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Sample records for big bang model

  1. The Whole Shebang: How Science Produced the Big Bang Model.

    Science.gov (United States)

    Ferris, Timothy

    2002-01-01

    Offers an account of the accumulation of evidence that has led scientists to have confidence in the big bang theory of the creation of the universe. Discusses the early work of Ptolemy, Copernicus, Kepler, Galileo, and Newton, noting the rise of astrophysics, and highlighting the birth of the big bang model (the cosmic microwave background theory…

  2. The Big Bang Singularity

    Science.gov (United States)

    Ling, Eric

    The big bang theory is a model of the universe which makes the striking prediction that the universe began a finite amount of time in the past at the so called "Big Bang singularity." We explore the physical and mathematical justification of this surprising result. After laying down the framework of the universe as a spacetime manifold, we combine physical observations with global symmetrical assumptions to deduce the FRW cosmological models which predict a big bang singularity. Next we prove a couple theorems due to Stephen Hawking which show that the big bang singularity exists even if one removes the global symmetrical assumptions. Lastly, we investigate the conditions one needs to impose on a spacetime if one wishes to avoid a singularity. The ideas and concepts used here to study spacetimes are similar to those used to study Riemannian manifolds, therefore we compare and contrast the two geometries throughout.

  3. Testing Big Bang Nucleosynthesis

    OpenAIRE

    Steigman, Gary

    1996-01-01

    Big Bang Nucleosynthesis (BBN), along with the cosmic background radiation and the Hubble expansion, is one of the pillars ofthe standard, hot, big bang cosmology since the primordial synthesis of the light nuclides (D, $^3$He, $^4$He, $^7$Li) must have occurred during the early evolution of a universe described by this model. The overall consistency between the predicted and observed abundances of the light nuclides, each of which spans a range of some nine orders of magnitude, provides impr...

  4. Primordial Big Bang Nucleosynthesis

    OpenAIRE

    Olive, Keith A.

    1999-01-01

    Big Bang Nucleosynthesis is the theory of the production of the the light element isotopes of D, He3, He4, and Li7. After a brief review of the essential elements of the standard Big Bang model at a temperature of about 1 MeV, the theoretical input and predictions of BBN are discussed. The theory is tested by the observational determinations of the light element abundances and the current status of these observations is reviewed. Concordance of standard model and the related observations is f...

  5. Expansion of the Universe - Standard Big Bang Model

    CERN Document Server

    Roos, Matts

    2008-01-01

    After a brief introduction to the sixteenth and seventeenth century views of the Universe and the nineteenth century paradox of Olbers, we start the history of the cosmic expansion with Hubble's epochal discovery of the recession velocities of spiral galaxies. By then Einstein's theories of relativity were well known, but no suitable metric was known. Prior to introducing General Relativity we embark on a non-chronological derivation of the Robertson-Walker metric directly from Special Relativity and the Minkowski metric endowed with a Gaussian curvature. This permits the definition of all relativistic distance measures needed in observational astronomy. Only thereafter do we come to General Relativity, and describe some of its consequences: gravitational lensing, black holes, various tests, and the cornerstone of the standard Big Bang model, the Friedmann-Lemaitre equations. Going backwards in time towards Big Bang we first have to trace the thermal history, and then understand the needs for a cosmic inflati...

  6. The big bang

    Science.gov (United States)

    Silk, Joseph

    Our universe was born billions of years ago in a hot, violent explosion of elementary particles and radiation - the big bang. What do we know about this ultimate moment of creation, and how do we know it? Drawing upon the latest theories and technology, this new edition of The big bang, is a sweeping, lucid account of the event that set the universe in motion. Joseph Silk begins his story with the first microseconds of the big bang, on through the evolution of stars, galaxies, clusters of galaxies, quasars, and into the distant future of our universe. He also explores the fascinating evidence for the big bang model and recounts the history of cosmological speculation. Revised and updated, this new edition features all the most recent astronomical advances, including: Photos and measurements from the Hubble Space Telescope, Cosmic Background Explorer Satellite (COBE), and Infrared Space Observatory; the latest estimates of the age of the universe; new ideas in string and superstring theory; recent experiments on neutrino detection; new theories about the presence of dark matter in galaxies; new developments in the theory of the formation and evolution of galaxies; the latest ideas about black holes, worm holes, quantum foam, and multiple universes.

  7. DLCQ and Plane Wave Matrix Big Bang Models

    OpenAIRE

    Blau, Matthias; O'Loughlin, Martin

    2008-01-01

    We study the generalisations of the Craps-Sethi-Verlinde matrix big bang model to curved, in particular plane wave, space-times, beginning with a careful discussion of the DLCQ procedure. Singular homogeneous plane waves are ideal toy-models of realistic space-time singularities since they have been shown to arise universally as their Penrose limits, and we emphasise the role played by the symmetries of these plane waves in implementing the flat space Seiberg-Sen DLCQ prescription for these c...

  8. Cosmological model without big-bang

    International Nuclear Information System (INIS)

    The modified field equations are transferred onto an isotropic homogeneous universe. In contrast to the Robertson-Walker model the cosmological equations are deducted by means of metric components. Assuming the total gravitational charge being constant in time positive mean densities of matter are only compatible with a spherical space. The solutions do not have any cosmological singularity in finite times, and they demonstrate that the universal red shift may not be explained by the Doppler effect but as a gravitational red shift. (orig.)

  9. A fully quantum model of Big Bang

    CERN Document Server

    Maydanyuk, Sergei P; Olkhovsky, Vladislav S

    2013-01-01

    In the paper the closed Friedmann-Robertson-Walker model with quantization in the presence of the positive cosmological constant and radiation is studied. For analysis of tunneling probability for birth of an asymptotically deSitter, inflationary Universe as a function of the radiation energy a new definition of a "free" wave propagating inside strong fields is proposed. On such a basis, tunneling boundary condition is corrected, penetrability and reflection concerning to the barrier are calculated in fully quantum stationary approach. For the first time non-zero interference between the incident and reflected waves has been taken into account which turns out to play important role inside cosmological potentials and could be explained by non-locality of barriers in quantum mechanics. Inside whole region of energy of radiation the tunneling probability for the birth of the inflationary Universe is found to be close to its value obtained in semiclassical approach. The reflection from the barrier is determined f...

  10. Big bang nucleosynthesis - The standard model and alternatives

    Science.gov (United States)

    Schramm, David N.

    1991-01-01

    The standard homogeneous-isotropic calculation of the big bang cosmological model is reviewed, and alternate models are discussed. The standard model is shown to agree with the light element abundances for He-4, H-2, He-3, and Li-7 that are available. Improved observational data from recent LEP collider and SLC results are discussed. The data agree with the standard model in terms of the number of neutrinos, and provide improved information regarding neutron lifetimes. Alternate models are reviewed which describe different scenarios for decaying matter or quark-hadron induced inhomogeneities. The baryonic density relative to the critical density in the alternate models is similar to that of the standard model when they are made to fit the abundances. This reinforces the conclusion that the baryonic density relative to critical density is about 0.06, and also reinforces the need for both nonbaryonic dark matter and dark baryonic matter.

  11. Big bang nucleosynthesis: The standard model and alternatives

    Science.gov (United States)

    Schramm, David N.

    1991-01-01

    Big bang nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the big bang cosmological model. This paper reviews the standard homogeneous-isotropic calculation and shows how it fits the light element abundances ranging from He-4 at 24% by mass through H-2 and He-3 at parts in 10(exp 5) down to Li-7 at parts in 10(exp 10). Furthermore, the recent large electron positron (LEP) (and the stanford linear collider (SLC)) results on the number of neutrinos are discussed as a positive laboratory test of the standard scenario. Discussion is presented on the improved observational data as well as the improved neutron lifetime data. Alternate scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conlusions on the baryonic density relative to the critical density, omega(sub b) remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the conclusion that omega(sub b) approximately equals 0.06. This latter point is the driving force behind the need for non-baryonic dark matter (assuming omega(sub total) = 1) and the need for dark baryonic matter, since omega(sub visible) is less than omega(sub b).

  12. A Big Bang model of human colorectal tumor growth.

    Science.gov (United States)

    Sottoriva, Andrea; Kang, Haeyoun; Ma, Zhicheng; Graham, Trevor A; Salomon, Matthew P; Zhao, Junsong; Marjoram, Paul; Siegmund, Kimberly; Press, Michael F; Shibata, Darryl; Curtis, Christina

    2015-03-01

    What happens in early, still undetectable human malignancies is unknown because direct observations are impractical. Here we present and validate a 'Big Bang' model, whereby tumors grow predominantly as a single expansion producing numerous intermixed subclones that are not subject to stringent selection and where both public (clonal) and most detectable private (subclonal) alterations arise early during growth. Genomic profiling of 349 individual glands from 15 colorectal tumors showed an absence of selective sweeps, uniformly high intratumoral heterogeneity (ITH) and subclone mixing in distant regions, as postulated by our model. We also verified the prediction that most detectable ITH originates from early private alterations and not from later clonal expansions, thus exposing the profile of the primordial tumor. Moreover, some tumors appear 'born to be bad', with subclone mixing indicative of early malignant potential. This new model provides a quantitative framework to interpret tumor growth dynamics and the origins of ITH, with important clinical implications. PMID:25665006

  13. DLCQ and Plane Wave Matrix Big Bang Models

    CERN Document Server

    Blau, Matthias

    2008-01-01

    We study the generalisations of the Craps-Sethi-Verlinde matrix big bang model to curved, in particular plane wave, space-times, beginning with a careful discussion of the DLCQ procedure. Singular homogeneous plane waves are ideal toy-models of realistic space-time singularities since they have been shown to arise universally as their Penrose limits, and we emphasise the role played by the symmetries of these plane waves in implementing the flat space Seiberg-Sen DLCQ prescription for these curved backgrounds. We then analyse various aspects of the resulting matrix string Yang-Mills theories, such as the relation between strong coupling space-time singularities and world-sheet tachyonic mass terms. In order to have concrete examples at hand, in an appendix we determine and analyse the IIA singular homogeneous plane wave - null dilaton backgrounds.

  14. DLCQ and plane wave matrix Big Bang models

    International Nuclear Information System (INIS)

    We study the generalisations of the Craps-Sethi-Verlinde matrix big bang model to curved, in particular plane wave, space-times, beginning with a careful discussion of the DLCQ procedure. Singular homogeneous plane waves are ideal toy-models of realistic space-time singularities since they have been shown to arise universally as their Penrose limits, and we emphasise the role played by the symmetries of these plane waves in implementing the flat space Seiberg-Sen DLCQ prescription for these curved backgrounds. We then analyse various aspects of the resulting matrix string Yang-Mills theories, such as the relation between strong coupling space-time singularities and world-sheet tachyonic mass terms. In order to have concrete examples at hand, in an appendix we determine and analyse the IIA singular homogeneous plane wave - null dilaton backgrounds.

  15. A Matrix Big Bang

    OpenAIRE

    Craps, Ben; Sethi, Savdeep; Verlinde, Erik

    2005-01-01

    The light-like linear dilaton background represents a particularly simple time-dependent 1/2 BPS solution of critical type IIA superstring theory in ten dimensions. Its lift to M-theory, as well as its Einstein frame metric, are singular in the sense that the geometry is geodesically incomplete and the Riemann tensor diverges along a light-like subspace of codimension one. We study this background as a model for a big bang type singularity in string theory/M-theory. We construct the dual Matr...

  16. THE BIG BANG THEORY AND UNIVERSE MODELING. MISTAKES IN THE RELATIVITY THEORY

    OpenAIRE

    Javadov, Khaladdin; Javadli, Elmaddin

    2014-01-01

    This article is about Theory of Big Bang and it describes some details of Universe Modelling. It is Physical and Mathematical modeling of Universe formation. Application of mathematical and physical formulas for Universe Calculations.

  17. Big Bang Darkleosynthesis

    CERN Document Server

    Krnjaic, Gordan

    2014-01-01

    In a popular class of models, dark matter comprises an asymmetric population of composite particles with short range interactions arising from a confined nonabelian gauge group. We show that coupling this sector to a well-motivated light mediator particle yields efficient darkleosynthesis, a dark-sector version of big-bang nucleosynthesis (BBN), in generic regions of parameter space. Dark matter self-interaction bounds typically require the confinement scale to be above \\Lambda_{QCD}, which generically yields large (>>MeV/dark-nucleon) binding energies. These bounds further suggest the mediator is relatively weakly coupled, so repulsive forces between dark-sector nuclei are much weaker than coulomb repulsion between standard-model nuclei, which results in an exponential barrier-tunneling enhancement over standard BBN. Thus, dark nuclei are easier to make and harder to break than visible species with comparable mass numbers. This process can efficiently yield a dominant population of states with masses signifi...

  18. The Big Bang

    CERN Multimedia

    Moods, Patrick

    2006-01-01

    How did the Universe begin? The favoured theory is that everything - space, time, matter - came into existence at the same moment, around 13.7 thousand million years ago. This event was scornfully referred to as the "Big Bang" by Sir Fred Hoyle, who did not believe in it and maintained that the Universe had always existed.

  19. From Big Crunch to Big Bang

    OpenAIRE

    Khoury, Justin; Ovrut, Burt A.; Seiberg, Nathan; Steinhardt, Paul J.(Princeton Center for Theoretical Science, Princeton University, Princeton, NJ, 08544, USA); Turok, Neil

    2001-01-01

    We consider conditions under which a universe contracting towards a big crunch can make a transition to an expanding big bang universe. A promising example is 11-dimensional M-theory in which the eleventh dimension collapses, bounces, and re-expands. At the bounce, the model can reduce to a weakly coupled heterotic string theory and, we conjecture, it may be possible to follow the transition from contraction to expansion. The possibility opens the door to new classes of cosmological models. F...

  20. Big Bang 8

    CERN Document Server

    Apolin, Martin

    2008-01-01

    Physik soll verständlich sein und Spaß machen! Deshalb beginnt jedes Kapitel in Big Bang mit einem motivierenden Überblick und Fragestellungen und geht dann von den Grundlagen zu den Anwendungen, vom Einfachen zum Komplizierten. Dabei bleibt die Sprache einfach, alltagsorientiert und belletristisch. Band 8 vermittelt auf verständliche Weise Relativitätstheorie, Kern- und Teilchenphysik (und deren Anwendungen in der Kosmologie und Astrophysik), Nanotechnologie sowie Bionik.

  1. Big Bang 7

    CERN Document Server

    Apolin, Martin

    2008-01-01

    Physik soll verständlich sein und Spaß machen! Deshalb beginnt jedes Kapitel in Big Bang mit einem motivierenden Überblick und Fragestellungen und geht dann von den Grundlagen zu den Anwendungen, vom Einfachen zum Komplizierten. Dabei bleibt die Sprache einfach, alltagsorientiert und belletristisch. In Band 7 werden neben einer Einführung auch viele aktuelle Aspekte von Quantenmechanik (z. Beamen) und Elektrodynamik (zB Elektrosmog), sowie die Klimaproblematik und die Chaostheorie behandelt.

  2. Big Bang 5

    CERN Document Server

    Apolin, Martin

    2007-01-01

    Physik soll verständlich sein und Spaß machen! Deshalb beginnt jedes Kapitel in Big Bang mit einem motivierenden Überblick und Fragestellungen und geht dann von den Grundlagen zu den Anwendungen, vom Einfachen zum Komplizierten. Dabei bleibt die Sprache einfach, alltagsorientiert und belletristisch. Der Band 5 RG behandelt die Grundlagen (Maßsystem, Größenordnungen) und die Mechanik (Translation, Rotation, Kraft, Erhaltungssätze).

  3. Big Bang 6

    CERN Document Server

    Apolin, Martin

    2008-01-01

    Physik soll verständlich sein und Spaß machen! Deshalb beginnt jedes Kapitel in Big Bang mit einem motivierenden Überblick und Fragestellungen und geht dann von den Grundlagen zu den Anwendungen, vom Einfachen zum Komplizierten. Dabei bleibt die Sprache einfach, alltagsorientiert und belletristisch. Der Band 6 RG behandelt die Gravitation, Schwingungen und Wellen, Thermodynamik und eine Einführung in die Elektrizität anhand von Alltagsbeispielen und Querverbindungen zu anderen Disziplinen.

  4. Big bang darkleosynthesis

    Directory of Open Access Journals (Sweden)

    Gordan Krnjaic

    2015-12-01

    Full Text Available In a popular class of models, dark matter comprises an asymmetric population of composite particles with short range interactions arising from a confined nonabelian gauge group. We show that coupling this sector to a well-motivated light mediator particle yields efficient darkleosynthesis, a dark-sector version of big-bang nucleosynthesis (BBN, in generic regions of parameter space. Dark matter self-interaction bounds typically require the confinement scale to be above ΛQCD, which generically yields large (≫MeV/dark-nucleon binding energies. These bounds further suggest the mediator is relatively weakly coupled, so repulsive forces between dark-sector nuclei are much weaker than Coulomb repulsion between standard-model nuclei, which results in an exponential barrier-tunneling enhancement over standard BBN. Thus, darklei are easier to make and harder to break than visible species with comparable mass numbers. This process can efficiently yield a dominant population of states with masses significantly greater than the confinement scale and, in contrast to dark matter that is a fundamental particle, may allow the dominant form of dark matter to have high spin (S≫3/2, whose discovery would be smoking gun evidence for dark nuclei.

  5. An embedding for the big bang

    Science.gov (United States)

    Wesson, Paul S.

    1994-01-01

    A cosmological model is given that has good physical properties for the early and late universe but is a hypersurface in a flat five-dimensional manifold. The big bang can therefore be regarded as an effect of a choice of coordinates in a truncated higher-dimensional geometry. Thus the big bang is in some sense a geometrical illusion.

  6. Big Bang Nucleosynthesis Calculation

    CERN Document Server

    Kurki-Suonio, H

    2001-01-01

    I review standard big bang nucleosynthesis and some versions of nonstandard BBN. The abundances of the primordial isotopes D, He-3, and Li-7 produced in standard BBN can be calculated as a function of the baryon density with an accuracy of about 10%. For He-4 the accuracy is better than 1%. The calculated abundances agree fairly well with observations, but the baryon density of the universe cannot be determined with high precision. Possibilities for nonstandard BBN include inhomogeneous and antimatter BBN and nonzero neutrino chemical potentials.

  7. Passport to the Big Bang

    CERN Multimedia

    De Melis, Cinzia

    2013-01-01

    Le 2 juin 2013, le CERN inaugure le projet Passeport Big Bang lors d'un grand événement public. Affiche et programme. On 2 June 2013 CERN launches a scientific tourist trail through the Pays de Gex and the Canton of Geneva known as the Passport to the Big Bang. Poster and Programme.

  8. Big Bang Nucleosynthesis: An Update

    OpenAIRE

    Olive, Keith A.; Scully, Sean T.

    1995-01-01

    WThe current status of big bang nucleosynthesis is reviewed with an emphasis on the comparison between the observational determination of the light element abundances of \\D, \\he3, \\he4 and \\li7 and the predictions from theory. In particular, we present new analyses for \\he4 and \\li7. Implications for physics beyond the standard model are also discussed. Limits on the effective number of neutrino flavors are also updated.

  9. The Last Big Bang

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, Austin D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-13

    As one of the very few people in the world to give the “go/no go” decision to detonate a nuclear device, Austin “Mac” McGuire holds a very special place in the history of both the Los Alamos National Laboratory and the world. As Commander of Joint Task Force Unit 8.1.1, on Christmas Island in the spring and summer of 1962, Mac directed the Los Alamos data collection efforts for twelve of the last atmospheric nuclear detonations conducted by the United States. Since data collection was at the heart of nuclear weapon testing, it fell to Mac to make the ultimate decision to detonate each test device. He calls his experience THE LAST BIG BANG, since these tests, part of Operation Dominic, were characterized by the dramatic displays of the heat, light, and sounds unique to atmospheric nuclear detonations – never, perhaps, to be witnessed again.

  10. Le Big Bang en laboratoire

    CERN Multimedia

    Roy, Christelle

    2006-01-01

    Physiciens have been dreaming of it for 30 years; Thanks to huge particle accelerators, they were able to observe the matter such as it was some instants after the Big Bang (three different articles in 10 pages)

  11. Effective Dynamics of the Matrix Big Bang

    OpenAIRE

    Craps, Ben; Rajaraman, Arvind; Sethi, Savdeep

    2006-01-01

    We study the leading quantum effects in the recently introduced Matrix Big Bang model. This amounts to a study of supersymmetric Yang-Mills theory compactified on the Milne orbifold. We find a one-loop potential that is attractive near the Big Bang. Surprisingly, the potential decays very rapidly at late times, where it appears to be generated by D-brane effects. Usually, general covariance constrains the form of any effective action generated by renormalization group flow. However, the form ...

  12. An origin of the universe: a model alternative to Big Bang

    OpenAIRE

    Mercik, Andrzej; Mercik, Szymon

    2006-01-01

    We propose a new approach to the model of an origin of the universe built by Oscar Klein and Hannes Alfv\\'{e}n. Some modifications of assumptions underlying the model result in a possible scenario of the universe creation consistent with observations. We explain the large scale structre of the universe and we estimate the Hubble constant value as well as the number of galaxies in the universe. The model does not require many assumptions made in the model based on the Big Bang idea.

  13. From Big Bang to Big Crunch and Beyond

    OpenAIRE

    Elitzur, S.; Giveon, A.; Kutasov, D.; Rabinovici, E.

    2002-01-01

    We study a quotient Conformal Field Theory, which describes a 3+1 dimensional cosmological spacetime. Part of this spacetime is the Nappi-Witten (NW) universe, which starts at a ``big bang'' singularity, expands and then contracts to a ``big crunch'' singularity at a finite time. The gauged WZW model contains a number of copies of the NW spacetime, with each copy connected to the preceeding one and to the next one at the respective big bang/big crunch singularities. The sequence of NW spaceti...

  14. Was the Big Bang hot?

    Science.gov (United States)

    Wright, E. L.

    1983-01-01

    Techniques for verifying the spectrum defined by Woody and Richards (WR, 1981), which serves as a base for dust-distorted models of the 3 K background, are discussed. WR detected a sharp deviation from the Planck curve in the 3 K background. The absolute intensity of the background may be determined by the frequency dependence of the dipole anisotropy of the background or the frequency dependence effect in galactic clusters. Both methods involve the Doppler shift; analytical formulae are defined for characterization of the dipole anisotropy. The measurement of the 30-300 GHz spectra of cold galactic dust may reveal the presence of significant amounts of needle-shaped grains, which would in turn support a theory of a cold Big Bang.

  15. Big Bang riddles and their revelations

    OpenAIRE

    Magueijo, Joao; Baskerville, Kim

    1999-01-01

    We describe how cosmology has converged towards a beautiful model of the Universe: the Big Bang Universe. We praise this model, but show there is a dark side to it. This dark side is usually called ``the cosmological problems'': a set of coincidences and fine tuning features required for the Big Bang Universe to be possible. After reviewing these ``riddles'' we show how they have acted as windows into the very early Universe, revealing new physics and new cosmology just as the Universe came i...

