatives. Moreover, deviations from the standard model in the gradient, curvature and the eccentricity tensor are studied in terms of extreme values on the data. As it is expected, the Cold Spot is detected as one of the most prominent peaks in terms of curvature, but additionally, when the information of the temperature and its Laplacian are combined, another feature with similar probability at the scale of 10o is also observed. However, the p-value of these two deviations increase above the 6% when they are referred to the variance calculated from the theoretical fiducial model, indicating that these deviations can be associated to the low variance anomaly. Finally, an estimator of the directional anisotropy for spinorial quantities is introduced, which is applied to the spinors derived from the field derivatives. An anisotropic direction whose probability is <1% is detected in the eccentricity tensor.
CMB component separation in the pixel domain
Doroshkevich, A.; Verkhodanov, O.
2011-02-01
We show that the popular internal linear combination approach is unstable with respect to division of the observed map pixels to a set of “homogeneous” subsamples. For various choices of such subsamples we can obtain a restored CMB signal with amplitudes ranging from zero to the amplitude of the observed signal. We propose an approach which allows us to obtain corrected estimates of the CMB power spectrum Cℓ at ℓ≤30 and provides results similar to WMAP for larger ℓ. Using this approach, we eliminate some anomalies of the WMAP results. In particular, our estimate of the quadrupole is consistent with the theoretically expected one. The effect of the “axis of evil” is suppressed, and the symmetry of the north and south galactic hemispheres increases. These results can change estimates of quadrupole polarization and the redshift of reionization of the Universe. We also propose a new simple approach which can improve the WMAP estimates of the high ℓ power spectrum.
Emulsion chamber experiments; critical comments and future prospects
Energy Technology Data Exchange (ETDEWEB)
Tamada, M. [School of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan)
2006-01-15
Emulsion chamber data give valuable information about particle production in the forward region of very high-energy nuclear interactions. Many characteristics of high-energy atmospheric families, observed by emulsion chambers, have not been fully described by simulations employing existing nuclear interaction models. Some of the events and the phenomena observed in emulsion chamber experiments have been considered to be unusual and new, never seen in lower energy accelerator experiments. We re-examine emulsion chamber data critically in order to get unbiased views of these unusual events and phenomena. It is shown that some of the previous interpretations need to be changed. We take up for the discussions scaling violation in C-jets, Centauro events, alignment of showers in high-energy families, hadrons of anomalous absorption in thick lead chambers. We will also discuss the results on the hybrid experiments of emulsion chamber and EAS-array.
Gravitational lensing of the CMB: A Feynman diagram approach
Energy Technology Data Exchange (ETDEWEB)
Jenkins, Elizabeth E.; Manohar, Aneesh V. [Department of Physics, University of California at San Diego, La Jolla, CA 92093 (United States); Waalewijn, Wouter J. [Nikhef, Theory Group, Science Park 105, 1098 XG, Amsterdam (Netherlands); ITFA, University of Amsterdam, Science Park 904, 1018 XE, Amsterdam (Netherlands); Yadav, Amit P.S., E-mail: ayadav@physics.ucsd.edu [Department of Physics, University of California at San Diego, La Jolla, CA 92093 (United States)
2014-09-07
We develop a Feynman diagram approach to calculating correlations of the Cosmic Microwave Background (CMB) in the presence of distortions. As one application, we focus on CMB distortions due to gravitational lensing by Large Scale Structure (LSS). We study the Hu–Okamoto quadratic estimator for extracting lensing from the CMB and derive the noise of the estimator up to O(ϕ{sup 4}) in the lensing potential ϕ. By identifying the diagrams responsible for the previously noted large O(ϕ{sup 4}) term, we conclude that the lensing expansion does not break down. The convergence can be significantly improved by a reorganization of the ϕ expansion. Our approach makes it simple to obtain expressions for quadratic estimators based on any CMB channel, including many previously unexplored cases. We briefly discuss other applications to cosmology of this diagrammatic approach, such as distortions of the CMB due to patchy reionization, or due to Faraday rotation from primordial axion fields/.
Gravitational lensing of the CMB: A Feynman diagram approach
Directory of Open Access Journals (Sweden)
Elizabeth E. Jenkins
2014-09-01
Full Text Available We develop a Feynman diagram approach to calculating correlations of the Cosmic Microwave Background (CMB in the presence of distortions. As one application, we focus on CMB distortions due to gravitational lensing by Large Scale Structure (LSS. We study the Hu–Okamoto quadratic estimator for extracting lensing from the CMB and derive the noise of the estimator up to O(ϕ4 in the lensing potential ϕ. By identifying the diagrams responsible for the previously noted large O(ϕ4 term, we conclude that the lensing expansion does not break down. The convergence can be significantly improved by a reorganization of the ϕ expansion. Our approach makes it simple to obtain expressions for quadratic estimators based on any CMB channel, including many previously unexplored cases. We briefly discuss other applications to cosmology of this diagrammatic approach, such as distortions of the CMB due to patchy reionization, or due to Faraday rotation from primordial axion fields.
CMB spectral distortions and energy release in the early universe
Tashiro, Hiroyuki
2014-06-01
Measuring the spectral deviation of the cosmic microwave background (CMB) from the blackbody spectrum has become a focus of attention as a probe of the thermal history of the Universe. It has been more than 20 years since COBE/FIRAS's measurement, which showed excellent agreement between the CMB spectrum and a perfect blackbody spectrum. Significant developments in the technology since then have allowed us to improve the sensitivity of the absolute spectrum measurement by a factor of {˜ }10^4. Therefore, the physics related to the generation of CMB spectral distortions should now be investigated in greater detail. To probe the physics in the early universe and to open an observational window for new physics, various energy release mechanisms both in and beyond standard cosmology need to be studied. In this paper, we provide a review of the physics of CMB distortions and the energy release that creates CMB distortions in the early universe.
Present Status and Future Perspectives of the NEXT Experiment
Directory of Open Access Journals (Sweden)
J. J. Gómez Cadenas
2014-01-01
Full Text Available NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector is a TPC, holding 100 kg of high-pressure xenon enriched in the 136Xe isotope. It is under construction in the Laboratorio Subterráneo de Canfranc in Spain, and it will begin operations in 2015. The NEXT detector concept provides an energy resolutionbetter than 1% FWHM and a topological signal that can be used to reduce the background. Furthermore, the NEXT technology can be extrapolated to a 1 ton-scale experiment.
Present status and future perspectives of the NEXT experiment
,
2013-01-01
NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector is a TPC, holding 100 kg of high-pressure xenon enriched in the $^{136}$Xe isotope. It is under construction in the Laboratorio Subterr\\'aneo de Canfranc in Spain, and it will begin operations in 2015. The NEXT detector concept provides an energy resolution better than 1% FWHM and a topological signal that can be used to reduce the background. Furthermore, the NEXT technology can be extrapolated to a 1-ton scale experiment.
Neutrinoless Double Beta Decay and Future Neutrino Oscillation Precision Experiments
Choubey, S
2005-01-01
We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the Delta m^2 corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter theta_{12} will govern large part of the uncertainty. We focus in particular on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses which allow to distinguish the normal from the inverted hierarchy. All aspects are discussed as a function of the uncertainty stemming from the involved nuclear matrix elements. The implications of a vanishing, or extremely small, effective mass are also investigated. By giving a large list of possible neutrino mass matrices and their predictions for the observables, we finally explore how a measurement of (or an improve...
Accelerator Challenges and Opportunities for Future Neutrino Experiments
Energy Technology Data Exchange (ETDEWEB)
Zisman, Michael S
2010-12-24
There are three types of future neutrino facilities currently under study, one based on decays of stored beta-unstable ion beams (?Beta Beams?), one based on decays of stored muon beams (?Neutrino Factory?), and one based on the decays of an intense pion beam (?Superbeam?). In this paper we discuss the challenges each design team must face and the R&D being carried out to turn those challenges into technical opportunities. A new program, the Muon Accelerator Program, has begun in the U.S. to carry out the R&D for muon-based facilities, including both the Neutrino Factory and, as its ultimate goal, a Muon Collider. The goals of this program will be briefly described.
Forming of Future Teachers’ ICT-Competence: Canadian Experience
Directory of Open Access Journals (Sweden)
Demchenko Iryna
2016-03-01
Full Text Available The article deals with the phenomenon of digital divide in the education in Canada. The domestic and foreign scientific and educational publications have been studied and analyzed. It has been found out that traditional means for training pedagogical specialists are gradually losing their relevance due to lack of educational dialogue between a teacher and a student. Information and communication technologies have entered today’s youth everyday life and become an essential means of communication, receiving and transmitting information. Based on the source study, the essence and reasons of digital divide have been revealed. Canadian researchers consider that it is possible to overcome this problem by revising the approach to teacher training which will focus on the forming of future teachers’ information and communication competence. Various definitions of the terms “information competence”, “ICT competence”, “digital literacy”, “e-literacy” have been described. The model of ICT competence, its structure and the process of its integration into education have been analyzed. The examples of forming future teachers’ ICT competence in universities of Canada have been given. It has been revealed that the problem of effective ICT implementation into educational activities is in the range of many Canadian studies, but in fact the phenomenon of digital divide in education is still topical due to insufficient activity of teachers of pedagogical faculties and students’ ignoring the problem. A number of studies have been examined, the authors of which give practical recommendations aimed at enhancing the role of new technologies in teacher training in Canada.
Designing a future Conditions Database based on LHC experience
Formica, Andrea; The ATLAS collaboration; Gallas, Elizabeth; Govi, Giacomo; Lehmann Miotto, Giovanna; Pfeiffer, Andreas
2015-01-01
The ATLAS and CMS Conditions Database infrastructures have served each of the respective experiments well through LHC Run 1, providing efficient access to a wide variety of conditions information needed in online data taking and offline processing and analysis. During the long shutdown between Run 1 and Run 2, we have taken various measures to improve our systems for Run 2. In some cases, a drastic change was not possible because of the relatively short time scale to prepare for Run 2. In this process, and in the process of comparing to the systems used by other experiments, we realized that for Run 3, we should consider more fundamental changes and possibilities. We seek changes which would streamline conditions data management, improve monitoring tools, better integrate the use of metadata, incorporate analytics to better understand conditions usage, as well as investigate fundamental changes in the storage technology, which might be more efficient while minimizing maintenance of the data as well as simplif...
Constraining decaying dark energy density models with the CMB temperature-redshift relation
Jetzer, Philippe
2012-01-01
We discuss the thermodynamic and dynamical properties of a variable dark energy model with density scaling as $\\rho_x \\propto (1+z)^{m}$, z being the redshift. These models lead to the creation/disruption of matter and radiation, which affect the cosmic evolution of both matter and radiation components in the Universe. In particular, we have studied the temperature-redshift relation of radiation, which has been constrained using a recent collection of cosmic microwave background (CMB) temperature measurements up to $z \\sim 3$. We find that, within the uncertainties, the model is indistinguishable from a cosmological constant which does not exchange any particles with other components. Future observations, in particular measurements of CMB temperature at large redshift, will allow to give firmer bounds on the effective equation of state parameter $w_{eff}$ for such types of dark energy models.
Limits on decaying dark energy density models from the CMB temperature-redshift relation
Jetzer, Philippe; Tortora, Crescenzo
2012-03-01
We discuss the thermodynamic and dynamical properties of a variable dark energy model with density scaling as ρx propto (1 + z)m, z being the redshift. These models lead to the creation/disruption of matter and radiation, which affect the cosmic evolution of both matter and radiation components in the Universe. In particular, we have studied the temperature-redshift relation of radiation, which has been constrained using a recent collection of cosmic microwave background (CMB) temperature measurements up to z ~ 3. We find that, within the uncertainties, the model is indistinguishable from a cosmological constant which does not exchange any particles with other components. Future observations, in particular measurements of CMB temperature at large redshift, will allow to give firmer bounds on the effective equation of state parameter weff for such types of dark energy models.
A large-aperture telescope to map the CMB 10X faster
Niemack, Michael D
2015-01-01
Current large-aperture cosmic microwave background (CMB) telescopes have nearly maximized the number of detectors that can be illuminated while maintaining diffraction-limited image quality. The polarization-sensitive detector arrays being deployed in these telescopes in the next few years will have roughly $10^4$ detectors. Increasing the mapping speed of future instruments by at least an order of magnitude is important to enable precise probes of the inflationary paradigm in the first fraction of a second after the big bang and provide strong constraints on cosmological parameters. This paper introduces new crossed Dragone telescope and receiver optics designs that increase the usable diffraction-limited field-of-view, and therefore the mapping speed, by over an order of magnitude to enable high efficiency illumination of $>10^5$ detectors in a next generation CMB telescope.
Searching for a holographic connection between dark energy and the low-l CMB multipoles
Enqvist, K; Sloth, M S; Enqvist, Kari; Hannestad, Steen; Sloth, Martin S.
2005-01-01
We consider the angular power spectrum in a finite universe with different boundary conditions and perform a fit to the CMB, LSS and supernova data. A finite universe could be the consequence of a holographic constraint, giving rise to an effective IR cutoff at the future event horizon. In such a model there is a cosmic duality relating the dark energy equation of state and the power spectrum, which shows a suppression and oscillatory behaviour that is found to describe the low l features extremely well. However, much of the discussion here will also apply if we actually live inside an expanding bubble that describes our universe. The best fit to the CMB and LSS data turns out to be better than in the standard Lambda-CDM model, but when combined with the supernova data, the holographic model becomes disfavored. We speculate on the possible implications.
Precipitation manipulation experiments – challenges and recommendations for the future
DEFF Research Database (Denmark)
Beier, Claus; Beierkuhnlein, Carl; Wohlgemuth, Thomas
2012-01-01
of these experiments indicates that they have provided important information on how water regulates ecosystem processes. However, they do not adequately represent global biomes nor forecasted precipitation scenarios and their potential contribution to advance our understanding of ecosystem responses to precipitation...... frequency and amplitude, seasonality, extremity and interactions with other global change drivers. A systematic and holistic approach to investigate how soil and plant community characteristics change with altered precipitation regimes and the consequent effects on ecosystem processes and functioning within...
Renovation of HEPnet-J for near-future experiments
Suzuki, Soh Y.; Yuasa, Fukuko; Nakamura, Tomoaki; Hara, Takanori
2015-12-01
Originally HEPnet-J had only one instance that is connected to Internet as the network connectivity by campus network of institutes in Japan was very limited, so the main purpose of HEPnet-J was providing enough connectivity for interactive use on domestic and international links funded by KEK. In last 10 years, the domestic and international connectivity provided by NRENs have been dramatically improved and they are enough for manual transfer of typical skimmed data files. Therefore, HEPnet-J has many closed networks that connect domestic sites related to specific projects, in order to access them on computer farms in private networks in their home institutes. The rapid growth of data volume makes it unable to apply same model to new generation experiments. As the tier structure for LHC computing sites has proved that the distributed computing model over collaboration sites is really applicable to the huge scale experiment, the external connectivity for international collaboration sites should be faster and secure. For example, the Belle II experiment in KEK will have many repositories in U.S. and EU. The expected throughput from KEK to U.S. is about 20 Gbps, thus it need the bypass of slow security devices like a firewall. Now bypass lines for Belle II are prepared and under tasting. This article reports the brief history of HEPnet- J and recent changes for project-specific networks.
Gaudi components for concurrency: Concurrency for existing and future experiments
Clemencic, M.; Funke, D.; Hegner, B.; Mato, P.; Piparo, D.; Shapoval, I.
2015-05-01
HEP experiments produce enormous data sets at an ever-growing rate. To cope with the challenge posed by these data sets, experiments’ software needs to embrace all capabilities modern CPUs offer. With decreasing memory/core ratio, the one-process-per-core approach of recent years becomes less feasible. Instead, multi-threading with fine-grained parallelism needs to be exploited to benefit from memory sharing among threads. Gaudi is an experiment-independent data processing framework, used for instance by the ATLAS and LHCbexperiments at CERN's Large Hadron Collider. It has originally been designed with only sequential processing in mind. In a recent effort, the frame work has been extended to allow for multi-threaded processing. This includes components for concurrent scheduling of several algorithms - either processingthe same or multiple events, thread-safe data store access and resource management. In the sequential case, the relationships between algorithms are encoded implicitly in their pre-determined execution order. For parallel processing, these relationships need to be expressed explicitly, in order for the scheduler to be able to exploit maximum parallelism while respecting dependencies between algorithms. Therefore, means to express and automatically track these dependencies need to be provided by the framework. In this paper, we present components introduced to express and track dependencies of algorithms to deduce a precedence-constrained directed acyclic graph, which serves as basis for our algorithmically sophisticated scheduling approach for tasks with dynamic priorities. We introduce an incremental migration path for existing experiments towards parallel processing and highlight the benefits of explicit dependencies even in the sequential case, such as sanity checks and sequence optimization by graph analysis.
The CMS Data Quality Monitoring software experience and future improvements
De Guio, Federico
2013-01-01
The Data Quality Monitoring (DQM) Software proved to be a central tool in the CMS experiment. Its flexibility allowed its integration in several environments Online, for real-time detector monitoring; Offline, for the final, fine-grained Data Certification; Release Validation, to constantly validate the functionality and the performance of the reconstruction software; in Monte Carlo productions. The central tool to deliver Data Quality information is a web site for browsing data quality histograms (DQM GUI). In this contribution the usage of the DQM Software in the different environments and its integration in the CMS Reconstruction Software Framework and in all production workflows are presented.
Experiences and Future Challenges of Bioleaching Research in South Korea
Directory of Open Access Journals (Sweden)
Danilo Borja
2016-12-01
Full Text Available This article addresses the state of the art of bioleaching research published in South Korean Journals. Our research team reviewed the available articles registered in the Korean Citation Index (KCI, Korean Journal Database addressing the relevant aspects of bioleaching. We systematically categorized the target metal sources as follows: mine tailings, electronic waste, mineral ores and metal concentrates, spent catalysts, contaminated soil, and other materials. Molecular studies were also addressed in this review. The classification provided in the present manuscript details information about microbial species, parameters of operation (e.g., temperature, particle size, pH, and process length, and target metals to compare recoveries among the bioleaching processes. The findings show an increasing interest in the technology from research institutes and mineral processing-related companies over the last decade. The current research trends demonstrate that investigations are mainly focused on determining the optimum parameters of operations for different techniques and minor applications at the industrial scale, which opens the opportunity for greater technological developments. An overview of bioleaching of each metal substrate and opportunities for future research development are also included.
Influence of student experiences in developing skills as future teachers
Directory of Open Access Journals (Sweden)
David Hortigüela Alcalá
2015-04-01
Full Text Available This study, conducted in four subjects in the Faculty of Education at the University of Burgos during the year 2013-2014, analyzes the student’s perceptions about the transfer of learning obtained in the future vocational skills, in this this case teaching. A pretest-posttest is done, checking how their perception towards learning transfer changes once they have completed the courses. Mixed methodology study is used, performing a both descriptive (mean and standard deviation factors and inferential (ANOVA and one qualitative, in which some interviews with teachers are use once they have completed the courses. Two groups are generated; A where they have been used as a tool peer-assessment and self-assessments and monitoring of learning, and B, in which there has been not formative evaluation process. In this case the teacher has been the only one who has participated in the evaluation and qualification. In group A has been a significant increase in factor related to the transfer of teaching skills. This change occurs in pretest and in group B. It was concluded that the inclusion of open and participatory methodologies in the classroom, that enable the learner part of their own learning process, produces a more positive impact on students’ perceptions of their learning transfer.
GMOs: building the future on the basis of past experience.
Reis, Luiz F L; Van Sluys, Marie-Anne; Garratt, Richard C; Pereira, Humberto M; Teixeira, Mauro M
2006-12-01
Biosafety of genetically modified organisms (GMOs) and their derivatives is still a major topic in the agenda of government and societies worldwide. The aim of this review is to bring into light that data that supported the decision taken back in 1998 as an exercise to stimulate criticism from the scientific community for upcoming discussions and to avoid emotional and senseless arguments that could jeopardize future development in the field. It must be emphasized that Roundup Ready soybean is just one example of how biotechnology can bring in significant advances for society, not only through increased productivity, but also with beneficial environmental impact, thereby allowing more rational use of agricultural pesticides for improvement of the soil conditions. The adoption of agricultural practices with higher yield will also allow better distribution of income among small farmers. New species of genetically modified plants will soon be available and society should be capable of making decisions in an objective and well-informed manner, through collegiate bodies that are qualified in all aspects of biosafety and environmental impact.
Solar sorptive cooling. Technologies, user requirements, practical experience, future prospects
Energy Technology Data Exchange (ETDEWEB)
Treffinger, P. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Hardthausen (Germany); Hertlein, H.P. [eds.] [Forschungsverbund Sonnenenergie, Koeln (Germany)
1998-09-01
Sorptive cooling techniques permit the use of low-temperature solar heat, i.e. a renewable energy of low cost and world-wide availability. The Forschungsverbund Sonnenenergie intends to develop solar sorptive cooling technologies to the prototype stage and, in cooperation with the solar industry and its end users, to promote practical application in air conditioning of buildings and cold storage of food. The workshop presents an outline of the state of development of solar sorptive cooling from the view of users and developers. Exemplary solar cooling systems are described, and the potential of open and closed sorptive processes is assessed. Future central activities will be defined in an intensive discussion between planners, producers, users and developers. [German] Der Einsatz von Sorptionstechniken zur Kaelteerzeugung erlaubt es, als treibende Solarenergie Niedertemperatur-Solarwaerme einzusetzen, also eine regenerative Energie mit sehr geringen Kosten und weltweiter Verfuegbarkeit. Der Forschungsverbund Sonnenenergie hat sich als Aufgabe gestellt, die Techniken der solaren Sorptionskuehlung bis zum Prototyp zu entwickeln und mit Industrie und Nutzern die praktische Anwendung voranzubringen. Die Anwendungsfelder sind die Klimatisierung von Gebaeuden und die Kaltlagerung von Lebensmitteln. Der Workshop gibt einen Ueberblick zum Entwicklungsstand der solaren Sorptionskuehlung aus der Sicht der Anwender und Entwickler. Bereits ausgefuehrte Beispiele zur solaren Kuehlung werden vorgestellt und das Potential geschlossener und offener Sorptionsverfahren angegeben. In intensiver Diskussion zwischen Planern, Herstellern, Nutzern und Entwicklern sollen kuenftige Arbeitsschwerpunkte herausgearbeitet werden. (orig.)
GMO quantification: valuable experience and insights for the future.
Milavec, Mojca; Dobnik, David; Yang, Litao; Zhang, Dabing; Gruden, Kristina; Zel, Jana
2014-10-01
Cultivation and marketing of genetically modified organisms (GMOs) have been unevenly adopted worldwide. To facilitate international trade and to provide information to consumers, labelling requirements have been set up in many countries. Quantitative real-time polymerase chain reaction (qPCR) is currently the method of choice for detection, identification and quantification of GMOs. This has been critically assessed and the requirements for the method performance have been set. Nevertheless, there are challenges that should still be highlighted, such as measuring the quantity and quality of DNA, and determining the qPCR efficiency, possible sequence mismatches, characteristics of taxon-specific genes and appropriate units of measurement, as these remain potential sources of measurement uncertainty. To overcome these problems and to cope with the continuous increase in the number and variety of GMOs, new approaches are needed. Statistical strategies of quantification have already been proposed and expanded with the development of digital PCR. The first attempts have been made to use new generation sequencing also for quantitative purposes, although accurate quantification of the contents of GMOs using this technology is still a challenge for the future, and especially for mixed samples. New approaches are needed also for the quantification of stacks, and for potential quantification of organisms produced by new plant breeding techniques.
Model independent approaches to reionization in the analysis of upcoming CMB data
Colombo, Loris P. L.; Pierpaoli, Elena
2008-01-01
On large angular scales, CMB polarization depends mostly on the evolution of the ionization level of the IGM during reionization. In order to avoid biasing parameter estimates, an accurate and model independent approach to reionization is needed when analyzing high precision data, like those expected from the Planck experiment. In this paper we consider two recently proposed methods of fitting for reionization and we discuss their respective advantages. We test both methods by performing a Mo...
The Development of silicon detectors for the CMS experiment and future experiments
Son, Seunghee
A hybrid pixel detector will be installed as the inner most layer of the tracking system of the CMS experiment, currently under construction at the Large Hardron Collider (LHC) at CERN (Geneva, Switzerland) to provide high resolution tracking and vertex identification. Due to the severe radiation environment of the LHC, the performance of the sensors must be carefully evaluated up to a fluence of 6 × 1014 1-MeV equivalent neutrons per square centimeter. The sensors were fabricated "n on n", which means highly segmented n+ implants with 150 × 100 μm2 pitch are in n-type bulk material and p+ implants are used to isolate pixels. The electrical properties of these sensors has been studied. Studies of charge collection efficiency were carried out with a 1064 nm wavelength laser. Comparisons of charge collection efficiency among different sensor designs is presented. In addition, present and future possibilities for the production of thin silicon detectors are discussed. The electrical characteristics and the pe...
Automated management of life cycle for future network experiment based on description language
Niu, Hongxia; Liang, Junxue; Lin, Zhaowen; Ma, Yan
2016-12-01
Future network is a complex resources pool including multiple physical resources and virtual resources. Establishing experiment on future network is complicate and tedious. That achieving the automated management of future network experiments is so important. This paper brings forward the way for researching and managing the life cycle of experiment based on the description language. The description language uses the framework, which couples with a low hierarchical structure and a complete description of the network experiment. In this way, the experiment description template can be generated by this description framework accurately and completely. In reality, we can also customize and reuse network experiment by modifying the description template. The results show that this method can achieve the aim for managing the life cycle of network experiment effectively and automatically, which greatly saves time, reduces the difficulty, and implements the reusability of services.
Yasini, Siavash
2016-01-01
We present a method aimed at separating the motion-induced dipole of the cosmic microwave background (CMB) from the intrinsic, primordial dipole component. We show that in a moving frame, the leakage of an intrinsic dipole moment into the CMB monopole and quadrupole induces spectral distortions with distinct frequency functions that respectively peak at 266 GHz and 310 GHz at $\\sim 10$nK level. The leakage into the quadrupole moment also induces a geometrical distortion to the spatial morphology of this mode. The combination of these effects can be used to lift the degeneracy between the motion-induced dipole and any intrinsic dipole that the CMB might possess. The leakage of an intrinsic dipole of order $\\sim 10^{-5}$ into the monopole and quadrupole moments will be detectable by a PIXIE--like experiment at $\\sim 6\\sigma$ at the peak frequency.
Exploring Astrobiology: Future and In-Service Teacher Research Experiences
Cola, J.; Williams, L. D.; Snell, T.; Gaucher, E.; Harris, B.; Usselman, M. C.; Millman, R. S.
2009-12-01
The Georgia Tech Center for Ribosome Adaptation and Evolution, a center funded by the NASA Astrobiology Institute, developed an educational Astrobiology program titled, “Life on the Edge: Astrobiology.” The purpose of the program was to provide educators with the materials, exposure, and skills necessary to prepare our future workforce and to foster student interest in scientific discovery on Earth and throughout the universe. A one-week, non-residential summer enrichment program for high school students was conducted and tested by two high school educators, an undergraduate student, and faculty in the Schools of Biology, and Chemistry and Biochemistry at Georgia Tech. In an effort to promote and encourage entry into teaching careers, Georgia Tech paired in-service teachers in the Georgia Intern-Fellowship for Teachers (GIFT) program with an undergraduate student interested in becoming a teacher through the Tech to Teaching program. The GIFT and Tech to Teaching fellows investigated extremophiles which have adapted to life under extreme environmental conditions. As a result, extremophiles became the focus of a week-long, “Life on the Edge: Astrobiology” curriculum aligned with the Georgia Performance Standards in Biology. Twenty-five high school students explored the adaptation and survival rates for various types of extremophiles exposed to UV radiation and desiccation; students were also introduced to hands-on activities and techniques such as genomic DNA purification, gel electrophoresis, and Polymerase Chain Reaction (PCR). The impact on everyone invested and involved in the Astrobiology program including the GIFT and Tech to Teaching fellows, high school students, and faculty are discussed.
Chinese rural reform:experience,problems and the future
Institute of Scientific and Technical Information of China (English)
韩俊
2009-01-01
Chinese rural reform has made great achievements and accumulated a wealth of experience since the beginning of reform and opening up 30 years ago.At the core is the rapid and sustained development of the national economy.Currently,there are obstacles in rural reform;for example,the supply and demand of primary products are frequently out of balance,shortages of rural labor occur thanks to structural problems on the supply side,and the equality system between rural and urban citizens has yet to be established.Therefore,to make important breakthroughs,we must change our ideas of controlling the food market;we must improve rural land policy, loosen rural financial supervision,adjust the fiscal expense structure,protect farmers’ legal rights and interests,accelerate the building-up of democracy at the grassroots level,and intensify overall planning and coordination.
Professional Learning between Past Experience and Future Work
DEFF Research Database (Denmark)
Weber, Kirsten
2010-01-01
This paper is about learning, qualification and possible professionalization in human service work. With human services we primarily refer to work related to health care, child care, social work, and education. I present empirical findings from different phases of training and workplace experience...... of Danish child care pedagogues. The investigation is part of a human resource centered research program studying the development of welfare institutions and systems in Denmark. Welfare institutions have been developing since World War II as an important aspect of and precondition for the socio......-economic development of Denmark from a predominantly rural, agricultural society to an entirely urban industrial and service producing society. This development has required a substantial new labor force in the first place. It has drawn on “spontaneous” qualifications, primarily by recruitment of female workers...
The ATLAS Trigger: Recent Experience and Future Plans
The ATLAS collaboration
2009-01-01
This paper will give an overview of the ATLAS trigger design and its innovative features. It will describe the valuable experience gained in running the trigger reconstruction and event selection in the fastchanging environment of the detector commissioning during 2008. It will also include a description of the trigger selection menu and its 2009 deployment plan from first collisions to the nominal luminosity. ATLAS is one of the two general-purpose detectors at the Large Hadron Collider (LHC). The trigger system needs to efficiently reject a large rate of background events and still select potentially interesting ones with high efficiency. After a first level trigger implemented in custom electronics, the trigger event selection is made by the High Level Trigger (HLT) system, implemented in software. To reduce the processing time to manageable levels, the HLT uses seeded, step-wise and fast selection algorithms, aiming at the earliest possible rejection of background events. The ATLAS trigger event selection...