  16. Pre-Big Bang, vacuum and noncyclic cosmologies

    OpenAIRE

    Gonzalez-Mestres, L.

    2011-01-01

    WMAP and Planck open the way to unprecedented Big Bang phenomenology, potentially allowing to test the standard Big Bang model as well as less conventional approaches including noncyclic pre-Big Bang cosmologies that would incorporate a new fundamental scale beyond the Planck scale and, possibly, new ultimate constituents of matter. Alternatives to standard physics can be considered from a cosmological point of view concerning vacuum structure, the nature of space-time, the origin and evoluti...

  17. 淀粉Big Bang!

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Big Bang,也叫"大爆炸",指的是宇宙诞生时期从密度极大且温度极高的太初状态开始发生不断膨胀的过程。换句话说,从Big Bang开始,我们现在的宇宙慢慢形成了。0K,从本期开始,"少电"将在微博引发Big Bang!——淀粉大爆炸!具体怎么爆呢?我想,看到本页版式的你已经明白了七八分了吧?

  18. The Standard Model Higgs as the origin of the hot Big Bang

    CERN Document Server

    Figueroa, Daniel G

    2016-01-01

    If the Standard Model (SM) Higgs is weakly coupled to the inflationary sector, the Higgs is expected to be universally in the form of a condensate towards the end of inflation. The Higgs decays rapidly after inflation -- via non-perturbative effects -- into an out-of-equilibrium distribution of SM species, which thermalize soon afterwards. If the post-inflationary equation of state of the universe is stiff, $w \\simeq +1$, the SM species eventually dominate the total energy budget. This provides a natural origin for the relativistic thermal plasma of SM species, required for the onset the `hot Big Bang' era. The viability of this scenario requires the inflationary Hubble scale $H_*$ to be lower than the instability scale for Higgs vacuum decay, the Higgs not to generate too large curvature perturbations at cosmological scales, and the SM dominance to occur before Big Bang Nucleosynthesis. We show that successful reheating into the SM can only be obtained in the presence of a non-minimal coupling to gravity $\\x...

  19. A Big Bang Lab

    Science.gov (United States)

    Scheider, Walter

    2005-01-01

    The February 2005 issue of The Science Teacher (TST) reminded everyone that by learning how scientists study stars, students gain an understanding of how science measures things that can not be set up in lab, either because they are too big, too far away, or happened in a very distant past. The authors of "How Far are the Stars?" show how the…

  20. The Biological Big Bang model for the major transitions in evolution

    Science.gov (United States)

    Koonin, Eugene V

    2007-01-01

    previously developed concepts of the emergence of protein folds by recombination of small structural units and origin of viruses and cells from a pre-cellular compartmentalized pool of recombining genetic elements. The model is extended to encompass other major transitions. It is proposed that bacterial and archaeal phyla emerged independently from two distinct populations of primordial cells that, originally, possessed leaky membranes, which made the cells prone to rampant gene exchange; and that the eukaryotic supergroups emerged through distinct, secondary endosymbiotic events (as opposed to the primary, mitochondrial endosymbiosis). This biphasic model of evolution is substantially analogous to the scenario of the origin of universes in the eternal inflation version of modern cosmology. Under this model, universes like ours emerge in the infinite multiverse when the eternal process of exponential expansion, known as inflation, ceases in a particular region as a result of false vacuum decay, a first order phase transition process. The result is the nucleation of a new universe, which is traditionally denoted Big Bang, although this scenario is radically different from the Big Bang of the traditional model of an expanding universe. Hence I denote the phase transitions at the end of each inflationary epoch in the history of life Biological Big Bangs (BBB). Conclusion A Biological Big Bang (BBB) model is proposed for the major transitions in life's evolution. According to this model, each transition is a BBB such that new classes of biological entities emerge at the end of a rapid phase of evolution (inflation) that is characterized by extensive exchange of genetic information which takes distinct forms for different BBBs. The major types of new forms emerge independently, via a sampling process, from the pool of recombining entities of the preceding generation. This process is envisaged as being qualitatively different from tree-pattern cladogenesis. Reviewers This article

  1. Neutrinos and Big Bang Nucleosynthesis

    Directory of Open Access Journals (Sweden)

    Gary Steigman

    2012-01-01

    Full Text Available According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders this neutrino background undetectable with current technology. The cosmic neutrino background can, however, be probed indirectly through its cosmological effects on big bang nucleosynthesis (BBN and the cosmic microwave background (CMB radiation. In this BBN review, focused on neutrinos and more generally on dark radiation, the BBN constraints on the number of “equivalent neutrinos” (dark radiation, on the baryon asymmetry (baryon density, and on a possible lepton asymmetry (neutrino degeneracy are reviewed and updated. The BBN constraints on dark radiation and on the baryon density following from considerations of the primordial abundances of deuterium and helium-4 are in excellent agreement with the complementary results from the CMB, providing a suggestive, but currently inconclusive, hint of the presence of dark radiation, and they constrain any lepton asymmetry. For all the cases considered here there is a “lithium problem”: the BBN-predicted lithium abundance exceeds the observationally inferred primordial value by a factor of ~3.

  2. Big-Bang reaction rates within the R-matrix model

    Science.gov (United States)

    Descouvemont, P.; Adahchour, A.; Angulo, C.; Coc, A.; Vangioni-Flam, E.

    2005-07-01

    We use the R-matrix theory to fit S-factor data on nuclear reactions involved in Big Bang nucleosynthesis. We derive the reaction rates with associated uncertainties, which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats (available at http://pntpm3.ulb.ac.be/bigbang).

  3. Big-Bang reaction rates within the R-matrix model

    Energy Technology Data Exchange (ETDEWEB)

    Descouvemont, P. [Physique Nucleaire Theorique et Physique Mathematique, CP229, Universite Libre de Bruxelles, B-1050 Brussels (Belgium); Adahchour, A. [Physique Nucleaire Theorique et Physique Mathematique, CP229, Universite Libre de Bruxelles, B-1050 Brussels (Belgium); Angulo, C. [Centre de Recherches du Cyclotron, Universite catholique de Louvain, Chemin du cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Coc, A. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CNRS/IN2P3/UPS, Bat. 104, F-91405 Orsay Campus (France); Vangioni-Flam, E. [Institut d' Astrophysique de Paris, CNRS, 98 bis Bd. Arago, F-75014 Paris (France)

    2005-07-25

    We use the R-matrix theory to fit S-factor data on nuclear reactions involved in Big Bang nucleosynthesis. We derive the reaction rates with associated uncertainties, which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats (available at http://pntpm3.ulb.ac.be/bigbang)

  4. Sailing through the big crunch-big bang transition

    OpenAIRE

    Bars, Itzhak; Steinhardt, Paul; Turok, Neil

    2013-01-01

    In a recent series of papers, we have shown that theories with scalar fields coupled to gravity (e.g., the standard model) can be lifted to a Weyl-invariant equivalent theory in which it is possible to unambiguously trace the classical cosmological evolution through the transition from big crunch to big bang. The key was identifying a sufficient number of finite, Weyl-invariant conserved quantities to uniquely match the fundamental cosmological degrees of freedom across the transition. In so ...

  5. Lemaitre's Big Bang

    CERN Document Server

    Luminet, Jean-Pierre

    2015-01-01

    I give an epistemological analysis of the developments of relativistic cosmology from 1917 to 1966, based on the seminal articles by Einstein, de Sitter, Friedmann, Lemaitre, Hubble, Gamow and other historical figures of the field. It appears that most of the ingredients of the present-day standard cosmological model, including the acceleration of the expansion due to a repulsive dark energy, the interpretation of the cosmological constant as vacuum energy or the possible non-trivial topology of space, had been anticipated by Georges Lemaitre, although his articles remain mostly unquoted.

  6. George and the big bang

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2012-01-01

    George has problems. He has twin baby sisters at home who demand his parents’ attention. His beloved pig Freddy has been exiled to a farm, where he’s miserable. And worst of all, his best friend, Annie, has made a new friend whom she seems to like more than George. So George jumps at the chance to help Eric with his plans to run a big experiment in Switzerland that seeks to explore the earliest moment of the universe. But there is a conspiracy afoot, and a group of evildoers is planning to sabotage the experiment. Can George repair his friendship with Annie and piece together the clues before Eric’s experiment is destroyed forever? This engaging adventure features essays by Professor Stephen Hawking and other eminent physicists about the origins of the universe and ends with a twenty-page graphic novel that explains how the Big Bang happened—in reverse!

  7. Georges et le big bang

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2011-01-01

    Georges et Annie, sa meilleure amie, sont sur le point d'assister à l'une des plus importantes expériences scientifiques de tous les temps : explorer les premiers instants de l'Univers, le Big Bang ! Grâce à Cosmos, leur super ordinateur, et au Grand Collisionneur de hadrons créé par Éric, le père d'Annie, ils vont enfin pouvoir répondre à cette question essentielle : pourquoi existons nous ? Mais Georges et Annie découvrent qu'un complot diabolique se trame. Pire, c'est toute la recherche scientifique qui est en péril ! Entraîné dans d'incroyables aventures, Georges ira jusqu'aux confins de la galaxie pour sauver ses amis...Une plongée passionnante au coeur du Big Bang. Les toutes dernières théories de Stephen Hawking et des plus grands scientifiques actuels.

  8. Baryon symmetric big bang cosmology

    Science.gov (United States)

    Stecker, F. W.

    1978-01-01

    Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.

  9. Rotational inhomogeneities from pre-big bang?

    CERN Document Server

    Giovannini, Massimo

    2005-01-01

    The evolution of the rotational inhomogeneities is investigated in the specific framework of four-dimensional pre-big bang models. While minimal (dilaton-driven) scenarios do not lead to rotational fluctuations, in the case of non-minimal (string-driven) models, fluid sources are present in the pre-big bang phase. The rotational modes of the geometry, coupled to the divergenceless part of the velocity field, can then be amplified depending upon the value of the barotropic index of the perfect fluids. In the light of a possible production of rotational inhomogeneities, solutions describing the coupled evolution of the dilaton field and of the fluid sources are scrutinized in both the string and Einstein frames. In semi-realistic scenarios, where the curvature divergences are regularized by means of a non-local dilaton potential, the rotational inhomogeneities are amplified during the pre-big bang phase but they decay later on. Similar analyses can also be performed when a contraction occurs directly in the str...

  10. Relative Energy Associated with a White Hole Model of the Big Bang

    CERN Document Server

    Binbay, F; Salti, M; Acikgoz, Irfan; Binbay, Figen; Salti, Mustafa

    2006-01-01

    A specific Lemaitre-Tolman model of a spherically symmetric non-rotating white hole model with a few adjustable parameters is investigated to calculate the momentum four-vector distribution (due to matter plus fields including gravity) in the teleparallel gravity. The energy-momentum distributions (due to matter and fields including gravity) of a model are found to be zero. The result that the total energy and momentum components of a white hole model of the big bang are zero supports the viewpoints of Albrow and Tryon. It is also independent of the teleparallel dimensionless coupling constant, which means that it is valid in any teleparallel model. The results we obtained support the viewpoint of Lessner that the Moller energy-momentum formulation is a powerful concept to calculate energy and momentum distributions associated with the universe, and sustains the importance of the energy-momentum definitions in the evaluation of the energy-momentum distribution of a given space-time. Furthermore, the results o...

  11. An Educational Look at an Alternative to the Simple Big Bang Model

    Science.gov (United States)

    Kriske, Richard

    2009-10-01

    The author often toys with a Positively Curved surface resembling a globe as an alternative to the simple Big Bang model on a flat surface. When one looks at the Horizon of the earth, say at the ocean, masts in the distance tip away from the observer. If three dimensions of space where curved with a perpendicular mast at each vertex, those time masts would tip away from the observer and be cut-off. A new optical effect would be observed, in which vertices in the distance, say pair annihilation, would result in gamma rays appearing to be redshifted, since by parallel displacement, their time axis would progressively tilt away from the observer and give them a red shift until they reached a distance were they where non- magnifiable. Just as the Earth's Horizon is a non-magnifiable line (since the objects are tilted over and cut-off), so should be the Universe's Horizon be tilted and cut-off (but like a Black-Hole, the Horizon will be an area). The tilt and cut-off can be used to calculate the size and mass of the Universe,given that the cutoff is taken to be 2.725K, the CMBR. This model turns out to be a model of constants and gives absolute meaning to spin. Since this is a brand new theory developed solely by the author at his coffee breaks, looking out the window, he presents it as an exercise.

  12. Concordance of X-ray cluster data with big bang nucleosynthesis in mixed dark matter models

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, R.W. [University of Chicago, Chicago, Illinois 60637 (United States); Schramm, D.N. [University of Chicago, Chicago, Illinois 60637 (United States)]|[NASA/Fermilab Theoretical Astrophysics Group, Fermilab, Batavia, Illinois 60510 (United States)

    1997-06-01

    If the hot, X-ray-emitting gas in rich clusters forms a fair sample of the universe as in cold dark matter (CDM) models and the universe is at the critical density {Omega}{sub T}=1, then the data appear to imply a baryon fraction {Omega}{sub b,X} ({Omega}{sub b,X}{equivalent_to}{Omega}{sub b} derived from X-ray cluster data), larger than that predicted by big bang nucleosynthesis (BBN). While other systematic effects such as clumping can lower {Omega}{sub b,X}, in this paper we use an elementary analysis to show that a simple admixture of hot dark matter (HDM; low-mass neutrinos) with CDM to yield mixed dark matter shifts {Omega}{sub b,X} down so that significant overlap with {Omega}{sub b} from BBN can occur for H{sub 0}{approx_lt}73kms{sup {minus}1}Mpc{sup {minus}1}, even without invoking the possible aforementioned effects. The overlap interval is slightly larger for lower mass neutrinos since fewer of them cluster on the scale of the hot X-ray gas. We illustrate this result quantitatively in terms of a simple isothermal model. More realistic velocity dispersion profiles, with less centrally peaked density profiles, imply that fewer neutrinos are trapped and thus further increase the interval of overlap. {copyright} {ital 1997} {ital The American Astronomical Society}

  13. The Big Bang and Cosmic Inflation

    Science.gov (United States)

    Guth, Alan H.

    2014-03-01

    A summary is given of the key developments of cosmology in the 20th century, from the work of Albert Einstein to the emergence of the generally accepted hot big bang model. The successes of this model are reviewed, but emphasis is placed on the questions that the model leaves unanswered. The remainder of the paper describes the inflationary universe model, which provides plausible answers to a number of these questions. It also offers a possible explanation for the origin of essentially all the matter and energy in the observed universe.

  14. Generating Ekpyrotic Curvature Perturbations Before the Big Bang

    OpenAIRE

    Lehners, Jean-Luc; McFadden, Paul; Turok, Neil; Steinhardt, Paul J.(Princeton Center for Theoretical Science, Princeton University, Princeton, NJ, 08544, USA)

    2007-01-01

    We analyze a general mechanism for producing a nearly scale-invariant spectrum of cosmological curvature perturbations during a contracting phase preceding a big bang, that can be entirely described using 4d effective field theory. The mechanism, based on first producing entropic perturbations and then converting them to curvature perturbations, can be naturally incorporated in cyclic and ekpyrotic models in which the big bang is modelled as a brane collision, as well as other types of cosmol...

  15. Cosmic relics from the big bang

    International Nuclear Information System (INIS)

    A brief introduction to the big bang picture of the early universe is given. Dark matter is discussed; particularly its implications for elementary particle physics. A classification scheme for dark matter relics is given. 21 refs., 11 figs., 1 tab

  16. Cosmic relics from the big bang

    Energy Technology Data Exchange (ETDEWEB)

    Hall, L.J.

    1988-12-01

    A brief introduction to the big bang picture of the early universe is given. Dark matter is discussed; particularly its implications for elementary particle physics. A classification scheme for dark matter relics is given. 21 refs., 11 figs., 1 tab.

  17. pp Wave Big Bangs: Matrix Strings and Shrinking Fuzzy Spheres

    OpenAIRE

    Das, Sumit R.; Michelson, Jeremy

    2005-01-01

    We find pp wave solutions in string theory with null-like linear dilatons. These provide toy models of big bang cosmologies. We formulate Matrix String Theory in these backgrounds. Near the big bang ``singularity'', the string theory becomes strongly coupled but the Yang-Mills description of the matrix string is weakly coupled. The presence of a second length scale allows us to focus on a specific class of non-abelian configurations, viz. fuzzy cylinders, for a suitable regime of parameters. ...

  18. COBE looks back to the Big Bang

    Science.gov (United States)

    Mather, John C.

    1993-01-01

    An overview is presented of NASA-Goddard's Cosmic Background Explorer (COBE), the first NASA satellite designed to observe the primeval explosion of the universe. The spacecraft carries three extremely sensitive IR and microwave instruments designed to measure the faint residual radiation from the Big Bang and to search for the formation of the first galaxies. COBE's far IR absolute spectrophotometer has shown that the Big Bang radiation has a blackbody spectrum, proving that there was no large energy release after the explosion.

  19. Probing the Big Bang with LEP

    Science.gov (United States)

    Schramm, David N.

    1990-01-01

    It is shown that LEP probes the Big Bang in two significant ways: (1) nucleosynthesis, and (2) dark matter constraints. In the first case, LEP verifies the cosmological standard model prediction on the number of neutrino types, thus strengthening the conclusion that the cosmological baryon density is approximately 6 percent of the critical value. In the second case, LEP shows that the remaining non-baryonic cosmological matter must be somewhat more massive and/or more weakly interacting than the favorite non-baryonic dark matter candidates of a few years ago.

  20. Big-bang nucleosynthesis revisited

    Science.gov (United States)

    Olive, Keith A.; Schramm, David N.; Steigman, Gary; Walker, Terry P.

    1989-01-01

    The homogeneous big-bang nucleosynthesis yields of D, He-3, He-4, and Li-7 are computed taking into account recent measurements of the neutron mean-life as well as updates of several nuclear reaction rates which primarily affect the production of Li-7. The extraction of primordial abundances from observation and the likelihood that the primordial mass fraction of He-4, Y(sub p) is less than or equal to 0.24 are discussed. Using the primordial abundances of D + He-3 and Li-7 we limit the baryon-to-photon ratio (eta in units of 10 exp -10) 2.6 less than or equal to eta(sub 10) less than or equal to 4.3; which we use to argue that baryons contribute between 0.02 and 0.11 to the critical energy density of the universe. An upper limit to Y(sub p) of 0.24 constrains the number of light neutrinos to N(sub nu) less than or equal to 3.4, in excellent agreement with the LEP and SLC collider results. We turn this argument around to show that the collider limit of 3 neutrino species can be used to bound the primordial abundance of He-4: 0.235 less than or equal to Y(sub p) less than or equal to 0.245.

  1. Bugs and the big bang.

    Science.gov (United States)

    Parsons, Jenni

    2008-10-01

    Now that's a cheery thought! Somewhere more than 100 km below the Geneva countryside two parallel beams of subatomic particles are whizzing around a 27 km circuit in opposite directions at about 99% of the speed of light, doing over 11 000 laps per second. Physicists hope to create a 'bang' that won't end the world, but will unlock some of its mysteries. I confess I have never thought of physicists as poets, but they certainly come up with some evocative models to explain the unknown such as 'dark matter', the invisible skeleton stretching through space; or 'dark energy', which drives the expansion of the universe; or the grandiose 'God's particle' (officially named 'Higgs boson') postulated to endow other particles with mass. These are concepts both too large and too small to grasp.

  2. The Hot Big Bang and Beyond

    OpenAIRE

    Turner, Michael S.

    1995-01-01

    The hot big-bang cosmology provides a reliable accounting of the Universe from about $10^{-2}\\sec$ after the bang until the present, as well as a robust framework for speculating back to times as early as $10^{-43}\\sec$. Cosmology faces a number of important challenges; foremost among them are determining the quantity and composition of matter in the Universe and developing a detailed and coherent picture of how structure (galaxies, clusters of galaxies, superclusters, voids, great walls, and...

  3. The new model of the Big Bang and the Universe expansion. A comparison with modern observational data and cosmological theories

    Science.gov (United States)

    Kraiko, A. N.; Valiyev, Kh. F.

    2016-10-01

    The new model of the Big Bang and the Universe expansion is constructed. It is based on solutions in classical and in relativistic statements of problem on the dispersion into the void of the gas compressed into a point or in a finite, but for further negligible, volume. If to restrict in relativistic statement gas speed value v by the speed of light (υ =| v | data not worse than modern cosmological theories with the dark energy and the dark matter. The conclusion is drawn on uselessness of the dark energy.

  4. One Second After the Big Bang

    CERN Document Server

    CERN. Geneva

    2014-01-01

    A new experiment called PTOLEMY (Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino Yield) is under development at the Princeton Plasma Physics Laboratory with the goal of challenging one of the most fundamental predictions of the Big Bang – the present-day existence of relic neutrinos produced less than one second after the Big Bang. Using a gigantic graphene surface to hold 100 grams of a single-atomic layer of tritium, low noise antennas that sense the radio waves of individual electrons undergoing cyclotron motion, and a massive array of cryogenic sensors that sit at the transition between normal and superconducting states, the PTOLEMY project has the potential to challenge one of the most fundamental predictions of the Big Bang, to potentially uncover new interactions and properties of the neutrinos, and to search for the existence of a species of light dark matter known as sterile neutrinos.

  5. Generating Ekpyrotic Curvature Perturbations Before the Big Bang

    CERN Document Server

    Lehners, J L; Steinhardt, P J; Turok, N G; Fadden, Paul Mc; Lehners, Jean-Luc; Steinhardt, Paul J.; Turok, Neil

    2007-01-01

    We analyze a general mechanism for producing a nearly scale-invariant spectrum of cosmological curvature perturbations during a contracting phase preceding a big bang, that can be entirely described using 4d effective field theory. The mechanism, based on first producing entropic perturbations and then converting them to curvature perturbations, can be naturally incorporated in cyclic and ekpyrotic models in which the big bang is modelled as a brane collision, as well as other types of cosmological models with a pre-big bang phase. We show that the correct perturbation amplitude can be obtained and that the scalar spectral tilt n tends to range from slightly blue to red, with 0.97 < n < 1.02 for the simplest models, a range compatible with current observations but shifted by a few per cent towards the blue compared to the prediction of the simplest, large-field inflationary models.

  6. Inflationary and Deflationary Branches in Extended Pre--Big Bang Cosmology

    OpenAIRE

    Lidsey, James E.

    1996-01-01

    The pre--big bang cosmological scenario is studied within the context of the Brans--Dicke theory of gravity. An epoch of superinflationary expansion may occur in the pre--big bang phase of the Universe's history in a certain region of parameter space. Two models are considered that contain a cosmological constant in the gravitational and matter sectors of the theory, respectively. Classical pre-- and post--big bang solutions are found for both models. The existence of a curvature singularity ...