The ATLAS Trigger System: Recent Experience and Future Plans
Farrington, S M
2009-01-01
Proceedings for EPS09. The ATLAS detector at the LHC will experience unprecedented rates of hadron hadron collisions. The trigger system needs to efficiently reject a large rate of background events and still select potentially interesting events with high efficiency. After a first level trigger implemented in custom electronics, the trigger event selection is made by the High Level Trigger (HLT) system, implemented in software. To reduce the processing time to manageable levels, the HLT uses seeded, step-wise and fast selection algorithms, aiming at the earliest possible rejection of background events. The ATLAS trigger event selection is based on the reconstruction of potentially interesting physical objects like electrons, muons, jets, etc. The recent LHC startup and short single-beam run provided the first test of the trigger system against real data. Following this period, ATLAS continued to collect cosmic-ray events for detector alignment and calibration purposes. Both running periods provided very impo...
RICH Particle Identification at the Present and Future LHCb Experiment
Kim, Graham Young-Min
2011-01-01
LHCb is a high-precision experiment for the study of CP violation and rare decays in B physics. It has two Ring Imaging Cherenkov (RICH) counters for particle identification. The RICH system uses Hybrid Photon Detectors (HPD) for single photon detection. This thesis describes tests performed on individual HPDs for quantum efficiency and vacuum quality. It then presents work done monitoring HPD vacuum quality through regular ion feedback measurements after they were mounted into the RICH. Also discussed is HPD vacuum degradation and how replacement and repair of deteriorated HPDs was implemented using data from the vacuum monitoring. Preparations for an upgrade to LHCb have started. The upgrade will extend the discovery potential of the LHCb by increasing the rate of data collection. This thesis presents particle identification and flavour tagging studies using upgrade simulations. Flavour tagging using kaons was then reoptimised for upgrade conditions and this work is described with discussions of the results...
A Future Polarized Drell-Yan Experiment at Fermilab
Energy Technology Data Exchange (ETDEWEB)
Kleinjan, David William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-06-04
The topic is treated in a series of slides under the following headings: Motivation (Nucleon Spin Puzzle, Quark Orbital Momentum and the Sivers Function, Accessing Sivers via Polarized Drell-Yan (p+p↑ → μ^{+}μ^{-})); Transition of Seaquest (E906 → E1039) (Building a Polarized proton Target, Status of Polarized Target); and Outlook. The nucleon spin puzzle: when the quark and gluon contributions to the proton spin are evaluated, nearly 50% of the measured spin is missing; lattice QCD calculations indicate as much as 50% may come from quark orbital angular momentum. Sea quarks should carry orbital angular momentum (O.A.M.). The E1039 Polarized Target Drell-Yan Experiment provides opportunity to study possible Sea Quark O.A.M. Data taking is expected to begin in the spring of 2017.
Observed parity-odd CMB temperature bispectrum
Shiraishi, Maresuke; Fergusson, James R
2015-01-01
Parity-odd non-Gaussianities create a variety of temperature bispectra in the cosmic microwave background (CMB), defined in the domain: $\\ell_1 + \\ell_2 + \\ell_3 = {\\rm odd}$. These models are yet unconstrained in the literature, that so far focused exclusively on the more common parity-even scenarios. In this work, we provide the first experimental constraints on parity-odd bispectrum signals in WMAP 9-year temperature data, using a separable modal parity-odd estimator. Comparing theoretical bispectrum templates to the observed bispectrum, we place constraints on the so-called nonlineality parameters of parity-odd tensor non-Gaussianities predicted by several Early Universe models. Our technique also generates a model-independent, smoothed reconstruction of the bispectrum of the data for parity-odd configurations.
Searching for Long Strings in CMB Maps
Perivolaropoulos, L
1998-01-01
Using analytical methods and Monte Carlo simulations, we analyze new statistics designed to detect isolated step-like discontinuities which are coherent over large areas of Cosmic Microwave Background (CMB) pixel maps. Such coherent temperature discontinuities are predicted by the Kaiser-Stebbins effect to form due to long cosmic strings present in our present horizon. The background of the coherent step-like seed is assumed to be a scale invariant Gaussian random field which could have been produced by a superposition of seeds on smaller scales and/or by inflationary quantum fluctuations. We find that the proposed statistics can detect the presense of a coherent discontinuity at a sensitivity level almost an order of magnitude better compared to more conventional statistics like the skewness or the kurtosis.
Distinguishing between inflationary models from CMB
Tsujikawa, Shinji
2014-01-01
The inflationary cosmology is reviewed paying particular attention to its observational signatures associated with large-scale density perturbations generated from quantum fluctuations. In the most general scalar-tensor theories with second-order equations of motion, we derive the scalar spectral index $n_s$, the tensor-to-scalar ratio $r$, and the nonlinear estimator $f_{NL}$ of primordial non-Gaussianities to confront models with the observations of Cosmic Microwave Background (CMB) temperature anisotropies. Our analysis includes the models such as potential-driven slow-roll inflation, k-inflation, Starobinsky inflation, and Higgs inflation with non-minimal/derivative/Galileon couplings. We discriminate between a host of inflationary models by using the Planck data combined with other measurements to find models most favored observationally in the current literature. We also study anisotropic inflation based on a scalar coupling with a vector (or, two-form) field and we discuss its observational signatures ...
CMB component separation in the pixel domain
Doroshkevich, A
2010-01-01
We show that the popular ILC approach is unstable in respect to the division of the sample of map pixels to the set of ``homogeneous'' subsamples. For suitable choice of such subsamples we can obtain the restored CMB signal with amplitudes ranged from zero to the amplitudes of the observed signal. We propose approach which allows us to obtain reasonable estimates of $C_\\ell$ at $\\ell\\leq 30$ and similar to WMAP $C_\\ell$ for larger $\\ell$. With this approach we reduce some anomalies of the WMAP results. In particular, our estimate of the quadrupole is well consistent to theoretical one, the effect of the ``axis of evil'' is suppressed and the symmetry of the north and south galactic hemispheres increases. This results can change estimates of quadrupole polarization and the redshift of reionization of the Universe. We propose also new simple approach which can improve WMAP estimates of high $\\ell$ power spectrum.
The Angular Trispectrum of the CMB
Hu, W
2001-01-01
We study the general properties of the CMB temperature four-point function, specifically its harmonic analogue the angular trispectrum, and illustrate its utility in finding optimal quadratic statistics through the weak gravitational lensing effect. We determine the general form of the trispectrum, under the assumptions of rotational, permutation, and parity invariance, its estimators on the sky, and their Gaussian noise properties. The signal-to-noise in the trispectrum can be highly configuration dependent and any quadratic statistic used to compress the information to a manageable two-point level must be carefully chosen. Through a systematic study, we determine that for the case of lensing a specific statistic, the divergence of a filtered temperature-weighted temperature-gradient map, contains the maximal signal-to-noise and reduces the variance of estimates of the large-scale convergence power spectrum by over an order of magnitude over previous gradient-gradient techniques. The total signal-to-noise fo...
Spherical Needlets for CMB Data Analysis
Marinucci, D; Balbi, A; Baldi, P; Cabella, P; Kerkyacharian, G; Natoli, P; Picard, D; Vittorio, N
2007-01-01
We discuss Spherical Needlets and their properties. Needlets are a form of spherical wavelets which do not rely on any kind of tangent plane approximation and enjoy good localization properties in both pixel and harmonic space; moreover needlets coefficients are asymptotically uncorrelated at any fixed angular distance, which makes their use in statistical procedures very promising. In view of these properties, we believe needlets may turn out to be especially useful in the analysis of Cosmic Microwave Background (CMB) data on the incomplete sky, as well as of other cosmological observations. As a final advantage, we stress that the implementation of needlets is computationally very convenient and may rely completely on standard data analysis packages such as HEALPix.
CMB Anisotropies from a Gradient Mode
Mirbabayi, Mehrdad
2014-01-01
A pure gradient mode must have no observable dynamical effect at linear level. We confirm this by showing that its contribution to the dipolar power asymmetry of CMB anisotropies vanishes, if Maldacena's consistency condition is satisfied. To this end, the existing second order Sachs-Wolfe formula in the squeezed limit is extended to include a gradient in the long mode and to account for the change in the location of the last scattering surface induced by this mode. At second order, a gradient mode generated in Single-field inflation is shown to induce a quadrupole moment. For instance in a matter-dominated model it is equal to 5/18 times the square of the linear gradient part. This quadrupole can be cancelled by superposing a quadratic perturbation. The result is shown to be a non-linear extension of Weinberg's adiabatic modes: a long-wavelength physical mode which looks locally like a coordinate transformation.
GMOs: building the future on the basis of past experience
Directory of Open Access Journals (Sweden)
Luiz F.L. Reis
2006-12-01
Full Text Available Biosafety of genetically modified organisms (GMOs and their derivatives is still a major topic in the agenda of government and societies worldwide. The aim of this review is to bring into light that data that supported the decision taken back in 1998 as an exercise to stimulate criticism from the scientific community for upcoming discussions and to avoid emotional and senseless arguments that could jeopardize future development in the field. It must be emphasized that Roundup Ready® soybean is just one example of how biotechnology can bring in significant advances for society, not only through increased productivity, but also with beneficial environmental impact, thereby allowing more rational use of agricultural pesticides for improvement of the soil conditions. The adoption of agricultural practices with higher yield will also allow better distribution of income among small farmers. New species of genetically modified plants will soon be available and society should be capable of making decisions in an objective and well-informed manner, through collegiate bodies that are qualified in all aspects of biosafety and environmental impact.A biosegurança dos organismos geneticamente modificados e seus derivados é um dos principais tópicos na agenda de discussões de governos e sociedades. O objetivo desta revisão é reviver os dados científicos que fundamentaram a decisão de liberação comercial da soja transgênica resistente ao Glifosate com o intuito de estimular uma posição crítica da comunidade científica para as próximas discussões no tema. A soja em questão é apenas um exemplo de como a biotecnologia pode contribuir para avanços na produtividade e na preservação do meio ambiente, com ganho de produtividade e lucratividade para agricultores em todas as escalas. Novas variedades trangênicas estarão na pauta de discussões que deverão estar fundamentadas em dados científicos objetivos, evitando argumentos emocionais que
3-flavor oscillations with current and future reactor experiments
Dwyer, Dan
2017-01-01
Nuclear reactors have been a crucial tool for our understanding of neutrinos. The disappearance of electron antineutrinos emitted by nuclear reactors has firmly established that neutrino flavor oscillates, and that neutrinos consequently have mass. The current generation of precision measurements rely on some of the world's most intense reactor facilities to demonstrate that the electron antineutrino mixes with the third antineutrino mass eigenstate (v3-). Accurate measurements of antineutrino energies robustly determine the tiny difference between the masses-squared of the v3- state and the two more closely-spaced v1- and v2- states. These results have given us a much clearer picture of neutrino mass and mixing, yet at the same time open major questions about how to account for these small but non-zero masses in or beyond the Standard Model. These observations have also opened the door for a new generation of experiments which aim to measure the ordering of neutrino masses and search for potential violation of CP symmetry by neutrinos. I will provide a brief overview of this exciting field. Work supported under DOE OHEP DE-AC02-05CH11231.
``Recent experiences and future expectations in data storage technology''
Pfister, Jack
1990-08-01
For more than 10 years the conventional media for High Energy Physics has been 9 track magnetic tape in various densities. More recently, especially in Europe, the IBM 3480 technology has been adopted while in the United States, especially at Fermilab, 8 mm is being used by the largest experiments as a primary recording media and where possible they are using 8 mm for the production, analysis and distribution of data summary tapes. VHS and Digital Audio tape have recurrently appeared but seem to serve primarily as a back-up storage media. The reasons for what appear to be a radical departure are many. Economics (media and controllers are inexpensive), form factor (two gigabytes per shirt pocket), and convenience (fewer mounts/dismounts per minute) are dominant among the reasons. The traditional data media suppliers seem to have been content to evolve the traditional media at their own pace with only modest enhancements primarily in ``value engineering'' of extant products. Meanwhile, start-up companies providing small system and workstations sought other media both to reduce the price of their offerings and respond to the real need of lower cost back-up for lower cost systems. This happening in a market context where traditional computer systems vendors were leaving the tape market altogether or shifting to ``3480'' technology which has certainly created a climate for reconsideration and change. The newest data storage products, in most cases, are not coming from the technologies developed by the computing industry but by the audio and video industry. Just where these flopticals, opticals, 19 mm tape and the new underlying technologies, such as, ``digital paper'' may fit in the HEP computing requirement picture will be reviewed. What these technologies do for and to HEP will be discussed along with some suggestions for a methodology for tracking and evaluating extant and emerging technologies.
Merkel, Philipp M.; Schäfer, Björn Malte
2017-10-01
Cross-correlating the lensing signals of galaxies and comic microwave background (CMB) fluctuations is expected to provide valuable cosmological information. In particular, it may help tighten constraints on parameters describing the properties of intrinsically aligned galaxies at high redshift. To access the information conveyed by the cross-correlation signal, its accurate theoretical description is required. We compute the bias to CMB lensing-galaxy shape cross-correlation measurements induced by non-linear structure growth. Using tree-level perturbation theory for the large-scale structure bispectrum, we find that the bias is negative on most angular scales, therefore mimicking the signal of intrinsic alignments. Combining Euclid-like galaxy lensing data with a CMB experiment comparable to the Planck satellite mission, the bias becomes significant only on smallest scales (ℓ ≳ 2500). For improved CMB observations, however, the corrections amount to 10-15 per cent of the CMB lensing-intrinsic alignment signal over a wide multipole range (10 ≲ ℓ ≲ 2000). Accordingly, the power spectrum bias, if uncorrected, translates into 2σ and 3σ errors in the determination of the intrinsic alignment amplitude in the case of CMB stage III and stage IV experiments, respectively.
Semi-blind Eigen-analyses of Recombination Histories Using CMB Data
Farhang, Marzieh; Chluba, Jens
2011-01-01
Cosmological parameter measurements from CMB experiments such as Planck, ACTpol, SPTpol and other high resolution follow-ons fundamentally rely on the accuracy of the assumed recombination model, or one with well prescribed uncertainties. Deviations from the standard recombination history might suggest new particle physics or modified atomic physics. Here we treat possible perturbative fluctuations in the free electron fraction, $\\Xe(z)$, by a semi-blind expansion in densely-packed modes in redshift. From these we construct parameter eigenmodes, which we rank order so that the lowest modes provide the most power to probe the $\\Xe(z)$ with CMB measurements. Since the eigenmodes are effectively weighed by the fiducial $\\Xe$ history, they are localized around the differential visibility peak, allowing for an excellent probe of hydrogen recombination, but a weaker probe of the higher redshift helium recombination and the lower redshift highly neutral freeze-out tail. We use an information-based criterion to trunc...
Correlating CMB spectral distortions with temperature: what do we learn on inflation?
Dimastrogiovanni, Emanuela; Emami, Razieh
2016-12-01
Probing correlations among short and long-wavelength cosmological fluctuations is known to be decisive for deepening the current understanding of inflation at the microphysical level. Spectral distortions of the CMB can be caused by dissipation of cosmological perturbations when they re-enter Hubble after inflation. Correlating spectral distortions with temperature anisotropies will thus provide the opportunity to greatly enlarge the range of scales over which squeezed limits can be tested, opening up a new window on inflation complementing the ones currently probed with CMB and LSS. In this paper we discuss a variety of inflationary mechanisms that can be efficiently constrained with distortion-temperature correlations. For some of these realizations (representative of large classes of models) we derive quantitative predictions for the squeezed limit bispectra, finding that their amplitudes are above the sensitivity limits of an experiment such as the proposed PIXIE.
DEFF Research Database (Denmark)
Jespersen, Per Homann; Drewes, Lise
2005-01-01
the experience and knowledge of actors in the freight transport sector are included directly in a scientific process in order to develop future and strategic studies. Future research is often produced as desktop research and presented as the results of scientists’ forecasting and scenario building...
Scintillator calorimeters for a future linear collider experiment
Energy Technology Data Exchange (ETDEWEB)
Hartbrich, Oskar
2016-07-15
shower start shows considerable differences between physics lists, especially for the higher end of beam energies available in this analysis. Two separate energy reconstruction algorithms are presented in this thesis. The standard reconstruction uses constant weights per sub-detector to reconstruct the primary pion energy. The implementation of a software compensation reconstruction developed for this analysis aims to distinguish electromagnetic sub-shower depositions in hadronic showers by the deposited energy in each hit. The implementation differs from a previous software compensation scheme used within CALICE by forcing less dependencies on the shapes of the optimised weights, increasing the number of free parameters but ultimately resulting in a more stable parameter optimisation. The software compensation reconstruction improves the energy resolution of data events by 10% to 20%. Applying the software compensation weights obtained from simulations to data events yields a similar performance compared to the native data weights, slightly degrading the response linearity while even slightly improving the energy resolution. The calorimeter prototypes used in the testbeam analysis presented in this thesis were built to prove the general feasibility of high granularity scintillator-SiPM calorimeters, which they fully accomplished. To demonstrate the scalability of such calorimeters to the size and requirements of a full-scale particle physics experiment as ILD, second generation prototypes with fully integrated readout electronics are developed within the CALICE collaboration. A toy simulation study performed for this thesis shows that the development of scintillator-SiPM tile systems should target a lightyield of 15 (px)/(MIP) in order to maintain a 95% MIP efficiency even for 2σ outliers, when assuming a hit energy threshold of 0.5 MIP. An efficient method to extract and validate trigger thresholds positions for all cells of the detector system is presented, requiring
The Szekeres Swiss Cheese model and the CMB observations
Bolejko, Krzysztof
2008-01-01
This paper presents the application of the Szekeres Swiss Cheese model to observations of the cosmic microwave background (CMB) radiation. It aims to study the CMB temperature fluctuations by the means of the exact inhomogeneous Szekeres model. So far the impact of inhomogeneous matter distribution on the CMB observations has been almost exclusively studied within the linear perturbations of the Friedmann model. However, since the density contrast of cosmic structures is larger than 1 this issue is worth studying using another approach. The Szekeres model is an inhomogeneous, non-symmetrical and exact solution of the Einstein equations. In this model, light propagation and matter evolution can be exactly calculated, without approximations such as small amplitude of the density contrast. This will allow us to examine the impact of light propagation effects on the CMB temperature fluctuations. The results of such analysis show that small-scale, non-linear inhomogeneities introduce - via light propagation effect...
CMB Constraint on Radion Evolution in the Brane World Scenario
Chan, K C
2007-01-01
In many versions of brane model, the modulus field of extra dimensions, the radion, could have cosmological evolution, which induces variation of the Higgs vacuum expectation value, $$, resulting in cosmological variation of the electron mass $m_e$. The formation of Cosmic Microwave Background (CMB) anisotropies is thus affected, causing changes both in the peaks positions and amplitudes in the CMB power spectra. Using the three-year WMAP CMB data, with the Hubble parameter $H_0$ fixed to be the HST result 72 km s$^{-1}$ Mpc$^{-1}$, we obtain a constraint on $\\rho$, the ratio of the value of $$ at CMB recombination to its present value, to be [0.97, 1.02].
Antenna-Coupled TES Bolometer Arrays for CMB Polarimetry Project
National Aeronautics and Space Administration — Develop and test transition edge sensor (TES) bolometer arrays for precision polarimetry of cosmic microwave background (CMB). Verify that critical antenna...
Planck 2013 results. XXIII. Isotropy and statistics of the CMB
National Research Council Canada - National Science Library
Ade, P.A.R; Rachen, J.P; Zonca, A
2014-01-01
The two fundamental assumptions of the standard cosmological model - that the initial fluctuations are statistically isotropic and Gaussian - are rigorously tested using maps of the CMB anisotropy from the \\Planck\\ satellite...
The isotropic blackbody CMB as evidence for a homogeneous universe
Clifton, Timothy; Clarkson, Chris; Bull, Philip
2011-01-01
The question of whether the Universe is spatially homogeneous and isotropic on the largest scales is of fundamental importance to cosmology, but has not yet been answered decisively. Surprisingly, neither an isotropic primary CMB nor combined observations of luminosity distances and galaxy number counts are sufficient to establish such a result. The inclusion of the Sunyaev-Zel'dovich effect in CMB observations, however, dramatically improves this situation. We show that even a solitary obser...
By Dawn's Early Light: CMB Polarization Impact on Cosmological Constraints
Das, Sudeep; Linder, Eric V.
2012-01-01
Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol significantly complement cosmological constraints from the Planck satellite, strengthening the CMB dark energy figure of merit and neutrino mass constraints by factors of 3-4. This changes the dark energy probe landscape. We evaluate the state of knowledge in...
Cosmological constant, violation of cosmological isotropy and CMB
Energy Technology Data Exchange (ETDEWEB)
Urban, Federico R.; Zhitnitsky, Ariel R., E-mail: urban@phas.ubc.ca, E-mail: arz@physics.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C. V6T 1Z1 (Canada)
2009-09-01
We suggest that the solution to the cosmological vacuum energy puzzle does not require any new field beyond the standard model, but rather can be explained as a result of the interaction of the infrared sector of the effective theory of gravity with standard model fields. The cosmological constant in this framework can be presented in terms of QCD parameters and the Hubble constant H as follows, ε{sub vac} ≅ H⋅m{sub q}( q-bar q)/m{sub η'} ≅ (4.3⋅10{sup −3}eV){sup 4}, which is amazingly close to the observed value today. In this work we explain how this proposal can be tested by analyzing CMB data. In particular, knowing the value of the observed cosmological constant fixes univocally the smallest size of the spatially flat, constant time 3d hypersurface which, for instance in the case of an effective 1-torus, is predicted to be around 74 Gpc. We also comment on another important prediction of this framework which is a violation of cosmological isotropy. Such anisotropy is indeed apparently observed by WMAP, and will be confirmed (or ruled out) by future PLANCK data.
Preferred axis of CMB parity asymmetry in the masked maps
Energy Technology Data Exchange (ETDEWEB)
Cheng, Cheng [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190 (China); Zhao, Wen, E-mail: wzhao7@ustc.edu.cn [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China); Huang, Qing-Guo [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190 (China); Santos, Larissa [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China)
2016-06-10
Both WMAP and Planck data show a significant odd-multipole preference in the large scales of the cosmic microwave background (CMB) temperature anisotropies. If this pattern originates from cosmological effects, then it can be considered a crucial clue for a violation in the cosmological principle. By defining various direction dependent statistics in the full-sky Planck 2015 maps (see, for instance, Naselsky et al. (2012); W. Zhao (2014)), we found that the CMB parity asymmetry has a preferred direction, which is independent of the choices of the statistics. In particular, this preferred axis is strongly aligned with those in the CMB quadrupole and octopole, as well as that in the CMB kinematic dipole, which hints to their non-cosmological origin. In realistic observations, the foreground residuals are inevitable, and should be properly masked out in order to avoid possible misinterpretation of the results. In this paper, we extend our previous analyses to the masked Planck 2015 data. By defining a similar direction dependent statistic in the masked map, we find a preferred direction of the CMB parity asymmetry, in which the axis also coincides with that found in the full-sky analysis. Therefore, our conclusions on the CMB parity violation and its directional properties are confirmed.
Foy, Jane Loring
The objectives of this research report are to gain insight into the main problems of the future and to ascertain the attitudes that the general population has toward the treatment of these problems. In the first section of this report the future is explored socially, psychologically, and environmentally. The second section describes the techniques…
Experience as a Basis for the Professional Development of Future Teacher of Music
Popovych, Natalia
2014-01-01
This paper investigates the problem of forming the professional and personal experience of the future music teacher as the basis for improving its professional excellence. The aim of the study was the theoretical justification and experimental verification of the contents of the experience gained and pedagogical technology of development of the…
Directory of Open Access Journals (Sweden)
Mariia T. Levochko
2010-08-01
Full Text Available In the article a value and role of experiment in professional preparation of future specialists opens up in the system “college-university”. An experiment plays a considerable role during realization of pedagogical, educational reforms, enables to check up the professional competence of specialists, professional abilities and skills, theoretical purchased knowledgе which are inculcated in practical activity in practicе. During research, by carrying out the experiments, the basic criteria of learning efficiency with use of test tasks and questioning for formation of professional competence and professional skills of the future specialists of economic branch in the system "college-university" have been offered.
The probability distribution for non-Gaussianity estimators constructed from the CMB trispectrum
Smith, Tristan L
2012-01-01
Considerable recent attention has focussed on the prospects to use the cosmic microwave background (CMB) trispectrum to probe the physics of the early universe. Here we evaluate the probability distribution function (PDF) for the standard estimator tau_nle for the amplitude tau_nl of the CMB trispectrum both for the null-hypothesis (i.e., for Gaussian maps with tau_nl = 0) and for maps with a non-vanishing trispectrum (|tau_nl|>0). We find these PDFs to be highly non-Gaussian in both cases. We also evaluate the variance with which the trispectrum amplitude can be measured, , as a function of its underlying value, tau_nl. We find a strong dependence of this variance on tau_nl. We also find that the variance does not, given the highly non-Gaussian nature of the PDF, effectively characterize the distribution. Detailed knowledge of these PDFs will therefore be imperative in order to properly interpret the implications of any given trispectrum measurement. For example, if a CMB experiment with a maximum multipole ...
Energy Technology Data Exchange (ETDEWEB)
Van Engelen, A.; Sehgal, N. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Bhattacharya, S. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Holder, G. P. [Department of Physics, McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8 (Canada); Zahn, O. [Berkeley Center for Cosmological Physics, Department of Physics, University of California, and Lawrence Berkeley National Labs, Berkeley, CA 94720 (United States); Nagai, D. [Department of Physics, Department of Astronomy and Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06520 (United States)
2014-05-01
The lensing power spectrum from cosmic microwave background (CMB) temperature maps will be measured with unprecedented precision with upcoming experiments, including upgrades to the Atacama Cosmology Telescope and the South Pole Telescope. Achieving significant improvements in cosmological parameter constraints, such as percent level errors on σ{sub 8} and an uncertainty on the total neutrino mass of ∼50 meV, requires percent level measurements of the CMB lensing power. This necessitates tight control of systematic biases. We study several types of biases to the temperature-based lensing reconstruction signal from foreground sources such as radio and infrared galaxies and the thermal Sunyaev-Zel'dovich effect from galaxy clusters. These foregrounds bias the CMB lensing signal due to their non-Gaussian nature. Using simulations as well as some analytical models we find that these sources can substantially impact the measured signal if left untreated. However, these biases can be brought to the percent level if one masks galaxies with fluxes at 150 GHz above 1 mJy and galaxy clusters with masses above M {sub vir} = 10{sup 14} M {sub ☉}. To achieve such percent level bias, we find that only modes up to a maximum multipole of l {sub max} ∼ 2500 should be included in the lensing reconstruction. We also discuss ways to minimize additional bias induced by such aggressive foreground masking by, for example, exploring a two-step masking and in-painting algorithm.
Application of beam deconvolution technique to power spectrum estimation for CMB measurements
Keihänen, Elina; Kurki-Suonio, Hannu; Reinecke, Martin
2016-01-01
We present two novel methods for the estimation of the angular power spectrum of cosmic microwave background (CMB) anisotropies. We assume an absolute CMB experiment with arbitrary asymmetric beams and arbitrary sky coverage. The methods differ from earlier ones in that the power spectrum is estimated directly from time-ordered data, without first compressing the data into a sky map, and they take into account the effect of asymmetric beams. In particular, they correct the beam-induced leakage from temperature to polarization. The methods are applicable to a case where part of the sky has been masked out to remove foreground contamination, leaving a pure CMB signal, but incomplete sky coverage. The first method (DQML) is derived as the optimal quadratic estimator, which simultaneously yields an unbiased spectrum estimate, and minimizes its variance. We successfully apply it to multipoles up to $\\ell$=200. The second method is derived as an weak-signal approximation from the first one. It yields an unbiased es...
CMB Constraints on Cosmic Strings and Superstrings
Charnock, Tom; Copeland, Edmund J; Moss, Adam
2016-01-01
We present the first complete MCMC analysis of cosmological models with evolving cosmic (super)string networks, using the Unconnected Segment Model in the unequal-time correlator formalism. For ordinary cosmic string networks, we derive joint constraints on {\\Lambda}CDM and string network parameters, namely the string tension G{\\mu}, the loop-chopping efficiency c_r and the string wiggliness {\\alpha}. For cosmic superstrings, we obtain joint constraints on the fundamental string tension G{\\mu}_F, the string coupling g_s, the self-interaction coefficient c_s, and the volume of compact extra dimensions w. This constitutes the most comprehensive CMB analysis of {\\Lambda}CDM cosmology + strings to date. For ordinary cosmic string networks our updated constraint on the string tension is, in relativistic units, G{\\mu}<1.1x10^-7, while for cosmic superstrings our constraint on the fundamental string tension is G{\\mu}_F<2.8x10^-8, both obtained using Planck2015 temperature and polarisation data.
CMB Signals of Neutrino Mass Generation
Chacko, Z; Okui, T; Oliver, S J; Hall, Lawrence J.; Okui, Takemichi; Oliver, Steven J.
2003-01-01
We propose signals in the cosmic microwave background to probe the type and spectrum of neutrino masses. In theories that have spontaneous breaking of approximate lepton flavor symmetries at or below the weak scale, light pseudo-Goldstone bosons recouple to the cosmic neutrinos after nucleosynthesis and affect the acoustic oscillations of the electron-photon fluid during the eV era. Deviations from the Standard Model are predicted for both the total energy density in radiation during this epoch, \\Delta N_nu, and for the multipole of the n'th CMB peak at large n, \\Delta l_n. The latter signal is difficult to reproduce other than by scattering of the known neutrinos, and is therefore an ideal test of our class of theories. In many models, the large shift, \\Delta l_n \\approx 8 n_S, depends on the number of neutrino species that scatter via the pseudo-Goldstone boson interaction. This interaction is proportional to the neutrino masses, so that the signal reflects the neutrino spectrum. The prediction for \\Delta N...