  7. Inhomogeneous Pre-Big Bang String Cosmology

    OpenAIRE

    Veneziano, G.

    1997-01-01

    An inhomogeneous version of pre--Big Bang cosmology emerges, within string theory, from quite generic initial conditions, provided they lie deeply inside the weak-coupling, low-curvature regime. Large-scale homogeneity, flatness, and isotropy appear naturally as late-time outcomes of such an evolution.

  8. "Big Bang" project put off to 2008

    CERN Multimedia

    Evans, Robert

    2007-01-01

    "First tests in a scientific project aimed at solving myteries of the universe and the "Big Bang" that created it have been put off from November to late April or early May next year, an official said on Wednesday" (1/2 page)

  9. The Big Bang (one more time)

    CERN Multimedia

    Spotts, P

    2002-01-01

    For 20 years, Paul Steinhardt has played a key role in helping to write and refine the inflationary "big bang" origin of the universe. But over the past few years, he decided to see if he could come up with a plausible alternative to the prevailing notion (1 page).

  10. Lifting gear crucial in Big Bang experiment

    CERN Multimedia

    2007-01-01

    "On November 26 2007, the most complex scientific instrument ever built will be turned on in an attempt to rerun the Big Bang - but i would never have got off the ground - litteraly - without the hundreds of hoists and cranes on site." (1/2 page)

  11. Antigravity and the big crunch/big bang transition

    Energy Technology Data Exchange (ETDEWEB)

    Bars, Itzhak [Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-2535 (United States); Chen, Shih-Hung [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Department of Physics and School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Steinhardt, Paul J., E-mail: steinh@princeton.edu [Department of Physics and Princeton Center for Theoretical Physics, Princeton University, Princeton, NJ 08544 (United States); Turok, Neil [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada)

    2012-08-29

    We point out a new phenomenon which seems to be generic in 4d effective theories of scalar fields coupled to Einstein gravity, when applied to cosmology. A lift of such theories to a Weyl-invariant extension allows one to define classical evolution through cosmological singularities unambiguously, and hence construct geodesically complete background spacetimes. An attractor mechanism ensures that, at the level of the effective theory, generic solutions undergo a big crunch/big bang transition by contracting to zero size, passing through a brief antigravity phase, shrinking to zero size again, and re-emerging into an expanding normal gravity phase. The result may be useful for the construction of complete bouncing cosmologies like the cyclic model.

  12. Antigravity and the big crunch/big bang transition

    Science.gov (United States)

    Bars, Itzhak; Chen, Shih-Hung; Steinhardt, Paul J.; Turok, Neil

    2012-08-01

    We point out a new phenomenon which seems to be generic in 4d effective theories of scalar fields coupled to Einstein gravity, when applied to cosmology. A lift of such theories to a Weyl-invariant extension allows one to define classical evolution through cosmological singularities unambiguously, and hence construct geodesically complete background spacetimes. An attractor mechanism ensures that, at the level of the effective theory, generic solutions undergo a big crunch/big bang transition by contracting to zero size, passing through a brief antigravity phase, shrinking to zero size again, and re-emerging into an expanding normal gravity phase. The result may be useful for the construction of complete bouncing cosmologies like the cyclic model.

  13. Antigravity and the big crunch/big bang transition

    CERN Document Server

    Bars, Itzhak; Steinhardt, Paul J; Turok, Neil

    2011-01-01

    We point out a new phenomenon which seems to be generic in 4d effective theories of scalar fields coupled to Einstein gravity, when applied to cosmology. A lift of such theories to a Weyl-invariant extension allows one to define classical evolution through cosmological singularities unambiguously, and hence construct geodesically complete background spacetimes. An attractor mechanism ensures that, at the level of the effective theory, generic solutions undergo a big crunch/big bang transition by contracting to zero size, passing through a brief antigravity phase, shrinking to zero size again, and re-emerging into an expanding normal gravity phase. The result may be useful for the construction of complete bouncing cosmologies like the cyclic model.

  14. Pre-Big Bang, vacuum and noncyclic cosmologies

    CERN Document Server

    Gonzalez-Mestres, Luis

    2012-01-01

    WMAP and Planck open the way to unprecedented Big Bang phenomenology, potentially allowing to test the standard Big Bang model as well as less conventional approaches including noncyclic pre-Big Bang cosmologies that would incorporate a new fundamental scale beyond the Planck scale and, possibly, new ultimate constituents of matter. Alternatives to standard physics can be considered from a cosmological point of view concerning vacuum structure, the nature of space-time, the origin and evolution of our Universe, the validity of quantum field theory and conventional symmetries, solutions to the cosmological constant problem, inflationary scenarios, dark matter and dark energy, the interpretation of string-like theories... Lorentz-like symmetries for the properties of matter (standard or superbradyonic) can then be naturally stable space-time configurations resulting from general cosmological scenarios that incorporate physics beyond the Planck scale and describe the formation and evolution of the present vacuum...

  15. Beyond the Friedmann-Lemaatre-Robertson-Walker Big Bang Singularity

    Institute of Scientific and Technical Information of China (English)

    Cristi Stoica

    2012-01-01

    Einstein's equation,in its standard form,breaks down at the Big Bang singularity.A new version,equivalent to Einstein's whenever the latter is defined,but applicable in wider situations,is proposed.The new equation remains smooth at the Big Bang singularity of the Friedmann-Lemaatre-Robertson-Walker model.It is a tensor equation defined in terms of the Ricci part of the Riemann curvature.It is obtained by taking the Kulkarni-Nomizu product between Einstein's equation and the metric tensor.

  16. New Cosmic Center Universe Model Matches Eight of Big Bang's Major Predictions Without The F-L Paradigm

    CERN Document Server

    Gentry, R V

    2003-01-01

    Accompanying disproof of the F-L expansion paradigm eliminates the basis for expansion redshifts, which in turn eliminates the basis for the Cosmological Principle. The universe is not the same everywhere. Instead the spherical symmetry of the cosmos demanded by the Hubble redshift relation proves the universe is isotropic about a nearby universal Center. This is the foundation of the relatively new Cosmic Center Universe (CCU) model, which accounts for, explains, or predicts: (i) The Hubble redshift relation, (ii) a CBR redshift relation that fits all current CBR measurements, (iii) the recently discovered velocity dipole distribution of radiogalaxies, (iv) the well-known time dilation of SNeIa light curves, (v) the Sunyaev-Zeldovich thermal effect, (vi) Olber's paradox, (vii) SN dimming for z 1 an enhanced brightness that fits SN 1997ff measurements, (ix) the existence of extreme redshift (z > 10) objects which, when observed, will further distinguish it from the big bang. The CCU model also plausibly expl...

  17. Pre-big bang in M-theory

    OpenAIRE

    Cavaglia, Marco

    2001-01-01

    We discuss a simple cosmological model derived from M-theory. Three assumptions lead naturally to a pre-big bang scenario: (a) 11-dimensional supergravity describes the low-energy world; (b) non-gravitational fields live on a three-dimensional brane; and (c) asymptotically past triviality.

  18. Constraints on massive gravity theory from big bang nucleosynthesis

    OpenAIRE

    Lambiase, G.

    2012-01-01

    The massive gravity cosmology is studied in the scenario of big bang nucleosynthesis. By making use of current bounds on the deviation from the fractional mass, we derive the constraints on the free parameters of the theory. The cosmological consequences of the model are also discussed in the framework of the PAMELA experiment.

  19. Big Bang Nucleosynthesis and Primordial Black Holes

    OpenAIRE

    Sivaram, C; Arun, Kenath

    2010-01-01

    There are ongoing efforts in detecting Hawking radiation from primordial black holes (PBH) formed during the early universe. Here we put an upper limit on the PBH number density that could have been formed prior to the big bang nucleosynthesis era, based on the constraint that the PBH evaporation energy consisting of high energy radiation not affect the observed abundances' of elements, by disintegrating the nuclei.

  20. Quantum Gravity and the Big Bang

    OpenAIRE

    Bojowald, M.

    2004-01-01

    Quantum gravity has matured over the last decade to a theory which can tell in a precise and explicit way how cosmological singularities of general relativity are removed. A branch of the universe "before" the classical big bang is obtained which is connected to ours by quantum evolution through a region around the singularity where the classical space-time dissolves. We discuss the basic mechanism as well as applications ranging to new phenomenological scenarios of the early universe expansi...

  1. Dark Radiation Emerging After Big Bang Nucleosynthesis?

    OpenAIRE

    Fischler, Willy; Meyers, Joel

    2010-01-01

    We show how recent data from observations of the cosmic microwave background may suggest the presence of additional radiation density which appeared after big bang nucleosynthesis. We propose a general scheme by which this radiation could be produced from the decay of non-relativistic matter, we place constraints on the properties of such matter, and we give specific examples of scenarios in which this general scheme may be realized.

  2. Laser interferometry for the Big Bang Observer

    OpenAIRE

    Harry, Gregory M.; Fritschel, Peter; Shaddock, Daniel A.; Folkner, William; Phinney, E. Sterl

    2006-01-01

    The Big Bang Observer is a proposed space-based gravitational-wave detector intended as a follow on mission to the Laser Interferometer Space Antenna (LISA). It is designed to detect the stochastic background of gravitational waves from the early universe. We discuss how the interferometry can be arranged between three spacecraft for this mission and what research and development on key technologies are necessary to realize this scheme.

  3. Five dimensional Gravity and Big Bang Singularity

    CERN Document Server

    Parthasarathy, R

    2015-01-01

    A 5-dimensional gravity theory, motivated by the brane world picture, with factorisable metric and with Kaluza scalar $G_{55}(r)$, is shown to give rise to a positive contribution to the Raychaudhuri equation. This inhibits the focusing of geodesics and possibly cause non-focusing of the geodesics. This feature is translated into the situation in which the universe has an infinite age and hence no beginning avoiding the big bang singularity.

  4. Science Big Bang comes to the Alps

    CERN Multimedia

    2008-01-01

    The most extensive and expensive scientific instrument in history is due to start working this summer at Cern, the European particle physics laboratory near Geneva. Two beams of protons will accelerate in opposite directions around a 27km tunnel under the Alpine foothills until they are travelling almost at the speed of light - and then smash together, reproducing on a tiny scale the intense energy of the new-born universe after the inaugural Big Bang 15bn years ago.

  5. Science: Big Bang comes to the Alps

    CERN Multimedia

    Cookson, Clive

    2008-01-01

    "The most extensive and expensive scientific instrument in history is due to start working this summer at CERN, the European particle physics laboratory near Geneva. Two beams of protons will accelerate in opposite directions around a 27 km tunnel under the alpine foothills until they are travelling almost at the speed of light - and then smash together, reproducing on a tiny scale the intense energy of the new-born universe after the inaugural Big Bang 15bn years ago. (1 page)

  6. Antigravity and the big crunch/big bang transition

    OpenAIRE

    Bars, Itzhak; Chen, Shih-Hung; Steinhardt, Paul J.(Princeton Center for Theoretical Science, Princeton University, Princeton, NJ, 08544, USA); Turok, Neil

    2011-01-01

    We point out a new phenomenon which seems to be generic in 4d effective theories of scalar fields coupled to Einstein gravity, when applied to cosmology. A lift of such theories to a Weyl-invariant extension allows one to define classical evolution through cosmological singularities unambiguously, and hence construct geodesically complete background spacetimes. An attractor mechanism ensures that, at the level of the effective theory, generic solutions undergo a big crunch/big bang transition...

  7. Quantum Fields in a Big Crunch/Big Bang Spacetime

    OpenAIRE

    Tolley, Andrew J.; Turok, Neil

    2002-01-01

    We consider quantum field theory on a spacetime representing the Big Crunch/Big Bang transition postulated in the ekpyrotic or cyclic cosmologies. We show via several independent methods that an essentially unique matching rule holds connecting the incoming state, in which a single extra dimension shrinks to zero, to the outgoing state in which it re-expands at the same rate. For free fields in our construction there is no particle production from the incoming adiabatic vacuum. When interacti...

  8. Big Bang synthesis of nuclear dark matter

    Science.gov (United States)

    Hardy, Edward; Lasenby, Robert; March-Russell, John; West, Stephen M.

    2015-06-01

    We investigate the physics of dark matter models featuring composite bound states carrying a large conserved dark "nucleon" number. The properties of sufficiently large dark nuclei may obey simple scaling laws, and we find that this scaling can determine the number distribution of nuclei resulting from Big Bang Dark Nucleosynthesis. For plausible models of asymmetric dark matter, dark nuclei of large nucleon number, e.g. ≳ 108, may be synthesised, with the number distribution taking one of two characteristic forms. If small-nucleon-number fusions are sufficiently fast, the distribution of dark nuclei takes on a logarithmically-peaked, universal form, independent of many details of the initial conditions and small-number interactions. In the case of a substantial bottleneck to nucleosynthesis for small dark nuclei, we find the surprising result that even larger nuclei, with size ≫ 108, are often finally synthesised, again with a simple number distribution. We briefly discuss the constraints arising from the novel dark sector energetics, and the extended set of (often parametrically light) dark sector states that can occur in complete models of nuclear dark matter. The physics of the coherent enhancement of direct detection signals, the nature of the accompanying dark-sector form factors, and the possible modifications to astrophysical processes are discussed in detail in a companion paper.

  9. The big-bang theory: construction, evolution and status

    OpenAIRE

    Uzan, Jean-Philippe

    2016-01-01

    Over the past century, rooted in the theory of general relativity, cosmology has developed a very successful physical model of the universe: the {\\em big-bang model}. Its construction followed different stages to incorporate nuclear processes, the understanding of the matter present in the universe, a description of the early universe and of the large scale structure. This model has been confronted to a variety of observations that allow one to reconstruct its expansion history, its thermal h...

  10. Echoes of Big Bang Found in Galaxies

    Institute of Scientific and Technical Information of China (English)

    Mark; Peplow; 吴铭

    2005-01-01

    想了解宇宙的奥秘吗?英澳等国的天文学家近日共同破解了宇宙大爆炸(BigBang)后物质如何分布的秘密,声称物质非平均分布的原因在于宇宙波纹和重力的共同作用,并对早期雾状宇宙的混沌状态如何发展到如今的状况做出了解释。

  11. Nuclear Receptors, RXR, and the Big Bang.

    Science.gov (United States)

    Evans, Ronald M; Mangelsdorf, David J

    2014-03-27

    Isolation of genes encoding the receptors for steroids, retinoids, vitamin D, and thyroid hormone and their structural and functional analysis revealed an evolutionarily conserved template for nuclear hormone receptors. This discovery sparked identification of numerous genes encoding related proteins, termed orphan receptors. Characterization of these orphan receptors and, in particular, of the retinoid X receptor (RXR) positioned nuclear receptors at the epicenter of the "Big Bang" of molecular endocrinology. This Review provides a personal perspective on nuclear receptors and explores their integrated and coordinated signaling networks that are essential for multicellular life, highlighting the RXR heterodimer and its associated ligands and transcriptional mechanism. PMID:24679540

  12. Gauge Approach to Gravitation and Regular Big Bang Theory

    OpenAIRE

    Minkevich, A. V.

    2005-01-01

    Field theoretical scheme of regular Big Bang in 4-dimensional physical space-time, built in the framework of gauge approach to gravitation, is discussed. Regular bouncing character of homogeneous isotropic cosmological models is ensured by gravitational repulsion effect at extreme conditions without quantum gravitational corrections. The most general properties of regular inflationary cosmological models are examined. Developing theory is valid, if energy density of gravitating matter is posi...

  13. Possible evidence for dark radiation from Big Bang Nucleosynthesis data

    Energy Technology Data Exchange (ETDEWEB)

    Flambaum, V.V. [New South Wales Univ., School of Physics, Sydney NSW (Australia); Argonne National Laboratory, Physics Div., Argonne, IL (United States); Shuryak, E.V. [State University of New York Stony Brook, Dept. of Physics and Astronomy, NY (United States)

    2006-06-15

    We address the emerging discrepancy between the Big Bang Nucleosynthesis data and standard cosmology, which asks for a bit longer evolution time. If this effect is real, one possible implication (in a framework of brane cosmology model) is that there is a 'dark radiation' component which is negative and makes few percents of ordinary matter density. If so, all scales of this model can be fixed, provided brane-to-bulk leakage problem is solved. (authors)

  14. Big Bang Day : The Great Big Particle Adventure - 3. Origins

    CERN Multimedia

    2008-01-01

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. If the LHC is successful, it will explain the nature of the Universe around us in terms of a few simple ingredients and a few simple rules. But the Universe now was forged in a Big Bang where conditions were very different, and the rules were very different, and those early moments were crucial to determining how things turned out later. At the LHC they can recreate conditions as they were billionths of a second after the Big Bang, before atoms and nuclei existed. They can find out why matter and antimatter didn't mutually annihilate each other to leave behind a Universe of pure, brilliant light. And they can look into the very structure of space and time - the fabric of the Universe

  15. Web Science Big Wins: Information Big Bang & Fundamental Constants

    OpenAIRE

    Carr, Les

    2010-01-01

    We take for granted a Web that provides free and unrestricted information exchange, but the Web is under pressure to change in order to respond to issues of security, commerce, criminality, privacy. Web Science needs to explain how the Web impacts society and predict the outcomes of proposed changes to Web infrastructure on business and society. Using the analogy of the Big Bang, this presentation describes how the Web spread the conditions of its initial creation throughout the whole of soci...

  16. Dual of Big-bang and Big-crunch

    OpenAIRE

    Bak, Dongsu

    2006-01-01

    Starting from the Janus solution and its gauge theory dual, we obtain the dual gauge theory description of the cosmological solution by procedure of the double anaytic continuation. The coupling is driven either to zero or to infinity at the big-bang and big-crunch singularities, which are shown to be related by the S-duality symmetry. In the dual Yang-Mills theory description, these are non singular at all as the coupling goes to zero in the N=4 Super Yang-Mills theory. The cosmological sing...

  17. Inhomogeneous big bang nucleosynthesis with late-decaying massive particles

    OpenAIRE

    Lopez-Suarez, J.; Canal, R.

    1998-01-01

    We investigate the possibility of accounting for the currently inferred primordial abundances of D, 3He, 4He, and 7Li by big bang nucleosynthesis in the presence of baryon density inhomogeneities plus the effects of late-decaying massive particles (X), and we explore the allowed range of baryonic fraction of the closure density Omega_b in such context. We find that, depending on the parameters of this composite model (characteristic size and density contrast of the inhomogeneities; mass-densi...

  18. The Quantum Big Bang in Global Time Theory

    OpenAIRE

    Burlankov, D. E.

    2004-01-01

    The it Global Time Theory (GTT) is the further development of the General Relativity (GR). GTT significantly differs from GR in the general physical concepts, but retains 90% of the mathematical structure and main results. The dynamics equations are derived from Lagrangian, and the Hamiltonian of gravitation is nonzero. The quantum theory of gravitation can be built on the basis of the Schroedinger equation, as for other fields. The quantum model of the Big Bang is demonstrated.

  19. Big-Bang Nucleosynthesis verifies classical Maxwell-Boltzmann distribution

    CERN Document Server

    Hou, S Q; Parikh, A; Daid, K; Bertulani, C

    2014-01-01

    We provide the most stringent constraint to date on possible deviations from the usually-assumed Maxwell-Boltzmann (MB) velocity distribution for nuclei in the Big-Bang plasma. The impact of non-extensive Tsallis statistics on thermonuclear reaction rates involved in standard models of Big-Bang Nucleosynthesis (BBN) has been investigated. We find that the non-extensive parameter $q$ may deviate by, at most, $|\\delta q|$=6$\\times$10$^{-4}$ from unity for BBN predictions to be consistent with observed primordial abundances; $q$=1 represents the classical Boltzmann-Gibbs statistics. This constraint arises primarily from the {\\em super}sensitivity of endothermic rates on the value of $q$, which is found for the first time. As such, the implications of non-extensive statistics in other astrophysical environments should be explored. This may offer new insight into the nucleosynthesis of heavy elements.

  20. Electron screening and its effects on big-bang nucleosynthesis

    International Nuclear Information System (INIS)

    We study the effects of electron screening on nuclear reaction rates occurring during the big-bang nucleosynthesis epoch. The sensitivity of the predicted elemental abundances on electron screening is studied in detail. It is shown that electron screening does not produce noticeable results in the abundances unless the traditional Debye-Hueckel model for the treatment of electron screening in stellar environments is enhanced by several orders of magnitude. This work rules out electron screening as a relevant ingredient to big-bang nucleosynthesis, confirming a previous study [see Itoh et al., Astrophys. J. 488, 507 (1997)] and ruling out exotic possibilities for the treatment of screening beyond the mean-field theoretical approach.

  1. Big-Bang nucleosynthesis with updated nuclear data

    International Nuclear Information System (INIS)

    Primordial nucleosynthesis is one of the three evidences for the Big-Bang model together with the expansion of the Universe and the Cosmic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4He, D, 3He and 7Li deduced from observations and calculated primordial nucleosynthesis. This comparison was used to determine the baryonic density of the Universe. For this purpose, it is now superseded by the analysis of the Cosmic Microwave Background (CMB) radiation anisotropies. Big-Bang nucleosynthesis remains, nevertheless, a valuable tool to probe the physics of the early Universe. However, the yet unexplained, discrepancy between the calculated and observed lithium primordial abundances, has not been reduced, neither by recent nuclear physics experiments, nor by new observations.

  2. Big-Bang nucleosynthesis with updated nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Coc, Alain [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM), CNRS/IN2P3, Universite Paris Sud 11, UMR 8609, Batiment 104, F-91405 Orsay Campus (France); Vangioni, Elisabeth, E-mail: Alain.Coc@csnsm.in2p3.f, E-mail: vangioni@iap.f [Institut d' Astrophysique de Paris, UMR-7095 du CNRS, Universite Pierre et Marie Curie, 98 bis bd Arago, 75014 Paris (France)

    2010-01-01

    Primordial nucleosynthesis is one of the three evidences for the Big-Bang model together with the expansion of the Universe and the Cosmic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of {sup 4}He, D, {sup 3}He and {sup 7}Li deduced from observations and calculated primordial nucleosynthesis. This comparison was used to determine the baryonic density of the Universe. For this purpose, it is now superseded by the analysis of the Cosmic Microwave Background (CMB) radiation anisotropies. Big-Bang nucleosynthesis remains, nevertheless, a valuable tool to probe the physics of the early Universe. However, the yet unexplained, discrepancy between the calculated and observed lithium primordial abundances, has not been reduced, neither by recent nuclear physics experiments, nor by new observations.

  3. Quantization of Big Bang in crypto-Hermitian Heisenberg picture

    CERN Document Server

    Znojil, Miloslav

    2015-01-01

    A background-independent quantization of the Universe near its Big Bang singularity is considered using a drastically simplified toy model. Several conceptual issues are addressed. (1) The observable spatial-geometry characteristics of our empty-space expanding Universe is sampled by the time-dependent operator $Q=Q(t)$ of the distance between two space-attached observers (``Alice and Bob''). (2) For any pre-selected guess of the simple, non-covariant time-dependent observable $Q(t)$ one of the Kato's exceptional points (viz., $t=\\tau_{(EP)}$) is postulated {\\em real-valued}. This enables us to treat it as the time of Big Bang. (3) During our ``Eon'' (i.e., at all $t>\\tau_{(EP)}$) the observability status of operator $Q(t)$ is mathematically guaranteed by its self-adjoint nature with respect to an {\\em ad hoc} Hilbert-space metric $\\Theta(t) \

  4. Constraining Big Bang lithium production with recent solar neutrino data

    CERN Document Server

    Takács, Marcell P; Szücs, Tamás; Zuber, Kai

    2015-01-01

    The 3He({\\alpha},{\\gamma})7Be reaction affects not only the production of 7Li in Big Bang nucleosynthesis, but also the fluxes of 7Be and 8B neutrinos from the Sun. This double role is exploited here to constrain the former by the latter. A number of recent experiments on 3He({\\alpha},{\\gamma})7Be provide precise cross section data at E = 0.5-1.0 MeV center-of-mass energy. However, there is a scarcity of precise data at Big Bang energies, 0.1-0.5 MeV, and below. This problem can be alleviated, based on precisely calibrated 7Be and 8B neutrino fluxes from the Sun that are now available, assuming the neutrino flavour oscillation framework to be correct. These fluxes and the standard solar model are used here to determine the 3He(alpha,gamma)7Be astrophysical S-factor at the solar Gamow peak, S(23+6-5 keV) = 0.548+/-0.054 keVb. This new data point is then included in a re-evaluation of the 3He({\\alpha},{\\gamma})7Be S-factor at Big Bang energies, following an approach recently developed for this reaction in the c...

  5. Quarks, leptons and the big bang

    CERN Document Server

    Allday, Jonathan

    2016-01-01

    Quarks, Leptons and The Big Bang, Third Edition, is a clear, readable and self-contained introduction to particle physics and related areas of cosmology. It bridges the gap between non-technical popular accounts and textbooks for advanced students. The book concentrates on presenting the subject from the modern perspective of quarks, leptons and the forces between them. This book will be of interest to students, teachers and general science readers interested in fundamental ideas of modern physics. This edition brings the book completely up to date by including advances in particle physics and cosmology, such as the discovery of the Higgs boson, the LIGO gravitational wave discovery and the WMAP and PLANCK results.

  6. L'Univers avant le Big Bang

    CERN Multimedia

    Rouat, Sylvie

    2003-01-01

    "Tout n'a pas commencé par une explosion. L'historie du cosmos avait débuté biena vant le Big Bang, si l'on suit la théorie défendue par les partisans d'une nouvelle cosmologie issue de la mystérieuse théorie des cordes. A l'heure où vacillent les scénarios classiques du XXe siècle, se prépare un grand chamboulement de nos idées sur la naissance de l'Univers et son devenir, sur l'existence possible d'univers parallèles. Des théories séduisantes qui seront mises à l'épreuve au cours de la prochaine décennie" (11 pages)

  7. On the Initial Conditions for Pre-Big-Bang Cosmology

    OpenAIRE

    Borunda, M.; Ruiz-Altaba, M.

    1998-01-01

    The beautiful scenario of pre-big-bang cosmology is appealling not only because it is more or less derived from string theory, but also because it separates clearly the problem of the initial conditions for the universe from that of high curvatures. Recently, the pre-big-bang program was subject to attack from on the grounds that pre-big-bang cosmology does not solve the horizon and flatness problems in a ``natural'' way, as customary exponential ``new'' inflation does. In particular, it appe...

  8. Big bang photosynthesis and pregalactic nucleosynthesis of light elements

    Science.gov (United States)

    Audouze, J.; Lindley, D.; Silk, J.

    1985-01-01

    Two nonstandard scenarios for pregalactic synthesis of the light elements (H-2, He-3, He-4, and Li-7) are developed. Big bang photosynthesis occurs if energetic photons, produced by the decay of massive neutrinos or gravitinos, partially photodisintegrate He-4 (formed in the standard hot big bang) to produce H-2 and He-3. In this case, primordial nucleosynthesis no longer constrains the baryon density of the universe, or the number of neutrino species. Alternatively, one may dispense partially or completely with the hot big bang and produce the light elements by bombardment of primordial gas, provided that He-4 is synthesized by a later generation of massive stars.

  9. The case for the relativistic hot big bang cosmology

    Science.gov (United States)

    Peebles, P. J. E.; Schramm, D. N.; Kron, R. G.; Turner, E. L.

    1991-01-01

    What has become the standard model in cosmology is described, and some highlights are presented of the now substantial range of evidence that most cosmologists believe convincingly establishes this model, the relativistic hot big bang cosmology. It is shown that this model has yielded a set of interpretations and successful predictions that substantially outnumber the elements used in devising the theory, with no well-established empirical contradictions. Brief speculations are made on how the open puzzles and work in progress might affect future developments in this field.

  10. Estudiarán el Big Bang por Internet

    CERN Multimedia

    2007-01-01

    The most powerful Internet, star of the present, goes for another challenge that mixes past and future: to join the scientific world community to clarify the orígines of the universe, the Big Bang. (1/2 page)

  11. Indian microchip for Big Bang research in Geneva

    CERN Multimedia

    Bhabani, Soudhriti

    2007-01-01

    "A premier nuclear physics institute here has come up with India's first indigenously designed microchip that will facilitate research on the Big Bang theory in Geneva's CERN, the world's largest particle physics laboratory." (1 page)

  12. Pre-big bang geometric extensions of inflationary cosmologies

    CERN Document Server

    Klein, David

    2016-01-01

    Robertson-Walker cosmologies within a large class are geometrically extended to larger spacetimes that include spacetime points with zero and negative cosmological times. In the extended spacetimes, the big bang is lightlike, and though singular, it inherits some geometric structure from the original spacetime. Spacelike geodesics are continuous across the cosmological time zero submanifold which is parameterized by the radius of Fermi space slices, i.e, by the proper distances along spacelike geodesics from a comoving observer to the big bang. The continuous extension of the metric, and the continuously differentiable extension of the leading Fermi metric coefficient g{\\tau}{\\tau} of the observer, restrict the geometry of spacetime points with pre-big bang cosmological time coordinates. In our extensions the big bang is two di- mensional in a certain sense, consistent with some findings in quantum gravity.

  13. Four-Neutrino Mixing, Oscillations and Big-Bang Nucleosynthesis

    OpenAIRE

    Bilenky, S. M.; Giunti, C.; Grimus, W.; Schwetz, T.

    1998-01-01

    We investigate the implications of the standard Big-Bang Nucleosynthesis constraint on the number of light neutrinos in the framework of the two four-neutrino schemes that are favored by the results of neutrino oscillation experiments.

  14. Big Bang test delayed at CERN's LHC until 2008

    CERN Multimedia

    Atkins, William

    2007-01-01

    "Scientists at the proton-proton Large Hadron Collider (LHC) particle accelerator and collider will postpone a test that could help solve the mystery of what happened a few nanoseconds after the Big Bang." (1 page)

  15. Scientists seek to explain how Big Bang let us live

    CERN Multimedia

    Hawke, N

    2000-01-01

    Scientists at CERN have opened an antimatter factory, the Antiproton Decelerator. They hope to discover why, in the Big Bang, the amount of matter and antimatter produced was not equal, so allowing the universe to exist at all (1 page).

  16. Unified Description of Plausible Cause and Effect of the Big Bang

    OpenAIRE

    Choudhury, D. C.

    2001-01-01

    Plausible cause and effect of the big bang model are presented without violating conventional laws of physics. The initial cosmological singularity is resolved by introducing the uncertainty principle of quantum theory. We postulate that, preceding the big bang at the end of the gravitational collapse, the total observed mass including all forms of energy of the universe condensed into the primordial black hole (PBH) in a state of isotropic and minimal chaos (i.e., nearest to the absolute zer...

  17. Global Fluctuation Spectra in Big Crunch/Big Bang String Vacua

    OpenAIRE

    Craps, Ben; Ovrut, Burt A.

    2003-01-01

    We study Big Crunch/Big Bang cosmologies that correspond to exact world-sheet superconformal field theories of type II strings. The string theory spacetime contains a Big Crunch and a Big Bang cosmology, as well as additional ``whisker'' asymptotic and intermediate regions. Within the context of free string theory, we compute, unambiguously, the scalar fluctuation spectrum in all regions of spacetime. Generically, the Big Crunch fluctuation spectrum is altered while passing through the bounce...

  18. Effects of a torsion field on Big Bang nucleosynthesis

    OpenAIRE

    Brüggen, M.

    1999-01-01

    In this paper it is investigated whether torsion, which arises naturally in most theories of quantum gravity, has observable implications for the Big Bang nucleosynthesis. Torsion can lead to spin flips amongst neutrinos thus turning them into sterile neutrinos. In the early Universe they can alter the helium abundance which is tightly constrained by observations. Here I calculate to what extent torsion of the string theory type leads to a disagreement with the Big Bang nucleosynthesis predic...

  19. Big-bang nucleosynthesis - observational aspects

    International Nuclear Information System (INIS)

    Extrapolation of observational data on the abundances of D, 3He, 4He and 7Li in various astrophysical objects to derive their primordial values leads to results in good accordance with calculations from Standard Big Bang nucleosynthesis theory over 9 orders of magnitude in abundance and has led to the following predictions: There are not more than 3 light neutrino species or other particles contributing relativistic degrees of freedom at temperatures of a few MeV; the neutron half-life is less than 10.4 minutes; and baryonic dark matter exists, but not in sufficient quantities to close the universe. (The first two of these predictions have been confirmed by laboratory experiments). Searches for a primordial component in the abundance of any other element heavier than hydrogen - such as might have resulted from inhomogeneities due to phase transitions in the early universe, notably the quark-hadron transition - have so far proved completely negative. The primordial helium abundance is found from observations of extragalactic ionized hydrogen clouds to be close to 0.230 by mass, a little lower than predicted, but the difference does not exceed likely errors. (orig.)

  20. Inhomogeneous neutrino degeneracy and big bang nucleosynthesis

    International Nuclear Information System (INIS)

    We examine big bang nucleosynthesis (BBN) in the case of inhomogeneous neutrino degeneracy, in the limit where the fluctuations are sufficiently small on large length scales that the present-day element abundances are homogeneous. We consider two representative cases: degeneracy of the electron neutrino alone and equal chemical potentials for all three neutrinos. We use a linear programming method to constrain an arbitrary distribution of the chemical potentials. For the current set of (highly restrictive) limits on the primordial element abundances, homogeneous neutrino degeneracy barely changes the allowed range of the baryon-to-photon ratio η. Inhomogeneous degeneracy allows for little change in the lower bound on η, but the upper bound in this case can be as large as η=1.1x10-8 (only νe degeneracy) or η=1.0x10-9 (equal degeneracies for all three neutrinos). For the case of inhomogeneous neutrino degeneracy, we show that there is no BBN upper bound on the neutrino energy density, which is bounded in this case only by limits from structure formation and the cosmic microwave background. (c) 2000 The American Physical Society

  1. The big-bang theory: construction, evolution and status

    CERN Document Server

    Uzan, Jean-Philippe

    2016-01-01

    Over the past century, rooted in the theory of general relativity, cosmology has developed a very successful physical model of the universe: the {\\em big-bang model}. Its construction followed different stages to incorporate nuclear processes, the understanding of the matter present in the universe, a description of the early universe and of the large scale structure. This model has been confronted to a variety of observations that allow one to reconstruct its expansion history, its thermal history and the structuration of matter. Hence, what we refer to as the big-bang model today is radically different from what one may have had in mind a century ago. This construction changed our vision of the universe, both on observable scales and for the universe as a whole. It offers in particular physical models for the origins of the atomic nuclei, of matter and of the large scale structure. This text summarizes the main steps of the construction of the model, linking its main predictions to the observations that bac...

  2. Primordial alchemy: from the Big Bang to the present universe

    Science.gov (United States)

    Steigman, Gary

    Of the light nuclides observed in the universe today, D, 3He, 4He, and 7Li are relics from its early evolution. The primordial abundances of these relics, produced via Big Bang Nucleosynthesis (BBN) during the first half hour of the evolution of the universe provide a unique window on Physics and Cosmology at redshifts ~1010. Comparing the BBN-predicted abundances with those inferred from observational data tests the consistency of the standard cosmological model over ten orders of magnitude in redshift, constrains the baryon and other particle content of the universe, and probes both Physics and Cosmology beyond the current standard models. These lectures are intended to introduce students, both of theory and observation, to those aspects of the evolution of the universe relevant to the production and evolution of the light nuclides from the Big Bang to the present. The current observational data is reviewed and compared with the BBN predictions and the implications for cosmology (e.g., universal baryon density) and particle physics (e.g., relativistic energy density) are discussed. While this comparison reveals the stunning success of the standard model(s), there are currently some challenge which leave open the door for more theoretical and observational work with potential implications for astronomy, cosmology, and particle physics.

  3. Primordial Alchemy From The Big Bang To The Present Universe

    CERN Document Server

    Steigman, G

    2002-01-01

    Of the light nuclides observed in the universe today, D, 3He, 4He, and 7Li are relics from its early evolution. The primordial abundances of these relics, produced via Big Bang Nucleosynthesis (BBN) during the first half hour of the evolution of the universe provide a unique window on Physics and Cosmology at redshifts of order 10^10. Comparing the BBN-predicted abundances with those inferred from observational data tests the consistency of the standard model of cosmology over ten orders of magnitude in redshift, constrains the baryon and other particle content of the universe, and probes both Cosmology and Physics beyond their current standard models. These lectures are intended to introduce students, both of theory and observation, to those aspects of the evolution of the universe relevant to the production and evolution of the light nuclides from the Big Bang to the present. The current observational data is reviewed and compared with the BBN predictions and the implications for cosmology (e.g., universal ...

  4. Passport to the Big Bang moves across the road

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    The ATLAS platform of the Passport to the Big Bang circuit has been relocated in front of the CERN Reception.   The ATLAS platform of the Passport to the Big Bang, outside the CERN Reception building. The Passport to the Big Bang platform of the ATLAS Experiment has been moved in front of the CERN Reception to make it more visible and accessible. It had to be dismantled and moved from its previous location in the garden of the Globe of Science and Innovation due to the major refurbishment work in progress on the Globe, and is now fully operational in its new location on the other side of the road, in the Main Reception car-park. The Passport to the Big Bang circuit, inaugurated in 2013, comprises ten platforms installed in front of ten CERN sites and aims to help local residents and visitors to the region understand CERN's research. Dedicated Passport to the Big Bang flyers, containing all necessary information and riddles for you to solve, are available at the CERN Rec...

  5. Dark/visible parallel universes and Big Bang nucleosynthesis

    International Nuclear Information System (INIS)

    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.

  6. Dark/visible parallel universes and Big Bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, C. A.; Frederico, T.; Fuqua, J.; Hussein, M. S.; Oliveira, O.; Paula, W. de [Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce TX 75429 (United States); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP (Brazil); Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce TX 75429 (United States); Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05314-970 Sao Paulo, SP (Brazil); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP, Brazil and Departamento de Fisica, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP (Brazil)

    2012-11-20

    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.

  7. Looking back in time beyond the big bang

    OpenAIRE

    Gasperini, M.

    1999-01-01

    String theory can (in principle) describe gravity at all curvature scales, and can be applied to cosmology to look back in time beyond the Planck epoch. The duality symmetries of string theory suggest a cosmological picture in which the imprint of a primordial, pre-big bang phase could still be accessible to present observations. The predictive power of such a scenario relies, however, on our ability to connect in a smooth way the pre-big bang to the present cosmological regime. Classical rad...

  8. Big-bang Nucleosynthesis Enters the Precision Era

    OpenAIRE

    Schramm, David N.; Turner, Michael S.

    1997-01-01

    The last parameter of big-bang nucleosynthesis, the baryon density, is being pinned down by measurements of the deuterium abundance in high-redshift hydrogen clouds. When it is determined, it will fix the primeval light-element abundances. D, ^3He and ^7Li will become ``tracers'' for the study of Galactic and stellar chemical evolution, and big-bang nucleosynthesis will become an even sharper probe of particle physics, e.g., the bound to the number of light neutrino species will be tightened ...

  9. Baryon symmetric big-bang cosmology. [matter-antimatter symmetry

    Science.gov (United States)

    Stecker, F. W.

    1978-01-01

    The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.

  10. Capture reactions on C-14 in nonstandard big bang nucleosynthesis

    Science.gov (United States)

    Wiescher, Michael; Gorres, Joachim; Thielemann, Friedrich-Karl

    1990-01-01

    Nonstandard big bang nucleosynthesis leads to the production of C-14. The further reaction path depends on the depletion of C-14 by either photon, alpha, or neutron capture reactions. The nucleus C-14 is of particular importance in these scenarios because it forms a bottleneck for the production of heavier nuclei A greater than 14. The reaction rates of all three capture reactions at big bang conditions are discussed, and it is shown that the resulting reaction path, leading to the production of heavier elements, is dominated by the (p, gamma) and (n, gamma) rates, contrary to earlier suggestions.

  11. Film Presentation: The Big Bang Machine by BBC (2008)

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Professor Brian Cox visits Geneva to take a look around CERN's Large Hadron Collider before the vast, 27km long machine is sealed off and a simulation experiment begins to try to create the conditions that existed a billionth of a second after the Big Bang. Cox is joined by fellow scientists, including CERN theorist John Ellis and Nobel Laureate Leon Lederman from Fermilab, who hope that the LHC will change our understanding of the early Universe and solve some of its mysteries. The Big Bang Machine will be presented on Friday, 15 October from 13:00 to 14:00 in the Council Chamber, Bldg.503 Language: English

  12. A Quantum Dynamic Cosmology Model Without Big Bang%一种无大爆炸量子动态宇宙模型

    Institute of Scientific and Technical Information of China (English)

    邵丹; 邵亮; 邵常贵

    2011-01-01

    According to the loop quantum gravity,calculates and obtains the results of the volume inflation and the metric fluctuation,and a creation way of gravity field is given,during the transition of the spacetime.Using finiteness of the representation of quantum group,a quantum dynamic cosmdogy model without singularity of spacetime is raised,and it is compared with the big bang cosmology model.%依据圈量子引力,计算出空时跃迁体积膨胀和度量起伏的结果,同时给出了引力场的一种生成途径.利用量子群SU 2 q表示的有限性,提出了一种不存在空时奇点的量子动态宇宙模型,并将其与大爆炸宇宙模型做了某些比较.

  13. Big bang nucleosynthesis and the quark-hadron transition

    Science.gov (United States)

    Kurki-Suonio, Hannu; Matzner, Richard A.; Olive, Keith A.; Schramm, David N.

    1990-01-01

    An examination and brief review is made of the effects of quark-hadron transition induced fluctuations on Big Bang nucleosynthesis. It is shown that cosmologically critical densities in baryons are difficult to reconcile with observation, but the traditional baryon density constraints from homogeneous calculations might be loosened by as much as 50 percent, to 0.3 of critical density, and the limit on the number of neutrino flavors remains about N(sub nu) is less than or approximately 4. To achieve baryon densities of greater than or approximately 0.3 of critical density would require initial density contrasts R is much greater the 10(exp e), whereas the simplest models for the transition seem to restrict R to less than of approximately 10(exp 2).

  14. COBE's search for structure in the Big Bang

    Science.gov (United States)

    Soffen, Gerald (Editor); Guerny, Gene (Editor); Keating, Thomas (Editor); Moe, Karen (Editor); Sullivan, Walter (Editor); Truszkowski, Walt (Editor)

    1989-01-01

    The launch of Cosmic Background Explorer (COBE) and the definition of Earth Observing System (EOS) are two of the major events at NASA-Goddard. The three experiments contained in COBE (Differential Microwave Radiometer (DMR), Far Infrared Absolute Spectrophotometer (FIRAS), and Diffuse Infrared Background Experiment (DIRBE)) are very important in measuring the big bang. DMR measures the isotropy of the cosmic background (direction of the radiation). FIRAS looks at the spectrum over the whole sky, searching for deviations, and DIRBE operates in the infrared part of the spectrum gathering evidence of the earliest galaxy formation. By special techniques, the radiation coming from the solar system will be distinguished from that of extragalactic origin. Unique graphics will be used to represent the temperature of the emitting material. A cosmic event will be modeled of such importance that it will affect cosmological theory for generations to come. EOS will monitor changes in the Earth's geophysics during a whole solar color cycle.

  15. Quark mass variation constraints from Big Bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Bedaque, P; Luu, T; Platter, L

    2010-12-13

    We study the impact on the primordial abundances of light elements created of a variation of the quark masses at the time of Big Bang nucleosynthesis (BBN). In order to navigate through the particle and nuclear physics required to connect quark masses to binding energies and reaction rates in a model-independent way we use lattice QCD data and an hierarchy of effective field theories. We find that the measured {sup 4}He abundances put a bound of {delta}-1% {approx}< m{sub q}/m{sub 1} {approx}< 0.7%. The effect of quark mass variations on the deuterium abundances can be largely compensated by changes of the baryon-to-photon ratio {eta}. Including the bounds on the variation of {eta} coming from WMAP results and some additional assumptions narrows the range of allowed values of {delta}m{sub q}/m{sub q} somewhat.

  16. Quantum Nature of the Big Bang: Improved dynamics

    CERN Document Server

    Ashtekar, A; Singh, P; Ashtekar, Abhay; Pawlowski, Tomasz; Singh, Parampreet

    2006-01-01

    An improved Hamiltonian constraint operator is introduced in loop quantum cosmology. Quantum dynamics of the spatially flat, isotropic model with a massless scalar field is then studied in detail using analytical and numerical methods. The scalar field continues to serve as `emergent time', the big bang is again replaced by a quantum bounce, and quantum evolution remains deterministic across the deep Planck regime. However, while with the Hamiltonian constraint used so far in loop quantum cosmology the quantum bounce can occur even at low matter densities, with the new Hamiltonian constraint it occurs only at a Planck-scale density. Thus, the new quantum dynamics retains the attractive features of current evolutions in loop quantum cosmology but, at the same time, cures their main weakness.

  17. Neutrino energy transport in weak decoupling and big bang nucleosynthesis

    CERN Document Server

    Grohs, E; Kishimoto, C T; Paris, M W; Vlasenko, A

    2015-01-01

    We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energy transport scheme. Such an approach allows a detailed accounting of the evolution of the $\

  18. A Guided Inquiry on Hubble Plots and the Big Bang

    Science.gov (United States)

    Forringer, Ted

    2014-01-01

    In our science for non-science majors course "21st Century Physics," we investigate modern "Hubble plots" (plots of velocity versus distance for deep space objects) in order to discuss the Big Bang, dark matter, and dark energy. There are two potential challenges that our students face when encountering these topics for the…

  19. Quantum Gravity Loses in the Big Bang and Black Holes

    OpenAIRE

    Rosenberg, David E.