CMB anisotropies from a gradient mode
Mirbabayi, Mehrdad; Zaldarriaga, Matias
2015-03-01
A linear gradient mode must have no observable dynamical effect on short distance physics. We confirm this by showing that if there was such a gradient mode extending across the whole observable Universe, it would not cause any hemispherical asymmetry in the power of CMB anisotropies, as long as Maldacena's consistency condition is satisfied. To study the effect of the long wavelength mode on short wavelength modes, we generalize the existing second order Sachs-Wolfe formula in the squeezed limit to include a gradient in the long mode and to account for the change in the location of the last scattering surface induced by this mode. Next, we consider effects that are of second order in the long mode. A gradient mode Φ = qṡx generated in Single-field inflation is shown to induce an observable quadrupole moment. For instance, in a matter-dominated model it is equal to Q = 5(qṡx)2/18. This quadrupole can be canceled by superposition of a quadratic perturbation. The result is shown to be a nonlinear extension of Weinberg's adiabatic modes: a long-wavelength physical mode which looks locally like a coordinate transformation.
Jetzer, Philippe; Tortora, Crescenzo
2011-08-01
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as ρx∝(1+z)m, z being the redshift, are discussed following the outline of Jetzer et al. [P. Jetzer, D. Puy, M. Signore, and C. Tortora, Gen. Relativ. Gravit. 43, 1083 (2011).GRGVA80001-770110.1007/s10714-010-1091-4]. These kinds of models are proven to lead to the creation/disruption of matter and radiation, which affect the cosmic evolution of both matter and radiation components in the Universe. In particular, we have concentrated on the temperature-redshift relation of radiation, which has been constrained using a very recent collection of cosmic microwave background (CMB) temperature measurements up to z˜3. For the first time, we have combined this observational probe with a set of independent measurements (Supernovae Ia distance moduli, CMB anisotropy, large-scale structure and observational data for the Hubble parameter), which are commonly adopted to constrain dark energy models. We find that, within the uncertainties, the model is indistinguishable from a cosmological constant which does not exchange any particles with other components. Anyway, while temperature measurements and Supernovae Ia tend to predict slightly decaying models, the contrary happens if CMB data are included. Future observations, in particular, measurements of CMB temperature at large redshift, will allow to give firmer bounds on the effective equation of state parameter weff of this kind of dark energy model.
CMB spectral distortion constraints on thermal inflation
Cho, Kihyun; Hong, Sungwook E.; Stewart, Ewan D.; Zoe, Heeseung
2017-08-01
Thermal inflation is a second epoch of exponential expansion at typical energy scales V1/4 ~ 106 ~ 8 GeV. If the usual primordial inflation is followed by thermal inflation, the primordial power spectrum is only modestly redshifted on large scales, but strongly suppressed on scales smaller than the horizon size at the beginning of thermal inflation, k > kb = ab Hb. We calculate the spectral distortion of the cosmic microwave background generated by the dissipation of acoustic waves in this context. For kb ll 103 Mpc-1, thermal inflation results in a large suppression of the μ-distortion amplitude, predicting that it falls well below the standard value of μ simeq 2× 10-8. Thus, future spectral distortion experiments, similar to PIXIE, can place new limits on the thermal inflation scenario, constraining kb gtrsim 103 Mpc-1 if μ simeq 2× 10-8 were found.
Physical effects involved in the measurements of neutrino masses with future cosmological data
Archidiacono, Maria; Lesgourgues, Julien; Poulin, Vivian
2016-01-01
Future Cosmic Microwave Background experiments together with upcoming galaxy and 21-cm surveys will provide extremely accurate measurements of different cosmological observables located at different epochs of the cosmic history. The new data will be able to constrain the neutrino mass sum with the best precision ever. In order to exploit the complementarity of the different redshift probes, a deep understanding of the physical effects driving the impact of massive neutrinos on CMB and large scale structures is required. The goal of this work is to describe these effects, assuming a summed neutrino mass close to its minimum allowed value. We find that parameter degeneracies can be removed by appropriate combinations, leading to robust and model independent constraints. A joint forecast of the sensitivity of Euclid and DESI surveys together with a CORE-like CMB experiment leads to a $1\\sigma$ uncertainty of $7$~meV on the summed neutrino mass. However this particular combination gives rise to a peculiar degener...
Circular polarization of the CMB: Foregrounds and detection prospects
King, Soma
2016-01-01
The cosmic microwave background (CMB) is one of the finest probes of cosmology. Its all-sky temperature and linear polarization (LP) fluctuations have been measured precisely at a level of deltaT/TCMB ~10^{-6}. In comparison, circular polarization (CP) of the CMB, however, has not been precisely explored. Current upper limit on the CP of the CMB is at a level of deltaV/TCMB ~10^{-4} and is limited on large scales. Some of the cosmologically important sources which can induce a CP in the CMB include early universe symmetry breaking, primordial magnetic field, galaxy clusters and Pop III stars (also known as the First stars). Among these sources, Pop III stars are expected to induce the strongest signal with levels strongly dependent on the frequency of observation and on the number, Np, of the Pop III stars per halo. Optimistically, a CP signal in the CMB due to the Pop III stars could be at a level of deltaV/TCMB ~ 2x10^{-7} in scales of 1 degree at 10 GHz, which is much smaller than the currently existing up...
Parity violation in the CMB trispectrum from the scalar sector
Shiraishi, Maresuke
2016-10-01
Under the existence of chiral non-Gaussian sources during inflation, the trispectrum of primordial curvature perturbations can break parity. We examine signatures of the induced trispectrum of the cosmic microwave background (CMB) anisotropies. It is confirmed via a harmonic-space analysis that, as a consequence of parity violation, such a CMB trispectrum has nonvanishing signal in the ℓ1+ℓ2+ℓ3+ℓ4=odd domain, which is prohibited in the concordance cosmology. When the curvature trispectrum is parametrized with Legendre polynomials, the CMB signal due to the Legendre dipolar term is enhanced at the squeezed configurations in ℓ space, yielding a high signal-to-noise ratio. A Fisher matrix computation results in a minimum detectable size of the dipolar coefficient in a cosmic-variance-limited-level temperature survey as d1odd=640 . In an inflationary model where the inflaton field couples to the gauge field via an f (ϕ )(F2+F F ˜) interaction, the curvature trispectrum contains such a parity-odd dipolar term. We find that, in this model, the CMB trispectrum yields a high signal-to-noise ratio compared with the CMB power spectrum or bispectrum. Therefore, the ℓ1+ℓ2+ℓ3+ℓ4=odd signal could be a promising observable of cosmological parity violation.
The role of personal goals in autonoetic experience when imagining future events.
Lehner, Edith; D'Argembeau, Arnaud
2016-05-01
Although autonoetic experience-a sense of mental time travel-has been considered as the hallmark of episodic future thinking, what determines this subjective feeling is not yet fully understood. Here, we investigated the role of autobiographical knowledge by manipulating the relevance of imagined events for personal goals. Participants were asked to imagine three types of events (goal-related future events, experimenter-provided future events, and atemporal events) and to assess various characteristics of their mental representations. The results showed that the three types of events were represented with similar levels of detail and vividness. Importantly, however, goal-related future events were associated with a stronger autonoetic experience. Furthermore, autonoetic experience was significantly predicted by the importance of imagined events for personal goals. These findings suggest that the subjective feeling of pre-experiencing one's personal future in part depends on the extent to which imagined events can be placed in an autobiographical context. Copyright © 2016 Elsevier Inc. All rights reserved.
Non-Gaussianity and CMB aberration and Doppler
Catena, Riccardo; Notari, Alessio; Renzi, Alessandro
2013-01-01
The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on Non-Gaussianity estimators $f_{NL}$. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax $= 2000$) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt Non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Usi...
Constraints on Disformal Couplings from the CMB Temperature Evolution
van de Bruck, Carsten; Vu, Susan
2013-01-01
Certain modified gravity theories predict the existence of an additional, non-conformally coupled scalar field. A disformal coupling of the field to the Cosmic Microwave Background (CMB) is shown to affect the evolution of the energy density in the radiation fluid. Therefore, measurements of the CMB temperature at various redshifts can be used to constrain these disformal couplings. Such measurements strongly support the predictions of General Relativity, that the CMB temperature evolution with redshift is linear. For both exponential and power law potentials for the scalar field we find an excluded range for the strength of this coupling, characterised by an energy scale $M$, to be few$\\times 10^{-5}$ eV$
Late time CMB anisotropies constrain mini-charged particles
Energy Technology Data Exchange (ETDEWEB)
Burrage, C.; Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Jaeckel, J. [Univ. of Durham, Inst. for Particle Physics Phenomenology (United Kingdom)
2009-09-15
Observations of the temperature anisotropies induced as light from the CMB passes through large scale structures in the late universe are a sensitive probe of the interactions of photons in such environments. In extensions of the Standard Model which give rise to mini-charged particles, photons propagating through transverse magnetic fields can be lost to pair production of such particles. Such a decrement in the photon flux would occur as photons from the CMB traverse the magnetic fields of galaxy clusters. Therefore late time CMB anisotropies can be used to constrain the properties of mini- charged particles. We outline how this test is constructed, and present new constraints on mini-charged particles from observations of the Sunyaev-Zel'dovich effect in the Coma cluster. (orig.)
A Bayesian framework for cosmic string searches in CMB maps
Ciuca, Razvan; Hernández, Oscar F.
2017-08-01
There exists various proposals to detect cosmic strings from Cosmic Microwave Background (CMB) or 21 cm temperature maps. Current proposals do not aim to find the location of strings on sky maps, all of these approaches can be thought of as a statistic on a sky map. We propose a Bayesian interpretation of cosmic string detection and within that framework, we derive a connection between estimates of cosmic string locations and cosmic string tension Gμ. We use this Bayesian framework to develop a machine learning framework for detecting strings from sky maps and outline how to implement this framework with neural networks. The neural network we trained was able to detect and locate cosmic strings on noiseless CMB temperature map down to a string tension of Gμ=5 ×10-9 and when analyzing a CMB temperature map that does not contain strings, the neural network gives a 0.95 probability that Gμ<=2.3×10-9.
Using inpainting to construct accurate cut-sky CMB estimators
Gruetjen, H F; Liguori, M; Shellard, E P S
2015-01-01
The direct evaluation of manifestly optimal, cut-sky CMB power spectrum and bispectrum estimators is numerically very costly, due to the presence of inverse-covariance filtering operations. This justifies the investigation of alternative approaches. In this work, we mostly focus on an inpainting algorithm that was introduced in recent CMB analyses to cure cut-sky suboptimalities of bispectrum estimators. First, we show that inpainting can equally be applied to the problem of unbiased estimation of power spectra. We then compare the performance of a novel inpainted CMB temperature power spectrum estimator to the popular apodised pseudo-$C_l$ (PCL) method and demonstrate, both numerically and with analytic arguments, that inpainted power spectrum estimates significantly outperform PCL estimates. Finally, we study the case of cut-sky bispectrum estimators, comparing the performance of three different approaches: inpainting, apodisation and a novel low-l leaning scheme. Providing an analytic argument why the loca...
Evidence against a supervoid causing the CMB Cold Spot
Mackenzie, Ruari; Shanks, Tom; Bremer, Malcolm N.; Cai, Yan-Chuan; Gunawardhana, Madusha L. P.; Kovács, András; Norberg, Peder; Szapudi, Istvan
2017-09-01
We report the results of the 2dF-VST ATLAS Cold Spot galaxy redshift survey (2CSz) based on imaging from VST ATLAS and spectroscopy from 2dF AAOmega over the core of the CMB Cold Spot. We sparsely surveyed the inner 5° radius of the Cold Spot to a limit of iAB ≤ 19.2, sampling ∼7000 galaxies at z data out to z ∼ 1, we conclude that the CMB Cold Spot could not have been imprinted by a void confined to the inner core of the Cold Spot. Additionally, we find that our 'control' field GAMA G23 shows a similarity in its galaxy redshift distribution to the Cold Spot. Since the GAMA G23 line of sight shows no evidence of a CMB temperature decrement, we conclude that the Cold Spot may have a primordial origin rather than being due to line-of-sight effects.
Can CMB spectral distortions test the Einstein equivalence principle?
Arai, Shun; Tashiro, Hiroyuki
2016-01-01
The Einstein Equivalence Principle (EEP) can be verified by the measurement of the spectral distortions of the Cosmic Microwave Background (CMB). The existence of energy-dependency in the cosmological redshift effect means the EEP violation. Introducing the energy-dependent Friedmann-Robertson-Walker metric motivated by rainbow gravity, we show that the energy-dependent redshift effect causes the CMB spectral distortions. Assuming the simple energy-dependent form of the metric, we evaluate the distortions. From the COBE/FIRAS bound, we find that the deviation degree from the EEP, which is comparable to the difference of the parameterized-post-Newtonian parameter "gamma" in energy, is less than 10^{-9} at the CMB energy scale. Our bound is the first constraint on the EEP at cosmological time scale.
Planck 2013 results. XXIII. Isotropy and Statistics of the CMB
DEFF Research Database (Denmark)
Planck Collaboration,; Ade, P. A. R.; Aghanim, N.
2013-01-01
The two fundamental assumptions of the standard cosmological model - that the initial fluctuations are statistically isotropic and Gaussian - are rigorously tested using maps of the CMB anisotropy from the \\Planck\\ satellite. The detailed results are based on studies of four independent estimates...... of the CMB that are compared to simulations using a fiducial $\\Lambda$CDM model and incorporating essential aspects of the \\Planck\\ measurement process. Deviations from isotropy have been found and demonstrated to be robust against component separation algorithm, mask and frequency dependence. Many......, we find that the quadrupole-octopole alignment is also connected to a low observed variance of the CMB signal. The dipolar power asymmetry is now found to persist to much smaller angular scales, and can be described in the low-$\\ell$ regime by a phenomenological dipole modulation model. Finally...
Planck 2015 results: XVI. Isotropy and statistics of the CMB
DEFF Research Database (Denmark)
Ade, P. A R; Aghanim, N.; Akrami, Y.
2016-01-01
We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we...... consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales......, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB...
Calculation of Production and Decay of Radio Isotopes for Future Irradiation Experiments and Ion Bea
M. Eller, J. Lettry, R. Catherall, T. Stora
The design of future radioactive ion beam (RIB) facilities requires the forecast of radio isotope inventory after irradiation. At CERN ISOLDE we developed a software tool that estimates the roduction and activation of materials for ISOLDE radioactive waste anagement. The tool can also be used in the design of new RIB facilities, for licensing procedures, for irradiation experiments and the estimation of production yields.
Errard, Josquin; Feeney, Stephen M.; Peiris, Hiranya V.; Jaffe, Andrew H.
2016-03-01
Recent results from the BICEP, Keck Array and Planck Collaborations demonstrate that Galactic foregrounds are an unavoidable obstacle in the search for evidence of inflationary gravitational waves in the cosmic microwave background (CMB) polarization. Beyond the foregrounds, the effect of lensing by intervening large-scale structure further obscures all but the strongest inflationary signals permitted by current data. With a plethora of ongoing and upcoming experiments aiming to measure these signatures, careful and self-consistent consideration of experiments' foreground- and lensing-removal capabilities is critical in obtaining credible forecasts of their performance. We investigate the capabilities of instruments such as Advanced ACTPol, BICEP3 and Keck Array, CLASS, EBEX10K, PIPER, Simons Array, SPT-3G and SPIDER, and projects as COrE+, LiteBIRD-ext, PIXIE and Stage IV, to clean contamination due to polarized synchrotron and dust from raw multi-frequency data, and remove lensing from the resulting co-added CMB maps (either using iterative CMB-only techniques or through cross-correlation with external data). Incorporating these effects, we present forecasts for the constraining power of these experiments in terms of inflationary physics, the neutrino sector, and dark energy parameters. Made publicly available through an online interface, this tool enables the next generation of CMB experiments to foreground-proof their designs, optimize their frequency coverage to maximize scientific output, and determine where cross-experimental collaboration would be most beneficial. We find that analyzing data from ground, balloon and space instruments in complementary combinations can significantly improve component separation performance, delensing, and cosmological constraints over individual datasets. In particular, we find that a combination of post-2020 ground- and space-based experiments could achieve constraints such as σ(r)~1.3×10-4, σ(nt)~0.03, σ( ns )~1.8×10
Power law cosmology model comparison with CMB scale information
Tutusaus, Isaac; Lamine, Brahim; Blanchard, Alain; Dupays, Arnaud; Zolnierowski, Yves; Cohen-Tanugi, Johann; Ealet, Anne; Escoffier, Stéphanie; Le Fèvre, Olivier; Ilić, Stéphane; Pisani, Alice; Plaszczynski, Stéphane; Sakr, Ziad; Salvatelli, Valentina; Schücker, Thomas; Tilquin, André; Virey, Jean-Marc
2016-11-01
Despite the ability of the cosmological concordance model (Λ CDM ) to describe the cosmological observations exceedingly well, power law expansion of the Universe scale radius, R (t )∝tn, has been proposed as an alternative framework. We examine here these models, analyzing their ability to fit cosmological data using robust model comparison criteria. Type Ia supernovae (SNIa), baryonic acoustic oscillations (BAO) and acoustic scale information from the cosmic microwave background (CMB) have been used. We find that SNIa data either alone or combined with BAO can be well reproduced by both Λ CDM and power law expansion models with n ˜1.5 , while the constant expansion rate model (n =1 ) is clearly disfavored. Allowing for some redshift evolution in the SNIa luminosity essentially removes any clear preference for a specific model. The CMB data are well known to provide the most stringent constraints on standard cosmological models, in particular, through the position of the first peak of the temperature angular power spectrum, corresponding to the sound horizon at recombination, a scale physically related to the BAO scale. Models with n ≥1 lead to a divergence of the sound horizon and do not naturally provide the relevant scales for the BAO and the CMB. We retain an empirical footing to overcome this issue: we let the data choose the preferred values for these scales, while we recompute the ionization history in power law models, to obtain the distance to the CMB. In doing so, we find that the scale coming from the BAO data is not consistent with the observed position of the first peak of the CMB temperature angular power spectrum for any power law cosmology. Therefore, we conclude that when the three standard probes (SNIa, BAO, and CMB) are combined, the Λ CDM model is very strongly favored over any of these alternative models, which are then essentially ruled out.
Measuring the cosmological lepton asymmetry through the CMB anisotropy
Kinney, W H; Kinney, William H.; Riotto, Antonio
1999-01-01
A large lepton asymmetry in the Universe is still a viable possibility and leads to many interesting phenomena such as gauge symmetry nonrestoration at high temperature. We show that a large lepton asymmetry changes the predicted cosmic microwave background (CMB) anisotropy and that any degeneracy in the relic neutrino sea will be measured to a precision of 1% or better when the CMB anisotropy is measured at the accuracy expected to result from the planned satellite missions MAP and Planck. In fact, the current measurements already put an upper limit on the lepton asymmetry of the Universe which is stronger than the one coming from considerations of primordial nucleosynthesis and structure formation.
Low-frequency measurements of the CMB spectrum
Energy Technology Data Exchange (ETDEWEB)
Kogut, A.; Bensadoun, M.; Amici, G.D.; Levin, S.; Limon, M.; Smoot, G. (U. C. Berkeley, Berkeley, CA (USA) Lawrence Berkeley Laboratory, Berkeley, CA (USA) Space Sciences Laboratory, Berkeley, CA (USA)); Sironi, G. (Physics Department, University of Milano (Italy)); Bersanelli, M.; Bonelli, G. (IFCTR/CNR-Milano (Italy))
1990-01-15
As part of an extended program to characterize the spectrum of the cosmic microwave background (CMB) at low frequencies, we have performed multiple measurements from a high-altitude site in Calfornia. On average, these measurements suggests a CMB temperature slightly lower than measurements at higher frequencies. Atmospheric conditions and the encroachment of civilization are now significant limitations from our present observing site. In November 1989, we will make new measurements from the South Pole Amundsen-Scott Station at frequencies 0.82, 1.5, 2.5, 3.8, 7.5, and 90 GHz. We discuss recent measurements and indicate improvements possible from a polar observing site.
Low-Frequency Measurements of the CMB Spectrum
Energy Technology Data Exchange (ETDEWEB)
Kogut, A.; Bensadoun, M.; De Amici, Giovanni; Levin, S.; Limon,M.; Smoot, George F.; Sironi, G.; Bersanelli, M.; Bonelli, G.
1989-10-01
As part of an extended program to characterize the spectrum of the cosmic microwave background (CMB) at low frequencies, we have performed multiple measurements from a high-altitude site in California. On average, these measurements suggest a CMB temperature slightly lower than measurements at higher frequencies. Atmospheric conditions and the encroachment of civilization are now significant limitations from our present observing site. In November 1989, we will make new measurements from the South Pole Amundsen-Scott Station at frequencies 0.82, 1.5, 2.5, 3.8, 7.5, and 90 GHz. We discuss recent measurements and indicate improvements possible from a polar observing site.
Scale-dependent CMB asymmetry from primordial configuration
Energy Technology Data Exchange (ETDEWEB)
Kohri, Kazunori [Cosmophysics group, Theory Center, IPNS, KEK, and The Graduate University for Advanced Study (Sokendai), Tsukuba 305-0801 (Japan); Lin, Chia-Min [Department of Physics, Chuo University, Bunkyo-ku, Tokyo 112 (Japan); Matsuda, Tomohiro, E-mail: kohri@post.kek.jp, E-mail: lin@chuo-u.ac.jp, E-mail: matsuda@sit.ac.jp [Laboratory of Physics, Saitama Institute of Technology, Fukaya, Saitama 369-0293 (Japan)
2014-08-01
We demonstrate that a topological defect can explain the hemispherical power asymmetry of the CMB. The first point is that a defect configuration, which already exists prior to inflation, can source asymmetry of the CMB. The second point is that modulation mechanisms, such as the curvaton and other modulation mechanisms, can explain scale-dependence of the asymmetry. Using a simple analysis of the δ N formalism, we show models in which scale-dependent hemispherical power asymmetry is explained by primordial configuration of a defect.
Reconciling CMB and structure growth measurements with dark energy interactions
Pourtsidou, Alkistis; Tram, Thomas
2016-08-01
We study a coupled quintessence model with pure momentum exchange and present the effects of such an interaction on the cosmic microwave background (CMB) and matter power spectrum. For a wide range of negative values of the coupling parameter β structure growth is suppressed and the model can reconcile the tension between cosmic microwave background observations and structure growth inferred from cluster counts. We find that this model is as good as Λ CDM for CMB and baryon acoustic oscillation data, while the addition of cluster data makes the model strongly preferred, improving the best-fit χ2 value by more than 16.
Loop quantum cosmology, non-Gaussianity, and CMB power asymmetry
Agullo, Ivan
2015-01-01
We argue that the anomalous power asymmetry observed in the cosmic microwave background (CMB) may have originated in a cosmic bounce preceding inflation. In loop quantum cosmology (LQC) the big bang singularity is generically replaced by a bounce due to quantum gravitational effects. We compute the spectrum of inflationary non-Gaussianity and show that strong correlation between observable scales and modes with longer (super-horizon) wavelength arise as a consequence of the evolution of perturbations across the LQC bounce. These correlations are strongly scale dependent and induce a dipole-dominated modulation on large angular scales in the CMB, in agreement with observations.
Planck 2015 results IX. Diffuse component separation: CMB maps
DEFF Research Database (Denmark)
Adam, R.; Ade, P. A R; Aghanim, N.
2016-01-01
We present foreground-reduced cosmic microwave background (CMB) maps derived from the full Planck data set in both temperature and polarization. Compared to the corresponding Planck 2013 temperature sky maps, the total data volume is larger by a factor of 3.2 for frequencies between 30 and 70 GHz....... As in 2013, four different CMB component separation algorithms are applied to these observations, providing a measure of stability with respect to algorithmic and modelling choices. The resulting polarization maps have rms instrumental noise ranging between 0.21 and 0.27μK averaged over 55′ pixels...
CMB Anisotropies at Second-Order II: Analytical Approach
Bartolo, N; Riotto, Antonio; Bartolo, Nicola; Matarrese, Sabino; Riotto, Antonio
2007-01-01
We provide an analytical approach to the second-order Cosmic Microwave Background (CMB) anisotropies generated by the non-linear dynamics taking place at last scattering. We study the acoustic oscillations of the photon-baryon fluid in the tight coupling limit and we extend at second-order the Meszaros effect.We allow for a generic set of initial conditions due to primordial non-Gaussianity and we compute all the additional contributions arising at recombination. Our results are useful to provide the full second-order radiation transfer function at all scales necessary for establishing the level of non-Gaussianity in the CMB.
Lessons from the GP-B Experience for Future Fundamental Physics Missions in Space
Kolodziejczak, Jeffery
2006-01-01
Gravity Probe B launched in April 2004 and completed its science data collection in September 2005, with the objective of sub-milliarcsec measurement of two General Relativistic effects on the spin axis orientation of orbiting gyroscopes. Much of the technology required by GP-B has potential application in future missions intended to make precision measurements. The philosophical approach and experiment design principles developed for GP-B are equally adaptable to these mission concepts. This talk will discuss GP-B's experimental approach and the technological and philosophical lessons learned that apply to future experiments in fundamental physics. Measurement of fundamental constants to high precision, probes of short-range forces, searches for equivalence principle violations, and detection of gravitational waves are examples of concepts and missions that will benefit kern GP-B's experience.
Recent results from CERN SPS experiments and the future heavy ion programme
Indian Academy of Sciences (India)
Y P Viyogi
2000-04-01
We describe the important results from the recent experiments using lead beams at the CERN SPS. The results of the WA98 experiment, which has substantial Indian participation along with the photon multiplicity detector is described in some detail. Combining the preliminary results from various experiments looking at different signals of phase transition, one ﬁnds enough evidences to suggest that phase transition has taken place in nuclear collisions at the SPS. Future programme of heavy ion physics at the LHC is being geared around the ALICE experiment. This will comprise of detector subsystems capable of studying almost all the signals in the same event. The photon multiplicity detector will be an important component of the ALICE experiment, being a totally Indian contribution to ALICE.
Stenzel, Ch.
2012-01-01
Materials science experiments have been a key issue already since the early days of research under microgravity conditions. A microgravity environment facilitates processing of metallic and semiconductor melts without buoyancy driven convection and sedimentation. Hence, crystal growth of semiconductors, solidification of metallic alloys, and the measurement of thermo-physical parameters are the major applications in the field of materials science making use of these dedicated conditions in space. In the last three decades a large number of successful experiments have been performed, mainly in international collaborations. In parallel, the development of high-performance research facilities and the technological upgrade of diagnostic and stimuli elements have also contributed to providing optimum conditions to perform such experiments. A review of the history of materials science experiments in space focussing on the development of research facilities is given. Furthermore, current opportunities to perform such experiments onboard ISS are described and potential future options are outlined.
Reconstructing cosmic growth with kSZ observations in the era of Stage IV experiments
Alonso, David; Bull, Philip; Ferreira, Pedro G
2016-01-01
Future ground-based CMB experiments will generate competitive large-scale structure datasets by precisely characterizing CMB secondary anisotropies over a large fraction of the sky. We describe a method for constraining the growth rate of structure to sub-1% precision out to $z\\approx 1$, using a combination of galaxy cluster peculiar velocities measured using the kinetic Sunyaev-Zel'dovich (kSZ) effect, and the velocity field reconstructed from galaxy redshift surveys. We consider only thermal SZ-selected cluster samples, which will consist of $\\mathcal{O}(10^4-10^5)$ sources for Stage 3 and 4 CMB experiments respectively. Three different methods for separating the kSZ effect from the primary CMB are compared, including a novel blind "constrained realization" method that improves signal-to-noise by a factor of $\\sim 2$ over a commonly-used aperture photometry technique. Measurements of the integrated tSZ $y$-parameter are used to break the kSZ velocity-optical depth degeneracy, and the effects of including C...
Constraining star formation through redshifted CO and CII emission in archival CMB data
Switzer, Eric
cross-power with galaxy surveys directly constrains the redshifted line emission. Residual foregrounds and interlopers increase errors but do not add bias. There are 300 resolution elements of the 7 degree FIRAS top-hat inside the BOSS quasar survey, spanning 66 spectral pixels to z 2. While FIRAS noise per voxel is 200 times brighter than the expected peak cosmological CII emission, strt-N averaging of spatial and spectral modes above results in a gain of 140. Intensity mapping is in its infancy, with predictions for surface brightness of line emission ranging over an order of magnitude, and limited knowledge of the intensity-weighted bias. Even if only upper bounds are possible, they complement existing measurements of individual galaxies, which can constitute a lower bound because they measure only a portion of the luminosity function. FIRAS and Planck provide unique opportunities to pursue CII and CO intensity mapping with well-characterized instruments that overlap with galaxy surveys in angular coverage and redshift. We will re-analyze the FIRAS data to optimize sensitivity and robustness, developing a spectral line response model, splitting the data into sub-missions to isolate noise properties, and re- evaluating data cuts. The tools and results here will support future survey concepts with significantly lower noise, such as PIXIE, PRISM, SPHEREX and proposed suborbital experiments designed specifically for intensity mapping. There is a growing appreciation that many phenomena could lie just below the published FIRAS bounds. The proposed work is an early step toward this new science.
CMB constraint on dark matter annihilation after Planck 2015
Energy Technology Data Exchange (ETDEWEB)
Kawasaki, Masahiro [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Nakayama, Kazunori, E-mail: kazunori@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, Faculty of Science, The University of Tokyo, Bunkyo-ku, Tokyo 133-0033 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Sekiguchi, Toyokazu [Institute for Basic Science, Center for Theoretical Physics of the Universe, Daejeon 34051 (Korea, Republic of)
2016-05-10
We update the constraint on the dark matter annihilation cross section by using the recent measurements of the CMB anisotropy by the Planck satellite. We fully calculate the cascade of dark matter annihilation products and their effects on ionization, heating and excitation of the hydrogen, hence do not rely on any assumption on the energy fractions that cause these effects.