    2000-01-01

    Applying the uncertainty principle to the stress-energy tensor, we investigate black holes, the big bang and galaxy formation. Dark energy, dark matter and other phenomena are readily explained using the principle of particle confinement. Evidence is presented that the universe results from a bounce and that black holes lose gravitational energy. PACS number 04.50Kd

  20. 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...

  1. Leadership in the Big Bangs of European Integration

    DEFF Research Database (Denmark)

    ? and, more importantly, what factors allowed specific actors to provide leadership in a given context? These conclusions provide a major step forward in the literature on the history-making bargains in the EU, allowing us to answer with more confidence the question of which actors have guided the big...... bangs in the European integration process in the past two decades, and why.  ...

  2. Big Bang Nucleosynthesis and the Observed Abundances of Light Elements

    OpenAIRE

    Hogan, Craig J.

    1996-01-01

    The predictions of Standard Big Bang Nucleosynthesis are summarized and compared with observations of abundances of helium in HII regions, deuterium in quasar absorbers, deuterium and helium-3 in the Galaxy, and lithium in metal-poor stars. It is concluded that the prospects are good for a precise test of the theory.

  3. Curing singularities: From the big bang to black holes

    OpenAIRE

    Levin, Janna

    1998-01-01

    Singular spacetimes are a natural prediction of Einstein's theory. Most memorable are the singular centers of black holes and the big bang. However, dilatonic extensions of Einstein's theory can support nonsingular spacetimes. The cosmological singularities can be avoided by dilaton driven inflation. Furthermore, a nonsingular black hole can be constructed in two dimensions.

  4. Film Presentation: Big Bang, mes ancêtres et moi

    CERN Multimedia

    2010-01-01

    Big Bang, mes ancêtres et moi, by Franco-German TV producer ARTE (2009)   What do we know about the origins of the world today? This documentary presents a voyage into the mystery of these origins, accompanied by passionate scientists such as paleoanthropologist Pascal Picq, astrophysicist Hubert Reeves, physicist Etienne Klein and quantum gravity theorist Abhay Ashtekar. Organized around three key moments – the birth of the Universe, the appearance of life and the origins of mankind – this investigation takes us to various research areas around the world, including the large underground particle accelerator at CERN. The German version of this film, Big Bang im Labor, will be presented on 1st October. Big Bang, mes ancêtres et moi will be shown on Friday, 24 September from 13:00 to 14:00 in room 222-R-001 Language: French Big Bang im Labor will be shown on Friday, 1 October from 13:00 to 14:00 in the Main Auditorium Language : German   &nbs...

  5. The Big Bang: UK Young Scientists' and Engineers' Fair 2010

    Science.gov (United States)

    Allison, Simon

    2010-01-01

    The Big Bang: UK Young Scientists' and Engineers' Fair is an annual three-day event designed to promote science, technology, engineering and maths (STEM) careers to young people aged 7-19 through experiential learning. It is supported by stakeholders from business and industry, government and the community, and brings together people from various…

  6. "Big Bang"test put off until May 2008

    CERN Multimedia

    2007-01-01

    "First tests in a scientific project aimed at solving mysteries of the universe and the "Big Bang" which created it have been put off from November to late april or early May next year, an official said yesterday." (2/3 page)

  7. Cosmologie L'Univers avant le Big Bang

    CERN Multimedia

    Rouat, Sylvie

    2003-01-01

    Tout n'a pas commencé par une explosion. L'histoire du cosmos avait débuté bien avant le Big Bang, si l'on suit la théorie défendue par les partisans d'une nouvelle cosmologie issue de la mystérieuse théorie des cordes

  8. Constructing "Nerdiness": Characterisation in "The Big Bang Theory"

    Science.gov (United States)

    Bednarek, Monika

    2012-01-01

    This paper analyses the linguistic construction of the televisual character Sheldon--the "main nerd" in the sitcom "The Big Bang Theory" (CBS, 2007-), approaching this construction of character through both computerised and "manual" linguistic analysis. More specifically, a computer analysis of dialogue (using concordances and keyword analysis) in…

  9. Small wormholes change our picture of the big bang

    CERN Multimedia

    1990-01-01

    Matt Visser has studied tiny wormholes, which may be produced on a subatomic scale by quantum fluctuations in the energy of the vacuum. He believes these quantum wormholes could change our picture of the origin of the Universe in the big bang (1/2 p)

  10. HydraPower out to make a big bang

    CERN Multimedia

    Revill, John

    2006-01-01

    "An engineering company has provided equipment for a £1.3 billion international project to recreate the conditions of the 'Big Bang". Garry Williams, technical director of hydraPower dynamics, has been asked to return to Switzerland by CERN."

  11. Recrean el Big Bang a nivel microscópico

    CERN Multimedia

    2007-01-01

    Although the scientists assure that the Universe was created from great explosion or Big Bang, that gave origin to the matter which we know today - including the alive beings - What happened after this strong snap is still a mystery regarding the formation of the cosmos. (1 page)

  12. Curing singularities From the big bang to black holes

    CERN Document Server

    Levin, J

    1998-01-01

    Singular spacetimes are a natural prediction of Einstein's theory. Most memorable are the singular centers of black holes and the big bang. However, dilatonic extensions of Einstein's theory can support nonsingular spacetimes. The cosmological singularities can be avoided by dilaton driven inflation. Furthermore, a nonsingular black hole can be constructed in two dimensions.

  13. Astrophysical Li-7 as a product of big bang nucleosynthesis and galactic cosmic-ray spallation

    Science.gov (United States)

    Olive, Keith A.; Schramm, David N.

    1992-01-01

    The astrophysical Li-7 abundance is considered to be largely primordial, while the Be and B abundances are thought to be due to galactic cosmic ray (GCR) spallation reactions on top of a much smaller big bang component. But GCR spallation should also produce Li-7. As a consistency check on the combination of big bang nucleosynthesis and GCR spallation, the Be and B data from a sample of hot population II stars is used to subtract from the measured Li-7 abundance an estimate of the amount generated by GCR spallation for each star in the sample, and then to add to this baseline an estimate of the metallicity-dependent augmentation of Li-7 due to spallation. The singly reduced primordial Li-7 abundance is still consistent with big bang nucleosynthesis, and a single GCR spallation model can fit the Be, B, and corrected Li-7 abundances for all the stars in the sample.

  14. Superhorizon curvaton amplitude in inflation and pre-big bang cosmology

    DEFF Research Database (Denmark)

    Sloth, Martin Snoager

    2002-01-01

    We follow the evolution of the curvaton on superhorizon scales and check that the spectral tilt of the curvaton perturbations is unchanged as the curvaton becomes non-relativistic. Both inflation and pre-big bang cosmology can be treated since the curvaton mechanism within the two scenarios works...... the same way. We also discuss the amplitude of the density perturbations, which leads to some interesting constrains on the pre-big bang scenario. It is shown that within a SL(3,R) non-linear sigma model one of the three axions has the right coupling to the dilaton and moduli to yield a flat spectrum...

  15. 革命者BIG BANG

    Institute of Scientific and Technical Information of China (English)

    刘岩

    2015-01-01

    <正>在鄂尔多斯的繁荣时代,我遇见了那里的一位"意见领袖",因为他从美国回来,见过外面的世界,有着对奢侈品辽阔的见识和独到的品味。他引领着那座神秘财富城市中一个小圈子的购物风潮,他们一块接一块儿地购入Big Bang。那个时候,我并不太清楚他们迷恋这款腕表的原因,直到我一次次地去到巴塞尔表展,一次次地了解到Big Bang的想象力。是的,Big Bang的确充满了魅力。Big Bang进化史2005年Big Bang系列诞生2006年Big Bang全黑"全黑"理念使Big Bang更加纯粹和简洁。Big Bang全黑腕表从表壳到表盘浑然天成的亚光质感和多层次、不同材料融合起来的黑色,蕴含"不可见的可见"之禅意。

  16. Entropy generation and inflation in collision induced pre-big-bang cosmology

    NARCIS (Netherlands)

    A. Feinstein; K.E. Kunze; M.A. Vazquez-Mozo

    2000-01-01

    We study inflation and entropy generation in a recently proposed pre-big-bang model universe produced in a collision of gravitational and dilaton waves. It is shown that enough inflation occurs provided the incoming waves are sufficiently weak. We also find that entropy in this model is dynamically

  17. Detailed behavioral modeling of bang-bang phase detectors

    DEFF Research Database (Denmark)

    Jiang, Chenhui; Andreani, Pietro; Keil, U. D.

    2006-01-01

    In this paper, the metastability of current-mode logic (CML) latches and flip-flops is studied in detail. Based on the results of this analysis, a behavioral model of bang-bang phase detectors (BBPDs) is proposed, which is able to reliably capture the critical deadzone effect. The impact of jitter...

  18. Fisicos argentinos reproduciran el Big Bang

    CERN Multimedia

    De Ambrosio, Martin

    2008-01-01

    Two groups of argentine physicists from La Plata and Buenos Aires Universities work in a sery of experiments who while recreate the conditions of the big explosion that was at the origin of the universe. (1 page)

  19. Limits to the primordial helium abundance in the baryon-inhomogeneous big bang

    Science.gov (United States)

    Mathews, G. J.; Schramm, D. N.; Meyer, B. S.

    1993-01-01

    The parameter space for baryon inhomogeneous big bang models is explored with the goal of determining the minimum helium abundance obtainable in such models while still satisfying the other light-element constraints. We find that the constraint of (D + He-3)/H less than 10 exp -4 restricts the primordial helium mass fraction from baryon-inhomogeneous big bang models to be greater than 0.231 even for a scenario which optimizes the effects of the inhomogeneities and destroys the excess lithium production. Thus, this modification to the standard big bang as well as the standard homogeneous big bang model itself would be falsifiable by observation if the primordial He-4 abundance were observed to be less than 0.231. Furthermore, a present upper limit to the observed helium mass fraction of Y(obs)(p) less than 0.24 implies that the maximum baryon-to-photon ratio allowable in the inhomogeneous models corresponds to eta less than 2.3 x 10 exp -9 (omega(b) h-squared less than 0.088) even if all conditions are optimized.

  20. Big bang nucleosynthesis and CMB constraints on dark energy

    International Nuclear Information System (INIS)

    Current observational data favor cosmological models which differ from the standard model due to the presence of some form of dark energy and, perhaps, by additional contributions to the more familiar dark matter. Primordial nucleosynthesis provides a window on the very early evolution of the universe and constraints from big bang nucleosynthesis (BBN) can bound the parameters of models for dark matter or energy at redshifts of the order of ten billion. The spectrum of temperature fluctuations imprinted on the cosmic microwave background (CMB) radiation opens a completely different window on the universe at epochs from redshifts of the order of ten thousand to nearly the present. The CMB anisotropy spectrum provides constraints on new physics which are independent of and complementary to those from BBN. Here we consider three classes of models for the dark matter or energy: extra particles which were relativistic during the early evolution of the universe ('X'); quintessence models involving a minimally coupled scalar field ('Q'); models with a non-minimally coupled scalar field which modify the strength of gravity during the early evolution of the universe ('G'). We constrain the parameters of these models using data from BBN and the CMB and identify the allowed regions in their parameter spaces consistent with the more demanding joint BBN and CMB constraints. For 'X' and 'Q' such consistency is relatively easy to find; it is more difficult for the 'G' models with an inverse power law potential for the scalar field

  1. Big Bang Day: 5 Particles - 3. The Anti-particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

  2. Constraining pre big-bang-nucleosynthesis expansion using cosmic antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Schelke, M. [Istituto Nazionale di Fisica Nucleare, Torino (Italy); Catena, R. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Fornengo, N. [Torino Univ. (Italy). Dipt. di Fisica Teorica]|[Istituto Nazionale di Fisica Nucleare, Torino (Italy); Masiero, A. [Pavoa Univ. (Italy). Dipt. di Fisica]|[Istituto Nazionale di Fisica Nucleare, Padova (Italy); Pietroni, M. [Istituto Nazionale di Fisica Nucleare, Padova (Italy)

    2006-06-15

    A host of dark energy models and non-standard cosmologies predict an enhanced Hubble rate in the early Universe: perfectly viable models, which satisfy Big Bang Nucleosynthesis (BBN), cosmic microwave background and general relativity tests, may nevertheless lead to enhancements of the Hubble rate up to many orders of magnitude. In this paper we show that strong bounds on the pre-BBN evolution of the Universe may be derived, under the assumption that dark matter is a thermal relic, by combining the dark matter relic density bound with constraints coming from the production of cosmic-ray antiprotons by dark matter annihilation in the Galaxy. The limits we derive can be sizable and apply to the Hubble rate around the temperature of dark matter decoupling. For dark matter masses lighter than 100 GeV, the bound on the Hubble-rate enhancement ranges from a factor of a few to a factor of 30, depending on the actual cosmological model, while for a mass of 500 GeV the bound falls in the range 50-500. Uncertainties in the derivation of the bounds and situations where the bounds become looser are discussed. We finally discuss how these limits apply to some specific realizations of non-standard cosmologies: a scalar-tensor gravity model, kination models and a Randall-Sundrum D-brane model. (Orig.)

  3. Physicists create a "perfect" way to study the Big Bang

    CERN Multimedia

    2005-01-01

    Physicists have created the state of matter thought to have filled the Universe just a few microseconds after the big bang and found it to be different from what they were expecting: instead of a gas, it is more like a liquid. Understanding why it is a liquid that should take physicists a step closer to explaining the earliest moments of our Universe (1 ½ page)

  4. American Humor reflected in English Film The Big Bang Theory

    Institute of Scientific and Technical Information of China (English)

    刘珍

    2016-01-01

    With the accelerated process of globalization, we are able to access to the wide variety of cultural forms from all over the world conveniently. The United States, a typical country of immigrants, enjoys the world's first place of ethnic cultural melt-ing. In this paper, the writer takes popular sitcom, The Big Bang Theory, for example to explore the humorous culture of the United States as well as its sources and characteristics from the perspective of subtitle translation.

  5. Brookhaven collider opens its quest for Big Bang conditions

    CERN Multimedia

    Nadis, S

    2000-01-01

    The collision of two gold nuclei releasing 10 x 10 to the power 12 electron volts of energy, marked the debut of the Relativistic Heavy Ion Collider. Over the next few weeks, scientists hope to increase the accelerator's power to generate collisions 40 x 10 to the power 12 eVs of energy to simulate the conditions that existed immediately after the Big Bang (1 page).

  6. Review of Big Bang Nucleosynthesis and Primordial Abundances

    OpenAIRE

    Tytler, David; O'Meara, John M.; SUZUKI, Nao; Lubin, Dan

    2000-01-01

    Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium, He3, He4 and Li7, during the first few minutes of the universe. This review concentrates on recent improvements in the measurement of the primordial (after BBN, and prior to modification) abundances of these nuclei. We mention improvement in the standard theory, and the non-standard extensions which are limited by the data. (abridged)

  7. Adiabatic CMB perturbations in pre-big bang string cosmology

    CERN Document Server

    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 $-0.1 \\lesssim \\Delta n \\lesssim 0.3$.

  8. big bang gene modulates gut immune tolerance in Drosophila.

    Science.gov (United States)

    Bonnay, François; Cohen-Berros, Eva; Hoffmann, Martine; Kim, Sabrina Y; Boulianne, Gabrielle L; Hoffmann, Jules A; Matt, Nicolas; Reichhart, Jean-Marc

    2013-02-19

    Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases. PMID:23378635

  9. big bang gene modulates gut immune tolerance in Drosophila

    Science.gov (United States)

    Bonnay, François; Cohen-Berros, Eva; Hoffmann, Martine; Kim, Sabrina Y.; Boulianne, Gabrielle L.; Hoffmann, Jules A.; Matt, Nicolas; Reichhart, Jean-Marc

    2013-01-01

    Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases. PMID:23378635

  10. Big Bang à Genève - French version only

    CERN Document Server

    2005-01-01

    C'est la dernière conférence du cycle organisé par la section de physique de l'Université de Genève à l'occasion de l'Année internationale de la physique. Pour le bouquet final, la section de physique a choisi le grand boum du Big Bang. Intitulée « Big Bang à Genève », la conférence donnée par Laurent Chevalier de l'institut français CEA Saclay évoquera les expériences qui se préparent au CERN avec le LHC. Leur but est de reproduire et d'analyser les conditions qui prévalaient à l'origine de l'Univers, juste après le Big Bang. L'exposé décrira de façon simple les techniques utilisées pour cette exploration, qui démarrera en 2007. Laurent Chevalier se demandera avec le public quels phénomènes nouveaux les physiciens espèrent découvrir dans ce monde inexploré. Comme les précédentes, la conférence débutera par une démonstration de détection de rayons cosmiques dans l'auditoire et l'utilisation de ces signaux pour créer une « musique cosmique », en collaboration avec le Pr...

  11. Constraining Axion Dark Matter with Big Bang Nucleosynthesis

    OpenAIRE

    Kfir Blum; Raffaele Tito D'Agnolo; Mariangela Lisanti; Benjamin R. Safdi

    2014-01-01

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD $\\theta$ angle that redshifts in the early universe, increasing the neutron-proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of 4He during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for time-varying ...

  12. Effects of anisotropy and spatial curvature on the pre-big bang scenario

    OpenAIRE

    Clancy, D.; Lidsey, J. E.; Tavakol, R.

    1998-01-01

    A class of exact, anisotropic cosmological solutions to the vacuum Brans-Dicke theory of gravity is considered within the context of the pre-big bang scenario. Included in this class are the Bianchi type III, V and VI_h models and the spatially isotropic, negatively curved Friedmann-Robertson-Walker universe. The effects of large anisotropy and spatial curvature are determined. In contrast to negatively curved Friedmann-Robertson-Walker model, there exist regions of the parameter space in whi...

  13. From the Big Bang to the Brain.

    Science.gov (United States)

    Boliek, Carol A.; Lohmeier, Heather

    1999-01-01

    Summarizes research findings that challenge long-standing theories of infant cognition and motor development and proposes alternative theoretical models to describe skill acquisition during the first several years of life. Findings are discussed with respect to research in the area of infant speech physiology and production. (Author/CR)

  14. Big Bang Day : Afternoon Play - Torchwood: Lost Souls

    CERN Multimedia

    2008-01-01

    Martha Jones, ex-time traveller and now working as a doctor for a UN task force, has been called to CERN where they're about to activate the Large Hadron Collider. Once activated, the Collider will fire beams of protons together recreating conditions a billionth of a second after the Big Bang - and potentially allowing the human race a greater insight into what the Universe is made of. But so much could go wrong - it could open a gateway to a parallel dimension, or create a black hole - and now voices from the past are calling out to people and scientists have started to disappear... Where have the missing scientists gone? What is the secret of the glowing man? What is lurking in the underground tunnel? And do the dead ever really stay dead? Lost Souls is a spin-off from the award-winning BBC Wales TV production Torchwood. It stars John Barrowman, Freema Agyeman, Eve Myles, Gareth David-Lloyd, Lucy Montgomery (of Titty Bang Bang) and Stephen Critchlow.

  15. Big Bang nucleosynthesis with a stiff fluid

    CERN Document Server

    Dutta, Sourish

    2010-01-01

    Models that lead to a cosmological stiff fluid component, with a density $\\rho_S$ that scales as $a^{-6}$, where $a$ is the scale factor, have been proposed recently in a variety of contexts. We calculate numerically the effect of such a stiff fluid on the primordial element abundances. Because the stiff fluid energy density decreases with the scale factor more rapidly than radiation, it produces a relatively larger change in the primordial helium-4 abundance than in the other element abundances, relative to the changes produced by an additional radiation component. We show that the helium-4 abundance varies linearly with the density of the stiff fluid at a fixed fiducial temperature. Taking $\\rho_{S10}$ and $\\rho_{R10}$ to be the stiff fluid energy density and the standard density in relativistic particles, respectively, at $T = 10$ MeV, we find that the change in the primordial helium abundance is well-fit by $\\Delta Y_p = 0.00024(\\rho_{S10}/\\rho_{R10})$. The changes in the helium-4 abundance produced by ad...

  16. The meta-analytic big bang.

    Science.gov (United States)

    Shadish, William R; Lecy, Jesse D

    2015-09-01

    This article looks at the impact of meta-analysis and then explores why meta-analysis was developed at the time and by the scholars it did in the social sciences in the 1970s. For the first problem, impact, it examines the impact of meta-analysis using citation network analysis. The impact is seen in the sciences, arts and humanities, and on such contemporaneous developments as multilevel modeling, medical statistics, qualitative methods, program evaluation, and single-case design. Using a constrained snowball sample of citations, we highlight key articles that are either most highly cited or most central to the systematic review network. Then, the article examines why meta-analysis came to be in the 1970s in the social sciences through the work of Gene Glass, Robert Rosenthal, and Frank Schmidt, each of whom developed similar theories of meta-analysis at about the same time. The article ends by explaining how Simonton's chance configuration theory and Campbell's evolutionary epistemology can illuminate why meta-analysis occurred with these scholars when it did and not in medical sciences. PMID:26212600

  17. Observable gravitational waves in pre-big bang cosmology: an update

    CERN Document Server

    Gasperini, M

    2016-01-01

    In the light of the recent results concerning CMB observations and GW detection we address the question of whether it is possible, in a self-consistent inflationary framework, to simultaneously generate a spectrum of scalar metric perturbations in agreement with Planck data and a stochastic background of primordial gravitational radiation compatible with the design sensitivity of aLIGO/Virgo and/or eLISA. We show that this is possible in a string cosmology context, for a wide region of the parameter space of the so-called pre-big bang models. We also discuss the associated values of the tensor-to-scalar ratio relevant to the CMB polarization experiments. We conclude that future, cross-correlated results from CMB observations and GW detectors will be able to confirm or disprove pre-big bang models and -- in any case -- will impose new significant constraints on the basic string theory/cosmology parameters.

  18. State of the Universe. If Not with a Big Bang, Then What?

    Science.gov (United States)

    Peterson, Ivars

    1991-01-01

    The Big Bang Theory and alternatives to the Big Bang Theory as an explanation for the origin of the universe are discussed. The importance of the discovery of redshift, the percentage of hydrogen found in old stars, and the existence of a uniform sea of radiation are explained. (KR)

  19. Cosmic inflation and big bang interpreted as explosions

    CERN Document Server

    Rebhan, Eckhard

    2012-01-01

    It has become common understanding that the recession of galaxies and the corresponding redshift of light received from them can only be explained by an expansion of the space between them and us. In this paper, for the presently favored case of a universe without spatial curvature, it is shown that this interpretation is restricted to comoving coordinates. It is proven by construction that within the framework of general relativity other coordinates exist in relation to which these phenomena can be explained by a motion of the cosmic substrate across space, caused by an explosion like big bang or by inflation preceding an almost big bang. At the place of an observer, this motion occurs without any spatial expansion. It is shown that in these "explosion coordinates" the usual redshift comes about by a Doppler shift and a subsequent gravitational shift. Making use of this interpretation, it can easily be understood why in comoving coordinates light rays of short spatial extensions expand and thus constitute an...

  20. Big Bang nucleosynthesis, microwave anisotropy, and the light element abundances

    Energy Technology Data Exchange (ETDEWEB)

    Coc, A. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CNRS/IN2P3/UPS, Bat. 104, F-91405 Orsay Campus (France); Angulo, C. [Centre de Recherches du Cyclotron, Universite catholique de Louvain, Chemin du cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Vangioni-Flam, E. [lnstitut d' Astrophysique de Paris, CNRS, 98bis Bd. Arago, F-75014 Paris (France); Descouvemont, P. [Physique Nucleaire Theorique et Physique Mathematique, CP229, Universite Libre de Bruxelles, B-1050 Brussels (Belgium); Adahchour, A. [Physique Nucleaire Theorique et Physique Mathematique, CP229, Universite Libre de Bruxelles, B-1050 Brussels (Belgium)

    2005-04-18

    From the observations of the anisotropies of the Cosmic Microwave Background (CMB) radiation, the WMAP satellite has provided a determination of the baryonic density of the Universe, with an unprecedented precision: 4%. This imposes a careful reanalysis of the standard Big-Bang Nucleosynthesis (SBBN) calculations. In a recent paper, we used the R-matrix theory to fit S-factor data on nuclear reactions involved in Big Bang nucleosynthesis. We derived the reaction rates with associated uncertainties, which were evaluated on statistical grounds (available at http://pntpm3.ulb.ac.be/bigbang). Combining these BBN results with the {omega}bh2 value from WMAP, we deduced the light element ({sup 4}He, D, {sup 3}He and {sup 7}Li) primordial abundances and compare them with spectroscopic observations. There is a very good agreement with deuterium observed in cosmological clouds, which strengthens the confidence on the estimated baryonic density of the Universe. However, there is a discrepancy between the deduced {sup 7}Li abundance and the one observed in halo stars of our Galaxy, supposed, until now, to represent the primordial abundance of this isotope. The origin of this discrepancy, observational, nuclear or more fundamental remains to be clarified. The possible role of the up to now neglected {sup 7}Be(d,p)2{alpha} and {sup 7}Be(d,{alpha}){sup 5}Li reactions is considered and we present here a dedicated experiment performed at Louvain-la-Neuve to measure these cross sections.

  1. Big Bang nucleosynthesis, microwave anisotropy, and the light element abundances

    Science.gov (United States)

    Coc, A.; Angulo, C.; Vangioni-Flam, E.; Descouvemont, P.; Adahchour, A.

    2005-04-01

    From the observations of the anisotropies of the Cosmic Microwave Background (CMB) radiation, the WMAP satellite has provided a determination of the baryonic density of the Universe, with an unprecedented precision: 4%. This imposes a careful reanalysis of the standard Big-Bang Nucleosynthesis (SBBN) calculations. In a recent paper, we used the R-matrix theory to fit S-factor data on nuclear reactions involved in Big Bang nucleosynthesis. We derived the reaction rates with associated uncertainties, which were evaluated on statistical grounds (available at http://pntpm3.ulb.ac.be/bigbang). Combining these BBN results with the Ωbh2 value from WMAP, we deduced the light element (4He, D,3He and 7Li) primordial abundances and compare them with spectroscopic observations. There is a very good agreement with deuterium observed in cosmological clouds, which strengthens the confidence on the estimated baryonic density of the Universe. However, there is a discrepancy between the deduced 7Li abundance and the one observed in halo stars of our Galaxy, supposed, until now, to represent the primordial abundance of this isotope. The origin of this discrepancy, observational, nuclear or more fundamental remains to be clarified. The possible role of the up to now neglected 7Be(d,p)2α and 7Be(d,α)5Li reactions is considered and we present here a dedicated experiment performed at Louvain-la-Neuve to measure these cross sections.

  2. Re-evaluation of the immunological Big Bang.

    Science.gov (United States)

    Flajnik, Martin F

    2014-11-01

    Classically the immunological 'Big Bang' of adaptive immunity was believed to have resulted from the insertion of a transposon into an immunoglobulin superfamily gene member, initiating antigen receptor gene rearrangement via the RAG recombinase in an ancestor of jawed vertebrates. However, the discovery of a second, convergent adaptive immune system in jawless fish, focused on the so-called variable lymphocyte receptors (VLRs), was arguably the most exciting finding of the past decade in immunology and has drastically changed the view of immune origins. The recent report of a new lymphocyte lineage in lampreys, defined by the antigen receptor VLRC, suggests that there were three lymphocyte lineages in the common ancestor of jawless and jawed vertebrates that co-opted different antigen receptor supertypes. The transcriptional control of these lineages during development is predicted to be remarkably similar in both the jawless (agnathan) and jawed (gnathostome) vertebrates, suggesting that an early 'division of labor' among lymphocytes was a driving force in the emergence of adaptive immunity. The recent cartilaginous fish genome project suggests that most effector cytokines and chemokines were also present in these fish, and further studies of the lamprey and hagfish genomes will determine just how explosive the Big Bang actually was. PMID:25517375

  3. Relationalism Evolves the Universe Through the Big Bang

    CERN Document Server

    Koslowski, Tim A; Sloan, David

    2016-01-01

    We investigate the singularities of homogeneous cosmologies from the point of view of relational (and physically relevant) degrees of freedom of the gravitational field. These do not depend on absolute units of length and duration - thus they do not include the volume and extrinsic curvature. We find that the fully relational dynamical system remains well posed for all physical times, even at the point that would be described as the big bang when evolving present day data backwards in time.This result is achieved in two steps: (1) for solutions which are gravity-dominated near the singularity, we show that any extended physical clock (whose readings only depend on the relational degrees of freedom) will undergo an infinite number of ticks before reaching the big bang. The singularity is therefore pushed into the infinite physical past of any physical clock. (2) for solutions where a stiff matter component (e.g. a massless scalar field) dominates at the singularity, we show that the relational degrees of freed...

  4. Pre-Big Bang, fundamental Physics and noncyclic cosmologies

    Directory of Open Access Journals (Sweden)

    Gonzalez-Mestres L.

    2014-04-01

    Full Text Available Detailed analyses of WMAP and Planck data can have significant implications for noncyclic pre-Big Bang approaches incorporating a new fundamental scale beyond the Planck scale and, potentially, new ultimate constituents of matter with unconventional basic properties as compared to standard particles. Cosmic-ray experiments at the highest energies can also yield relevant information. Hopefully, future studies will be able to deal with alternatives: i to standard physics for the structure of the physical vacuum, the nature of space-time, the validity of quantum field theory and conventional symmetries, the interpretation of string-like theories...; ii to standard cosmology concerning the origin and evolution of our Universe, unconventional solutions to the cosmological constant problem, the validity of inflationary scenarios, the need for dark matter and dark energy... Lorentz-like symmetries for the properties of matter can then be naturally stable space-time configurations resulting from more general primordial scenarios that incorporate physics beyond the Planck scale and describe the formation and evolution of the physical vacuum. A possible answer to the question of the origin of half-integer spins can be provided by a primordial spinorial space-time with two complex coordinates instead of the conventional four real ones, leading to a really new cosmology. We discuss basic questions and phenomenological topics concerning noncyclic pre-Big Bang cosmologies and potentially related physics.

  5. Big Bang pour le grand public - French version only

    CERN Multimedia

    2004-01-01

    Pour commémorer les 50 ans du CERN et l'année de la physique en 2005, la section de physique de l'Université de Genève ouvre une fois de plus ses portes aux non initiés et organise une série de conférences de vulgarisation scientifique. La première conférence, le 7 décembre prochain aura pour thème le Big-Bang et les observations qui corroborent cette théorie. Le Professeur Georges Meylan, Directeur du Laboratoire d'Astrophysique de l'EPFL, donnera cette conférence destinée à tous les publics. Chacune des conférences débutera par une démonstration de détection de rayons cosmiques dans l'auditoire et l'utilisation de ces signaux venus du fond de l'univers pour créer une ?musique cosmique', en collaboration avec le Professeur Ellberger et Nikolai Mihailov du conservatoire de musique de Genève. Ces processus cosmiques étant aléatoires, chacun de ces concerts sera unique. Les preuves observationnelles du Big Bang par le Professeur Georges Meylan Directeur du Laboratoire d'Astrophysique ...

  6. Constraints on pre-big bang parameter space from CMBR anisotropies

    OpenAIRE

    Bozza, V.; Gasperini, M.; Giovannini, M.; Veneziano, G.

    2002-01-01

    The so-called curvaton mechanism --a way to convert isocurvature perturbations into adiabatic ones-- is investigated both analytically and numerically in a pre-big bang scenario where the role of the curvaton is played by a sufficiently massive Kalb--Ramond axion of superstring theory. When combined with observations of CMBR anisotropies at large and moderate angular scales, the present analysis allows us to constrain quite considerably the parameter space of the model: in particular, the ini...

  7. The music of the Big Bang the cosmic microwave background and the new cosmology

    CERN Document Server

    Balbi, Amedeo

    2008-01-01

    The cosmic microwave background radiation is the afterglow of the big bang: a tenuous signal, more than 13 billion years old, which carries the answers to many of the questions about the nature of our Universe. It was serendipitously discovered in 1964, and thoroughly investigated in the last four decades by a large number of experiments. Two Nobel Prizes in Physics have already been awarded for research on the cosmic background radiation: one in 1978 to Arno Penzias and Robert Wilson, who first discovered it, the other in 2006, to George Smoot and John Mather, for the results of the COBE satellite. Most cosmological information is encoded in the cosmic background radiation by acoustic oscillations in the dense plasma that filled the primordial Universe: a "music" of the big bang, which cosmologists have long been trying to reconstruct and analyze, in order to distinguish different cosmological models, much like one can distinguish different musical instruments by their timbre and overtones. Only lately, this...

  8. Superhorizon curvaton amplitude in inflation and pre-big bang cosmology

    CERN Document Server

    Sloth, M S

    2003-01-01

    We follow the evolution of the curvaton on superhorizon scales and check that the spectral tilt of the curvaton perturbations is unchanged as the curvaton becomes non-relativistic. Both inflation and pre-big bang cosmology can be treated since the curvaton mechanism within the two scenarios works the same way. We also discuss the amplitude of the density perturbations, which leads to some interesting constrains on the pre-big bang scenario. It is shown that within a SL(3,R) non-linear sigma model one of the three axions has the right coupling to the dilaton and moduli to yield a flat spectrum with a high string scale, if a quadratic non-perturbative potential is generated and an intermediate string phase lasts long enough.

  9. Waarop is sy voetstukke ingesink? - 'n Besinning oor die skepping en die big bang

    Directory of Open Access Journals (Sweden)

    L.C. Bezuidenhout

    1998-08-01

    Full Text Available Through the ages the debate between theology and the natural sciencesconcerning the origin of the universe was turbulent. Today the big bangtheory is almost generally accepted in scientific circles. In this article thedebate between theology and science is evaluated critically. The theologicalimplications of the big bang theory is discussed and the relevance of thecosmogony in Genesis 1 for a modem society is evaluated. Biblical modelsand scientific models of the birth of the cosmos do not have to be in conflictwith each other.

  10. A New Damage Detection Method: Big Bang-Big Crunch (BB-BC Algorithm

    Directory of Open Access Journals (Sweden)

    Zahra Tabrizian

    2013-01-01

    Full Text Available The present paper aims to explore damage assessment methodology based on the changes in dynamic parameters properties of vibration of a structural system. The finite-element model is used to apply at an element level. Reduction of the element stiffness is considered for structural damage. A procedure for locating and quantifying damaged areas of the structure based on the innovative Big Bang-Big Crunch (BB-BC optimization method is developed for continuous variable optimization. For verifying the method a number of damage scenarios for simulated structures have been considered. For the purpose of damage location and severity assessment the approach is applied in three examples by using complete and incomplete modal data. The effect of noise on the accuracy of the results is investigated in some cases. A great unbraced frame with a lot of damaged element is considered to prove the ability of proposed method. More over BB-BC optimization method in damage detection is compared with particle swarm optimizer with passive congregation (PSOPC algorithm. This work shows that BB-BC optimization method is a feasible methodology to detect damage location and severity while introducing numerous advantages compared to referred method.

  11. Out of the white hole: a holographic origin for the Big Bang

    International Nuclear Information System (INIS)

    While most of the singularities of General Relativity are expected to be safely hidden behind event horizons by the cosmic censorship conjecture, we happen to live in the causal future of the classical Big Bang singularity, whose resolution constitutes the active field of early universe cosmology. Could the Big Bang be also hidden behind a causal horizon, making us immune to the decadent impacts of a naked singularity? We describe a braneworld description of cosmology with both 4d induced and 5D bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature: the universe emerges as a spherical 3-brane out of the formation of a 5D Schwarzschild black hole. In particular, we show that a pressure singularity of the holographic fluid, discovered earlier, happens inside the white hole horizon, and thus need not be real or imply any pathology. Furthermore, we outline a novel mechanism through which any thermal atmosphere for the brane, with comoving temperature of ∼20% of the 5D Planck mass can induce scale-invariant primordial curvature perturbations on the brane, circumventing the need for a separate process (such as cosmic inflation) to explain current cosmological observations. Finally, we note that 5D space-time is asymptotically flat, and thus potentially allows an S-matrix or (after minor modifications) an AdS/CFT description of the cosmological Big Bang

  12. Out of the white hole: a holographic origin for the Big Bang

    Energy Technology Data Exchange (ETDEWEB)

    Pourhasan, Razieh; Afshordi, Niayesh; Mann, Robert B., E-mail: rpourhasan@perimeterinstitute.ca, E-mail: nafshordi@pitp.ca, E-mail: rbmann@uwaterloo.ca [Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W., Waterloo, Ontario, N2L 3G1 Canada (Canada)

    2014-04-01

    While most of the singularities of General Relativity are expected to be safely hidden behind event horizons by the cosmic censorship conjecture, we happen to live in the causal future of the classical Big Bang singularity, whose resolution constitutes the active field of early universe cosmology. Could the Big Bang be also hidden behind a causal horizon, making us immune to the decadent impacts of a naked singularity? We describe a braneworld description of cosmology with both 4d induced and 5D bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature: the universe emerges as a spherical 3-brane out of the formation of a 5D Schwarzschild black hole. In particular, we show that a pressure singularity of the holographic fluid, discovered earlier, happens inside the white hole horizon, and thus need not be real or imply any pathology. Furthermore, we outline a novel mechanism through which any thermal atmosphere for the brane, with comoving temperature of ∼20% of the 5D Planck mass can induce scale-invariant primordial curvature perturbations on the brane, circumventing the need for a separate process (such as cosmic inflation) to explain current cosmological observations. Finally, we note that 5D space-time is asymptotically flat, and thus potentially allows an S-matrix or (after minor modifications) an AdS/CFT description of the cosmological Big Bang.

  13. The Quark Dirac Sea and the Contracted Universe cooperate to produce the Big Bang

    CERN Document Server

    Xu, Jiao-Lin

    2009-01-01

    The Big Bang theory cannot and does not provide any explanation for the primordial hot and dense initial condition. In order to give an explanation for the cause of the Big Bang, this paper expands the original Dirac sea (which includes only electrons) to the quark Dirac sea (QDS) including quarks (u and d) for producing the Big Bang with quark energy. The QDS is composed of "relatively infinite" u-quarks and d-quarks as well as electrons with negative energy in the vacuum. A huge number of domains with sizes much smaller than $10^{-18}$m of the body-central cubic quark lattice with a lattice constant "a" = Planck length ($1.62\\times10^{-35}m$) are distributed randomly over the QDS. The QDS is a homogeneous, isotropic, equivalent "continuous" and "empty" (no net electric charge, no net color charge, no gravitational force field since the gravitational potential is the same at any physical point in the QDS) perfect vacuum model. The gravity of the universe pulls on the quarks inside the QDS. The pulling force ...

  14. Big Bang nucleosynthesis revisited via Trojan Horse Method measurements

    CERN Document Server

    Pizzone, R G; Bertulani, C A; Spitaleri, C; La Cognata, M; Lalmansingh, J; Lamia, L; Mukhamedzhanov, A; Tumino, A

    2014-01-01

    Nuclear reaction rates are among the most important input for understanding the primordial nucleosynthesis and therefore for a quantitative description of the early Universe. An up-to-date compilation of direct cross sections of 2H(d,p)3H, 2H(d,n)3He, 7Li(p,alpha)4He and 3He(d,p)4He reactions is given. These are among the most uncertain cross sections used and input for Big Bang nucleosynthesis calculations. Their measurements through the Trojan Horse Method (THM) are also reviewed and compared with direct data. The reaction rates and the corresponding recommended errors in this work were used as input for primordial nucleosynthesis calculations to evaluate their impact on the 2H, 3,4He and 7Li primordial abundances, which are then compared with observations.

  15. Big bang nucleosynthesis revisited via Trojan Horse method measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pizzone, R. G.; Spartá, R.; Spitaleri, C.; La Cognata, M.; Tumino, A. [INFN—Laboratori Nazionali del Sud, Via Santa Sofia 62, I-95123 Catania (Italy); Bertulani, C. A.; Lalmansingh, J. [Department of Physics and Astronomy, Texas A and M University, Commerce, TX 75025 (United States); Lamia, L. [Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via Santa Sofia 64, I-95123 Catania (Italy); Mukhamedzhanov, A., E-mail: rgpizzone@lns.infn.it [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)

    2014-05-10

    Nuclear reaction rates are among the most important input for understanding primordial nucleosynthesis and, therefore, for a quantitative description of the early universe. An up-to-date compilation of direct cross-sections of {sup 2}H(d, p){sup 3}H, {sup 2}H(d, n){sup 3}He, {sup 7}Li(p, α){sup 4}He, and {sup 3}He(d, p){sup 4}He reactions is given. These are among the most uncertain cross-sections used and input for big bang nucleosynthesis calculations. Their measurements through the Trojan Horse method are also reviewed and compared with direct data. The reaction rates and the corresponding recommended errors in this work were used as input for primordial nucleosynthesis calculations to evaluate their impact on the {sup 2}H, {sup 3,4}He, and {sup 7}Li primordial abundances, which are then compared with observations.

  16. Cosmologie l'univers avant le Big Bang

    CERN Multimedia

    Larousserie, David

    2003-01-01

    Tout n'a pas commencé par une explosion. L'histoire du cosmos avait débuté bien avant le Big Bang, si l'on suit la théorie défendue par les partisans d'une nouvelle cosmologie issue de la mystérieuse théorie des cords. A l'heure où vacillent les scénarios classiques du XXe siècle, se prépare un grand chamboulement de nos idées sur la naissance de l'Univers et son devenir, sur l'existence possible d'univers parallèles.

  17. Big Bang Nucleosynthesis: Probing the First 20 Minutes

    CERN Document Server

    Steigman, G

    2003-01-01

    Within the first 20 minutes of the evolution of the hot, dense, early Universe, astrophysically interesting abundances of deuterium, helium-3, helium-4, and lithium-7 were synthesized by the cosmic nuclear reactor. The primordial abundances of these light nuclides produced during Big Bang Nucleosynthesis (BBN) are sensitive to the universal density of baryons and to the early-Universe expansion rate which at early epochs is governed by the energy density in relativistic particles (``radiation'') such as photons and neutrinos. Some 380 kyr later, when the cosmic background radiation (CBR) radiation was freed from the embrace of the ionized plasma of protons and electrons, the spectrum of temperature fluctuations imprinted on the CBR also depended on the baryon and radiation densities. The comparison between the constraints imposed by BBN and those from the CBR reveals a remarkably consistent picture of the Universe at two widely separated epochs in its evolution. Combining these two probes leads to new and tig...

  18. Big Bang Nucleosynthesis Revisited via Trojan Horse Method Measurements

    Science.gov (United States)

    Pizzone, R. G.; Spartá, R.; Bertulani, C. A.; Spitaleri, C.; La Cognata, M.; Lalmansingh, J.; Lamia, L.; Mukhamedzhanov, A.; Tumino, A.

    2014-05-01

    Nuclear reaction rates are among the most important input for understanding primordial nucleosynthesis and, therefore, for a quantitative description of the early universe. An up-to-date compilation of direct cross-sections of 2H(d, p)3H, 2H(d, n)3He, 7Li(p, α)4He, and 3He(d, p)4He reactions is given. These are among the most uncertain cross-sections used and input for big bang nucleosynthesis calculations. Their measurements through the Trojan Horse method are also reviewed and compared with direct data. The reaction rates and the corresponding recommended errors in this work were used as input for primordial nucleosynthesis calculations to evaluate their impact on the 2H, 3, 4He, and 7Li primordial abundances, which are then compared with observations.

  19. Sharpening the Predictions of Big-Bang Nucleosynthesis

    International Nuclear Information System (INIS)

    We have reexamined the nuclear inputs to big-bang nucleosynthesis using Monte Carlo realization of the cross-section data to directly estimate theoretical uncertainties for the yields of D , 3He , and 7Li . Our results indicate that previous estimates of the uncertainties were too large by a factor of 2. Using the Burles - Tytler deuterium measurement, we infer a baryon density ΩBh2=0.019±0.0024 , predict a primeval 4He mass fraction YP=0.246±0.0014 , and obtain a limit to the equivalent number of neutrino species Nν<3.20 (all at 95% C.L.). We also identify key reactions and the energies, where improved data would allow further progress. copyright 1999 The American Physical Society

  20. Resolution of Cosmological Singularity and a Plausible Mechanism of the Big Bang

    OpenAIRE

    Choudhury, D. C.

    2001-01-01

    The initial cosmological singularity in the framework of the general theory of relativity is resolved by introducing the effect of the uncertainty principle of quantum theory without violating conventional laws of physics. A plausible account of the mechanism of the big bang, analogous to that of a nuclear explosion, is given and the currently accepted Planck temperature of about 10^(32)K at the beginning of the big bang is predicted. Subj-class: cosmology: theory-pre-big bang; mechanism of t...

  1. The Quark Dirac Sea and the Contracted Universe cooperate to produce the Big Bang

    OpenAIRE

    Xu, Jiao-Lin

    2009-01-01

    The Big Bang theory cannot and does not provide any explanation for the primordial hot and dense initial condition. In order to give an explanation for the cause of the Big Bang, this paper expands the original Dirac sea (which includes only electrons) to the quark Dirac sea (QDS) including quarks (u and d) for producing the Big Bang with quark energy. The QDS is composed of "relatively infinite" u-quarks and d-quarks as well as electrons with negative energy in the vacuum. A huge number of d...