Planck 2013 results. XV. CMB power spectra and likelihood
DEFF Research Database (Denmark)
Tauber, Jan; Bartlett, J.G.; Bucher, M.;
2014-01-01
This paper presents the Planck 2013 likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations that accounts for all known relevant uncertainties, both instrumental and astrophysical in nature. We use this likelihood to derive our best...
The Szekeres Swiss Cheese model and the CMB observations
Bolejko, Krzysztof
2009-08-01
This paper presents the application of the Szekeres Swiss Cheese model to the analysis of observations of the cosmic microwave background (CMB) radiation. The impact of inhomogeneous matter distribution on the CMB observations is in most cases studied within the linear perturbations of the Friedmann model. However, since the density contrast and the Weyl curvature within the cosmic structures are large, this issue is worth studying using another approach. The Szekeres model is an inhomogeneous, non-symmetrical and exact solution of the Einstein equations. In this model, light propagation and matter evolution can be exactly calculated, without such approximations as small amplitude of the density contrast. This allows to examine in more realistic manner the contribution of the light propagation effect to the measured CMB temperature fluctuations. The results of such analysis show that small-scale, non-linear inhomogeneities induce, via Rees-Sciama effect, temperature fluctuations of amplitude 10-7-10-5 on angular scale ϑ 750). This is still much smaller than the measured temperature fluctuations on this angular scale. However, local and uncompensated inhomogeneities can induce temperature fluctuations of amplitude as large as 10-3, and thus can be responsible the low multipoles anomalies observed in the angular CMB power spectrum.
Symmetry and Antisymmetry of the CMB Anisotropy Pattern
Directory of Open Access Journals (Sweden)
Jaiseung Kim
2012-01-01
Full Text Available Given an arbitrary function, we may construct symmetric and antisymmetric functions under a certain operation. Since statistical isotropy and homogeneity of our Universe has been a fundamental assumption of modern cosmology, we do not expect any particular symmetry or antisymmetry in our Universe. Besides fundamental properties of our Universe, we may also figure our contamination and improve the quality of the CMB data products, by matching the unusual symmetries and antisymmetries of the CMB data with known contaminantions. If we let the operation to be a coordinate inversion, the symmetric and antisymmetric functions have even and odd-parity respectively. The investigation on the parity of the recent CMB data shows a large-scale odd-parity preference, which is very unlikely in the statistical isotropic and homogeneous Universe. We investigated the association of the WMAP systematics with the anomaly, but did not find a definite non-cosmological cause. Besides the parity anomaly, there is anomalous lack of large-scale correlation in CMB data. We show that the odd-parity preference at low multipoles is, in fact, phenomenologically identical with the lack of large-angle correlation.
Institute of Scientific and Technical Information of China (English)
原思国; 周小会
2010-01-01
首次研究了非苯乙烯型CMB-CMB-XDC吸附树脂对甲苯的吸附性能,考察了树脂结构、体系浓度、时间等对吸附的影响.结果表明:在含甲苯的水溶液(C0=341.93 mg/L)、蒸气和水面液膜体系中,该树脂对甲苯的吸附量分别可达241,2580,2.536 mg/g,明显高于苯乙烯型H103吸附树脂的吸附量223,507,1453 mg/g;该树脂对水溶液中甲苯的吸附75 min达到完全平衡,平衡吸附量随体系质量浓度的增加而增大.CMB-CMB-XDC树脂吸附速度快、容量大,可经再生反复使用,预期在非极性芳烃废气(水)净化及突发污染事故中的快速处理领域具有很好的应用前景.
Gauss-Legendre Sky Pixelization (glesp) for CMB Maps
Doroshkevich, A. G.; Naselsky, P. D.; Verkhodanov, O. V.; Novikov, D. I.; Turchaninov, V. I.; Novikov, I. D.; Christensen, P. R.; Chiang, L.-Y.
A new scheme of sky pixelization is developed for CMB maps. The scheme is based on the Gauss-Legendre polynomials zeros and allows one to create strict orthogonal expansion of the map. A corresponding code has been implemented and comparison with other methods has been done.
Gauss--Legendre Sky Pixelization (GLESP) for CMB maps
Doroshkevich, A G; Verkhodanov, O V; Novikov, D I; Turchaninov, V I; Novikov, I D; Christensen, P R
2003-01-01
A new scheme of sky pixelization is developed for CMB maps. The scheme is based on the Gauss--Legendre polynomials zeros and allows one to create strict orthogonal expansion of the map. A corresponding code has been implemented and comparison with other methods has been done.
CMB constraint on dark matter annihilation after Planck 2015
Directory of Open Access Journals (Sweden)
Masahiro Kawasaki
2016-05-01
Full Text Available We update the constraint on the dark matter annihilation cross section by using the recent measurements of the CMB anisotropy by the Planck satellite. We fully calculate the cascade of dark matter annihilation products and their effects on ionization, heating and excitation of the hydrogen, hence do not rely on any assumption on the energy fractions that cause these effects.
CMB reconstruction from the WMAP and Planck PR2 data
Bobin, J; Starck, J-L
2015-01-01
In this article, we describe a new estimate of the Cosmic Microwave Background (CMB) intensity map reconstructed by a joint analysis of the full Planck 2015 data (PR2) and WMAP nine-years. It provides more than a mere update of the CMB map introduced in (Bobin et al. 2014b) since it benefits from an improvement of the component separation method L-GMCA (Local-Generalized Morphological Component Analysis) that allows the efficient separation of correlated components (Bobin et al. 2015). Based on the most recent CMB data, we further confirm previous results (Bobin et al. 2014b) showing that the proposed CMB map estimate exhibits appealing characteristics for astrophysical and cosmological applications: i) it is a full sky map that did not require any inpainting or interpolation post-processing, ii) foreground contamination is showed to be very low even on the galactic center, iii) it does not exhibit any detectable trace of thermal SZ contamination. We show that its power spectrum is in good agreement with the ...
Instability of reconstruction of the low CMB multipoles
DEFF Research Database (Denmark)
Naselsky, Pavel D.; Verkhodanov, Oleg V.; Nielsen, Mikkel T. B.
2007-01-01
We discuss the problem of the bias of the Internal Linear Combination (ILC) CMB map and show that it is closely related to the coefficient of cross-correlation K(l) of the true CMB and the foreground for each multipole l. We present analysis of the cross-correlation for the WMAP ILC quadrupole...... and octupole from the first (ILC(I)) and the third (ILC(III)) year data releases and show that these correlations are about -0.52-0.6. Analysing 10^4 Monte Carlo simulations of the random Gaussian CMB signals, we show that the distribution function for the corresponding coefficient of the cross-correlation has...... of debiasing of the ILC CMB and pointed out that reconstruction of the bias seems to be very problematic due to statistical uncertainties. In addition, instability of the debiasing illuminates itself for the quadrupole and octupole components through the flip-effect, when the even (l+m) modes can...
Adiabatic CMB perturbations in pre-big bang string cosmology
DEFF Research Database (Denmark)
Enqvist, Kari; Sloth, Martin Snoager
2001-01-01
We consider the pre-big bang scenario with a massive axion field which starts to dominate energy density when oscillating in an instanton-induced potential and subsequently reheats the universe as it decays into photons, thus creating adiabatic CMB perturbations. We find that the fluctuations...
Development of Silicon Sensor Characterization System for Future High Energy Physics Experiments
Directory of Open Access Journals (Sweden)
Preeti kumari
2015-08-01
Full Text Available The Compact Muon Solenoid (CMS is one of the general purpose experiments at the Large Hadron Collider (LHC, CERN and has its Tracker built of all silicon strip and pixel sensors. Si sensors are expected to play extremely important role in the upgrades of the existing Tracker for future high luminosity environment and will also be used in future lepton colliders. However, properties of the silicon sensors have to be carefully understood before they can be put in the extremely high luminosity condition. At Delhi University (DU, we have been working on the development of Si sensor characterization system, as part of the collaboration with the CMS Experiment and RD50 collaboration. This works reports the installation of current-voltage (I-V and capacitance-voltage (C-V systems at DU.
CMB Lensing as a probe of beyond ΛCDM Cosmology
Hassani, F.; Baghram, S.; Firouzjahi, H.
2016-09-01
The observation of the Cosmic Microwave Background Radiation (CMB) and the Large Structures indicate that the standard model of Cosmology known as ΛCDM works well. In this essay we propose that the CMB lensing is a prominent probe to study any deviation from this model. Deviations from cosmological constant and nearly Gaussian, adiabatic, nearly scale invariant and isotropic initial conditions can be studied by CMB lensing. We show how the angular power spectrum of CMB lensing potential is an observable which encapsulates the effect of initial conditions and Dark Energy. The amplitude and the scale dependence of a dipole modulation in initial conditions is studied with CMB lensing potential and convergence.
Kulkarni, Girish; Puchwein, Ewald; Haehnelt, Martin G
2016-01-01
We present here 21 cm predictions from high dynamic range simulations for a range of reionization histories that have been tested against available Lyman-alpha and CMB data. We assess the observability of the predicted spatial 21 cm fluctuations by ongoing and upcoming experiments in the late stages of reionization in the limit in which the hydrogen spin temperature is significantly larger than the CMB temperature. Models consistent with the available Lyman-alpha data and CMB measurement of the Thomson optical depth predict typical values of 10--20 mK^2 for the variance of the 21 cm brightness temperature at redshifts z=7--10 at scales accessible to ongoing and upcoming experiments (k < 1 h/cMpc). This is only a factor of a few below the sensitivity claimed to have been already reached by ongoing experiments. Our different models for the reionization history make markedly different predictions for the redshift evolution and thus frequency dependence of the 21 cm power spectrum and should be easily discerni...
Alonso, David; Louis, Thibaut; Bull, Philip; Ferreira, Pedro G.
2016-08-01
Future ground-based cosmic microwave background (CMB) experiments will generate competitive large-scale structure data sets by precisely characterizing CMB secondary anisotropies over a large fraction of the sky. We describe a method for constraining the growth rate of structure to sub-1% precision out to z ≈1 , using a combination of galaxy cluster peculiar velocities measured using the kinetic Sunyaev-Zel'dovich (kSZ) effect, and the velocity field reconstructed from galaxy redshift surveys. We consider only thermal SZ-selected cluster samples, which will consist of O (1 04- 1 05) sources for Stage 3 and 4 CMB experiments respectively. Three different methods for separating the kSZ effect from the primary CMB are compared, including a novel blind "constrained realization" method that improves signal-to-noise by a factor of ˜2 over a commonly-used aperture photometry technique. Assuming a correlation between the integrated tSZ y -parameter and the cluster optical depth, it should then be possible to break the kSZ velocity-optical depth degeneracy. The effects of including CMB polarization and SZ profile uncertainties are also considered. In the absence of systematics, a combination of future Stage 4 experiments should be able to measure the product of the growth and expansion rates, α ≡f H , to better than 1% in bins of Δ z =0.1 out to z ≈1 —competitive with contemporary redshift-space distortion constraints from galaxy surveys. We conclude with a discussion of the likely impact of various systematics.
Bucher, Martin
2016-01-01
We present an exact expression for the $1/f$ contribution to the noise of the CMB temperature and polarization maps for a survey in which the scan pattern is isotropic. The result for polarization applies likewise to surveys with and without a rotating half-wave plate. A representative range of survey parameters is explored and implications for the design and optimization of future surveys are discussed. These results are most directly applicable to space-based surveys, which afford considerable freedom in the choice of the scan pattern on the celestial sphere. We discuss the applicability of the methods developed here to analyzing past experiments and present some conclusions pertinent to the design of future experiments. The techniques developed here do not require that the excess low frequency noise have exactly the $1/f$ shape and readily generalize to other functional forms for the detector noise power spectrum. In the case of weakly anisotropic scanning patterns the techniques in this paper can be used ...
Effect of lensing non-Gaussianity on the CMB power spectra
Lewis, Antony
2016-01-01
Observed CMB anisotropies are lensed, and the lensed power spectra can be calculated accurately assuming the lensing deflections are Gaussian. However, the lensing deflections are actually slightly non-Gaussian due to both non-linear large-scale structure growth and post-Born corrections. We calculate the leading correction to the lensed CMB power spectra from the non-Gaussianity, which is determined by the lensing bispectrum. The lowest-order result gives $\\sim 0.3\\%$ corrections to the BB and EE polarization spectra on small-scales, however we show that the effect on EE is reduced by about a factor of two by higher-order Gaussian lensing smoothing, rendering the total effect safely negligible for the foreseeable future. We give a simple analytic model for the signal expected from skewness of the large-scale lensing field; the effect is similar to a net demagnification and hence a small change in acoustic scale (and therefore out of phase with the dominant lensing smoothing that predominantly affects the pea...
Shiraishi, Maresuke; Namba, Ryo; Namikawa, Toshiya; Hazumi, Masashi
2016-01-01
The B-mode polarization in the cosmic microwave background (CMB) anisotropies at large angular scales provides a smoking-gun evidence for the primordial gravitational waves (GWs). It is often stated that a discovery of the GWs establishes the quantum fluctuation of vacuum during the cosmic inflation. Since the GWs could also be generated by source fields, however, we need to check if a sizable signal exists due to such source fields before reaching a firm conclusion when the B-mode is discovered. Source fields of particular types can generate non-Gaussianity (NG) in the GWs. Testing statistics of the B-mode is a powerful way of detecting such NG. As a concrete example, we show a model in which a gauge field sources chiral GWs via a pseudoscalar coupling, and forecast the detection significance at the future CMB satellite LiteBIRD. Effects of residual foregrounds and lensing B-mode are both taken into account. We find the B-mode bispectrum "BBB" is in particular sensitive to the source-field NG, which is detec...
Lensing-induced morphology changes in CMB temperature maps in modified gravity theories
Munshi, D; Matsubara, T; Coles, P; Heavens, A
2016-01-01
Lensing of the Cosmic Microwave Background (CMB) changes the morphology of pattern of temperature fluctuations, so topological descriptors such as Minkowski Functionals can probe the gravity model responsible for the lensing. We show how the recently introduced two-to-two and three-to-one kurt-spectra (and their associated correlation functions), which depend on the power spectrum of the lensing potential, can be used to probe modified gravity theories such as $f({R})$ theories of gravity and quintessence models. We also investigate models based on effective field theory, which include the constant-$\\Omega$ model, and low-energy Ho\\vrava theories. Estimates of the cumulative signal-to-noise for detection of lensing-induced morphology changes, reaches ${\\cal O}(10^3)$ for the future planned CMB polarization mission COrE$^{+}$. Assuming foreground removal is possible to $\\ell_{max}=3000$, we show that many modified gravity theories can be rejected with a high level of significance, making this technique compara...
Lensing-induced morphology changes in CMB temperature maps in modified gravity theories
Munshi, D.; Hu, B.; Matsubara, T.; Coles, P.; Heavens, A.
2016-04-01
Lensing of the Cosmic Microwave Background (CMB) changes the morphology of pattern of temperature fluctuations, so topological descriptors such as Minkowski Functionals can probe the gravity model responsible for the lensing. We show how the recently introduced two-to-two and three-to-one kurt-spectra (and their associated correlation functions), which depend on the power spectrum of the lensing potential, can be used to probe modified gravity theories such as f(R) theories of gravity and quintessence models. We also investigate models based on effective field theory, which include the constant-Ω model, and low-energy Hořava theories. Estimates of the cumulative signal-to-noise for detection of lensing-induced morphology changes, reaches Script O(103) for the future planned CMB polarization mission COrE+. Assuming foreground removal is possible to lmax=3000, we show that many modified gravity theories can be rejected with a high level of significance, making this technique comparable in power to galaxy weak lensing or redshift surveys. These topological estimators are also useful in distinguishing lensing from other scattering secondaries at the level of the four-point function or trispectrum. Examples include the kinetic Sunyaev-Zel'dovich (kSZ) effect which shares, with lensing, a lack of spectral distortion. We also discuss the complication of foreground contamination from unsubtracted point sources.
Righi, M; Sunyaev, R
2007-01-01
Future observations of CMB anisotropies will be able to probe high multipole regions of the angular power spectrum, corresponding to a resolution of a few arcminutes. Dust emission from merging haloes is one of the foregrounds that will affect such very small scales. We estimate the contribution to CMB angular fluctuations from objects which are bright in the sub-millimeter band due to intense star formation bursts following merging episodes. We also consider the effect of the intergalactic dust expelled from galaxies by strong winds and AGN activity. We base our approach on the Lacey-Cole merger model and on the Kennicutt relation which connects the star formation rate in galaxies with their infrared luminosity. We set the free parameters of the model in order to not exceed the SCUBA source counts, the Madau plot of star formation rate in the universe and COBE/FIRAS data on the intensity of the sub-millimeter cosmic background radiation. We show that the angular power spectrum arising from the distribution o...
Optical Characterization of the BICEP3 CMB Polarimeter at the South Pole
Karkare, K S; Ahmed, Z; Alexander, K D; Amiri, M; Barkats, D; Benton, S J; Bischoff, C A; Bock, J J; Boenish, H; Bowens-Rubin, R; Buder, I; Bullock, E; Buza, V; Connors, J; Filippini, J P; Fliescher, S T; Grayson, J A; Halpern, M; Harrison, S A; Hilton, G C; Hristov, V V; Hui, H; Irwin, K D; Kang, J H; Karpel, E; Kefeli, S; Kernasovskiy, S A; Kovac, J M; Kuo, C L; Leitch, E M; Lueker, M; Megerian, K G; Monticue, V; Namikawa, T; Netterfield, C B; Nguyen, H T; O'Brient, R; Ogburn, R W; Pryke, C; Reintsema, C D; Richter, S; Germaine, M T St; Schwarz, R; Sheehy, C D; Staniszewski, Z K; Steinbach, B; Teply, G P; Thompson, K L; Tolan, J E; Tucker, C; Turner, A D; Vieregg, A G; Wandui, A; Weber, A; Willmert, J; Wong, C L; Wu, W L K; Yoon, K W
2016-01-01
BICEP3 is a small-aperture refracting cosmic microwave background (CMB) telescope designed to make sensitive polarization maps in pursuit of a potential B-mode signal from inflationary gravitational waves. It is the latest in the BICEP/Keck Array series of CMB experiments at the South Pole, which has provided the most stringent constraints on inflation to date. For the 2016 observing season, BICEP3 was outfitted with a full suite of 2400 optically coupled detectors operating at 95 GHz. In these proceedings we report on the far field beam performance using calibration data taken during the 2015-2016 summer deployment season in situ with a thermal chopped source. We generate high-fidelity per-detector beam maps, show the array-averaged beam profile, and characterize the differential beam response between co-located, orthogonally polarized detectors which contributes to the leading instrumental systematic in pair differencing experiments. We find that the levels of differential pointing, beamwidth, and elliptici...
Development of Polarized HD Target for Future LEPS Experiments at Spring-8
Institute of Scientific and Technical Information of China (English)
H.Kohri; M.Fujiwara; K.Fukuda; T.Kunimatsu; C.Morisaki; T.Ohta; K.S.Ueda; M.Uraki; M.Utsuro; M.Yosoi; S.Y.Wang
2009-01-01
We are carrying out hadron photoproduction experiments by using polarized photon beams at SPring-8 in Japan.In 2005,we started developing a polarized HD target for future experiments using both the polarized photon beams and the polarized target.The polarized HD target is an idealistic target for experiments observing reactions with small cross sections because the HD does not include heavy nuclei which produce many background events.The measurement of double polarization asymmetries is expected to give much important information to investigate the nucleon hidden structure,hadron photoproduction dynamics,and exotic hadron property.We report on the present status of the development of the polarized HD target al RCNP.
Energy Technology Data Exchange (ETDEWEB)
Migliaccio, M.; Natoli, P.; De Troia, G. [Dipartimento di Fisica, Universita di Roma ' Tor Vergata' , Via della Ricerca Scientifica, 1 I-00133 Roma (Italy); Hikage, C. [School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA (United Kingdom); Komatsu, E. [Texas Cosmology Center, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States); Ade, P.A.R. [School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA (United Kingdom); Bock, J.J. [Jet Propulsion Laboratory, Pasadena, CA (United States); Bond, J.R. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, Ontario (Canada); Borrill, J. [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Boscaleri, A. [IFAC-CNR, Firenze (Italy); Contaldi, C.R. [Theoretical Physics Group, Imperial College, London (United Kingdom); Crill, B.P. [Jet Propulsion Laboratory, Pasadena, CA (United States); Bernardis, P. de [Dipartimento di Fisica, Universita La Sapienza, Roma (Italy); Gasperis, G. de [Dipartimento di Fisica, Universita di Roma ' Tor Vergata' , Via della Ricerca Scientifica, 1 I-00133 Roma (Italy); Oliveira-Costa, A. de [Department of Physics, MIT, Cambridge, MA 02139 (United States); Di Stefano, G. [Istituto Nazionale di Geofisica e Vulcanologia, 00143 Rome (Italy); Hivon, E. [Institut d' Astrophysique, Paris (France); Kisner, T.S. [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Jones, W.C. [Department of Physics, Princeton University, Princeton, NJ 0854 (United States); Lange, A.E. [Observational Cosmology, California Institute of Technology, Pasadena, CA (United States)
2009-10-15
Minkowski functionals are a powerful tool to constrain the Gaussianity of the Cosmic Microwave Background (CMB). In the limit of a weakly non Gaussian field, a perturbative approach can be derived [Hikage C., Komatsu E., and Matsubara T., 2006, ApJ, 653, 11] that is completely based on analytical formulae without requiring computationally intensive, dedicated Monte Carlo non Gaussian simulations of the CMB anisotropy. We apply this machinery to an intensity map derived from the 1998 and 2003 flights of BOOMERanG, analyzed here together for the first time. We set limits on the non-linear coupling parameter f{sub NL} as -1020
The future cost of electrical energy storage based on experience rates
Schmidt, O.; Hawkes, A.; Gambhir, A.; Staffell, I.
2017-08-01
Electrical energy storage could play a pivotal role in future low-carbon electricity systems, balancing inflexible or intermittent supply with demand. Cost projections are important for understanding this role, but data are scarce and uncertain. Here, we construct experience curves to project future prices for 11 electrical energy storage technologies. We find that, regardless of technology, capital costs are on a trajectory towards US$340 ± 60 kWh‑1 for installed stationary systems and US$175 ± 25 kWh‑1 for battery packs once 1 TWh of capacity is installed for each technology. Bottom-up assessment of material and production costs indicates this price range is not infeasible. Cumulative investments of US$175-510 billion would be needed for any technology to reach 1 TWh deployment, which could be achieved by 2027-2040 based on market growth projections. Finally, we explore how the derived rates of future cost reduction influence when storage becomes economically competitive in transport and residential applications. Thus, our experience-curve data set removes a barrier for further study by industry, policymakers and academics.
May, Wilhelm; Rummukainen, Markku; Chéruy, Frederique; Hagemann, Stefan; Meier, Arndt
2017-09-01
Changes in soil moisture are likely to contribute to future changes in latent heat flux and various characteristics of daily precipitation. Such contributions during the second half of the twenty-first century are assessed using the simulations from the GLACE-CMIP5 experiment, applying a linear regression analysis to determine the magnitude of these contributions. As characteristics of daily precipitation, mean daily precipitation, the frequency of wet days and the intensity of precipitation on wet days are considered. Also, the frequency and length of extended wet and dry spells are studied. Particular focus is on the regional (for nine selected regions) as well as seasonal variations in the magnitude of the contributions of the projected differences in soil moisture to the future changes in latent heat flux and in the characteristics of daily precipitation. The results reveal the overall tendency that the projected differences in soil moisture contribute to the future changes in response to the anthropogenic climate forcing for all the meteorological variables considered here. These contributions are stronger and more robust (i.e., there are smaller deviations between individual climate models) for the latent heat flux than for the characteristics of daily precipitation. It is also found that the contributions of the differences in soil moisture to the future changes are generally stronger and more robust for the frequency of wet days than for the intensity of daily precipitation. Consistent with the contributions of the projected differences in soil moisture to the future changes in the frequency of wet days, soil moisture generally contributes to the future changes in the characteristics of wet and dry spells. The magnitude of these contributions does not differ systematically between the frequency and the length of such extended spells, but the contributions are generally slightly stronger for dry spells than for wet spells. Distinguishing between the nine
CMB distortions from superconducting cosmic strings
Tashiro, Hiroyuki; Sabancilar, Eray; Vachaspati, Tanmay
2012-05-01
We reconsider the effect of electromagnetic radiation from superconducting strings on cosmic microwave background μ and y distortions and derive present (COBE-FIRAS) and future (PIXIE) constraints on the string tension, μs, and electric current, I. We show that absence of distortions of the cosmic microwave background in PIXIE will impose strong constraints on μs and I, leaving the possibility of light strings (Gμs≲10-18) or relatively weak currents (I≲10TeV).
Experience as a Basis for the Professional Development of Future Teacher of Music
Directory of Open Access Journals (Sweden)
Natalia Popovych
2014-06-01
Full Text Available This paper investigates the problem of forming the professional and personal experience of the future music teacher as the basis for improving its professional excellence. The aim of the study was the theoretical justification and experimental verification of the contents of the experience gained and pedagogical technology of development of the professional excellence of the future music teacher. The scientific research proved that the essence of the professional excellence of music teachers should be considered as a complex of musical and pedagogical personality traits formed in the process of training, that it is creative and focuses on the social and cultural active end result, i.e. the established high-level commitment to musical and pedagogical activities. The findings of this study indicate that one of the key tasks in training of a music teacher is to develop its professional and personal experience as a prerequisite for improving the professional excellence, professional stability, targeting a wide arsenal of innovative movements, scientific research and high-quality arrangement of the educational and upbringing process.
Study the radiation damage effects in Si microstrip detectors for future HEP experiments
Lalwani, Kavita; Jain, Geetika; Dalal, Ranjeet; Ranjan, Kirti; Bhardwaj, Ashutosh
2016-07-01
Silicon (Si) detectors are playing a key role in High Energy Physics (HEP) experiments due to their superior tracking capabilities. In future HEP experiments, like upgrade of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC), CERN, the silicon tracking detectors will be operated in a very intense radiation environment. This leads to both surface and bulk damage in Si detectors, which in turn will affect the operating performance of Si detectors. It is important to complement the measurements of the irradiated Si strip detectors with device simulation, which helps in understanding of both the device behavior and optimizing the design parameters needed for the future Si tracking system. An important ingredient of the device simulation is to develop a radiation damage model incorporating both bulk and surface damage. In this work, a simplified two-trap model is incorporated in device simulation to describe the type-inversion. Further, an extensive simulation of effective doping density as well as electric field profile is carried out at different temperatures for various fluences.
Doroshkevich, Andrei G.; Verkhodanov, Oleg V.; Naselsky, Pavel D.; Kim, Jaiseung; Novikov, Dmitry I.; Turchaninov, Viktor I.; Novikov, Igor D.; Chiang, Lung-Yih; Hansen, Martin
We present the development of the method for numerical analysis of polarization in the Gauss-Legendre sky pixelization (GLESP) scheme for CMB maps. This incorporation of the polarization transforms in the pixelization scheme GLESP completes the creation of our new method for numerical analysis of CMB maps. A comparison of GLESP and HEALPix calculations is done.
Doroshkevich, Andrei G; Naselsky, Pavel D; Kim, Jaiseung; Novikov, Dmitry I; Turchaninov, Viktor I; Novikov, Igor D; Chiang, Lung-Yih; Hansen, Martin
2009-01-01
We present developing of method of the numerical analysis of polarization in the Gauss--Legendre Sky Pixelization (GLESP) scheme for the CMB maps. This incorporation of the polarization transforms in the pixelization scheme GLESP completes the creation of our new method for the numerical analysis of CMB maps. The comparison of GLESP and HEALPix calculations is done.
Experience of Future Economists’ Self-Study Organization in Foreign Higher Education Institutions
Directory of Open Access Journals (Sweden)
Aliyev Oktay
2016-06-01
Full Text Available The article consolidates information sources on the issues of future economists’ self-study organization at foreign universities. There has been carried out the study of approaches to the interpretation of the term “self-study process” in the contemporary scientific thought abroad. There have been specified the productive ideas of foreign experience which are to be understood and implemented into practice of domestic higher education institutions in terms of professional training of future specialists in the field of social and behavioural sciences majoring in Economics, including the following: 1 student self-study is supposed to be a mandatory part of the educational process, with the amount of time dedicated to being less than 65 percent. At the same time a student-personalized approach to each student should be implemented and the course of study, specifics of the subject being learnt should be taken into account; the teachers are expected to offer verbal consulting and ICT support (including university web resources of student self-study; 2 while organizing the educational process (syllabi, curricula for students of different educational levels it should be taken into account that there is a link between self-education of future economists with his/her practical activities along with development prospects of the sector; 3 organization of future economists’ self-study should be based on the student’s conscious attitude to learning, recognition of its role in meeting the challenges and solving the urgent problems of economic education (motivational component; on knowledge forming the basis for the individual’s self-study and determining his/her readiness for self-education in their future careers (cognitive component; on combination of skills and abilities of the individual, determining his/her functional readiness for professional self-education on challenging issues of economic sphere (operational and pragmatist component.
Probing early-universe phase transitions with CMB spectral distortions
Amin, Mustafa A.; Grin, Daniel
2014-10-01
Global, symmetry-breaking phase transitions in the early universe can generate scaling seed networks which lead to metric perturbations. The acoustic waves in the photon-baryon plasma sourced by these metric perturbations, when Silk damped, generate spectral distortions of the cosmic microwave background (CMB). In this work, the chemical potential distortion (μ ) due to scaling seed networks is computed and the accompanying Compton y -type distortion is estimated. The specific model of choice is the O (N ) nonlinear σ -model for N ≫1 , but the results remain the same order of magnitude for other scaling seeds. If CMB anisotropy constraints to the O (N ) model are saturated, the resulting chemical potential distortion μ ≲2 ×1 0-9 .
The large-scale angular correlations in CMB temperature maps
Bernui, A
2005-01-01
Observations show that the Cosmic Microwave Background (CMB) contains tiny variations at the 10^{-5} level around its black-body equilibrium temperature. The detection of these temperature fluctuations provides to modern Cosmology evidence for the existence of primordial density perturbations that seeded all the structures presently observed. The vast majority of the cosmological information is contained in the 2-point temperature function, which measures the angular correlation of these temperature fluctuations distributed on the celestial sphere. Here we study such angular correlations using a recently introduced statistic-geometrical method. Moreover, we use Monte Carlo simulated CMB temperature maps to show the equivalence of this method with the 2-point temperature function (best known as the 2-Point Angular Correlation Function). We also investigate here the robustness of this new method under possible divisions of the original catalog-data in sub-catalogs. Finally, we show some applications of this new...
Probing early-universe phase transitions with CMB spectral distortions
Amin, Mustafa A
2014-01-01
Global, symmetry-breaking phase transitions in the early universe can generate scaling seed networks which lead to metric perturbations. The acoustic waves in the photon-baryon plasma sourced by these metric perturbations, when Silk damped, generate spectral distortions of the cosmic microwave background (CMB). In this work, the chemical potential distortion ($\\mu$) due to scaling seed networks is computed and the accompanying Compton $y$-type distortion is estimated. The specific model of choice is the $O(N)$ nonlinear $\\sigma$-model for $N\\gg 1$, but the results remain the same order of magnitude for other scaling seeds. If CMB anisotropy constraints to the $O(N)$ model are saturated, the resulting chemical potential distortion $\\mu \\lesssim 2\\times 10^{-9}$.
Hidden in the background: A local approach to CMB anomalies
Sanchez, Juan C Bueno
2016-01-01
We investigate a framework aiming to provide a common origin for the large-angle anomalies detected in the Cosmic Microwave Background (CMB), which are hypothesized as the result of the statistical inhomogeneity developed by different isocurvature fields of mass $m\\sim H$ present during inflation. The inhomogeneity arises as the combined effect of $(i)$ the initial conditions for isocurvature fields (obtained after a fast-roll stage finishing many $e$-foldings before cosmological scales exit the horizon), $(ii)$ their inflationary fluctuations and $(iii)$ their coupling to other degrees of freedom. Our case of interest is when these fields (interpreted as the precursors of large-angle anomalies) leave an observable imprint only in isolated patches of the Universe. When the latter intersect the last scattering surface, such imprints arise in the CMB. Nevertheless, due to their statistically inhomogeneous nature, these imprints are difficult to detect, for they become hidden in the background similarly to the C...
Power law cosmology model comparison with CMB scale information
Tutusaus, Isaac; Blanchard, Alain; Dupays, Arnaud; Zolnierowski, Yves; Cohen-Tanugi, Johann; Ealet, Anne; Escoffier, Stéphanie; Fèvre, Olivier Le; Ilić, Stéphane; Piazza, Federico; Pisani, Alice; Plaszczynski, Stéphane; Sakr, Ziad; Salvatelli, Valentina; Schücker, Thomas; Tilquin, André; Virey, Jean-Marc
2016-01-01
Despite the ability of the cosmological concordance model ($\\Lambda$CDM) to describe the cosmological observations exceedingly well, power law expansion of the Universe scale radius has been proposed as an alternative framework. We examine here these models, analyzing their ability to fit cosmological data using robust model comparison criteria. Type Ia supernovae (SNIa), baryonic acoustic oscillations (BAO) and acoustic scale information from the cosmic microwave background (CMB) have been used. We find that SNIa data either alone or combined with BAO, can be well reproduced by both $\\Lambda$CDM and power law expansion models with $n \\sim 1.5$, while the constant expansion rate model ($n = 1$) is clearly disfavored. Allowing for some redshift evolution in the SNIa luminosity essentially removes any clear preference for a specific model. The CMB data is well known to provide the most stringent constraints on standard cosmological models, in particular through the position of the first peak of the temperature ...
Planck 2015 results. XVI. Isotropy and statistics of the CMB
Ade, P.A.R.; Akrami, Y.; Aluri, P.K.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Casaponsa, B.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Contreras, D.; Couchot, F.; Coulais, A.; Crill, B.P.; Cruz, M.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Desert, F.X.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Fantaye, Y.; Fergusson, J.; Fernandez-Cobos, R.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Ghosh, T.; Giard, M.; Giraud-Heraud, Y.; Gjerlow, E.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huang, Z.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kim, J.; Kisner, T.S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Liu, H.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mikkelsen, K.; Mitra, S.; Miville-Deschenes, M.A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Pant, N.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T.J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Rotti, A.; Roudier, G.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Souradeep, T.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; Yvon, D.; Zacchei, A.; Zibin, J.P.; Zonca, A.
2016-01-01
We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold S...
The ISW imprints of voids and superclusters on the CMB
Hotchkiss, S.; Nadathur, S.; Gottlöber, S.; Iliev, I. T.; Knebe, A.; Watson, W. A.; Yepes, G.
2016-10-01
We examine the stacked integrated Sachs-Wolfe (ISW) imprints on the CMB along the lines of sight of voids and superclusters in galaxy surveys, using the Jubilee ISW simulation and mock luminous red galaxy (LRG) catalogues. We show that the expected signal in the concordance \\Lam CDM model is much smaller than the primary anisotropies arising at the last scattering surface and therefore any currently claimed detections of such an imprint cannot be caused by the ISW effect in \\Lam CDM. We look for the existence of such a signal in the Planck CMB using a catalogue of voids and superclusters from the Sloan Digital Sky Survey (SDSS), but find a result completely consistent with \\Lam CDM - i.e., a null detection.
Large-Angle CMB Suppression and Polarisation Predictions
Copi, C.J.; Schwarz, D.J.; Starkman, G.D.
2013-01-01
The anomalous lack of large angle temperature correlations has been a surprising feature of the CMB since first observed by COBE-DMR and subsequently confirmed and strengthened by WMAP. This anomaly may point to the need for modifications of the standard model of cosmology or may show that our Universe is a rare statistical fluctuation within that model. Further observations of the temperature auto-correlation function will not elucidate the issue; sufficiently high precision statistical observations already exist. Instead, alternative probes are required. In this work we explore the expectations for forthcoming polarisation observations. We define a prescription to test the hypothesis that the large-angle CMB temperature perturbations in our Universe represent a rare statistical fluctuation within the standard cosmological model. These tests are based on the temperature-Q Stokes parameter correlation. Unfortunately these tests cannot be expected to be definitive. However, we do show that if this TQ-correlati...
Planck 2013 results. XXIII. Isotropy and Statistics of the CMB
Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Battaner, E.; Battye, R.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.R.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Cruz, M.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Fantaye, Y.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Frommert, M.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, M.; Hansen, F.K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kim, J.; Kisner, T.S.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Leahy, J.P.; Leonardi, R.; Leroy, C.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McEwen, J.D.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mikkelsen, K.; Mitra, S.; Miville-Deschenes, M.A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Peiris, H.V.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Pogosyan, D.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rath, C.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rotti, A.; Roudier, G.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Souradeep, T.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutter, P.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Turler, M.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; White, M.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.
2014-01-01
The two fundamental assumptions of the standard cosmological model - that the initial fluctuations are statistically isotropic and Gaussian - are rigorously tested using maps of the cosmic microwave background (CMB) anisotropy from the Planck satellite. Deviations from isotropy have been found and demonstrated to be robust against component separation algorithm, mask choice and frequency dependence. Many of these anomalies were previously observed in the WMAP data, and are now confirmed at similar levels of significance (about 3 sigma). However, we find little evidence for non-Gaussianity, with the exception of a few statistical signatures that seem to be associated with specific anomalies. In particular, we find that the quadrupole-octopole alignment is also connected to a low observed variance of the CMB signal. A power asymmetry is now found to persist to scales corresponding to about l=600, and can be described in the low-l regime by a phenomenological dipole modulation model. However, any primordial powe...
CMB and reheating constraints to \\alpha-attractor inflationary models
Eshaghi, Mehdi; Riazi, Nematollah; Kiasatpour, Ahmad
2016-01-01
After Planck 2013, a broad class of inflationary models called \\alpha-attractors was developed which has universal observational predictions. For small values of the parameter \\alpha, the models have good consistency with the recent CMB data. In this work, we first calculate analytically (and verify numerically) the predictions of these models for spectral index, n_s and tensor-to-scalar ratio, r and then using BICEP2/Keck 2015 data we impose constraints on \\alpha-attractors. Then, we study the reheating in \\alpha-attractors. The reheating temperature, T_{re} and the number of e-folds during reheating, N_{re} are calculated as functions of n_s. Using these results, we determine the range of free parameter \\alpha for two clasees of \\alpha-attractors which satisfy the constraints of recent CMB data.
Signatures of Relativistic Neutrinos in CMB Anisotropy and Matter Clustering
Bashinsky, S V; Bashinsky, Sergei; Seljak, Uros
2004-01-01
We present a detailed analytical study of ultra-relativistic neutrinos in cosmological perturbation theory and of the observable signatures of inhomogeneities in the cosmic neutrino background. We note that a modification of perturbation variables that removes all the time derivatives of scalar gravitational potentials from the dynamical equations simplifies their solution notably. The used perturbations of particle number per coordinate, not proper, volume are generally constant on superhorizon scales. In real space an analytical analysis can be extended beyond fluids to neutrinos. The faster cosmological expansion due to the neutrino background changes the acoustic and damping angular scales of the cosmic microwave background (CMB). But we find that equivalent changes can be produced by varying other standard parameters, including the primordial helium abundance. The low-l integrated Sachs-Wolfe effect is also not sensitive to neutrinos. However, the gravity of neutrino perturbations suppresses the CMB acou...
$\\mu$-Distortions or Running: A Guaranteed Discovery from CMB Spectrometry
Cabass, Giovanni; Pajer, Enrico
2016-01-01
We discuss the implications of a PIXIE-like experiment, which would measure $\\mu$-type spectral distortions of the CMB at a level of $\\sigma_{\\mu}=(1/n)\\times 10^{-8}$, with $n\\geq1$ representing an improved sensitivity (e.g. $n=10$ corresponds to PRISM). Using Planck data and considering the six-parameter $\\Lambda$CDM model, we compute the posterior for $\\mu_8\\equiv\\mu\\times 10^{8}$ and find $\\mu_8=1.57^{+0.11}_{-0.13}$ ($68\\%\\,\\mathrm{CL}$). This becomes $\\mu_{8} = 1.28^{+0.30}_{-0.52}$ ($68\\%\\,\\mathrm{CL}$) when the running $\\alpha_\\mathrm{s}$ of the spectral index is included. We point out that a sensitivity of about $3\\times$ PIXIE implies a guaranteed discovery: $\\mu$-distortion is detected or $\\alpha_\\mathrm{s}\\geq 0$ is excluded (both at $95\\%\\,\\mathrm{CL}$ or higher). This threshold sensitivity sets a clear benchmark for CMB spectrometry. For a combined analysis of PIXIE and current Planck data, we discuss the improvement on measurements of the tilt $n_\\mathrm{s}$ and the running $\\alpha_\\mathrm{s}$ ...
The Atacama B-Mode Search: CMB Polarimetry with Transition-Edge-Sensor Bolometers
Essinger-Hileman, T; Beall, J A; Cho, H M; Fowler, J; Halpern, M; Hasselfield, M; Irwin, K D; Marriage, T A; Niemack, M D; Page, L; Parker, L P; Pufu, S; Staggs, S T; Stryzak, O; Visnjic, C; Yoon, K W; Zhao, Y
2010-01-01
The Atacama B-mode Search (ABS) experiment is a 145 GHz polarimeter designed to measure the B-mode polarization of the Cosmic Microwave Background (CMB) at large angular scales. The ABS instrument will ship to the Atacama Desert of Chile fully tested and ready to observe in 2010. ABS will image large-angular-scale CMB polarization anisotropies onto a focal plane of 240 feedhorn-coupled, transition-edge sensor (TES) polarimeters, using a cryogenic crossed-Dragone design. The ABS detectors, which are fabricated at NIST, use orthomode transducers to couple orthogonal polarizations of incoming radiation onto separate TES bolometers. The incoming radiation is modulated by an ambient-temperature half-wave plate in front of the vacuum window at an aperture stop. Preliminary detector characterization indicates that the ABS detectors can achieve a sensitivity of 300 $\\mu K \\sqrt{s}$ in the field. This paper describes the ABS optical design and detector readout scheme, including feedhorn design and performance, magneti...
Second Season QUIET Observations: Measurements of the CMB Polarization Power Spectrum at 95 GHz
Araujo, D; Brizius, A; Buder, I; Chinone, Y; Cleary, K; Dumoulin, R N; Kusaka, A; Monsalve, R; Næss, S K; Newburgh, L B; Reeves, R; Wehus, I K; Zwart, J T L; Bronfman, L; Bustos, R; Church, S E; Dickinson, C; Eriksen, H K; Gaier, T; Gundersen, J O; Hasegawa, M; Hazumi, M; Huffenberger, K M; Ishidoshiro, K; Jones, M E; Kangaslahti, P; Kapner, D J; Kubik, D; Lawrence, C R; Limon, M; McMahon, J J; Miller, A D; Nagai, M; Nguyen, H; Nixon, G; Pearson, T J; Piccirillo, L; Radford, S J E; Readhead, A C S; Richards, J L; Samtleben, D; Seiffert, M; Shepherd, M C; Smith, K M; Staggs, S T; Tajima, O; Thompson, K L; Vanderlinde, K; Williamson, R
2012-01-01
The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95GHz. The 43-GHz results have been published in QUIET Collaboration et al. (2011), and here we report the measurement of CMB polarization power spectra using the 95-GHz data. This data set comprises 5337 hours of observations recorded by an array of 84 polarized coherent receivers with a total array sensitivity of 87 uK sqrt(s). Four low-foreground fields were observed, covering a total of ~1000 square degrees with an effective angular resolution of 12.8', allowing for constraints on primordial gravitational waves and high-signal-to-noise measurements of the E-modes across three acoustic peaks. The data reduction was performed using two independent analysis pipelines, one based on a pseudo-Cl (PCL) cross-correlation approach, and the other on a maximum-likelihood (ML) approach. All data selection criteria and filters were modified until a predefined set of null tests had been satisfied before inspecting any non-nu...
Constraints on dark matter interactions with standard model particles from CMB spectral distortions
Ali-Haïmoud, Yacine; Kamionkowski, Marc
2015-01-01
We propose a new method to constrain elastic scattering between dark matter (DM) and standard model particles in the early Universe. Direct or indirect thermal coupling of non-relativistic DM with photons leads to a heat sink for the latter. This results in spectral distortions of the cosmic microwave background (CMB), the amplitude of which can be as large as a few times the DM-to-photon number ratio. We compute CMB spectral distortions due to DM-proton, DM-electron and DM-photon scattering for generic energy-dependent cross sections and DM mass m_DM >~ 1 keV. Using FIRAS measurements we set constraints on the cross sections for m_DM <~ 0.1 MeV. In particular, for energy-independent scattering we obtain sigma[DM-proton] <~ 10^(-24) cm^2 (keV/m_DM)^(1/2), sigma[DM-electron] <~ 10^(-27) cm^2 (keV/m_DM)^(1/2) and sigma[DM-photon] <~ 10^(-39) cm^2 (m_DM/keV). An experiment with the characteristics of PIXIE would extend the regime of sensitivity up to masses m_DM ~ 1 GeV.
Semi-Digital hadronic calorimeter for future high energy physics experiments
Energy Technology Data Exchange (ETDEWEB)
Laktineh, Imad, E-mail: laktineh@in2p3.f [Universite de Lyon, Universite de Lyon 1, CNRS/IN2P3, IPNL 4 rue E.Fermi 69622 Villeurbanne cedex (France)
2009-04-01
A new concept of high granularity hadronic calorimeter based on a semi-digital readout for future ILC experiments is presented. The aim of this concept is to provide the HCAL with a tracking capacity in addition to a good energy measurement resolution. The sensitive medium of this HCAL is made of very thin gas detectors. The readout is based on detector-embedded electronic boards equipped with low consumption daisy-chained 64-channel chips. The nice results obtained with a slice test made of small detectors show that the concept is successful and can be used to build a 1m3 semi-digital HCAL prototype.
Testing keV sterile neutrino dark matter in future direct detection experiments
Campos, Miguel D
2016-01-01
We determine constraints on sterile neutrino warm dark matter through direct detection experiments, taking XENON100 and its future stages as example. If keV-scale sterile neutrinos scatter inelastically with bound electrons of the target material, an electron recoil signal is generated. This can be used to set limits on the sterile neutrino mass and its mixing with the active sector. While not competitive with astrophysical constraints from X-ray data, the constraints are the first direct laboratory bounds on sterile neutrino warm dark matter, and will be in some parts of parameter space the strongest limits on keV-scale neutrinos.
New evidence for lack of CMB power on large scales
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum of the cosmic microwave background (CMB) is derived. The amplitudes of the low multipoles (low-l) measured from the preliminary Planck power spectrum are significantly lower than those reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences.
Conformal invariance, dark energy, and CMB non-gaussianity
Energy Technology Data Exchange (ETDEWEB)
Antoniadis, Ignatios [Department of Physics, CERN, Theory Division CH-1211 Geneva 23 (Switzerland); Mazur, Pawel O. [Department of Physics and Astronomy, University of South Carolina Columbia SC 29208 (United States); Mottola, Emil, E-mail: ignatios.antoniadis@cern.ch, E-mail: mazur@physics.sc.edu, E-mail: emil@lanl.gov [Theoretical Division, MS B285 Los Alamos National Laboratory Los Alamos, NM 87545 (United States)
2012-09-01
In addition to simple scale invariance, a universe dominated by dark energy naturally gives rise to correlation functions possessing full conformal invariance. This is due to the mathematical isomorphism between the conformal group of certain three dimensional slices of de Sitter space and the de Sitter isometry group SO(4,1). In the standard homogeneous, isotropic cosmological model in which primordial density perturbations are generated during a long vacuum energy dominated de Sitter phase, the embedding of flat spatial R{sup 3} sections in de Sitter space induces a conformal invariant perturbation spectrum and definite prediction for the shape of the non-Gaussian CMB bispectrum. In the case in which the density fluctuations are generated instead on the de Sitter horizon, conformal invariance of the S{sup 2} horizon embedding implies a different but also quite definite prediction for the angular correlations of CMB non-Gaussianity on the sky. Each of these forms for the bispectrum is intrinsic to the symmetries of de Sitter space, and in that sense, independent of specific model assumptions. Each is different from the predictions of single field slow roll inflation models, which rely on the breaking of de Sitter invariance. We propose a quantum origin for the CMB fluctuations in the scalar gravitational sector from the conformal anomaly that could give rise to these non-Gaussianities without a slow roll inflaton field, and argue that conformal invariance also leads to the expectation for the relation n{sub S}−1 = n{sub T} between the spectral indices of the scalar and tensor power spectrum. Confirmation of this prediction or detection of non-Gaussian correlations in the CMB of one of the bispectral shape functions predicted by conformal invariance can be used both to establish the physical origins of primordial density fluctuations, and distinguish between different dynamical models of cosmological vacuum dark energy.
Adiabatic CMB perturbations in pre-big bang string cosmology
Enqvist, Kari; Enqvist, Kari; Sloth, Martin S.
2002-01-01
We consider the pre-big bang scenario with a massive axion field which starts to dominate energy density when oscillating in an instanton-induced potential and subsequently reheats the universe as it decays into photons, thus creating adiabatic CMB perturbations. We find that the fluctuations in the axion field can give rise to a nearly flat spectrum of adiabatic perturbations with a spectral tilt $\\Delta n$ in the range $-0.1 \\lesssim \\Delta n \\lesssim 0.3$.
Future wishes and constraints from the experiments at the LHC for the proton-proton programme
Jacobsson, R
2014-01-01
Hosting six different experiments at four different interaction points and widely different requirements for the running conditions, the LHC machine has been faced with a long list of challenges in the first three years of luminosity production 2010 – 2012 (Run 1), many of which were potentially capable of limiting the performance due to instabilities resulting from the extremely high bunch brightness. Nonetheless, LHC met the challenges and performed extremely well at high efficiency and routinely with beam brightness at twice the design, well over 1/3 of the time in collision for physics, average luminosity lifetimes in excess of 10h, and extremely good background conditions in the experiments. While the experimental running configurations remain largely the same for the future high luminosity proton-proton operational mode, the energy and the luminosity should increase significantly making a prior assessment of related beam-beam effects extremely important to guarantee high performance. Of particular in...
Probing gravity at large scales through CMB lensing
Pullen, Anthony R; Ho, Shirley
2014-01-01
We describe a methodology to probe gravity with the CMB lensing convergence $\\kappa$, specifically by measuring $E_G$, the ratio of the Laplacian of the gravitational scalar potential difference with the peculiar velocity divergence. Using $\\kappa$ from CMB lensing as opposed to galaxy-galaxy lensing avoids intrinsic alignments while also lacking a hard limit on the lens redshift or significant uncertainties in the source plane. We model $E_G$ for general relativity and modified gravity, finding that $E_G$ for $f(R)$ gravity should be scale-dependent due to the scale-dependence of the growth rate $f$. Next, we construct an estimator for $E_G$ in terms of the lensing convergence-galaxy and galaxy angular power spectra, along with the RSD parameter $\\beta$. We also forecast statistical errors of $E_G$ from the current Planck CMB lensing map and the CMASS and LOWZ spectroscopic galaxy samples measured from the BOSS survey, as well as BOSS spectroscopic quasars, from the SDSS Data Release 11. We expect this exper...
The Temperature of the CMB at 10 GHz
Fixsen, D J; Levin, S; Limon, M; Lubin, P; Mirel, P G A; Seiffert, M; Wollack, E
2004-01-01
We report the results of an effort to measure the low frequency portion of the spectrum of the Cosmic Microwave Background Radiation (CMB), using a balloon-borne instrument called ARCADE (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission). These measurements are to search for deviations from a thermal spectrum that are expected to exist in the CMB due to various processes in the early universe. The radiometric temperature was measured at 10 and 30 GHz using a cryogenic open-aperture instrument with no emissive windows. An external blackbody calibrator provides an in situ reference. A linear model is used to compare the radiometer output to a set of thermometers on the instrument. The unmodeled residuals are less than 50 mK peak-to-peak with a weighted RMS of 6 mK. Small corrections are made for the residual emission from the flight train, atmosphere, and foreground Galactic emission. The measured radiometric temperature of the CMB is 2.721 +/- 0.010 K at 10 GHz and 2.694 +/- 0.032 K at 30 ...
Parity violation in the CMB trispectrum from the scalar sector
Shiraishi, Maresuke
2016-01-01
Under the existence of chiral non-Gaussian sources during inflation, the trispectrum of primordial curvature perturbations can break parity. We examine signatures of the induced trispectrum of the cosmic microwave background (CMB) anisotropies. It is confirmed via harmonic-space analysis that such CMB trispectrum has nonvanishing signal in the $\\ell_1 + \\ell_2 + \\ell_3 + \\ell_4 = \\text{odd}$ domain, as a consequence of parity violation. When the curvature trispectrum is parametrized with Legendre polynomials, the CMB signal due to the Legendre dipolar term is enhanced at the squeezed configurations in $\\ell$ space, yielding a high signal-to-noise ratio. A Fisher matrix computation results in a minimum detectable size of the dipolar coefficient in a cosmic-variance-limited-level temperature survey as $d_1^{\\rm odd} = 640$. In an inflationary model where the inflaton field couples to the gauge field via a $f(\\phi)(F^2 + F\\tilde{F})$ interaction, the curvature trispectrum contains such parity-odd dipolar term. W...
Echoes of Inflationary Particle Phase Transitions in the CMB
Jiang, Hongliang; Sun, Sichun; Wang, Yi
2015-01-01
Cosmological phase transitions (CPTs), such as the Grand Unified Theory (GUT) and the electroweak (EW) ones, play a significant role in both particle physics and cosmology. In this letter, we propose to probe the first-order CPTs, by detecting gravitational waves (GWs) which are generated during the phase transitions through the cosmic microwave background (CMB). If happened around the inflation era, the first-order CPTs may yield low-frequency GWs due to bubble dynamics, leaving imprints on the CMB. In contrast to the nearly scale-invariant primordial GWs caused by vacuum fluctuation, these bubble-generated GWs are scale dependent and have non-trivial B-mode spectra. If decoupled from inflaton, the EWPT during inflation may serve as a mirror image of the one after reheating where the baryon asymmetry could be generated via EW baryogenesis (EWBG). The CMB thus provides a potential way to test the feasibility of the EWBG, complementary to the collider measurements of Higgs potential and the direct detection of...
Lensing bias to CMB measurements of compensated isocurvature perturbations
Heinrich, Chen He; Grin, Daniel; Hu, Wayne
2016-08-01
Compensated isocurvature perturbations (CIPs) are modes in which the baryon and dark matter density fluctuations cancel. They arise in the curvaton scenario as well as some models of baryogenesis. While they leave no observable effects on the cosmic microwave background (CMB) at linear order, they do spatially modulate two-point CMB statistics and can be reconstructed in a manner similar to gravitational lensing. Due to the similarity between the effects of CMB lensing and CIPs, lensing contributes nearly Gaussian random noise to the CIP estimator that approximately doubles the reconstruction noise power. Additionally, the cross correlation between lensing and the integrated Sachs-Wolfe effect generates a correlation between the CIP estimator and the temperature field even in the absence of a correlated CIP signal. For cosmic-variance limited temperature measurements out to multipoles l ≤2500 , subtracting a fixed lensing bias degrades the detection threshold for CIPs by a factor of 1.3, whether or not they are correlated with the adiabatic mode.
A CMB GIBBS SAMPLER FOR LOCALIZED SECONDARY ANISOTROPIES
Energy Technology Data Exchange (ETDEWEB)
Bull, Philip; Eriksen, Hans Kristian; Fuskeland, Unni [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Wehus, Ingunn K.; Ferreira, Pedro G. [Astrophysics, University of Oxford, DWB, Keble Road, Oxford OX1 3RH (United Kingdom); Górski, Krzysztof M.; Jewell, Jeffrey B., E-mail: p.j.bull@astro.uio.no [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
2015-07-20
In addition to primary fluctuations, cosmic microwave background (CMB) temperature maps contain a wealth of additional information in the form of secondary anisotropies. However, secondary effects that can be identified with individual objects, such as the thermal and kinetic Sunyaev–Zel’dovich (TSZ–KSZ) effects due to galaxy clusters, are difficult to unambiguously disentangle from foreground contamination and the primary CMB. We develop a Bayesian formalism to rigorously characterize anisotropies that are localized on the sky, taking the TSZ and KSZ effects as an example. Using a Gibbs sampling scheme, we are able to efficiently sample from the joint posterior distribution for a multi-component model of the sky with many thousands of correlated physical parameters. The posterior can then be exactly marginalized to estimate the properties of the secondary anisotropies, fully taking into account degeneracies with the other signals in the CMB map. We show that this method is computationally tractable using a simple implementation based on the existing Commander component separation code and discuss how other types of secondary anisotropy can be accommodated within our framework.
Improved Measurements of the CMB Power Spectrum with ACBAR
Kuo, C L; Bock, J J; Bond, J R; Contaldi, C R; Daub, M D; Goldstein, J H; Holzapfel, W L; Lange, A E; Lueker, M; Newcomb, M; Peterson, J B; Reichardt, C; Ruhl, J; Runyan, M C; Staniszweski, Z
2006-01-01
We report improved measurements of temperature anisotropies in the cosmic microwave background (CMB) radiation made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). In this paper, we use a new analysis technique and include 30% more data from the 2001 and 2002 observing seasons than the first release to derive a new set of band-power measurements with significantly smaller uncertainties. The planet-based calibration used previously has been replaced by comparing the flux of RCW38 as measured by ACBAR and BOOMERANG to transfer the WMAP-based BOOMERANG calibration to ACBAR. The resulting power spectrum is consistent with the theoretical predictions for a spatially flat, dark energy dominated LCDM cosmology including the effects of gravitational lensing. Despite the exponential damping on small angular scales, the primary CMB fluctuations are detected with a signal-to-noise ratio of greater than 4 up to multipoles of l=2000. This increase in the precision of the fine-scale CMB power spectrum leads ...
Electron-Phonon Decoupling NbSi CMB Bolometers
Marnieros, S.; Nones, C.; Dumoulin, L.; Bergé, L.; Rigaut, O.; Monfardini, A.; Camus, P.; Benoit, A.
2012-06-01
Precise measurements of the cosmic microwave background (CMB) is crucial to cosmology, since any proposed model of the Universe must account for the features of this radiation. E_cient very large bolometer arrays (>10,000 pixels) constitute an important challenge for CMB observations and are actually developed by many groups worldwide. We present here an explorative new bolometer design based on a structure that simplifies the fabrication process and exhibits high sensitivity. This innovative device replaces delicate membrane-based structures and eliminates the mediation of phonons: the incoming energy is directly captured and measured in the electron bath of an appropriate sensor and the thermal decoupling is achieved via the intrinsic electron-phonon decoupling of the sensor at very low temperature. Reported results come from a 204-pixel matrix of Nb x Si1- x transition edge sensors with a meander structure fabricated on a 2-inch silicon wafer using electron-beam co-evaporation and standard lithography process. To validate the application to CMB measurements, we have realized an optical calibration of our sample in the focal plane of a dilution cryostat test bench.
Planck 2013 results. XV. CMB power spectra and likelihood
Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Gaier, T.C.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Heraud, Y.; Gjerlow, E.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, T.R.; Jaffe, A.H.; Jewell, J.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kiiveri, K.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Laureijs, R.J.; Lawrence, C.R.; Le Jeune, M.; Leach, S.; Leahy, J.P.; Leonardi, R.; Leon-Tavares, J.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Lindholm, V.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Marinucci, D.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Millea, M.; Mitra, S.; Miville-Deschenes, M.A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Dwyer, I.J.; Orieux, F.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Paykari, P.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rahlin, A.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ringeval, C.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Sanselme, L.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Turler, M.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; White, M.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.
2014-01-01
We present the Planck likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations. We use this likelihood to derive the Planck CMB power spectrum over three decades in l, covering 2 = 50, we employ a correlated Gaussian likelihood approximation based on angular cross-spectra derived from the 100, 143 and 217 GHz channels. We validate our likelihood through an extensive suite of consistency tests, and assess the impact of residual foreground and instrumental uncertainties on cosmological parameters. We find good internal agreement among the high-l cross-spectra with residuals of a few uK^2 at l <= 1000. We compare our results with foreground-cleaned CMB maps, and with cross-spectra derived from the 70 GHz Planck map, and find broad agreement in terms of spectrum residuals and cosmological parameters. The best-fit LCDM cosmology is in excellent agreement with preliminary Planck polarisation spectra. The standard LCDM cosmology is well constrained b...