  2. Cosmic Heritage Evolution from the Big Bang to Conscious Life

    CERN Document Server

    Shaver, Peter

    2011-01-01

    This book follows the evolutionary trail all the way from the Big Bang 13.7 billion years ago to conscious life today. It is an accessible introductory book written for the interested layperson – anyone interested in the ‘big picture’ coming from modern science. It covers a wide range of topics including the origin and evolution of our universe, the nature and origin of life, the evolution of life including questions of birth and death, the evolution of cognition, the nature of consciousness, the possibility of extraterrestrial life and the future of the universe. The book is written in a narrative style, as these topics are all parts of a single story. It concludes with a discussion on the nature and future of science.  “Peter Shaver has written engagingly for anyone curious about the world we inhabit.  If you'd like to know how the Universe began, where the chemical elements originated, how life may have started on Earth, how man, ants and bacteria are related to each other, or why we humans think...

  3. String theory and pre-big bang cosmology

    Science.gov (United States)

    Gasperini, M.; Veneziano, G.

    2016-09-01

    In string theory, the traditional picture of a Universe that emerges from the inflation of a very small and highly curved space-time patch is a possibility, not a necessity: quite different initial conditions are possible, and not necessarily unlikely. In particular, the duality symmetries of string theory suggest scenarios in which the Universe starts inflating from an initial state characterized by very small curvature and interactions. Such a state, being gravitationally unstable, will evolve towards higher curvature and coupling, until string-size effects and loop corrections make the Universe "bounce" into a standard, decreasing-curvature regime. In such a context, the hot big bang of conventional cosmology is replaced by a "hot big bounce" in which the bouncing and heating mechanisms originate from the quantum production of particles in the high-curvature, large-coupling pre-bounce phase. Here we briefly summarize the main features of this inflationary scenario, proposed a quarter century ago. In its simplest version (where it represents an alternative and not a complement to standard slow-roll inflation) it can produce a viable spectrum of density perturbations, together with a tensor component characterized by a "blue" spectral index with a peak in the GHz frequency range. That means, phenomenologically, a very small contribution to a primordial B-mode in the CMB polarization, and the possibility of a large enough stochastic background of gravitational waves to be measurable by present or future gravitational wave detectors.

  4. Edwin Hubble, The Discoverer of the Big Bang Universe

    Science.gov (United States)

    Sharov, Alexander S.; Novikov, Igor D.

    1993-10-01

    This book is the first complete account of the scientific life and work of Edwin Hubble, whose discoveries form the basis of all theories of the evolution of the universe. One of the outstanding astronomers of the twentieth century, Hubble studied the velocities or redshifts of galaxies and discovered that the universe is expanding. He convincingly proved that our galaxy is only one of countless galaxies and thus paved the way for the exploration of an immense world beyond the limits of our knowledge. The exploding universe proposed by Hubble, now termed the Big Bang, is used to explain the origin of the elements, of stars, and of galaxies. The second part of the book describes the fundamental discoveries on the nature of the universe made subsequently, and thus sets his achievements in context. Hubble's vision, particularly his efforts to help build the big telescope at Mt. Palomar, firmly established the United States as a leader in observational astronomy. Written by two prominent astronomers (Dr. Novikov is the author of Black Holes and the Universe, CUP, 1990) who have built on Hubble's work, this book is a classic of science, setting out the thrilling story of the exploding universe.

  5. THE 2H(alpha, gamma6LI REACTION AT LUNA AND BIG BANG NUCLEOSYNTHETIS

    Directory of Open Access Journals (Sweden)

    Carlo Gustavino

    2013-12-01

    Full Text Available The 2H(α, γ6Li reaction is the leading process for the production of 6Li in standard Big Bang Nucleosynthesis. Recent observations of lithium abundance in metal-poor halo stars suggest that there might be a 6Li plateau, similar to the well-known Spite plateau of 7Li. This calls for a re-investigation of the standard production channel for 6Li. As the 2H(α, γ6Li cross section drops steeply at low energy, it has never before been studied directly at Big Bang energies. For the first time the reaction has been studied directly at Big Bang energies at the LUNA accelerator. The preliminary data and their implications for Big Bang nucleosynthesis and the purported 6Li problem will be shown.

  6. An Extension of Friedmann-Robertson-Walker Theory beyond Big Bang

    OpenAIRE

    Schroeter, Joachim

    2009-01-01

    Starting from the classic Friedmann–Robertson–Walker theory with big bang it is shown that the solutions of the field equations can be extended to negative times. Choosing a new cosmic time scale instead of proper time one achieves complete differentiability of the scale factor and of suitable thermodynamic quantities equivalent to pressure and energy density. Then, the singularity of big bang manifests itself only by the vanishing of the scale factor at time zero. Moreover,...

  7. Resolution of cosmological singularity and a plausible mechanism of the big bang

    International Nuclear Information System (INIS)

    The initial cosmological singularity in the framework of the general theory of relativity is resolved by introducing the effect of the uncertainty principle of quantum theory without violating conventional laws of physics. A plausible account of the mechanism of the big bang, analogous to that of a nuclear explosion, is given and the currently accepted Planck temperature of ≅1032 K at the beginning of the big bang is predicted

  8. Beyond Einstein: From the Big Bang to Black Holes

    Science.gov (United States)

    2005-01-01

    How did the Universe begin? Does time have a beginning and an end? Does space have edges? The questions are clear and simple. They are as old as human curiosity. But the answers have always seemed beyond the reach of science. Until now. In their attempts to understand how space, time, and matter are connected, Einstein and his successors made three predictions. First, space is expanding from a Big Bang; second, space and time can tie themselves into contorted knots called black holes where time actually comes to a halt; third, space itself contains some kind of energy that is pull- ing the Universe apart. Each of these three predictions seemed so fantastic when it was made that everyone, including Einstein himself, regarded them as unlikely. Incredibly, all three have turned out to be true. Yet Einstein's legacy is one of deep mystery, because his theories are silent on three questions raised by his fantastic predictions: (1) What powered the Big Bang? (2) What happens to space, time, and matter at the edge of a black hole? (3) What is the mysterious dark energy pulling the Universe apart? The answers to these questions-which lie at the crux of where our current theories fail us-will lead to a profound, new understanding of the nature of time and space. To find answers, however, we must venture beyond Einstein. The answers require new theories, such as the inflationary Universe and new insights in high-energy particle theory. Like Einstein s theories, these make fantastic predictions that seem hard to believe: unseen dimensions and entire universes beyond our own. We must find facts to confront and guide these new theories. Powerful new technologies now make this possible. And NASA and its partners are developing an armada of space-based observatories to chart the path to discovery. Here is where the Beyond Einstein story begins. By exploring the three questions that are Einstein s legacy, we begin the next revolution in understanding our Universe. We plot our way

  9. Classical propagation of strings across a big crunch/big bang singularity

    Science.gov (United States)

    Niz, Gustavo; Turok, Neil

    2007-01-01

    One of the simplest time-dependent solutions of M theory consists of nine-dimensional Euclidean space times 1+1-dimensional compactified Milne space-time. With a further modding out by Z2, the space-time represents two orbifold planes which collide and re-emerge, a process proposed as an explanation of the hot big bang [J. Khoury, B. A. Ovrut, P. J. Steinhardt, and N. Turok, Phys. Rev. D 64, 123522 (2001).PRVDAQ0556-282110.1103/PhysRevD.64.123522][P. J. Steinhardt and N. Turok, Science 296, 1436 (2002).SCIEAS0036-807510.1126/science.1070462][N. Turok, M. Perry, and P. J. Steinhardt, Phys. Rev. D 70, 106004 (2004).PRVDAQ0556-282110.1103/PhysRevD.70.106004]. When the two planes are near, the light states of the theory consist of winding M2-branes, describing fundamental strings in a particular ten-dimensional background. They suffer no blue-shift as the M theory dimension collapses, and their equations of motion are regular across the transition from big crunch to big bang. In this paper, we study the classical evolution of fundamental strings across the singularity in some detail. We also develop a simple semiclassical approximation to the quantum evolution which allows one to compute the quantum production of excitations on the string and implement it in a simplified example.

  10. Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

    Directory of Open Access Journals (Sweden)

    Masahiro Kawasaki

    2015-12-01

    Full Text Available We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons emitted by the annihilation of dark matter and the interconversion reactions of neutron and proton at inelastic scatterings of energetic nucleons. Comparing the theoretical prediction of the primordial light-element abundances with the latest observational constraints, we derive upper bounds on the dark-matter pair-annihilation cross section. Implication to some of particle-physics models are also discussed.

  11. Quantum origin of pre-big bang collapse from Induced Matter theory of gravity

    OpenAIRE

    Bellini, Mauricio

    2011-01-01

    We revisit a collapsing pre-big-bang model of the universe to study with detail the non-perturbative quantum dynamics of the dispersal scalar field whose dynamics becomes from the dynamical foliation of test massless scalar field $\\phi$ on a 5D Riemann-flat metric, such that the extra space-like coordinate is noncompact. The important result here obtained is that the evolution of the system, which is described thorough the equation of state has the unique origin in the quantum contributions o...

  12. Gamma rays and the case for baryon symmetric big-bang cosmology

    Science.gov (United States)

    Stecker, F. W.

    1977-01-01

    The baryon symmetric big-bang cosmologies offer an explanation of the present photon-baryon ratio in the universe, the best present explanation of the diffuse gamma-ray background spectrum in the 1 to 200 MeV range, and a mechanism for galaxy formation. In the context of an open universe model, the value of omega which best fits the present gamma-ray data is omega equals approx. 0.1 which does not conflict with upper limits on Comptonization distortion of the 3K background radiation. In regard to He production, evidence is discussed that nucleosynthesis of He may have taken place after the galaxies were formed.

  13. Gravitationally induced adiabatic particle production: from big bang to de Sitter

    Science.gov (United States)

    de Haro, Jaume; Pan, Supriya

    2016-08-01

    In the background of a flat homogeneous and isotropic space–time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology.

  14. The Theological Basis of Big Bang Cosmology and the Failure of General Relativity

    Science.gov (United States)

    Crothers, Stephen J.

    2013-09-01

    It is shown in this paper that the Big Bang Cosmology has its basis in theology, not in science, that it pertains to a Universe entirely filled by a single spherically symmetric continuous indivisible homogeneous body and therefore models nothing, that it violates the physical principles of General Relativity, that it violates the conservation of energy, and that General Relativity itself violates the usual conservation of energy and momentum and is therefore in conflict with experiment on a deep level, rendering Einstein's conception of the physical Universe and the gravitational field invalid.

  15. Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

    Science.gov (United States)

    Kawasaki, Masahiro; Kohri, Kazunori; Moroi, Takeo; Takaesu, Yoshitaro

    2015-12-01

    We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons emitted by the annihilation of dark matter and the interconversion reactions of neutron and proton at inelastic scatterings of energetic nucleons. Comparing the theoretical prediction of the primordial light-element abundances with the latest observational constraints, we derive upper bounds on the dark-matter pair-annihilation cross section. Implication to some of particle-physics models are also discussed.

  16. Lithium-6 Evolution from Big Bang to Present

    CERN Document Server

    Vangioni-Flam, E; Cayrel, R; Audouze, Jean; Spite, M; Spite, F; Vangioni-Flam, Elisabeth; Casse, Michel; Cayrel, Roger; Audouze, Jean; Spite, Monique; Spite, Francois

    1998-01-01

    The primordial abundances of Deuterium, he4, and li7 are crucial to determination of the baryon density of the Universe in the framework of standard Big Bang nucleosynthesis (BBN). li6 which is only produced in tiny quantities and it is generally not considered to be a cosmological probe. However, recent major observational advances have produced an estimate of the li6/li7 ratio in a few very old stars in the galactic halo which impacts the question whether or not the lithium isotopes are depleted in the outer layers of halo stars, through proton induced reactions at the base of (or below) the convective zone. li6 is a pure product of spallation through the major production reactions, fast oxygen and alphas interacting on interstellar H, He (especially in the early Galaxy). The rapid nuclei are both synthesized and accelerated by SN II. In this context, the \\li6 evolution should go in step with that of beryllium and boron, recently observed by the Keck and HST telescopes. Li6 adds a new constraint on the earl...

  17. Classical Propagation of Strings across a Big Crunch/Big Bang Singularity

    OpenAIRE

    Niz, Gustavo(Departamento de Física, Universidad de Guanajuato, DCI, Campus León, C.P. 37150, León, Guanajuato, México); Turok, Neil

    2006-01-01

    One of the simplest time-dependent solutions of M theory consists of nine-dimensional Euclidean space times 1+1-dimensional compactified Milne space-time. With a further modding out by Z_2, the space-time represents two orbifold planes which collide and re-emerge, a process proposed as an explanation of the hot big bang. When the two planes are near, the light states of the theory consist of winding M2-branes, describing fundamental strings in a particular ten-dimensional background. They suf...

  18. Neutrino energy transport in weak decoupling and big bang nucleosynthesis

    Science.gov (United States)

    Grohs, E.; Fuller, G. M.; Kishimoto, C. T.; Paris, M. W.; Vlasenko, A.

    2016-04-01

    We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multienergy group Boltzmann neutrino energy transport scheme. The modular structure of our code provides the ability to dissect the relative contributions of each process responsible for evolving the dynamics of the early universe in the absence of neutrino flavor oscillations. Such an approach allows a detailed accounting of the evolution of the νe, ν¯e, νμ, ν¯μ, ντ, ν¯τ energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. This calculation reveals nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions (e.g., electron-positron pair densities), with implications for the phasing between scale factor and plasma temperature; the neutron-to-proton ratio; light-element abundance histories; and the cosmological parameter Neff. We find that our approach of following the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma results in changes in the computed value of the BBN deuterium yield. For example, for particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium. These changes are potentially significant in the context of anticipated improvements in observational and nuclear physics uncertainties.

  19. Molecular evolution of colorectal cancer: from multistep carcinogenesis to the big bang.

    Science.gov (United States)

    Amaro, Adriana; Chiara, Silvana; Pfeffer, Ulrich

    2016-03-01

    Colorectal cancer is characterized by exquisite genomic instability either in the form of microsatellite instability or chromosomal instability. Microsatellite instability is the result of mutation of mismatch repair genes or their silencing through promoter methylation as a consequence of the CpG island methylator phenotype. The molecular causes of chromosomal instability are less well characterized. Genomic instability and field cancerization lead to a high degree of intratumoral heterogeneity and determine the formation of cancer stem cells and epithelial-mesenchymal transition mediated by the TGF-β and APC pathways. Recent analyses using integrated genomics reveal different phases of colorectal cancer evolution. An initial phase of genomic instability that yields many clones with different mutations (big bang) is followed by an important, previously not detected phase of cancer evolution that consists in the stabilization of several clones and a relatively flat outgrowth. The big bang model can best explain the coexistence of several stable clones and is compatible with the fact that the analysis of the bulk of the primary tumor yields prognostic information. PMID:26947218

  20. Review of Big Bang Nucleosynthesis and Primordial Abundances

    Science.gov (United States)

    Tytler, David; O'Meara, John M.; Suzuki, Nao; Lubin, Dan

    2001-03-01

    Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium (D or 2H), 3He, 4He and 7Li during the first few minutes of the universe. This review concentrates on recent improvements in the measurement of the primordial (after BBN, and prior to modification) abundances of these nuclei. We mention improvement in the standard theory, and the non-standard extensions which are limited by the data. We have achieved an order of magnitude improvement in the precision of the measurement of primordial D/H, using the HIRES spectrograph on the W. M. Keck telescope to measure D in gas with very nearly primordial abundances towards quasars. From 1994 - 1996, it appeared that there could be a factor of ten range in primordial D/H, but today four examples of low D are secure. High D/H should be much easier to detect, and since there are no convincing examples, it must be extremely rare or non-existent. All data are consistent with a single low value for D/H, and the examples which are consistent with high D/H are readily interpreted as H contamination near the position of D. The new D/H measurements give the most accurate value for the baryon to photon ratio, η, and hence the cosmological baryon density. A similar density is required to explain the amount of Lyα absorption from neutral Hydrogen in the intergalactic medium (IGM) at redshift z ≃ 3, and to explain the fraction of baryons in local clusters of galaxies. The D/H measurements lead to predictions for the abundances of the other light nuclei, which generally agree with measurements. The remaining differences with some measurements can be explained by a combination of measurement and analysis errors or changes in the abundances after BBN. The measurements do not require physics beyond the standard BBN model. Instead, the agreement between the abundances is used to limit the non-standard physics. New measurements are giving improved understanding of the difficulties in estimating the abundances of all

  1. From Big Crunch to Big Bang with AdS/CFT

    CERN Document Server

    Turok, Neil; Hertog, Thomas

    2007-01-01

    The AdS/CFT correspondence is used to describe a five-dimensional cosmology with a big crunch singularity in terms of a super-Yang-Mills theory on $\\Rbar\\times S^3$ deformed by a potential which is unbounded below. Classically, a Higgs field in the dual theory rolls to infinity in finite time. But since the $S^3$ is finite, the unstable mode spreads quantum mechanically and the singularity is resolved when self-adjoint boundary conditions are imposed at infinity. Asymptotic freedom of the coupling governing the instability gives us computational control and the quantum spreading provides a UV cutoff on particle creation. The bulk translation of our result is a quantum transition from a big crunch to a big bang. An intriguing consequence of the near scale-invariance of the dual theory is that a nearly scale-invariant spectrum of stress-energy perturbations is automatically generated in the boundary theory. We comment on implications for more realistic cosmologies.

  2. No ``explosion'' in Big Bang cosmology: teaching kids the truth of what cosmologists really know

    Science.gov (United States)

    Gangui, Alejandro

    2011-06-01

    Common wisdom says that cosmologists are smart: they have developed a theory that can explain the ``origin of the universe''. Every time an astro-related, heavily funded ``big-science'' project comes to the media, naturally the question arises: will science -through this or that experiment- explain the origin of the cosmos? Can this be done with the LHC, for example? Will this dream machine create other universes? Of course, the very words we employ in cosmology reinforce this misconception: so Big Bang must be associated with an ``explosion'', even if a ``peculiar'' one, as it took place nowhere (there was presumably no space before the beginning) and happened virtually in no time (supposedly, space-time was created on this peculiar -singular- event). Right, the issue sounds confusing. Let us imagine what kids may get out of all this. We have recently presented a series of brief astronomy and cosmology books aimed at helping both kids and their teachers in these and other arcane subjects, all introduced with carefully chosen words and images that young children can understand. In particular, Volume Four deals with the Big Bang and emphasizes the notion of ``evolution'' as opposed to the -wrong- notion of ``origin'' behind the scientific model. We then explain some of the pillars of Big Bang cosmology: the expansion of space that drags away distant galaxies, as seen in the redshift of their emitted light; the build-up of light elements in a cooling bath of radiation, as explained by primordial nucleosynthesis; and the existence and main features of the ubiquitous cosmic microwave background radiation, where theory and observations agree to a highly satisfactory degree. Of course, one cannot attempt to answer the ``origins'' question when it is well known that all theories so far break down close to this origin (if there was actually an origin). It is through observations, analyses, lively discussions and recognition of the basic limitations of current theories and

  3. From big bang to bing bang - From the origin of the universe to the origin of the solar system

    Science.gov (United States)

    Lee, L.

    An outline is given of the evolution of the Galaxy between the Big Bang and the Bing Bang (explosions of supernovae billions of years ago, providing materials and possibly the impetus for the formation of the solar system). During the long interval prior to the birth of the sun, the Galaxy evolved by converting gas to stars and by enriching the gas with heavy elements created in the stars. Some radioactive nuclides suggest that the interval between their production in stellar sources and the accumulation of planets of at least a few kilometers in size was only a few million years. The formation of the sun may have taken place in a stellar association and may have been preceded immediately by SN-type explosions, which may even have been the triggering mechanism of the formation process.

  4. El concepto de big bang como inicio del proceso creativo del dibujo

    Directory of Open Access Journals (Sweden)

    Manuel Bru Serrano

    2015-01-01

    Full Text Available Este artículo establece un paralelismo entre la teoría del big bang y el comienzo de elaboración de un dibujo. Pretende sintetizar una serie de planteamientos de artistas, teóricos del arte y los experimentados a través del dibujo gracias a una propuesta artística personal. Unos trabajos, expuestos como un ejemplo de proceso creativo basado en el big bang, que muestran cómo los nuevos parámetros del dibujo contemporáneo ofrecen al artista numerosas posibilidades para enfocar la investigación artística.

  5. On Subtitle Translation of Sitcoms-A Case Study of The Big Bang Theory

    Institute of Scientific and Technical Information of China (English)

    杨雯婷

    2013-01-01

    As we all know that exquisite subtitle translation of foreign film and television series is the fatal elements for them to spread among Chinese audiences. This article is based on Eugene·Nida’s“the Functional Equivalence”principle with three char⁃acteristics of sitcoms’subtitle to study the type, form and features of the Big Bang Theory, which lead to the conclusion of sitcom subtitle’s characteristics. It helps us to analyze its subtitle from six aspects. As the result, the author of the paper makes the conclu⁃sion of translation tactic about Big Bang Theory, which could help the subtitle translation of similar sitcoms.

  6. An Analysis of Verbal Humor in American Sitcom The Big Bang Theory

    Institute of Scientific and Technical Information of China (English)

    吴珍; 芮艳芳

    2015-01-01

    Humor plays an indispensable part in human communication. This thesis is a tentative analysis of verbal humor under-standing within the framework of Relevance Theory. This paper, using The Big Bang Theory as a corpus, analyzes the humor gener-ated in the cognitive process of searching for relevance. According to the Relevance Theory, the understanding of humor is a pro-cess in which the hearer finds"relevance"in what seems"irrelevant". The author hopes that this analysis can help more people un-derstand and appreciate the humor in The Big Bang Theory. And meanwhile their personal sense of humor can also be improved.

  7. Inhomogeneous Big Bang Nucleosynthesis and the High Baryon Density Suggested by Boomerang and MAXIMA

    OpenAIRE

    Kurki-Suonio, Hannu; Sihvola, Elina

    2000-01-01

    The recent Boomerang and MAXIMA data on the cosmic microwave background suggest a large value for the baryonic matter density of the universe, omega_b = 0.03. This density is larger than allowed by standard big bang nucleosynthesis theory and observations on the abundances of the light elements. We explore here the possibility of accommodating this high density in inhomogeneous big bang nucleosynthesis (IBBN). It turns out that in IBBN the observed D and Y_p values are quite consistent with t...

  8. The Big Bang and the Search for a Theory of Everything

    Science.gov (United States)

    Kogut, Alan

    2010-01-01

    How did the universe begin? Is the gravitational physics that governs the shape and evolution of the cosmos connected in a fundamental way to the sub-atomic physics of particle colliders? Light from the Big Bang still permeates the universe and carries within it faint clues to the physics at the start of space and time. I will describe how current and planned measurements of the cosmic microwave background will observe the Big Bang to provide new insight into a "Theory of Everything" uniting the physics of the very large with the physics of the very small.