CMB Anomalies from Imperfect Dark Energy: Confrontation with the Data
Axelsson, Magnus J; Koivisto, Tomi; Mota, David F
2011-01-01
We test anisotropic dark energy models with the 7-year WMAP temperature observations data. In the presence of imperfect sources, due to large-scale gradients or anisotropies in the dark energy field, the CMB sky will be distorted anisotropically on its way to us by the ISW effect. The signal covariance matrix then becomes nondiagonal for small multipoles, but at $\\ell \\gtrsim 20$ the anisotropy is negligible. We parametrize possible violations of rotational invariance in the late universe by the magnitude of a post-Friedmannian deviation from isotropy and its scale dependence. This allows to obtain hints on possible imperfect nature of dark energy and the large-angle anomalous features in the CMB. A robust statistical analysis, subjected to various tests and consistency checks, is performed to compare the predicted correlations with those obtained from the satellite-measured CMB full sky maps. The preferred axis point towards $(l,b) = (168^\\circ, -31^\\circ)$ and the amplitude of the anisotropy is $\\varpi_0 = ...
Cosmological Avatars of the Landscape II: CMB and LSS Signatures
Holman, R; Takahashi, T; Mersini-Houghton, Laura; Takahashi, Tomo
2006-01-01
This is the second paper in the series that confronts predictions of a model of the landscape with cosmological observations. We show here how the modifications of the Friedmann equation due to the decohering effects of long wavelength modes on the wavefunction of the Universe defined on the landscape leave unique signatures on the CMB spectra and large scale structure (LSS). We show that the effect of the string corrections is to suppress $\\sigma_8$ and the CMB $TT$ spectrum at large angles, thereby bringing WMAP and SDSS data for $\\sigma_8$ into agreement. We find interesting features imprinted on the matter power spectrum $P(k)$: power is suppressed at large scales indicating the possibility of primordial voids competing with the ISW effect. Furthermore, power is enhanced at structure and substructure scales, $k\\simeq 10^{-2-0} h~{\\rm Mpc}^{-1}$. Our smoking gun for discriminating this proposal from others with similar CMB and LSS predictions come from correlations between cosmic shear and temperature anis...
Kohri, Kazunori; Nakama, Tomohiro; Suyama, Teruaki
2014-10-01
Supermassive black holes and intermediate mass black holes are believed to exist in the Universe. There is no established astrophysical explanation for their origin, and considerations have been made in the literature that those massive black holes (MBHs) may be primordial black holes (PBHs), black holes which are formed in the early universe (well before the matter-radiation equality) due to the direct collapse of primordial overdensities. This paper aims at discussing the possibility of excluding the PBH scenario as the origin of the MBHs. We first revisit the constraints on PBHs obtained from the cosmic microwave background (CMB) distortion that the seed density perturbation causes. By adopting a recent computation of the CMB distortion sourced by the seed density perturbation and the stronger constraint on the CMB distortion set by the COBE/FIRAS experiment used in the literature, we find that PBHs in the mass range 6×104 M⊙-5×1013 M⊙ are excluded. Since PBHs lighter than 6×104 M⊙ are not excluded from the nonobservation of the CMB distortion, we propose a new method which can potentially exclude smaller PBHs as well. Based on the observation that large density perturbations required to create PBHs also result in the copious production of ultracompact minihalos (UCMHs), compact dark matter halos formed at around the recombination, we show that weakly interacting massive particles (WIMPs) as dark matter annihilate efficiently inside UCMHs to yield cosmic rays far exceeding the observed flux. Our bound gives severe restriction on the compatibility between the particle physics models for WIMPs and the PBH scenario as the explanation of MBHs.
Chluba, Jens
2014-01-01
In the expanding Universe, the average temperature of the cosmic microwave background (CMB) is expected to depend like TCMB (1+z) on redshift z. Adiabatic photon production (or destruction) or deviations from isotropy and homogeneity could modify this scaling and several observational tests have been carried out in response. Here, we explain why `adiabatic' conditions are extremely difficult to establish in the redshift range targeted by these tests. Thus, instead of leading to a simple rescaling of the CMB temperature, a spectral distortion should be produced, which can be constrained using COBE/FIRAS. For scenarios with late photon production, tests of the temperature-redshift relation (TRR) should therefore be reinterpreted as weak spectral distortion limits, directly probing the energy dependence of the photon production process. For inhomogeneous cosmologies, a y-type distortion is produced, but this type of distortion can be created in several ways. Here, we briefly discuss possible effects that may hel...
Foreign Experience in Forming Social Competency of Future Specialists in Service Sector
Directory of Open Access Journals (Sweden)
Shpychko Inna
2015-12-01
Full Text Available Foreign experience in forming social competency of future specialists in service sector being the system of social, psychological and pedagogical knowledge, skills, life and professional experience, values, motives of life activities and personal qualities that makes it possible to effectively execute social functions in the society has been revealed in the article. The specificity and influence of the educational process in the educational establishment on the forming of social competency of a student’s personality have been analyzed. The social competency requires from an individual such qualities as integrity, ability to protect his/her own opinion, to resist unwanted influence as well as tolerance and the ability to adapt and, moreover, to operate effectively in constantly changing social conditions. The socially competent person should not only understand the nature and the specific character of a situation or a problem, but also be able to solve it practically, be motivated to do it, be able to analyze both his/her own performance and its consequences. The study of theory and practice of training specialists in service sector has showed that nowadays there are only few researches dedicated to theoretical study and approbation of the content and methodology of forming social competency of future specialists in service sector.
Errard, Josquin; Peiris, Hiranya V; Jaffe, Andrew H
2015-01-01
[Abridged] Recent results from the BICEP, Keck Array and Planck collaborations demonstrate that Galactic foregrounds are an unavoidable obstacle in the search for evidence of inflationary gravitational waves in the cosmic microwave background (CMB) polarization. Beyond the foregrounds, the effect of lensing by intervening large-scale structure further obscures all but the strongest inflationary signals permitted by current data. With a plethora of ongoing and upcoming experiments aiming to measure these signatures, careful and self-consistent consideration of experiments' foreground- and lensing-removal capabilities is critical in obtaining credible forecasts of their performance. We investigate the capabilities of instruments such as Advanced ACTPol, BICEP3 and Keck Array, CLASS, EBEX10K, PIPER, Simons Array, SPT-3G and SPIDER, and projects as COrE+, LiteBIRD-ext, PIXIE and Stage IV, to clean contamination due to polarized synchrotron and dust from raw multi-frequency data, and remove lensing from the result...
Breaking CMB degeneracy in dark energy through LSS
Energy Technology Data Exchange (ETDEWEB)
Lee, Seokcheon [Korea Institute for Advanced Study, School of Physics, Seoul (Korea, Republic of)
2016-03-15
The cosmic microwave background (CMB) and large-scale structure (LSS) are complementary probes in the investigation of the early and late time Universe. After the current accomplishment of the high accuracies of CMB measurements, accompanying precision cosmology from LSS data is emphasized. We investigate the dynamical dark energy (DE) models which can produce the same CMB angular power spectra as that of the CDM model with less than a sub-percent level accuracy. If one adopts the dynamical DE models using the so-called Chevallier-Polarski-Linder (CPL) parametrization, ω ≡ ω{sub 0} + ω{sub a} (1-a), then one obtains models (ω{sub 0}, ω{sub a}) = (-0.8, -0.767), (-0.9, -0.375), (-1.1, 0.355), (-1.2, 0.688) named M8, M9, M11, and M12, respectively. The differences of the growth rate, f, which is related to the redshift-space distortions (RSD) between different DE models and the ΛCDM model are about 0.2 % only at z = 0. The difference of f between M8 (M9, M11, M12) and the ΛCDM model becomes maximum at z ≅ 0.25 with -2.4(-1.2, 1.2, 2.5) %. This is a scale-independent quantity. One can investigate the one-loop correction of the matter power spectrum of each model using the standard perturbation theory in order to probe the scale-dependent quantity in the quasi-linear regime (i.e. k ≤ 0.4 h{sup -1} Mpc). The differences in the matter power spectra including the one-loop correction between M8 (M9, M11, M12) and the ΛCDM model for the k = 0.4 h{sup -1} Mpc scale are 1.8 (0.9, 1.2, 3.0) % at z = 0, 3.0 (1.6, 1.9, 4.2) % at z = 0.5, and 3.2 (1.7, 2.0, 4.5) % at z = 1.0. The larger departure from -1 of ω{sub 0}, the larger the difference in the power spectrum. Thus, one should use both the RSD and the quasi-linear observable in order to discriminate a viable DE model among a slew of the models which are degenerate in CMB.Alsowe obtain the lower limit on ω{sub 0} > -1.5 from the CMB acoustic peaks and this will provide a useful limitation on phantom models
Re-evaluation of the Cosmic Microwave Background (CMB)
Haynes, R.
2009-12-01
The cosmic microwave background (CMB) has an almost perfect black-body spectrum, with polarization. These characteristics are inconsistent with the Standard Big Bang (SBB) model. An almost perfect spectrum can arise only from a surface of last scattering which is an almost perfect black-body. Thermodynamically, this is matter in thermal equilibrium, absorbing almost 100% of incident radiation and re-emitting it as black-body radiation. By definition, a perfect black-body is matter at zero kelvin, and cold matter better approaches this perfection. SBB theory describes the CMB as originating from a hydrogen-helium plasma, condensing at a temperature of about 3,000 K. Such a surface would exhibit a continuous radiation spectrum, not unlike that of the sun, which is shown to have a spectrum similar, but not identical to, a black-body spectrum. An imperfect spectrum, even stretched 1100 fold as in the SBB model, remains an imperfect spectrum. Also, a plasma would not support the orientation required to impart polarization to the CMB. A better explanation of the observational evidence is possible if one views the observable universe as part of, and originating from, a much larger structure. Here we propose a defined physical description for such a model. It is shown how a "cosmic fabric" of spin-oriented atomic hydrogen, at zero kelvin, surrounding a matter-depletion zone and the observable universe, would produce the CMB observations. The cosmic fabric would be a perfect black-body and subsequently re-emit an almost perfect black-body spectrum. The radiation would be almost perfectly isotropic, imposed by the spherical distribution of the surface of last scattering, and spin-oriented hydrogen would impart the observed polarization. This geometry also obviates the so-called "horizon problem" of the SBB, why the CMB radiation is essentially isotropic when coming from points of origin with no apparent causal contact. This problem was supposedly "solved" with the
Correlation between sphere distributions of gamma-ray bursts and CMB fluctuations
Verkhodanov, O. V.; Sokolov, V. V.; Khabibullina, M. L.
2016-06-01
Distribution of gamma-ray bursts (GRBs) from catalogs of the BATSE and BeppoSAX space observatories relative to the cosmic microwave background (CMB) data by Planck space mission is studied. Three methods were applied for data analysis: (1) a histogram of CMB signal values in GRB directions, (2) mosaic correlation maps calculated for GRB locations and CMB distribution, (3) calculation of an average response in the area of "average GRB population" on the CMB map. A correlation between GRB locations and CMB fluctuations was detected which can be interpreted as systematic effects in the process of observations. Besides, in the averaged areas of CMB maps, a difference between the distributions of average fluctuations for short and long GRBs was detected which can be caused by different natures of these events.
Choi, S. Y.; Lai, S.; Klotz, R.; Popova, Y.; Chakravarty, K.; Beegle, J. E.; Wigley, C. L.; Globus, R. K.
2014-01-01
To better understand how mammals adapt to long duration habitation in space, a system for performing rodent experiments on the ISS is under development; Rodent Research-1 is the first flight and will include validation of both on-orbit animal support and tissue preservation. To evaluate plans for on-orbit sample dissection and preservation, we simulated conditions for euthanasia, tissue dissection, and prolonged sample storage on the ISS, and we also developed methods for post-flight dissection and recovery of high quality RNA from multiple tissues following prolonged storage in situ for future science. Mouse livers and spleens were harvested under conditions that simulated nominal, on-orbit euthanasia and dissection operations including storage at -80 C for 4 months. The RNA recovered was of high quality (RNA Integrity Number, RIN(is) greater than 8) and quantity, and the liver enzyme contents and activities (catalase, glutathione reductase, GAPDH) were similar to positive controls, which were collected under standard laboratory conditions. We also assessed the impact of possible delayed on-orbit dissection scenarios (off-nominal) by dissecting and preserving the spleen (RNAlater) and liver (fast-freezing) at various time points post-euthanasia (from 5 min up to 105 min). The RNA recovered was of high quality (spleen, RIN (is) greater than 8; liver, RIN (is) greater than 6) and liver enzyme activities were similar to positive controls at all time points, although an apparent decline in select enzyme activities was evident at the latest time (105 min). Additionally, various tissues were harvested from either intact or partially dissected, frozen carcasses after storage for approximately 2 months; most of the tissues (brain, heart, kidney, eye, adrenal glands and muscle) were of acceptable RNA quality for science return, whereas some tissues (small intestine, bone marrow and bones) were not. These data demonstrate: 1) The protocols developed for future flight
Chluba, J.
2014-09-01
In the expanding Universe, the average temperature of the cosmic microwave background (CMB) is expected to depend like TCMB ∝ (1 + z) on redshift z. Adiabatic photon production (or destruction) or deviations from isotropy and homogeneity could modify this scaling and several observational tests have been carried out in response. Here, we explain why `adiabatic' conditions are extremely difficult to establish in the redshift range targeted by these tests. Thus, instead of leading to a simple rescaling of the CMB temperature, a spectral distortion should be produced, which can be constrained using COBE/FIRAS. For scenarios with late photon production, tests of the temperature-redshift relation (TRR) should therefore be reinterpreted as weak spectral distortion limits, directly probing the energy dependence of the photon production process. For inhomogeneous cosmologies, an average y-type distortion is produced, but this type of distortion can be created in several other ways. Here, we briefly discuss possible effects that may help disentangling different contributions to the distortion signal, finding this to be very challenging. We furthermore argue that tests of the TRR using the Sunyaev-Zeldovich effect have limited applicability and that for non-gravitational changes to the TRR, the CMB anisotropy spectrum should exhibit an additional y-type dependence.
CMB Anisotropy due to Cosmic Strings in an Accelerated Expanding Universe
Rokni, S Y; Bordbar, M R
2013-01-01
We want to find the cosmological constant influence on cosmic microwave background (CMB) anisotropy due to cosmic strings. Considering the space-time metric of a cosmic string under the effect of a positive cosmological constant, the CMB anisotropy is studied. The result shows that a positive cosmological constant (i.e. the presence of cosmic strings in an accelerated expanding universe) weakens the anisotropy so that more strong resolution is needed to detect the corresponding influences on the CMB power spectrum.
Exploring the sensitivity of current and future experiments to $\\theta_{\\odot}$
Bandyopadhyay, A; Goswami, S; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati
2003-01-01
The first results from the KamLAND experiment in conjunction with the global solar neutrino data has demonstrated striking ability to constrain the $\\Delta m^2_\\odot$ ($\\Delta m^2_{21}$) very precisely. However the allowed range of $\\theta_{\\odot}$ ($\\theta_{12}$) did not change much with the inclusion of the KamLAND results. In this paper we probe if future data from KamLAND can increase the accuracy of the allowed range in $\\theta_{\\odot}$ and conclude that even after 3 kton-year of statistics, KamLAND may find it hard to improve the bounds on the mixing angle obtained from the current solar neutrino data. We discuss the $\\theta_{12}$ sensitivity of the survival probabilities in matter (vacuum) as is relevant for the solar (KamLAND) experiments. We find that the presence of matter effects in the survival probabilities for $^8B$ neutrinos give the solar neutrino experiments SK and SNO an edge over KamLAND, as far as $\\theta_{12}$ sensitivity is concerned, particularly near maximal mixing. Among solar neutrin...
Probing neutrino masses with future galaxy redshift surveys
Lesgourgues, Julien; Perotto, Laurence; Lesgourgues, Julien; Pastor, Sergio; Perotto, Laurence
2004-01-01
We perform a new study of future sensitivities of galaxy redshift surveys to the free-streaming effect caused by neutrino masses, adding the information on cosmological parameters from measurements of primary anisotropies of the cosmic microwave background (CMB). Our reference cosmological scenario has nine parameters and three different neutrino masses, with a hierarchy imposed by oscillation experiments. Within the present decade, the combination of the Sloan Digital Sky Survey (SDSS) and CMB data from the PLANCK experiment will have a 2-sigma detection threshold on the total neutrino mass close to 0.2 eV. This estimate is robust against the inclusion of extra free parameters in the reference cosmological model. On a longer term, the next generation of experiments may reach values of order sum m_nu = 0.1 eV at 2-sigma, or better if a galaxy redshift survey significantly larger than SDSS is completed. We also discuss how the small changes on the free-streaming scales in the normal and inverted hierarchy sche...
Kuhn, Nikolaus J.
2015-04-01
The 2015 UN Year of Soils (IYS), implemented by the FAO, aims to increase awareness and understanding of the importance of soil for food security and essential ecosystem functions. The IYS has six specific objectives, ranging from raising the awareness among civil society and decision makers about the profound importance of soils, to the development of policies supporting the sustainable use of the non-renewable soil resource. For scientists and academic teachers using experiments to study soil erosion processes, two objectives appear of particular relevance. First is need for the rapid capacity enhancement for soil information collection and monitoring at all levels (global, regional and national). While at first glance, this objective appears to relate mostly to traditional mapping, sampling and monitoring, the threat of large-scale soil loss, at least with regards to their ecosystem services, illustrates the need for approaches of studying soils that avoids such irreversible destruction. Relying on often limited data and their extrapolation does not cover this need for soil information because rapid change of the drivers of change itself carry the risk of unprecedented soil reactions not covered by existing data sets. Experiments, on the other hand, offer the possibility to simulate and analyze future soil change in great detail. Furthermore, carefully designed experiments may also limit the actual effort involved in collecting the specific required information, e.g. by applying tests designed to study soil system behavior under controlled conditions, compared to field monitoring. For rainfall simulation, experiments should therefore involve the detailed study of erosion processes and include detailed recording and reporting of soil and rainfall properties. The development of a set of standardised rainfall simulations would widen the use data collected by such experiments. A second major area for rainfall simulation lies in the the education of the public about
The Development of Future Technology Teachers’ Artistic-Projective Abilities: Foreign Experience
Directory of Open Access Journals (Sweden)
Kurach Mykola
2016-03-01
Full Text Available The necessity to form and develop future technology teachers’ creative abilities has been stressed in the article. The psychologic-pedagogical researches of the leading specialists from Europe, the USA and Japan in the field of creative work and creativity have been analyzed. The main problems of the creative artistic-projective abilities development have been determined based on the analysis and synthesis of foreign and native philosophic, pedagogical and psychological literature dedicated to characteristics of such notions as “creative work” and “creativity”. Approaches and conceptions providing students – future technology teachers – with creative activities have been singled out. The gist of psychological mechanism for forming teachers’ creative personality has been established and its basic features have been determined as a result of the world experience of the theory and methods of creative abilities development generalization. The main features are as follows: an independence and an inclination towards divergent behavior; flexibility of thinking and readiness for everything new; motivation for self-actualization; striving for self-expressing and ability to creative work; ability to find out how to set and solve the problems. It has been mentioned that the technology teachers’ artistic-projective activity requires their creative abilities development, which, in their turn, are formed on the ground of well-developed general and special (art, projective, technological, pedagogical potencies. Therefore, the effectiveness of the students’ art-projective knowledge and skills forming depends upon the extent their general, special and creative abilities have been developed. That is why skillful and pedagogically correct organization of future technology teachers’ artistic-projective activities will inevitably provide the higher qualitatively new level of their creative abilities and creativity.
Probing lepton flavour (universality) violation at NA62 and future kaon experiments
Tunstall, Lewis C; D'Ambrosio, Giancarlo; Hoferichter, Martin
2016-01-01
Recent results from the LHC's first run have revealed intriguing departures from lepton flavour universality in the semi-leptonic decays of $B$-mesons. We discuss the complementary role that rare kaon decays can provide in testing new physics explanations of these flavour anomalies. In the framework of minimal flavour violation, we relate the chiral low-energy constants involved in $K\\to\\pi\\ell\\ell'$ and $K\\to\\ell\\ell'$ ($\\ell = \\mu \\mbox{ or } e$) with the new physics Wilson coefficients of the $b\\to s$ effective Hamiltonian. We comment on the determination of these low-energy constants at NA62 and future kaon experiments, as well as the required improvements in sensitivity necessary to test the $B$-physics anomalies in the kaon sector.
Bem, Daryl; Tressoldi, Patrizio; Rabeyron, Thomas; Duggan, Michael
2015-01-01
In 2011, one of the authors (DJB) published a report of nine experiments in the Journal of Personality and Social Psychology purporting to demonstrate that an individual's cognitive and affective responses can be influenced by randomly selected stimulus events that do not occur until after his or her responses have already been made and recorded, a generalized variant of the phenomenon traditionally denoted by the term precognition. To encourage replications, all materials needed to conduct them were made available on request. We here report a meta-analysis of 90 experiments from 33 laboratories in 14 countries which yielded an overall effect greater than 6 sigma, z = 6.40, p = 1.2 × 10 (-10 ) with an effect size (Hedges' g) of 0.09. A Bayesian analysis yielded a Bayes Factor of 5.1 × 10 (9), greatly exceeding the criterion value of 100 for "decisive evidence" in support of the experimental hypothesis. When DJB's original experiments are excluded, the combined effect size for replications by independent investigators is 0.06, z = 4.16, p = 1.1 × 10 (-5), and the BF value is 3,853, again exceeding the criterion for "decisive evidence." The number of potentially unretrieved experiments required to reduce the overall effect size of the complete database to a trivial value of 0.01 is 544, and seven of eight additional statistical tests support the conclusion that the database is not significantly compromised by either selection bias or by intense " p-hacking"-the selective suppression of findings or analyses that failed to yield statistical significance. P-curve analysis, a recently introduced statistical technique, estimates the true effect size of the experiments to be 0.20 for the complete database and 0.24 for the independent replications, virtually identical to the effect size of DJB's original experiments (0.22) and the closely related "presentiment" experiments (0.21). We discuss the controversial status of precognition and other anomalous effects
Estimating SI violation in CMB due to non-circular beam and complex scan in minutes
Pant, Nidhi; Rotti, Aditya; Mitra, Sanjit; Souradeep, Tarun
2015-01-01
Mild, unavoidable deviations from circular-symmetry of instrumental beams along with scan strategy can give rise to measurable Statistical Isotropy (SI) violation in Cosmic Microwave Background (CMB) experiments. If not accounted properly, this spurious signal can complicate the extraction of other SI violation signals (if any) in the data. However, estimation of this effect through exact numerical simulation is computationally intensive and time consuming. A generalized analytical formalism not only provides a quick way of estimating this signal, but also gives a detailed understanding connecting the leading beam anisotropy components to a measurable BipoSH characterisation of SI violation. In this paper, we provide an approximate generic analytical method for estimating the SI violation generated due to a non-circular (NC) beam and arbitrary scan strategy, in terms of the Bipolar Spherical Harmonic (BipoSH) spectra. Our analytical method can predict almost all the features introduced by a NC beam in a compl...
QuickPol: Fast effective beam matrices calculation for CMB polarization
Hivon, Eric; Ponthieu, Nicolas
2016-01-01
Current and planned observations of the Cosmic Microwave Background (CMB) polarization anisotropies, with their ever increasing number of detectors, have reached a potential accuracy that requires a very demanding control of systematic effects. While some of these systematics can be reduced in the design of the instruments, others will be have to be modeled and hopefully accounted for or corrected a posteriori. We propose QuickPol, a quick and accurate calculation of the full effective beam transfer function and of temperature to polarization leakage at the power spectra level, as induced by beam imperfections and mismatches between detector optical and electronic responses. All the observation details such as exact scanning strategy, imperfect polarization measurements and flagged samples are accounted for. Our results are validated on Planck-HFI simulations. We show how the pipeline can be used to propagate instrumental uncertainties up to the final science products, and could be applied to experiments with...
Kogut, Alan
Measurements of the linear polarization of the cosmic microwave background (CMB) provide a critical test of the inflationary paradigm. Gravity waves excited during an inflationary epoch in the early universe interact with the CMB to impart a characteristic signal in linear polarization. The distinctive spatial pattern and frequency dependence of the inflationary signal provide a unique signature to characterize physics at energies approaching Grand Unification, a trillion times beyond the energies accessible to particle accelerators. At millimeter wavelengths where the CMB is brightest, the dominant foreground is thermal emission from interstellar dust. As highlighted by the recent BICEP2 and Planck results, dust emission is brighter than the anticipated inflationary signal even in the cleanest regions of the sky, and is 1-2 orders of magnitude brighter over most of the sky. Robust detection and characterization of the primordial signal requires subtracting the dust foreground to sub-percent accuracy. Despite the importance of dust to CMB measurements, far-IR dust emission is poorly constrained. Popular phenomenological models treat the dust as a superposition of components at one or two temperatures although the actual temperature distribution must be more complex. Disturbingly, use of these models can bias the inflationary CMB results at levels large compared to planned sensitivities, despite fitting the combined sky emission to sub-percent precision. Foreground models must be accurate as well as precise. We propose to use archival data at millimeter through far-IR wavelengths to improve models of far-IR dust emission, explicitly deriving the temperature distribution within the diffuse dust cirrus to separate temperature effects from intrinsic emission effects (spectral index). The proposed analysis is tightly focused and likely to succeed. Simple toy models demonstrate that far-IR data such as FIRAS can distinguish the temperature distribution within the diffuse
Grandis, S.; Rapetti, D.; Saro, A.; Mohr, J. J.; Dietrich, J. P.
2016-08-01
Recent measurements of the Cosmic Microwave Background (CMB) by the Planck Collaboration have produced arguably the most powerful observational evidence in support of the standard model of cosmology, i.e. the spatially flat ΛCDM paradigm. In this work, we perform model selection tests to examine whether the base CMB temperature and large scale polarization anisotropy data from Planck 2015 (P15) prefer any of eight commonly used one-parameter model extensions with respect to flat ΛCDM. We find a clear preference for models with free curvature, ΩK, or free amplitude of the CMB lensing potential, AL. We also further develop statistical tools to measure tension between datasets. We use a Gaussianization scheme to compute tensions directly from the posterior samples using an entropy-based method, the surprise, as well as a calibrated evidence ratio presented here for the first time. We then proceed to investigate the consistency between the base P15 CMB data and six other CMB and distance datasets. In flat ΛCDM we find a 4.8σ tension between the base P15 CMB data and a distance ladder measurement, whereas the former are consistent with the other datasets. In the curved ΛCDM model we find significant tensions in most of the cases, arising from the well-known low power of the low-ℓ multipoles of the CMB data. In the flat ΛCDM+AL model, however, all datasets are consistent with the base P15 CMB observations except for the CMB lensing measurement, which remains in significant tension. This tension is driven by the increased power of the CMB lensing potential derived from the base P15 CMB constraints in both models, pointing at either potentially unresolved systematic effects or the need for new physics beyond the standard flat ΛCDM model.
Hurlbert, Eric; Morehead, Robert; Melcher, John C.; Atwell, Matt
2016-01-01
An integrated liquid oxygen (LOx) and methane propulsion system where common propellants are fed to the reaction control system and main engines offers advantages in performance, simplicity, reliability, and reusability. LOx/Methane provides new capabilities to use propellants that are manufactured on the Mars surface for ascent return and to integrate with power and life support systems. The clean burning, non-toxic, high vapor pressure propellants provide significant advantages for reliable ignition in a space vacuum, and for reliable safing or purging of a space-based vehicle. The NASA Advanced Exploration Systems (AES) Morpheus lander demonstrated many of these key attributes as it completed over 65 tests including 15 flights through 2014. Morpheus is a prototype of LOx/Methane propellant lander vehicle with a fully integrated propulsion system. The Morpheus lander flight demonstrations led to the proposal to use LOx/Methane for a Discovery class mission, named Moon Aging Regolith Experiment (MARE) to land an in-situ science payload for Southwest Research Institute on the Lunar surface. Lox/Methane is extensible to human spacecraft for many transportation elements of a Mars architecture. This paper discusses LOx/Methane propulsion systems in regards to trade studies, the Morpheus project experience, the MARE NAVIS (NASA Autonomous Vehicle for In-situ Science) lander, and future possible applications. The paper also discusses technology research and development needs for Lox/Methane propulsion systems.
Energy Technology Data Exchange (ETDEWEB)
Wagener, T; Hogue, T; Schaake, J; Duan, Q; Gupta, H; Andreassian, V; Hall, A; Leavesley, G
2006-05-08
The Model Parameter Estimation Experiment (MOPEX) is an international project aimed at developing enhanced techniques for the a priori estimation of parameters in hydrologic models and in land surface parameterization schemes connected to atmospheric models. The MOPEX science strategy involves: database creation, a priori parameter estimation methodology development, parameter refinement or calibration, and the demonstration of parameter transferability. A comprehensive MOPEX database has been developed that contains historical hydrometeorological data and land surface characteristics data for many hydrologic basins in the United States (US) and in other countries. This database is being continuously expanded to include basins from various hydroclimatic regimes throughout the world. MOPEX research has largely been driven by a series of international workshops that have brought interested hydrologists and land surface modelers together to exchange knowledge and experience in developing and applying parameter estimation techniques. With its focus on parameter estimation, MOPEX plays an important role in the international context of other initiatives such as GEWEX, PUB and PILPS. This paper outlines the MOPEX initiative, discusses its role in the scientific community and briefly states future directions.
Recent experience and future evolution of the CMS High Level Trigger System
Bauer, Gerry; Branson, James; Bukowiec, Sebastian Czeslaw; Chaze, Olivier; Cittolin, Sergio; Coarasa Perez, Jose Antonio; Deldicque, Christian; Dobson, Marc; Dupont, Aymeric; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez-Reino Garrido, Robert; Hartl, Christian; Holzner, Andre Georg; Masetti, Lorenzo; Meijers, Franciscus; Meschi, Emilio; Mommsen, Remigius; Nunez Barranco Fernandez, Carlos; O'Dell, Vivian; Orsini, Luciano; Paus, Christoph Maria Ernst; Petrucci, Andrea; Pieri, Marco; Polese, Giovanni; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schwick, Christoph; Spataru, Andrei Cristian; Stoeckli, Fabian; Sumorok, Konstanty
2012-01-01
The CMS experiment at the LHC uses a two-stage trigger system, with events flowing from the first level trigger at a rate of 100 kHz. These events are read out by the Data Acquisition system (DAQ), assembled in memory in a farm of computers, and finally fed into the high-level trigger (HLT) software running on the farm. The HLT software selects interesting events for offline storage and analysis at a rate of a few hundred Hz. The HLT algorithms consist of sequences of offline-style reconstruction and filtering modules, executed on a farm of 0(10000) CPU cores built from commodity hardware. Experience from the 2010-2011 collider run is detailed, as well as the current architecture of the CMS HLT, and its integration with the CMS reconstruction framework and CMS DAQ. The short- and medium-term evolution of the HLT software infrastructure is discussed, with future improvements aimed at supporting extensions of the HLT computing power, and addressing remaining performance and maintenance issues.
Back to the future--the history and philosophy of medicine experiment at Sydney University.
Cossart, Y E; Pegler, M A; Givney, R C
1996-09-01
History and Philosophy of Medicine has been a compulsory unit in the first year of the medical curriculum at Sydney University for the past decade. Volunteer tutors are drawn from most clinical and basic science departments, and each year the programme is organized on a theme of current importance in medical practice. This course began as an experiment because no resources were available for specialist staff, but has proved outstandingly successful in generating both student and teaching staff interest and support for the programme. Students present short tutorial papers to their peer group followed by submission of an essay which takes into account the tutorial discussion. The open book examination includes analysis of an unseen piece of primary source material as well as questions derived from the classwork. The Faculties of Arts and Science encouraged this educational experiment and several medical students have now opted to undertake a year of historical research during the intercalated B Sci(Med) programme, and a number of the tutors have enrolled in postgraduate historial or ethical programmes. We suggest that this model may permit introduction of novel courses in times of financial cutback within the Universities, and even allow a foundation to be laid for future development.
The Present and Future Challenges of Distributed Computing in the ATLAS experiment
Ueda, I; The ATLAS collaboration
2012-01-01
The ATLAS experiment has collected more than 5 fb-1 of data in 2011 at the energy of 7 TeV. Several billions of events had been promptly reconstructed and stored in the ATLAS remote data centers spanning tens of petabytes of disk and tape storage. In addition, a similar amount of data has been simulated on the Grid to study the detector performance and efficiencies. The data processing and distribution on the Grid sites with more than 100.000 computing cores is centrally controlled by the system developed by ATLAS, managing a coherent data processing and analysis of almost one million jobs daily. An increased collision energy of 8 TeV in 2012 and much larger expected data collection rate due to improved LHC operation impose new requirements on the system and suggests a further evolution of the computing model to be able the meet the new challenges in the future. The experience of large-scale data processing and analysis on the Grid is presented through the evolving model and organization of the ATLAS Distribu...
A Complete Treatment of CMB Anisotropies in a FRW Universe
Hu, W; White, M; Zaldarriaga, M; Hu, Wayne; Seljak, Uros; White, Martin; Zaldarriaga, Matias
1998-01-01
We generalize the total angular momentum method for computing Cosmic Microwave Background anisotropies to Friedman-Robertson-Walker (FRW) spaces with arbitrary geometries. This unifies the treatment of temperature and polarization anisotropies generated by scalar, vector and tensor perturbations of the fluid, seed, or a scalar field, in a universe with constant comoving curvature. The resulting formalism generalizes and simplifies the calculation of anisotropies and, in its integral form, allows for a fast calculation of model predictions in linear theory for any FRW metric. With this work, the perturbation theory of CMB temperature and polarization anisotropy formation through gravitational instability in an FRW universe may be considered complete.
BBN And The CMB Constrain Light, Electromagnetically Coupled WIMPs
Nollett, Kenneth M
2013-01-01
(Abridged) In the presence of a light WIMP ( 99% confidence. Allowing a light WIMP and Delta N_nu equivalent neutrinos together, the combined BBN and CMB data provide lower limits to the WIMP masses (> 0.5 - 5 MeV) that depend on the nature of the WIMP, favor m_chi ~8 MeV slightly over no WIMP, and loosen constraints on equivalent neutrinos, Delta N_nu = 0.65+0.46-0.35. While Delta N_nu = 0 is still disfavored at ~95% confidence with a light WIMP, Delta N_nu = 1 is now allowed.
Pure pseudo- Cℓ estimators for CMB B-modes
Smith, Kendrick M.
2006-12-01
Fast heuristically weighted, or pseudo-Cℓ, estimators are a frequently used method for estimating power spectra in CMB surveys with large numbers of pixels. Recently, Challinor and Chon showed that the E-B mixing in these estimators can become a dominant contaminant at low noise levels, ultimately limiting the gravity wave signal which can be detected on a finite patch of sky. We define a modified version of the estimators which eliminates E-B mixing and is near-optimal at all noise levels.
Dipole modulation in tensor modes: signatures in CMB polarization
Energy Technology Data Exchange (ETDEWEB)
Zarei, Moslem [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Astronomy, P. O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2015-06-15
In this work we consider a dipole asymmetry in tensor modes and study the effects of this asymmetry on the angular power spectra of CMB. We derive analytical expressions for the C{sub l}{sup TT} and C{sub l}{sup BB} in the presence of such dipole modulation in tensor modes for l < 100. We also discuss on the amplitude of modulation term and show that the C{sub l}{sup BB} is considerably modified due to this term. (orig.) 3.
Inflation in de Sitter spacetime and CMB large scales anomaly
Zhao, Dong; Wang, Ping; Chang, Zhe
2014-01-01
The influence of cosmological constant type dark energy in the early universe is investigated. This is accommodated by a new dispersion relation in de Sitter spacetime. We perform a global fitting to explore the cosmological parameters space by using the CosmoMC package with the recently released Planck TT and WMAP Polarization datasets. Using the results from global fitting, we compute a new CMB temperature-temperature spectrum. The obtained TT spectrum has lower power compared with the one based on $\\Lambda$CDM model at large scales.
Shiraishi, Maresuke; Hikage, Chiaki; Namba, Ryo; Namikawa, Toshiya; Hazumi, Masashi
2016-08-01
The B -mode polarization in the cosmic microwave background (CMB) anisotropies at large angular scales provides compelling evidence for the primordial gravitational waves (GWs). It is often stated that a discovery of the GWs establishes the quantum fluctuation of vacuum during the cosmic inflation. Since the GWs could also be generated by source fields, however, we need to check if a sizable signal exists due to such source fields before reaching a firm conclusion when the B mode is discovered. Source fields of particular types can generate non-Gaussianity (NG) in the GWs. Testing statistics of the B mode is a powerful way of detecting such NG. As a concrete example, we show a model in which gauge field sources chiral GWs via a pseudoscalar coupling and forecast the detection significance at the future CMB satellite LiteBIRD. Effects of residual foregrounds and lensing B mode are both taken into account. We find the B -mode bispectrum "BBB" is in particular sensitive to the source-field NG, which is detectable at LiteBIRD with a >3 σ significance. Therefore the search for the BBB will be indispensable toward unambiguously establishing quantum fluctuation of vacuum when the B mode is discovered. We also introduced the Minkowski functional to detect the NGs. While we find that the Minkowski functional is less efficient than the harmonic-space bispectrum estimator, it still serves as a useful cross-check. Finally, we also discuss the possibility of extracting clean information on parity violation of GWs and new types of parity-violating observables induced by lensing.
Barnard, Michael; Albrecht, Andreas; Bozek, Brandon; Yashar, Mark
2008-01-01
We evaluate the ability of future data sets to discriminate among different quintessence dark energy models. This approach gives an alternative measure for assessing the impact of future experiments, as compared with the large body of literature that compares experiments in abstract parameter spaces and more recent work that evaluates the constraining power of experiments on individual parameter spaces of specific quintessence models. We use the Dark Energy Task Force (DETF) models of future data sets, and compare the discriminative power of experiments designated by the DETF as Stages 2, 3, and 4. Our work reveals a minimal increase in discriminating power when comparing Stage 3 to Stage 2, but a very striking increase in discriminating power when going to Stage 4. We also see evidence that even modest improvements over DETF Stage 4 could result in even more dramatic discriminating power among quintessence dark energy models. We develop and demonstrate the technique of using the independently measured modes ...
Energy Technology Data Exchange (ETDEWEB)
Perotto, Laurence [Universite Paris 7 - Denis Diderot, UFR de Physique, 75205 Paris Cedex 13 (France)
2006-01-15
This thesis is motivated by the upcoming high-resolution, high-sensitivity microwave background experiments, which should be sensitive to the CMB polarization and lensing. The first chapter provides a review of the CMB polarization with emphasis on future related experiments. The PLANCK experiment is described in a second chapter, where I develop a fast simulation code of PLANCK time-ordered data optimized to ease elaboration and test of data analysis methods. The two last chapters deal with gravitational lensing of the cosmic background radiation. First, I evaluate the capability of the upcoming experiments mentioned above to measure the power spectrum of Large Scale Structure by means of the extraction of weak lensing. Then I derive their sensitivity to the total neutrino mass, using the suppression of power due to free-streaming of massive neutrinos. Finally, I develop a method to estimate the foreground effects in the gravitational lensing extraction process. This method uses the best linear estimator available in the literature and is validated by numerical simulations that include non-Gaussian CMB lensed maps and extra-galactic radio sources maps. I find that sources emission reduces the sensitivity of future experiments to the weak lensing and leads to an overestimate of the convergence power spectrum. (author)
Kulkarni, Girish; Choudhury, Tirthankar Roy; Puchwein, Ewald; Haehnelt, Martin G.
2016-12-01
We present here 21 cm predictions from high dynamic range simulations for a range of reionization histories that have been tested against available Ly α and cosmic microwave background (CMB) data. We assess the observability of the predicted spatial 21 cm fluctuations by ongoing and upcoming experiments in the late stages of reionization in the limit in which the hydrogen spin temperature is significantly larger than the CMB temperature. Models consistent with the available Ly α data and CMB measurement of the Thomson optical depth predict typical values of 10-20 mK2 for the variance of the 21 cm brightness temperature at redshifts z = 7-10 at scales accessible to ongoing and upcoming experiments (k ≲ 1 cMpc-1h). This is within a factor of a few magnitude of the sensitivity claimed to have been already reached by ongoing experiments in the signal rms value. Our different models for the reionization history make markedly different predictions for the redshift evolution and thus frequency dependence of the 21 cm power spectrum and should be easily discernible by Low-Frequency Array (and later Hydrogen Epoch of Reionization Array and Square Kilometre Array1) at their design sensitivity. Our simulations have sufficient resolution to assess the effect of high-density Lyman limit systems that can self-shield against ionizing radiation and stay 21 cm bright even if the hydrogen in their surroundings is highly ionized. Our simulations predict that including the effect of the self-shielded gas in highly ionized regions reduces the large-scale 21 cm power by about 30 per cent.
Detectability of the 21-cm CMB cross-correlation from the epoch of reionization
Tashiro, Hiroyuki; Aghanim, Nabila; Langer, Mathieu; Douspis, Marian; Zaroubi, Saleem; Jelic, Vibor
2010-01-01
The 21-cm line fluctuations and the cosmic microwave background (CMB) are powerful probes of the epoch of reionization of the Universe. We study the potential of the cross-correlation between 21-cm line fluctuations and CMB anisotropy to obtain further constraints on the reionization history. We ana
COBE and the Absolute Assignment of the CMB to the Earth.
Robitaille, Pierre-Marie; Rabounski, Dmitri
2007-03-01
The FIRAS instrument on COBE initially reported a CMB temperature of 2.730+/-0.001 K (1σ). At the same time, using the 1st derivative, FIRAS reported a CMB temperature of 2.717+/-0.003 K (1σ). These two values are significantly different at the 99% confidence interval. In order to remove this significance, NASA lowered the absolute value of the CMB by changing the calibration on the external calibrator long after launch. It also raised the error bars on the second value. However, the observed difference in the CMB temperature measured by these two methods may well constitute evidence that the CMB monopole arises from the Earth. It should be assumed that a second, much weaker, microwave field exists both at L2 (the WMAP position) and at the COBE position. Motion through this much weaker field is responsible for the dipole observed. The value of the CMB temperature obtained by the 1st derivative is sensitive to motion. It is also sensitive to the complicating effect of the weak field also present at L2 when sampling the CMB temperature using FIRAS. The presence of a second weak field at L2 and the Earth is required in order for COBE to be able to resolve this situation. The PLANCK satellite should soon reveal that that CMB monopole does not exist at L2.
Filipic, Brankica; Golic, Natasa; Jovcic, Branko; Tolinacki, Maja; Bay, Denice C; Turner, Raymond J; Antic-Stankovic, Jelena; Kojic, Milan; Topisirovic, Ljubisa
2013-01-01
Functional characterization of the multidrug resistance CmbT transporter was performed in Lactococcus lactis. The cmbT gene is predicted to encode an efflux protein homologous to the multidrug resistance major facilitator superfamily. The cmbT gene (1377 bp) was cloned and overexpressed in L. lactis NZ9000. Results from cell growth studies revealed that the CmbT protein has an effect on host cell resistance to lincomycin, cholate, sulbactam, ethidium bromide, Hoechst 33342, sulfadiazine, streptomycin, rifampicin, puromycin and sulfametoxazole. Moreover, in vivo transport assays showed that overexpressed CmbT-mediated extrusion of ethidium bromide and Hoechst 33342 was higher than in the control L. lactis NZ9000 strain. CmbT-mediated extrusion of Hoechst 33342 was inhibited by the ionophores nigericin and valinomycin known to dissipate proton motive force. This indicates that CmbT-mediated extrusion is based on a drug-proton antiport mechanism. Taking together results obtained in this study, it can be concluded that CmbT is a novel major facilitator multidrug resistance transporter candidate in L. lactis, with a possible signaling role in sulfur metabolism.
Hartmann, Jens; Weiss, Andreas; Struyf, Eric; Schoelynck, Jonas; Meire, Patrick; Amann, Thorben
2015-04-01
Understanding the evolution of geogenic matter fluxes in soils due the application of rock products ontop of soils is relevant to evaluate alteration of soil solutions and saturation states of solutes. In the future the practice of applying rock products will continue and areas affected will likely spread (Hartmann et al., 2013). This trend will likely be fuelled by attempts to optimize carbon dioxide removal by increasing biomass production, soil organic carbon stocks, increase crop production or afforestation. All those efforts demand a certain amount of geogenic nutrients, which need to be replaced. To investigate the release patterns and the downward transport of an array of elements, and to study their fate as well as reaction processes, altered through this practice, a mesocosm experiment was established at Antwerp University. Extended results will be presented (c.f., Weiss et al., 2014) focusing on the release and transport of DIC (dissolved inorganic carbon) and Mg (magnesium) in the soil column downwards after the application of 22 kg m-2 olivine powder. Elevated DIC and Mg concentrations are detected in case of olivine is applied to mesocosms with wheat and barley, if compared to the mesocsoms without plants, and without olivine. The change patterns in concentrations and fluxes will be discussed. Hartmann, J., et al. (2013) Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification. Reviews of Geophysics; 51(2), 113-149. doi: 10.1002/rog.20004 Weiss, A., et al. (2014) The overlooked compartment of the critical-zone-complex, considering the evolution of future geogenic matter fluxes: Agricultural topsoils. Procedia Earth and Planetary Science, 10, 339-342. doi:10.1016/j.proeps.2014.08.032
The Public Health Nutrition workforce and its future challenges: the US experience.
Haughton, Betsy; George, Alexa
2008-08-01
To describe the US public health nutrition workforce and its future social, biological and fiscal challenges. Literature review primarily for the four workforce surveys conducted since 1985 by the Association of State and Territorial Public Health Nutrition Directors. The United States. Nutrition personnel working in governmental health agencies. The 1985 and 1987 subjects were personnel in full-time budgeted positions employed in governmental health agencies providing predominantly population-based services. In 1994 and 1999 subjects were both full-time and part-time, employed in or funded by governmental health agencies, and provided both direct-care and population-based services. The workforce primarily focuses on direct-care services for pregnant and breast-feeding women, infants and children. The US Department of Agriculture funds 81.7 % of full-time equivalent positions, primarily through the WIC Program (Special Supplemental Nutrition Program for Women, Infants, and Children). Of those personnel working in WIC, 45 % have at least 10 years of experience compared to over 65 % of the non-WIC workforce. Continuing education needs of the WIC and non-WIC workforces differ. The workforce is increasingly more racially/ethnically diverse and with 18.2 % speaking Spanish as a second language. The future workforce will need to focus on increasing its diversity and cultural competence, and likely will need to address retirement within leadership positions. Little is known about the workforce's capacity to address the needs of the elderly, emergency preparedness and behavioural interventions. Fiscal challenges will require evidence-based practice demonstrating both costs and impact. Little is known about the broader public health nutrition workforce beyond governmental health agencies.
The Martian rotation from Doppler measurements: Simulations of future radioscience experiments
Péters, Marie-Julie; Yseboodt, Marie; Dehant, Véronique; Le Maistre, Sebastien; Marty, Jean-Charles
2016-10-01
The radioscience experiment onboard the future InSight and ExoMars missions consists in two-way Doppler shift measurement from a X-band radio link between a lander on Mars and the ground stations on Earth. The Doppler effect on the radio signal is related to the revolution of the planets around the Sun and to the variations of the orientation and the rotation of Mars. The variations of the orientation of the rotation axis are the precession and nutations, related to the deep interior of Mars and the variations of the rotation rate are the length-of-day variation, related to the dynamic of the atmosphere.We perform numerical simulations of the Doppler measurements in order to quantify the precision that can be achieved on the determination of the Mars rotation and orientation parameters (MOP). For this purpose, we use the GINS (Géodésie par Intégrations Numériques Simultanées) software developed by the CNES and further adapted at the Royal Observatory of Belgium for planetary geodesy applications. This software enables to simulate the relative motion of the lander at the surface of Mars relative to the ground stations and to compute the MOP signature on the Doppler shift. The signature is the difference between the Doppler observable estimated taking into account a MOP and the Doppler estimated without this parameter.The objective is to build a strategy to be applied to future data processing in order to improve our estimation of the MOP. We study the effect of the elevation of the Earth in the sky of the lander, of the tracking duration and number of pass per week, of the tracking time, of the lander position and of Doppler geometry on the signatures. Indeed, due to the geometry, the Doppler data are highly sensitive to the position variations along the line of sight.
CMB Imprints of a Pre-Inflationary Climbing Phase
Dudas, E; Patil, S P; Sagnotti, A
2012-01-01
We discuss the implications for cosmic microwave background (CMB) observables, of a class of pre-inflationary dynamics suggested by string models where SUSY is broken due to the presence of D-branes and orientifolds preserving incompatible portions of it. In these models the would-be inflaton is forced to emerge from the initial singularity climbing up a mild exponential potential, until it bounces against a steep exponential potential of "brane SUSY breaking" scenarios, and as a result the ensuing descent gives rise to an inflationary epoch that begins when the system is still well off its eventual attractor. If a pre-inflationary climbing phase of this type had occurred within 6-7 e-folds of the horizon exit for the largest observable wavelengths, displacement off the attractor and initial-state effects would conspire to suppress power in the primordial scalar spectrum, enhancing it in the tensor spectrum and typically superposing oscillations on both. We investigate these imprints on CMB observables over a...
A neutrino model fit to the CMB power spectrum
Shanks, T; Schewtschenko, J A; Whitbourn, J R
2014-01-01
The current standard cosmological model, LCDM, provides an excellent fit to the WMAP and Planck CMB data. However, the model has well known problems. For example, the cosmological constant is fine tuned to 1 part in 10^100 and the cold dark matter (CDM) particle is not yet detected in the laboratory. Here we seek an alternative model to LCDM which makes minimal assumptions about new physics. This is based on previous work by Shanks who investigated a model which assumed neither exotic particles nor a cosmological constant but instead postulated a low Hubble constant (H_0) to help allow a baryon density which was compatible with an inflationary model with zero spatial curvature. However, the recent Planck results make it more difficult to reconcile such a model with the cosmic microwave background (CMB) temperature fluctuations. Here we relax the previous assumptions to assess the effects of assuming standard model neutrinos of moderate mass (~5eV) but with no CDM and no cosmological constant. If we assume a l...
Joint Planck and WMAP Assessment of Low CMB Multipoles
Iqbal, Asif; Souradeep, Tarun; Malik, Manzoor A
2015-01-01
The remarkable progress in cosmic microwave background (CMB) studies over past decade has led to the era of precision cosmology in striking agreement with the $\\Lambda$CDM model. However, the lack of power in the CMB temperature anisotropies at large angular scales (low-$\\ell$), as has been confirmed by the recent Planck data also (up to $\\ell=40$), is still an open problem. One can avoid to seek an explanation for this problem by attributing the lack of power to cosmic variance or can look for explanations i.e., different inflationary potentials or initial conditions for inflation to begin with, non-trivial topology, ISW effect etc. Features in the primordial power spectrum (PPS) motivated by the early universe physics has been the most common solution to address this problem. In the present work we also follow this approach and consider a set of PPS which have features and constrain the parameters of those using WMAP 9 year and Planck data employing Markov-Chain Monte Carlo (MCMC) analysis. The prominent fe...
Planck 2015 results. IX. Diffuse component separation: CMB maps
Adam, R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Casaponsa, B.; Castex, G.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.R.; Chiang, H.C.; Christensen, P.R.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Falgarone, E.; Fantaye, Y.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Giraud-Heraud, Y.; Gjerlow, E.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Le Jeune, M.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T.J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Racine, B.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; Yvon, D.; Zacchei, A.; Zonca, A.
2015-01-01
We present foreground-reduced CMB maps derived from the full Planck data set in both temperature and polarization. Compared to the corresponding Planck 2013 temperature sky maps, the total data volume is larger by a factor of 3.2 for frequencies between 30 and 70 GHz, and by 1.9 for frequencies between 100 and 857 GHz. In addition, systematic errors in the forms of temperature-to-polarization leakage, analogue-to-digital conversion uncertainties, and very long time constant errors have been dramatically reduced, to the extent that the cosmological polarization signal may now be robustly recovered on angular scales $\\ell\\gtrsim40$. On the very largest scales, instrumental systematic residuals are still non-negligible compared to the expected cosmological signal, and modes with $\\ell < 20$ are accordingly suppressed in the current polarization maps by high-pass filtering. As in 2013, four different CMB component separation algorithms are applied to these observations, providing a measure of stability with re...
The mildly nonlinear imprint of structure on the CMB
Gebbie, T
1999-01-01
I outline some nonperturbative relativistic effects that arise from gravitational corrections to the Boltzmann equations. These may be important for the study of CMB temperature anisotropies, particularly their interpretation. These terms are not included in the canonical treatment as they arise from the exact equations. Here a weakly nonlinear investigation of these effects is defined and investigated with an emphasis on a Rees-Sciama sourced effect -- the imprint of structure evolution on the CMB. It is shown that gravitational nonlinearity in the weakly nonlinear extension of almost-FLRW temperature anisotropies leads to cancellation on small-scales when threading in the Newtonian frame. In the general frame this cancellation does not occur. In the context of a flat almost-FLRW CDM model I provide a heuristic argument for a nonperturbative small scale correction, due to the Rees-Sciama effect, of not more than $\\Delta T/T \\sim 10^{-6}-10^{-5}$ near $\\ell \\sim 100 - 300$. The effect of mild gravitational no...
Cosmological Parameters from CMB Maps without Likelihood Approximation
Racine, Benjamin; Eriksen, Hans Kristian K; Wehus, Ingunn K
2015-01-01
We propose an efficient Bayesian MCMC algorithm for estimating cosmological parameters from CMB data without use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the joint CMB sky signal and power spectrum posterior, P(s,Cl|d), and addresses a long-standing problem of efficient parameter estimation simultaneously in high and low signal-to-noise regimes. To achieve this, our new algorithm introduces a joint Markov Chain move in which both the signal map and power spectrum are synchronously modified, by rescaling the map according to the proposed power spectrum before evaluating the Metropolis-Hastings accept probability. Such a move was already introduced by Jewell et al. (2009), who used it to explore low signal-to-noise posteriors. However, they also found that the same algorithm is inefficient in the high signal-to-noise regime, since a brute-force rescaling operation does not account for phase information. This problem is mitigated in...
Statistical simulations of the dust foreground to CMB polarization
Vansyngel, Flavien; Ghosh, Tuhin; Wandelt, Benjamin D; Aumont, Jonathan; Bracco, Andrea; Levrier, François; Martin, Peter G; Montier, Ludovic
2016-01-01
The characterization of the dust polarization foreground to the Cosmic Microwave Background (CMB) is a necessary step towards the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate maps of polarized dust emission on the sphere, similarly to what is done for the CMB anisotropies. This method builds on the understanding of Galactic polarization stemming from the analysis of Planck data. It relates the dust polarization sky to the structure of the Galactic magnetic field and its coupling with interstellar matter and turbulence. The Galactic magnetic field is modelled as a superposition of a mean uniform field and a random component with a power-law power spectrum of exponent $\\alpha_{\\rm M}$. The model parameters are constrained to fit the power spectra of dust polarization EE, BB and TE measured using Planck data. We find that the slopes of the E and B power spectra of dust polarization are matched for $\\alpha_{\\rm M} = -2.5$. The model allows us to co...
Tensor Minkowski Functionals: first application to the CMB
Ganesan, Vidhya
2016-01-01
Tensor Minkowski Functionals (TMFs) are tensorial generalizations of the usual Minkowski Functionals which are scalar quantities. We introduce them here for use in cosmological analysis, in particular to analyze CMB maps. They encapsulate information about the shapes and the orientation of structures. We focus on one of the TMFs, namely $W_2^{1,1}$, which is the generalization of the genus. The ratio of the eigenvalues of the average of $W_2^{1,1}$ over all structures, $\\alpha$, encodes the net orientation; and the average of the ratios of the eigenvalues of $W_2^{1,1}$ for each structure, $\\beta$, encodes the net anisotropy. We have developed a code that computes $W_2^{1,1}$, and from it $\\alpha$ and $\\beta$, for a set of structures on the plane. We compute $\\alpha$ and $\\beta$ as functions of threshold levels for simulated Gaussian and isotropic CMB fields. We obtain $\\alpha$ to be one for both temperature and $E$ mode, which means that we recover the input statistical isotropy of density fluctuations in th...
Non Gaussian Minkowski functionals and extrema counts for CMB maps
Pogosyan, Dmitri; Codis, Sandrine; Pichon, Christophe
2016-10-01
In the conference presentation we have reviewed the theory of non-Gaussian geometrical measures for 3D Cosmic Web of the matter distribution in the Universe and 2D sky data, such as Cosmic Microwave Background (CMB) maps that was developed in a series of our papers. The theory leverages symmetry of isotropic statistics such as Minkowski functionals and extrema counts to develop post Gaussian expansion of the statistics in orthogonal polynomials of invariant descriptors of the field, its first and second derivatives. The application of the approach to 2D fields defined on a spherical sky was suggested, but never rigorously developed. In this paper we present such development treating the effects of the curvature and finiteness of the spherical space $S_2$ exactly, without relying on flat-sky approximation. We present Minkowski functionals, including Euler characteristic and extrema counts to the first non-Gaussian correction, suitable for weakly non-Gaussian fields on a sphere, of which CMB is the prime example.
Angular dependence of primordial trispectra and CMB spectral distortions
Shiraishi, Maresuke; Bartolo, Nicola; Liguori, Michele
2016-10-01
Under the presence of anisotropic sources in the inflationary era, the trispectrum of the primordial curvature perturbation has a very specific angular dependence between each wavevector that is distinguishable from the one encountered when only scalar fields are present, characterized by an angular dependence described by Legendre polynomials. We examine the imprints left by curvature trispectra on the TTμ bispectrum, generated by the correlation between temperature anisotropies (T) and chemical potential spectral distortions (μ) of the Cosmic Microwave Background (CMB). Due to the angular dependence of the primordial signal, the corresponding TTμ bispectrum strongly differs in shape from TTμ sourced by the usual gNL or τNL local trispectra, enabling us to obtain an unbiased estimation. From a Fisher matrix analysis, we find that, in a cosmic-variance-limited (CVL) survey of TTμ, a minimum detectable value of the quadrupolar Legendre coefficient is d2 ~ 0.01, which is 4 orders of magnitude better than the best value attainable from the TTTT CMB trispectrum. In the case of an anisotropic inflationary model with a f(phi)F2 interaction (coupling the inflaton field phi with a vector kinetic term F2), the size of the curvature trispectrum is related to that of quadrupolar power spectrum asymmetry, g*. In this case, a CVL measurement of TTμ makes it possible to measure g* down to 10‑3.
Testing large-angle deviation from Gaussianity in CMB maps
Bernui, A; Teixeira, A F F
2010-01-01
A detection of the level of non-Gaussianity in the CMB data is essential to discriminate among inflationary models and also to test alternative primordial scenarios. However, the extraction of primordial non-Gaussianity is a difficult endeavor since several effects of non-primordial nature can produce non-Gaussianity. On the other hand, different statistical tools can in principle provide information about distinct forms of non-Gaussianity. Thus, any single statistical estimator cannot be sensitive to all possible forms of non-Gaussianity. In this context, to shed some light in the potential sources of deviation from Gaussianity in CMB data it is important to use different statistical indicators. In a recent paper we proposed two new large-angle non-Gaussianity indicators which provide measures of the departure from Gaussianity on large angular scales. We used these indicators to carry out analyses of non-Gaussianity of the bands and of the foreground-reduced WMAP maps with and without the KQ75 mask. Here we ...
Angular dependence of primordial trispectra and CMB spectral distortions
Shiraishi, Maresuke; Liguori, Michele
2016-01-01
Under the presence of anisotropic sources in the inflationary era, the trispectrum of the primordial curvature perturbation is sensitive to the angles between each wave vector. We examine the imprints left by curvature trispectra, in which the angular dependence is described by Legendre polynomials, on the $TT\\mu$ bispectrum, generated by the correlation between temperature anisotropies (T) and chemical potential spectral distortions ($\\mu$) of the Cosmic Microwave Background (CMB). Due to the angular dependence of the primordial signal, the corresponding $TT\\mu$ bispectrum strongly differs in shape from $TT\\mu$ sourced by the usual $g_{\\rm NL}$ or $\\tau_{\\rm NL}$ local trispectra, enabling us to obtain an unbiased estimation. From a Fisher matrix analysis, we find that, in a cosmic-variance-limited (CVL) survey of $TT\\mu$, a minimum detectable value of the quadrupolar Legendre coefficient is $d_2 \\sim 0.01$, which is 4 orders of magnitude better than the best value attainable from the $TTTT$ CMB trispectrum....
CMB Constraints On The Thermal WIMP Annihilation Cross Section
Steigman, Gary
2015-01-01
A thermal relic, often referred to as a weakly interacting massive particle (WIMP),is a particle produced during the early evolution of the Universe whose relic abundance (e.g., at present) depends only on its mass and its thermally averaged annihilation cross section (annihilation rate factor) sigma*v_ann. Late time WIMP annihilation has the potential to affect the cosmic microwave background (CMB) power spectrum. Current observational constraints on the absence of such effects provide bounds on the mass and the annihilation cross section of relic particles that may, but need not be dark matter candidates. For a WIMP that is a dark matter candidate, the CMB constraint sets an upper bound to the annihilation cross section, leading to a lower bound to their mass that depends on whether or not the WIMP is its own antiparticle. For a self-conjugate WIMP, m_min = 50f GeV, where f is an electromagnetic energy efficiency factor. For a non self-conjugate WIMP, the minimum mass is a factor of two larger. For a WIMP t...
New CMB constraints for Abelian Higgs cosmic strings
Lizarraga, Joanes; Daverio, David; Hindmarsh, Mark; Kunz, Martin
2016-01-01
We present cosmic microwave background (CMB) power spectra from recent numerical simulations of cosmic strings in the Abelian Higgs model and compare them to CMB power spectra measured by Planck. We obtain revised constraints on the cosmic string tension parameter $G\\mu$. For example, in the $\\Lambda$CDM model with the addition of strings and no primordial tensor perturbations, we find $G\\mu < 2.0 \\times 10^{-7}$ at 95% confidence, about 20% lower than the value obtained from previous simulations, which had 1/64 of the spatial volume. We investigate the source of the difference, showing that the main cause is an improved treatment of the string evolution across the radiation-matter transition. The increased computational volume also makes possible to simulate fully the physical equations of motion, in which the string cores shrink in comoving coordinates. This, and the larger dynamic range, changes the amplitude of the power spectra by only about 10%, demonstrating that field theory simulations of cosmic s...
CMB Science: Opportunities for a Cryogenic Filter-Bank Spectrometer
Tartari, A.; Battistelli, E. S.; Piat, M.; Prêle, D.
2016-08-01
Cosmic microwave background (CMB) spectral science is experiencing a renewed interest after the impressive result of COBE-FIRAS in the early Nineties. In 2011, the PIXIE proposal contributed to reopen the prospect of measuring deviations from a perfect 2.725 K planckian spectrum. Both COBE-FIRAS and PIXIE are differential Fourier transform spectrometers (FTSes) capable to operate in the null condition across ˜ 2 frequency decades (in the case of PIXIE, the frequency span is 30 GHz-6 THz). We discuss a complementary strategy to observe CMB spectral distortions at frequencies lower than 250 GHz, down to the Rayleigh-Jeans tail of the spectrum. The throughput advantage that makes the FTS capable of achieving exquisite sensitivity via multimode operation becomes limited at lower frequencies. We demonstrate that an array of 100 cryogenic planar filter-bank spectrometers coupled to single mode antennas, on a purely statistical ground, can perform better than an FTS between tens of GHz and 200 GHz (a relevant frequency window for cosmology) in the hypothesis that (1) both instruments have the same frequency resolution and (2) both instruments are operated at the photon noise limit (with the FTS frequency band extending from ˜ tens of GHz up to 1 THz). We discuss possible limitations of these hypotheses, and the constraints that have to be fulfilled (mainly in terms of efficiency) in order to operate a cryogenic filter-bank spectrometer close to its ultimate sensitivity limit.
Low-ℓ CMB from string-scale SUSY breaking?
Sagnotti, A.
2017-01-01
Models of inflation are instructive playgrounds for supersymmetry (SUSY) breaking in Supergravity and String Theory. In particular, combinations of branes and orientifolds that are not mutually BPS can lead to brane SUSY breaking, a phenomenon where nonlinear realizations are accompanied, in tachyon-free vacua, by the emergence of steep exponential potentials. When combined with milder terms, these exponentials can lead to slow-roll after a fast ascent and a turning point. This leaves behind distinctive patterns of scalar perturbations, where pre-inflationary peaks can lie well apart from an almost scale invariant profile. I review recent attempts to connect these power spectra to the low-ℓ cosmic microwave background (CMB), and a corresponding one-parameter extension of Lambda cold dark matter (ΛCDM) with a low-frequency cut Δ. A detailed likelihood analysis led to Δ = (0.351 ± 0.114) × 10-3Mpc-1, at 99.4% confidence level, in an extended Galactic mask with fsky = 39%, to be compared with a nearby value at 88.5% in the standard Planck 2015 mask with fsky = 94%. In these scenarios, one would be confronted, in the CMB, with relics of an epoch of deceleration that preceded the onset of slow-roll.
Hidden in the background: a local approach to CMB anomalies
Bueno Sánchez, Juan C.
2016-09-01
We investigate a framework aiming to provide a common origin for the large-angle anomalies detected in the Cosmic Microwave Background (CMB), which are hypothesized as the result of the statistical inhomogeneity developed by different isocurvature fields of mass m~ H present during inflation. The inhomogeneity arises as the combined effect of (i) the initial conditions for isocurvature fields (obtained after a fast-roll stage finishing many e-foldings before cosmological scales exit the horizon), (ii) their inflationary fluctuations and (iii) their coupling to other degrees of freedom. Our case of interest is when these fields (interpreted as the precursors of large-angle anomalies) leave an observable imprint only in isolated patches of the Universe. When the latter intersect the last scattering surface, such imprints arise in the CMB. Nevertheless, due to their statistically inhomogeneous nature, these imprints are difficult to detect, for they become hidden in the background similarly to the Cold Spot. We then compute the probability that a single isocurvature field becomes inhomogeneous at the end of inflation and find that, if the appropriate conditions are given (which depend exclusively on the preexisting fast-roll stage), this probability is at the percent level. Finally, we discuss several mechanisms (including the curvaton and the inhomogeneous reheating) to investigate whether an initial statistically inhomogeneous isocurvature field fluctuation might give rise to some of the observed anomalies. In particular, we focus on the Cold Spot, the power deficit at low multipoles and the breaking of statistical isotropy.
Quantifying discordance in the 2015 Planck CMB spectrum
Addison, G E; Watts, D J; Bennett, C L; Halpern, M; Hinshaw, G; Weiland, J L
2015-01-01
We examine the internal consistency of the Planck 2015 cosmic microwave background (CMB) temperature anisotropy power spectrum. We show that tension exists between cosmological constant cold dark matter (LCDM) model parameters inferred from multipoles l=1000, particularly the CDM density, Omega_ch^2, which is discrepant at 2.5 sigma for a Planck-motivated prior on the optical depth, tau=0.07+/-0.02. We find some parameter tensions to be larger than previously reported because of inaccuracy in the code used by the Planck Collaboration to generate model spectra. The Planck l>=1000 constraints are also in tension with low-redshift data sets, including Planck's own measurement of the CMB lensing power spectrum (2.4 sigma), and the most precise baryon acoustic oscillation (BAO) scale determination (2.5 sigma). The Hubble constant predicted by Planck from l>=1000, H_0=64.1+/-1.7 km/s/Mpc, disagrees with the most precise local distance ladder measurement of 73.0+/-2.4 km/s/Mpc at the 3.0 sigma level, while the Planc...
Foreign Experience in Training Future Engineering Educators for Modeling Technological Processes
Directory of Open Access Journals (Sweden)
Bokhonko Yevhen
2017-03-01
Full Text Available The article deals with the study of foreign experience in training engineering educators for modeling technological processes. It has been stated that engineering education is a field that is being dramatically developed taking into account the occurring changes in educational paradigms, global higher education space, national higher education systems, economics, society, etc. It has been indicated that the abundance of the latest information and communication technologies alter the approaches to training various specialists, and, in particular, engineering educators. It has been mentioned that engineering teacher education is undergoing significant development. The activities of the International Society for Engineering Education – IGIP have been justified. It has been found out that there is the vital need for those specialists able to combine the techniques of traditional teaching and innovative scientific achievements, design technical structures, be leader and facilitator of the education process. It has been defined that the activity of the society is aimed at providing engineering educators with relevant training that involves their obtaining the qualification that is accorded with European education standards. US experience in training engineering educators for professional activity has been analyzed. It has been specified that engineering education has become more integrated into the curricula of elementary, middle and high school because of the increasing focus on STEM subjects; the demand for engineering educators is dramatically growing at all the levels of the education system. The peculiarities of engineering educators’ training have been demonstrated on the example of the Purdue Polytechnic Institute. It has been concluded that Bachelor of Science in Engineering Technology Teacher Education is a rather interdisciplinary degree program and trains future engineering educators for a wide range of fields. The organization of the
Searching for primordial non-Gaussianity in Planck CMB maps using a combined estimator
Novaes, C P; Ferreira, I S; Wuensche, C A
2013-01-01
The extensive search for deviations from Gaussianity in cosmic microwave background radiation (CMB) data is very important due to the information about the very early moments of the universe encoded there. Recent analyses from Planck CMB data do not exclude the presence of non-Gaussianity of small amplitude, although they are consistent with the Gaussian hypothesis. The use of different techniques is essential to provide information about types and amplitudes of non-Gaussianities in the CMB data. In particular, we find interesting to construct an estimator based upon the combination of two powerful statistical tools that appears to be sensitive enough to detect tiny deviations from Gaussianity in CMB maps. This estimator combines the Minkowski functionals with a Neural Network, maximizing a tool widely used to study non-Gaussian signals with a reinforcement of another tool designed to identify patterns in a data set. We test our estimator by analyzing simulated CMB maps contaminated with different amounts of ...
A Measurement of CMB Cluster Lensing with SPT and DES Year 1 Data
Energy Technology Data Exchange (ETDEWEB)
Baxter, E.J.; et al.
2017-08-03
Clusters of galaxies gravitationally lens the cosmic microwave background (CMB) radiation, resulting in a distinct imprint in the CMB on arcminute scales. Measurement of this effect offers a promising way to constrain the masses of galaxy clusters, particularly those at high redshift. We use CMB maps from the South Pole Telescope Sunyaev-Zel'dovich (SZ) survey to measure the CMB lensing signal around galaxy clusters identified in optical imaging from first year observations of the Dark Energy Survey. We detect lensing of the CMB by the galaxy clusters at 6.5$\\sigma$ significance. Using the measured lensing signal, we constrain the amplitude of the relation between cluster mass and optical richness to roughly $20\\%$ precision, finding good agreement with recent constraints obtained with galaxy lensing. The error budget is dominated by statistical noise but includes significant contributions from systematic biases due to the thermal SZ effect and cluster miscentering.
Hagiwara, K; Szalapski, R
1995-01-01
Extensions of the Standard Model which involve a new scale, \\Lambda, may, for energies sufficiently small compared to this new scale, be expressed in terms of operators with energy dimension greater than four. The coefficients of just four SU(2)\\timesU(1)-gauge-inva riant energy-dimension-six operators are sufficient to parameterize the contributions of new physics in the electroweak bosonic sector to electroweak precision measurements. In this letter we update constraints on the coefficients of these four operators due to recent precision measurements of electroweak observables. We further demonstrate how such constraints may be improved by experiments at TRISTAN, LEP2 and at a future linear e^+e^- collider. The relationship of these operators to the oblique parameters S, T and U is examined. Two of the operators contribute to a non-standard running of the electroweak charge form-factors \\overline{\\alpha}(q^2), \\overline{s}^2(q^2), \\overline{g}_Z^2(q^2) and \\overline{g}_W^2(q^2); in the special case where th...
Present and Future Kaon Physics ( Kaon Decays: Status and Prospects of Experiments)
Energy Technology Data Exchange (ETDEWEB)
Bryman, Doug (University of British Columbia)
2005-05-04
Study of the ultra-rare K {yields} {pi}{nu}{bar {nu}} decays is highly motivated by their unique theoretical access to short distance physics allowing deep probing of physics beyond the Standard Model including possible new sources of CP violation and flavor symmetry breaking. It also appears that through the development of targeted experimental techniques, both the charged and neutral processes, K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} and K{sub L}{sup 0} {yields} {pi}{sup 0}{nu}{bar {nu}}, are accessible to detailed measurement. Three events consistent with K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} decay have been observed by BNL E787/E949 and further measurements of this reaction are being planned. The new KOPIO experiment at BNL is aiming to study the special CP-violating decay K{sub L}{sup 0} {yields} {pi}{sup 0}{nu}{bar {nu}} with a precision of 10%. The motivations, experimental methods, prospects, and possible impact of KOPIO and other future measurements will be discussed.
Energy Technology Data Exchange (ETDEWEB)
Akerib, D.S.; et al.
2017-02-08
The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of $^{238}$U$_{e}$~$<$1.6~mBq/kg, $^{238}$U$_{l}$~$<$0.09~mBq/kg, $^{232}$Th$_{e}$~$=0.28\\pm 0.03$~mBq/kg, $^{232}$Th$_{l}$~$=0.25\\pm 0.02$~mBq/kg, $^{40}$K~$<$0.54~mBq/kg, and $^{60}$Co~$<$0.02~mBq/kg (68\\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of $0.160\\pm0.001$(stat)$\\pm0.030$(sys) counts.
Bruton's tyrosine kinase inhibitors in B-cell lymphoma: current experience and future perspectives.
Seiler, T; Dreyling, M
2017-08-01
The Bruton tyrosine kinase (BTK) is a central hub in the B cell receptor (BCR) pathway and strongly influences B cell maturation, differentiation and proliferation. Not surprisingly, BTK plays an essential role in the pathogenesis of various B cell lymphomas. Inhibitors of BTK have broadened our therapeutic options in several B cell lymphomas and already are an integral element in the treatment of Mantle Cell Lymphoma (MCL), chronic lymphocytic leukemia (CLL) and Waldenström's marcoglobulinemia. Several second generation BTK inhibitors are in clinical development and might further improve tolerability and efficacy of therapy in advanced stage CLL and MCL. Areas covered: This review illustrates the mechanism of action of BTK inhibitors and provides a comprehensive summary of key clinical trials in the development of BTK inhibitors. Characteristics of second generation BTK-inhibitors are described. Expert opinion: With accumulation of clinical experience after drug approval, longer patient follow-up and larger numbers of treated patients, future development will focus on the identification of intelligent treatment combinations. Individual selection of patients with distinct biologically properties might guide treatment decisions. While BTK inhibitors are moving to earlier treatment lines, the incorporation of these drugs into a comprehensive therapeutic strategy is still difficult to date.
Ma, Bernice Hua; Yong, Hua-Hie; Borland, Ron; McNeill, Ann; Hitchman, Sara C
2017-05-31
Personal vaporisers (PV), including e-cigarettes, may be a harm reduction strategy for tobacco control. This study aims to identify factors associated with future intentions to vape among smokers and ex-smokers in Australia and the UK. Cross-sectional data of smokers and ex-smokers (n = 1199, mean age = 45.3 years, 44.8% male), collected in 2014/2015 and divided into four subgroups: smoking past vapers (SPV), smoking vapers (SV), ex-smoking past vapers (ESPV) and ex-smoking vapers (ESV), from the International Tobacco Control Australia and UK surveys were analysed by using regression models. Higher vaping satisfaction increased vaping intentions for all groups except ESPV. Perceiving PVs as less harmful predicted intentions to vape for all groups except ESV. The importance of PVs for stopping smoking predicted lower intentions to continue vaping for SV, but higher intentions to initiate vaping for SPV. The importance of PVs for cutting down smoking was a positive predictor only for SPV. Among ex-smokers, importance for maintaining not smoking was a positive predictor for ESPV, but not for ESV. The importance of perceiving vapour being less harmful also depended on vaping status for ex-smokers. The only country interaction was that only in the UK was perceiving PVs as less harmful associated with intention among SPV. Factors influencing intentions vary by smoking and/or vaping status, with greater differences between the ex-smoker subgroups. This is consistent with PVs being seen as a way of managing smoking, rather than something that has intrinsic value, for all except the ex-smoking vapers. [Ma BH, Yong H-H, Borland R, McNeill A, Hitchman SC. Factors associated with future intentions to use personal vaporisers among those with some experience of vaping. Drug Alcohol Rev 2017;00:000-000]. © 2017 The Authors Drug and Alcohol Review published by John Wiley & Sons Australia, Ltd on behalf of Australasian Professional Society on Alcohol and other Drugs.
Joint Planck and WMAP assessment of low CMB multipoles
Iqbal, Asif; Prasad, Jayanti; Souradeep, Tarun; Malik, Manzoor A.
2015-06-01
The remarkable progress in cosmic microwave background (CMB) studies over past decade has led to the era of precision cosmology in striking agreement with the ΛCDM model. However, the lack of power in the CMB temperature anisotropies at large angular scales (low-l), as has been confirmed by the recent Planck data also (up to 0l=4), although statistically not very strong (less than 3σ), is still an open problem. One can avoid to seek an explanation for this problem by attributing the lack of power to cosmic variance or can look for explanations i.e., different inflationary potentials or initial conditions for inflation to begin with, non-trivial topology, ISW effect etc. Features in the primordial power spectrum (PPS) motivated by the early universe physics has been the most common solution to address this problem. In the present work we also follow this approach and consider a set of PPS which have features and constrain the parameters of those using WMAP 9 year and Planck data employing Markov-Chain Monte Carlo (MCMC) analysis. The prominent feature of all the models of PPS that we consider is an infra-red cut off which leads to suppression of power at large angular scales. We consider models of PPS with maximum three extra parameters and use Akaike information criterion (AIC) and Bayesian information criterion (BIC) of model selection to compare the models. For most models, we find good constraints for the cut off scale kc, however, for other parameters our constraints are not that good. We find that sharp cut off model gives best likelihood value for the WMAP 9 year data, but is as good as power law model according to AIC. For the joint WMAP 9 + Planck data set, Starobinsky model is slightly preferred by AIC which is also able to produce CMB power suppression up to 0l<=3 to some extent. However, using BIC criteria, one finds model(s) with least number of parameters (power law model) are always preferred.
Miller, Kari Knutson; Gonzalez, Amber M.
2016-01-01
This paper examines outcomes associated with participation in short-term, international internship experiences. Results suggest short-term international internship experiences contribute to rich personal and professional development outcomes. Findings highlight participant challenges associated with initial internship experiences, professional…
Sundin, George W; Castiblanco, Luisa F; Yuan, Xiaochen; Zeng, Quan; Yang, Ching-Hong
2016-12-01
Plant diseases caused by bacterial pathogens place major constraints on crop production and cause significant annual losses on a global scale. The attainment of consistent effective management of these diseases can be extremely difficult, and management potential is often affected by grower reliance on highly disease-susceptible cultivars because of consumer preferences, and by environmental conditions favouring pathogen development. New and emerging bacterial disease problems (e.g. zebra chip of potato) and established problems in new geographical regions (e.g. bacterial canker of kiwifruit in New Zealand) grab the headlines, but the list of bacterial disease problems with few effective management options is long. The ever-increasing global human population requires the continued stable production of a safe food supply with greater yields because of the shrinking areas of arable land. One major facet in the maintenance of the sustainability of crop production systems with predictable yields involves the identification and deployment of sustainable disease management solutions for bacterial diseases. In addition, the identification of novel management tactics has also come to the fore because of the increasing evolution of resistance to existing bactericides. A number of central research foci, involving basic research to identify critical pathogen targets for control, novel methodologies and methods of delivery, are emerging that will provide a strong basis for bacterial disease management into the future. Near-term solutions are desperately needed. Are there replacement materials for existing bactericides that can provide effective disease management under field conditions? Experience should inform the future. With prior knowledge of bactericide resistance issues evolving in pathogens, how will this affect the deployment of newer compounds and biological controls? Knowledge is critical. A comprehensive understanding of bacterial pathosystems is required to not
Education and Public Outreach at EGO/Virgo: past experiences and future projects
Razzano, Massimiliano
2015-08-01
We are approaching the new generation Gravitational Wave (GW) detector Era and in the next months a new exiting period for GW scientists will start enforcing collaboration and interactions among different scientific communities. We aim to reach a wider audience to spread this enthusiasm in the general public about our every day activities and let them know how it will change our understanding of the Universe, once revealed the Gravitational waves. In this talk, we will report about the activities of the last years and about the EGO/Virgo outreach plans for the future. The main goal of the Virgo/EGO outreach activity is to raise awareness and curiosity about the GW research projects. In the past years we informed the general public about science we do at EGO/Virgo site, trying to attract students in doing research, letting them know about the Virgo detector and involving them in small research activities. We run a regular program of site visits, and we often organized astronomical observations and science cafe' events which attracted a large number of people. Efforts were made also to involve kids in understanding our scientific job. We started a series of regular events in which art and science were fused.We are strengthening our outreach activities with common efforts in the Virgo laboratories which are spread all over in Europe.We plan to make available a scientific path within Virgo, where the public can do little experiences of science or for example tile, for a day, the activity of our researchers.
Past, present, and future of stroke in middle-income countries: the Brazilian experience.
Martins, Sheila Cristina Ouriques; Pontes-Neto, Octávio Marques; Alves, Cloer Vescia; de Freitas, Gabriel Rodriguez; Filho, Jamary Oliveira; Tosta, Elza Dias; Cabral, Norberto Luiz
2013-10-01
Stroke is one of the major public health challenges in middle-income countries. Brazil is the world's sixth largest economy but was clearly behind the milestones in the fight against stroke, which is the leading cause of death and disability in the country. Nevertheless, many initiatives are now reshaping stroke prevention, care, and rehabilitation in the country. The present article discusses the evolution of stroke care in Brazil over the last decade. We describe the main characteristics of stroke care before 2008; a pilot study in a Southern Brazilian city between 2008 and 2010, the Brazilian Stroke Project initiative; and the 2012 National Stroke Policy Act. The National Stroke Project was followed by a major increased on the number of stroke center in the country. The key elements of the 2012 National Stroke Policy Act included: definition of the requirements and levels of stroke centers; improved reimbursement for stroke care; promotion of stroke telemedicine; definition of the Line of Stroke Care (to integrate available resources and other health programs); increased funding for stroke rehabilitation; funding for training of healthcare professionals and initiatives to increase awareness about stroke within the population. The evolution of stroke care in Brazil over the last decade is a pathway that exemplifies the challenges that middle-income countries have to face in order to improve stroke prevention, treatment and rehabilitation. The reported Brazilian experience can be extrapolated to understand the past, present, and future of stroke care in middle-income countries. © 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.
Constraining CMB-consistent primordial voids with cluster evolution
Mathis, H; Griffiths, L M; Kunz, M
2004-01-01
Using cosmological simulations, we make predictions for the distribution of clusters in a plausible non-gaussian model where primordial voids nucleated during inflation act together with scale-invariant adiabatic gaussian fluctuations as seeds for the formation of large-scale structure. This model agrees with most recent observations of the anisotropies of the cosmic microwave background (CMB) and can account for the excess of power measured on cluster scales by the Cosmic Background Imager (CBI), the large empty regions apparent in nearby galaxy redshift surveys and the number of giant arcs measured in deep cluster lensing surveys. We show that the z=0 cluster mass function differs from predictions for a standard LCDM cosmology with the same sigma_8. Moreover, as massive clusters also form much earlier in the "void" scenario, we show that integrated number counts of SZ sources and simple statistics of strong lensing can easily falsify this model.
Optimal analysis of azimuthal features in the CMB
Osborne, Stephen; Smith, Kendrick
2013-01-01
We present algorithms for searching for azimuthally symmetric features in CMB data. Our algorithms are fully optimal for masked all-sky data with inhomogeneous noise, computationally fast, simple to implement, and make no approximations. We show how to implement the optimal analysis in both Bayesian and frequentist cases. In the Bayesian case, our algorithm for evaluating the posterior likelihood is so fast that we can do a brute-force search over parameter space, rather than using a Monte Carlo Markov chain. Our motivating example is searching for bubble collisions, a pre-inflationary signal which can be generated if multiple tunneling events occur in an eternally inflating spacetime, but our algorithms are general and should be useful in other contexts.
Minkowski Functionals and Cluster Analysis for CMB Maps
Novikov, D; Shandarin, S F; Feldman, Hume A.; Shandarin, Sergei F.
1999-01-01
We suggest novel statistics for the CMB maps that are sensitive to non-Gaussian features. These statistics are natural generalizations of the geometrical and topological methods that have been already used in cosmology such as the cumulative distribution function and genus. We compute the distribution functions of the Partial Minkowski Functionals for the excursion set above or bellow a constant temperature threshold. Minkowski Functionals are additive and are translationally and rotationally invariant. Thus, they can be used for patchy and/or incomplete coverage. The technique is highly efficient computationally (it requires only $O(N)$ operations, where $N$ is the number of pixels per one threshold level). Further, it allows to split large data sets into smaller subsets. The full advantage of these statistics can be obtained only on very large data sets. We apply it to the 4-year DMR COBE data corrected for the Galaxy contamination as an illustration of the technique.
Low-l CMB power loss in string inflation
Energy Technology Data Exchange (ETDEWEB)
Pedro, Francisco G.; Westphal, Alexander
2013-09-15
The lack of power on large scales (l
Contribution of domain wall networks to the CMB power spectrum
Lazanu, A; Shellard, E P S
2015-01-01
We use three domain wall simulations from the radiation era to the late time dark energy domination era based on the PRS algorithm to calculate the energy-momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined.
Contribution of domain wall networks to the CMB power spectrum
Directory of Open Access Journals (Sweden)
A. Lazanu
2015-07-01
Full Text Available We use three domain wall simulations from the radiation era to the late-time dark energy domination era based on the PRS algorithm to calculate the energy–momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined.
Contribution of domain wall networks to the CMB power spectrum
Energy Technology Data Exchange (ETDEWEB)
Lazanu, A., E-mail: A.Lazanu@damtp.cam.ac.uk [Centre for Theoretical Cosmology, Department of Applied Mathematics and Theoretical Physics, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Martins, C.J.A.P., E-mail: Carlos.Martins@astro.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto (Portugal); Shellard, E.P.S., E-mail: E.P.S.Shellard@damtp.cam.ac.uk [Centre for Theoretical Cosmology, Department of Applied Mathematics and Theoretical Physics, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2015-07-30
We use three domain wall simulations from the radiation era to the late-time dark energy domination era based on the PRS algorithm to calculate the energy–momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined.
Cosmology with the CMB temperature-polarization correlation
Couchot, F; Perdereau, O; Plaszczynski, S; d'Orfeuil, B Rouillé; Spinelli, M; Tristram, M
2016-01-01
We demonstrate that the CMB temperature-polarization cross-correlation provides accurate and robust constraints on cosmological parameters. We compare them with the results from temperature or polarization and investigate the impact of foregrounds, cosmic variance and instrumental noise. This analysis makes use of the Planck high-l HiLLiPOP likelihood based on angular power spectra that takes into account systematics from the instrument and foreground residuals directly modeled using Planck measurements. The temperature-polarization correlation (TE) spectrum is less contaminated by astrophysical emissions than the temperature power-spectrum (TT) allowing to derive constraints that are less sensitive to foreground uncertainties. For LCDM parameters, TE gives very competitive results compared to TT. For LCDM model extensions, it is limited by the instrumental noise level in the polarization maps.
Template fitting and the large-angle CMB anomalies
Land, K; Land, Kate; Magueijo, Joao
2006-01-01
We investigate two possible explanations for the large-angle anomalies in the Cosmic Microwave Background (CMB): an intrinsically anisotropic model and an inhomogeneous model. We take as an example of the former a Bianchi model (which leaves a spiral pattern in the sky) and of the latter a background model that already contains a non-linear long-wavelength plane wave (leaving a stripy pattern in the sky). We make use of an adaptation of the ``template'' formalism, previously designed to detect galactic foregrounds, to recognize these patterns and produce confidence levels for their detection. The ``corrected'' maps, from which these patterns have been removed, are free of anomalies, in particular their quadrupole and octupole are not planar and their intensities not low. We stress that although the ``template'' detections are not found to be statistically significant they do correct statistically significant anomalies.
Inflation in the closed FLRW model and the CMB
Bonga, Béatrice; Gupt, Brajesh; Yokomizo, Nelson
2016-10-01
Recent cosmic microwave background (CMB) observations put strong constraints on the spatial curvature via estimation of the parameter Ωk assuming an almost scale invariant primordial power spectrum. We study the evolution of the background geometry and gauge-invariant scalar perturbations in an inflationary closed FLRW model and calculate the primordial power spectrum. We find that the inflationary dynamics is modified due to the presence of spatial curvature, leading to corrections to the nearly scale invariant power spectrum at the end of inflation. When evolved to the surface of last scattering, the resulting temperature anisotropy spectrum (CTTl) shows deficit of power at low multipoles (l cosmological parameters remains robust under inclusion of positive spatial curvature.
Offset balancing in pseudo-correlation radiometers for CMB measurements
Mennella, A.; Bersanelli, M.; Seiffert, M.; Kettle, D.; Roddis, N.; Wilkinson, A.; Meinhold, P.
2003-11-01
Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the PLANCK-LFI pseudo-correlation receivers which uses a tunable gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to PLANCK-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to PLANCK-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.