  9. Pre-Big Bang, space-time structure, asymptotic Universe

    Directory of Open Access Journals (Sweden)

    Gonzalez-Mestres Luis

    2014-04-01

    Full Text Available Planck and other recent data in Cosmology and Particle Physics can open the way to controversial analyses concerning the early Universe and its possible ultimate origin. Alternatives to standard cosmology include pre-Big Bang approaches, new space-time geometries and new ultimate constituents of matter. Basic issues related to a possible new cosmology along these lines clearly deserve further exploration. The Planck collaboration reports an age of the Universe t close to 13.8 Gyr and a present ratio H between relative speeds and distances at cosmic scale around 67.3 km/s/Mpc. The product of these two measured quantities is then slightly below 1 (about 0.95, while it can be exactly 1 in the absence of matter and cosmological constant in patterns based on the spinorial space-time we have considered in previous papers. In this description of space-time we first suggested in 1996-97, the cosmic time t is given by the modulus of a SU(2 spinor and the Lundmark-Lemaître-Hubble (LLH expansion law turns out to be of purely geometric origin previous to any introduction of standard matter and relativity. Such a fundamental geometry, inspired by the role of half-integer spin in Particle Physics, may reflect an equilibrium between the dynamics of the ultimate constituents of matter and the deep structure of space and time. Taking into account the observed cosmic acceleration, the present situation suggests that the value of 1 can be a natural asymptotic limit for the product H t in the long-term evolution of our Universe up to possible small corrections. In the presence of a spinorial space-time geometry, no ad hoc combination of dark matter and dark energy would in any case be needed to get an acceptable value of H and an evolution of the Universe compatible with observation. The use of a spinorial space-time naturally leads to unconventional properties for the space curvature term in Friedmann-like equations. It therefore suggests a major modification of

  10. Low-lying resonances and relativistic screening in Big Bang nucleosynthesis

    Science.gov (United States)

    Famiano, M. A.; Balantekin, A. B.; Kajino, T.

    2016-04-01

    We explore effects of the screening due to the relativistic electron-positron plasma and presence of resonances in the secondary reactions leading to A =7 nuclei during the Big Bang nucleosynthesis. In particular, we investigate and examine possible low-lying resonances in the 7Be (3He,γ ) 10C reaction and examine the resultant destruction of 7Be for various resonance locations and strengths. While a resonance in the 10C compound nucleus is thought to have negligible effects we explore the possibility of an enhancement from plasma screening that may adjust the final 7Be abundance. We find the effects of relativistic screening and possible low-lying resonances to be relatively small in the standard Early Universe models.

  11. Sneutrino condensate as a candidate for the hot big bang cosmology

    International Nuclear Information System (INIS)

    If the inflationary paradigm is correct, then it must create conditions for the hot big bang model with all observed matter, baryons, and the seed perturbations for structure formation. In this paper we propose a scenario where the inflaton energy density is dumped into the bulk in a brane world setup, and all the required physical conditions are created by the right-handed neutrino sector within supersymmetry. The scalar component of the right-handed Majorana neutrino is responsible for generating the scale invariant fluctuations in the cosmic microwave background radiation, reheating the Universe at a temperature Trh≤109 GeV and finally generating the lepton/baryon asymmetry nB/s∼10-10 with no lepton/baryon-isocurvature fluctuations

  12. Low-lying Resonances and Relativistic Screening in Big Bang Nucleosynthesis

    CERN Document Server

    Famiano, Michael A; Kajino, Toshitaka

    2016-01-01

    We explore effects of the screening due to the relativistic electron-positron plasma and presence of resonances in the secondary reactions leading to A=7 nuclei during the Big Bang Nucleosynthesis. In particular, we investigate and examine possible low-lying resonances in the 7Be(3He, g)10C reaction and examine the resultant destruction of 7Be for various resonance locations and strengths. While a resonance in the 10C compound nucleus is thought to have negligible effects we explore the possibility of an enhancement from plasma screening that may adjust the final 7Be abundance. We find the effects of relativistic screening and possible low-lying resonances to be relatively small in the standard Early Universe models.

  13. The Archaic Universe: Big Bang, Cosmological Term and the Quantum Origin of Time in Projective Cosmology

    OpenAIRE

    Licata, Ignazio; Chiatti, Leonardo

    2008-01-01

    This article proposes some cosmological reflections at the qualitative and conjectural level, suggested by the Fantappie & Arcidiacono projective relativity theory. The difference will firstly be discussed between two types of singularity in this theory: geometric (de Sitter horizon) and physical (big bang, big crunch). The reasons for the existence of geometric singularities are deeply rooted in the principle of inertia and in the principle of relativity, while physical singularities are ass...

  14. Initial conditions and the structure of the singularity in pre-big-bang cosmology

    NARCIS (Netherlands)

    A. Feinstein; K.E. Kunze; M.A. Vazquez-Mozo

    2000-01-01

    We propose a picture, within the pre-big-bang approach, in which the universe emerges from a bath of plane gravitational and dilatonic waves. The waves interact gravitationally breaking the exact plane symmetry and lead generically to gravitational collapse resulting in a singularity with the Kasner

  15. Phenomenological Aspects of the Pre-Big-Bang Scenario in String Cosmology

    OpenAIRE

    Gasperini, M.

    1994-01-01

    I review various aspects of the pre-big-bang scenario and of its main open problems, with emphasis on the role played by the dilaton. Since the dilaton is a compelling consequence of string theory, tests of this scenario are direct tests of string theory and also, more generally, of Planck scale physics.

  16. Big Bang Nucleosynthesis in the presence of sterile neutrinos with altered dispersion relations

    CERN Document Server

    Aeikens, Elke; Pakvasa, Sandip; Weiler, Thomas J

    2016-01-01

    Big Bang Nucleosynthesis imposes stringent bounds on light sterile neutrinos mixing with the active flavors. Here we discuss how altered dispersion relations can weaken such bounds and allow compatibility of new sterile neutrino degrees of freedom with a successful generation of the light elements in the early Universe.

  17. In search of the big bang the life and the death of the universe

    CERN Document Server

    Gribbin, John

    1998-01-01

    Where do we come from? How did the universe of stars, planets and people come into existence? Now revised and expanded, this second edition takes into account developments in cosmology and quantum physics since its first publication in 1986, and traces the historical path which has led physicists to an understanding of the big bang, the fireball in which our universe was born.

  18. From the Big Bang to the Nobel Prize and on to James Webb Space Telescope

    Science.gov (United States)

    Mather, John C.

    2009-01-01

    The history of the universe in a nutshell, from the Big Bang to now, and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA s Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein s biggest mistake, show how Edwin Hubble discovered the expansion of the universe, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA s plans for the next great telescope in space, the James Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where stars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  19. From the Big Bang to the Nobel Prize and on to the James Webb Space Telescope

    Science.gov (United States)

    Mather, John C.

    2008-01-01

    The history of the universe in a nutshell, from the Big Bang to now. and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA's Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein's biggest mistake, show how Edwin Hubble discovered the expansion of the univerre, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA's plans for the next great telescope in space, the Jarnes Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where rtars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  20. After the Big Bang: What's Next in Design Education? Time to Relax?

    Science.gov (United States)

    Fleischmann, Katja

    2015-01-01

    The article "Big Bang technology: What's next in design education, radical innovation or incremental change?" (Fleischmann, 2013) appeared in the "Journal of Learning Design" Volume 6, Issue 3 in 2013. Two years on, Associate Professor Fleischmann reflects upon her original article within this article. Although it has only been…

  1. From the big bang to the eureka moment

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, Peter

    2002-02-01

    A Brief History of Time made Stephen Hawking famous, but he was already a world leader in cosmology. Peter Rodgers reports from the celebrations to mark Hawking's 60th birthday. Masters of the universe Stephen Hawking is the most famous physicist in the world. Indeed, the sales of Hawking's books and his appearances on The Simpsons and Star Trek have tended to overshadow his scientific achievements. But that was not the case in Cambridge last month when Hawking's contributions to physics and cosmology were celebrated at a week-long conference to mark his 60th birthday. 'We organized the meeting to look back on the immense contribution that Stephen has made to many areas of gravitational physics and cosmology,' said Gary Gibbons, one of Hawking's colleagues at Cambridge. 'We also wanted to look forward to what the future might hold for theoretical physics and cosmology, with special reference to the areas that Stephen has been most interested and most active in.' Hawking made his name with a series of papers in the 1960s on singularities in cosmology. Building on work by Roger Penrose, he showed that Einstein's general theory of relativity implied that space and time would have a beginning in the big bang and would end in a singularity. 'How unlike particle physics, where people were falling over themselves to latch onto the latest idea. They still are.' Hawking then switched his attention to black holes - regions of space where gravity is so strong that nothing can escape. He was also one of the first physicists to make progress in combining general relativity - the classical theory of gravity - and quantum mechanics. First he showed that when two black holes collide and merge, the area of the 'event horizon' around the resulting black hole is greater than the sum of the two original areas. This led Hawking and co-workers to link the area of the event horizon, A, with the entropy of a black hole, S

  2. Interview de l'astrophysicien Trinh Xuan Thuan: du Big Bang à la naissance de la vie

    CERN Multimedia

    Lorens, Sachat

    2006-01-01

    Born in Hanoi, the astrophysicist is Professor of astronomy at Virginia University, and wrote many books of scientific popularization. His last book "Origines" makes the family treee of the world, from the Big Bang to the birth of alive beings

  3. After the Big Bang? Obstacles to the emergence of the rule of law in post-communist societies

    OpenAIRE

    Hoff, Karla; STIGLITZ, Joseph E.

    2002-01-01

    With the collapse of communism in Eastern Europe and the Soviet Union in 1989-91, many economic reformers supported "Big Bang" privatization-the rapid transfer of state-owned enterprises to private individuals. It was hoped that Big Bang privatization would create the conditions for a demand-led evolution of legal institutions. But there was no theory to explain how this process of institu...

  4. Time, space, stars and man the story of the Big Bang

    CERN Document Server

    Woolfson, Michael M

    2013-01-01

    The three greatest scientific mysteries, which remain poorly understood, are the origin of the universe, the origin of life and the development of consciousness. This book describes the processes preceding the Big Bang, the creation of matter, the concentration of that matter into stars and planets, the development of simple life forms and the theory of evolution that has given higher life forms, including mankind. Readership: Members of the general public who have an interest in popular science. There are many popular and excellent science books that present various aspects of science. However, this book follows a narrow scientific pathway from the Big Bang to mankind, and depicts the causal relationship between each step and the next. The science covered will be enough to satisfy most readers. Many important areas of science are dealt with, and these include cosmology, particle physics, atomic physics, galaxy and star formation, planet formation and aspects of evolution. The necessary science is described i...

  5. Effects of variation of fundamental constants from Big Bang to atomic clocks

    Science.gov (United States)

    Flambaum, Victor

    2004-05-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental "constants" in expanding Universe. I discuss effects of variation of the fine structure constant, strong interaction, quark mass and gravitational constant. The measurements of these variations cover the lifespan of the Universe from few minutes after Big Bang to the present time and give controversial results. There are some hints for the variations in Big Bang nucleosynthesis, quasar absorption spectra and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. A billion times enhancement of the variation effects happens in transitions between accidentally degenerate atomic energy levels.

  6. Gigantic particle collision machine does "mini Big Bangs"

    CERN Multimedia

    2007-01-01

    "The world's largest machine is reputed to be the Large Hadron Collider (LHC) at CERN in Geneva and everything about it is big. Designed to carry out high energy particle collisions, when completed next year, one of the collider's experiments includes a 10'000 ton detector." (1/2 page)

  7. Analysis of Humor in The Big Bang Theory Based on the Conversational Relevance

    Institute of Scientific and Technical Information of China (English)

    XU Yang

    2014-01-01

    Humor is the life buoy in waves of life. Pragmatics and humor are closely linked. Relevance is one of the important topics of Pragmatics. This paper takes the lines from The Big Bang Theory as a case study and analyzes the humorous effect from the perspective of Principle of Relevance and Conversational Relevance, hoping to help people deepen the appreciation and un⁃derstanding of humor.

  8. Compilation and R-matrix analysis of Big Bang nuclear reaction rates

    OpenAIRE

    Descouvemont, Pierre; Adahchour, Abderrahim; Angulo, Carmen; Coc, Alain; Vangioni-Flam, Elisabeth

    2004-01-01

    We use the R-matrix theory to fit low-energy data on nuclear reactions involved in Big Bang nucleosynthesis. A special attention is paid to the rate uncertainties which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats. Comment: 40 pages, accepted for publication at ADNDT, web site at http://pntpm3.ulb.ac.be/bigbang

  9. The 'Big Bang' theory reconsidered: Some thoughts on the fabric of early Ghanaian history

    OpenAIRE

    Chouin, Gérard

    2012-01-01

    Paper presented at the 50th Anniversary Conference, Centre of African Studies, University of Edinburgh, 6-8 June 2012; Panel on 'Recent Research in the Early Modern History of Atlantic Africa' The 'big bang' theory - best articulated by Ivor Wilks in the late 1970s and recently revisited - is a complex heuristic monument that must be carefully deconstructed. Its claim that before the integration of forested West Africa into the European bullion market and the opening of the Atlantic trade,...

  10. The Cold Big-Bang Cosmology as a Counter-example to Several Anthropic Arguments

    OpenAIRE

    Aguirre, Anthony

    2001-01-01

    A general Friedmann big-bang cosmology can be specified by fixing a half-dozen cosmological parameters such as the photon-to-baryon ratio Eta, the cosmological constant Lambda, the curvature scale R, and the amplitude Q of (assumed scale-invariant) primordial density fluctuations. There is currently no established theory as to why these parameters take the particular values we deduce from observations. This has led to proposed `anthropic' explanations for the observed value of each parameter,...

  11. Le big bang n'est pas une théorie comme les autres

    CERN Document Server

    Bonnet-Bidaud, Jean-Marc; Leglu, Dominique; Reinisch, Gilbert

    2009-01-01

    Le big bang n'est pas une théorie comme les autres. Ce n'est d'ailleurs pas une théorie physique au sens propre du terme, mais un scénario cosmologique issu des équations de la relativité générale. Il est le modèle qui s'ajuste le mieux aux observations actuelles, mais à quel prix ? Il nous livre un Univers composé à 96 % de matière et d'énergie noires inconnues. C'est donc un euphémisme que de dire que le big bang semble poser autant - sinon plus - de questions qu'il n'en résout. En ce sens, le big bang apparaît davantage comme une paramétrisation de notre ignorance plutôt que comme une modélisation d'un phénomène. Pourtant, le succès du big bang et l'adhésion qu'il suscite, tant dans la sphère scientifique que dans la sphère médiatique, ne se démentent pas. Surmédiatisé, son statut dépasse celui de modèle théorique, et la simple évocation de son nom suffit pour justifier des opérations de marketing scientifique ou rejeter des cosmologies alternatives. Pour éclaircir les pr...

  12. Calixarenes and cations: a time-lapse photography of the big-bang.

    Science.gov (United States)

    Casnati, Alessandro

    2013-08-01

    The outstanding cation complexation properties emerging from the pioneering studies on calixarene ligands during a five-year period in the early 1980s triggered a big-bang burst of publications on such macrocycles that is still lasting at a distance of more than 30 years. A time-lapse photography of this timeframe is proposed which allows the readers to pinpoint the contributions of the different research groups. PMID:23792898

  13. Gamma-rays and the case for baryon symmetric big-bang cosmology

    Science.gov (United States)

    Stecker, F. W.

    1977-01-01

    The baryon symmetric big-bang cosmologies offer an explanation of the present photon-baryon ratio in the universe, the best present explanation of the diffuse gamma-ray background spectrum in the 1-200 MeV range, and a mechanism for galaxy formation. In regard to He production, evidence is discussed that nucleosynthesis of He may have taken place after the galaxies were formed.

  14. Physics and the Making of ``The Big Bang'' TV Comedy Series

    Science.gov (United States)

    Saltzberg, David

    2010-03-01

    For the last three years I have served as the physics consultant for the popular television situation-comedy ``The Big Bang Theory'' which features physicists, astronomers, and engineers as its main characters. I will describe my role in the production. I will also describe the opportunities it has afforded for public outreach for physics and astronomy education. Based on my experience, I will discuss methods for interested scientists to get involved in the entertainment industry.

  15. The moment of creation big bang physics from before the first millisecond to the present universe

    CERN Document Server

    Trefil, James S

    2004-01-01

    ""Trefil surpasses almost all other scientists writing about science"" "- The New York Times""Fascinating reading. A mind-stretching book."" - John Barkham ReviewsCompelling and lucid, this reader-friendly narrative travels billions of years back in time to depict the events that culminated in the Big Bang: the colossal explosion that initiated the existence of the universe. James Trefil is one of the founders of modern quark theory, and he specializes in explaining complex scientific matters to nonspecialists.

  16. The Passport to the Big Bang: a trail of discovery of CERN and its sites

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Sunday 2 June 2013 will see the launch of CERN’s Passport to the Big Bang, a scientific tourist trail linking ten of the Laboratory’s sites in the Pays de Gex and the Canton of Geneva. CERN is organising a public event to celebrate the launch and needs lots of volunteers – you could be one of them!   The exhibition platform in Sergy, in front of the ALICE experiment. Does your grocer insist that the Pays de Gex is going to be swallowed up by a black hole made by the LHC? Do your neighbours ask you questions about the CERN site visible from your houses, leaving you stumped when you don’t have the answers?  Well then, take them on an accelerator tour – but above ground and with no need for access cards! How? By taking advantage of the Passport to the Big Bang, a cross-border scientific tourist trail that will be inaugurated on 2 June. The goal of the Passport to the Big Bang is provide the local population wi...

  17. Big Bang Bifurcation Analysis and Allee Effect in Generic Growth Functions

    Science.gov (United States)

    Leonel Rocha, J.; Taha, Abdel-Kaddous; Fournier-Prunaret, D.

    2016-06-01

    The main purpose of this work is to study the dynamics and bifurcation properties of generic growth functions, which are defined by the population size functions of the generic growth equation. This family of unimodal maps naturally incorporates a principal focus of ecological and biological research: the Allee effect. The analysis of this kind of extinction phenomenon allows to identify a class of Allee’s functions and characterize the corresponding Allee’s effect region and Allee’s bifurcation curve. The bifurcation analysis is founded on the performance of fold and flip bifurcations. The dynamical behavior is rich with abundant complex bifurcation structures, the big bang bifurcations of the so-called “box-within-a-box” fractal type being the most outstanding. Moreover, these bifurcation cascades converge to different big bang bifurcation curves with distinct kinds of boxes, where for the corresponding parameter values several attractors are associated. To the best of our knowledge, these results represent an original contribution to clarify the big bang bifurcation analysis of continuous 1D maps.

  18. Inflation and initial conditions in the pre-big bang scenario

    CERN Document Server

    Gasperini, M

    2000-01-01

    The pre-big bang scenario describes the evolution of the Universe from an initial state approaching the flat, cold, empty, string perturbative vacuum. The choice of such an initial state is suggested by the present state of our Universe if we accept that the cosmological evolution is (at least partially) duality-symmetric. Recently, the initial conditions of the pre-big bang scenario have been criticized as they introduce large dimensionless parameters allowing the Universe to be "exponentially large from the very beginning". We agree that a set of initial parameters (such as the initial homogeneity scale, the initial entropy) different from those determined by the initial horizon scale, $H^{-1}$, would be somewhat unnatural to start with. However, in the pre-big bang scenario, the initial parameters are all controlled by the size of the initial horizon. The basic question thus becomes: is the initial state necessarily unnatural if the curvature scale is small and, consequently, $H^{-1}$ is very large in Plan...

  19. 总星系局爆宇宙理论%Theory of Local Big Bang of Metagalaxy on Universe

    Institute of Scientific and Technical Information of China (English)

    殷业; 胡素辉

    2013-01-01

    大爆炸宇宙理论是一个非常成功的宇宙理论,它在经过古斯等人提出的暴涨理论修正后日趋完善。但即使这样也还存在几个难题无法解决:(1)欧洲普朗克望远镜揭示的宇宙背景辐射的不对称性;(2)宇宙中所有物质来源于大爆炸没有实验依据;(3)存在暴涨中宇宙膨胀的超光速问题。为了解释上述难题,本文提出了一种建立在大爆炸宇宙理论基础上的多宇宙模型:总星系局爆宇宙模型。该模型可以很好地解决上述难题,文中提出了检验理论模型新的实验方法,通过实验可以最终确认真实的宇宙到底更符合哪个模型。%Big Bang Theory is a very successful theory of the Universe, which is maturing after being cor-rected by Alan Guth proposed inflation theory. But even so, there are several problems can’t be solved:(a) European Planck telescope reveals the cosmic background radiation asymmetry; (b) Big Bang created all matter in the Universe there isn’t experimental evidence; (c) superluminal in inflation theory is contra-diction with relativistic invariance of light speed assumption. In order to explain these problems, this pa-per presents a new model of the Universe based on the Big Bang Theory: Model of Local Big Bang of Metagalaxy. The model can be a good solution to these problems, it is also proposed an experimental methods of tested theoretical model, the experiment can finally confirm which model is more in line with the real Universe in the end.

  20. On the relation between boundary proposals and hidden symmetries of the extended pre-big bang quantum cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Jalalzadeh, S.; Rostami, T. [Shahid Beheshti University, Department of Physics, Tehran (Iran, Islamic Republic of); Moniz, P.V. [Centro de Matematica e Aplicacoes-UBI, Covilha (Portugal); Universidade da Beira Interior, Departamento de Fisica, Covilha (Portugal)

    2015-01-01

    A framework associating quantum cosmological boundary conditions to minisuperspace hidden symmetries has been introduced in Jalalzadeh and Moniz (Phys Rev D 89:083504, 2014). The scope of the application was, notwithstanding the novelty, restrictive because it lacked a discussion involving realistic matter fields. Therefore, in the present letter, we extend the framework scope to encompass elements from a scalar-tensor theory in the presence of a cosmological constant. More precisely, it is shown that hidden minisuperspace symmetries present in a pre-big bang model suggest a process from which boundary conditions can be selected. (orig.)

  1. An Accurate Calculation of the Big-Bang Prediction for the Abundance of Primordial Helium

    CERN Document Server

    López, R E; Lopez, Robert E.; Turner, Michael S.

    1999-01-01

    Within the standard model of particle physics and cosmology we have calculated the big-bang prediction for the primordial abundance of Helium to a theoretical uncertainty of $0.1 \\pct$ $(\\delta Y_P = \\pm 0.0002)$. At this accuracy the uncertainty in the abundance is dominated by the experimental uncertainty in the neutron mean lifetime, $\\tau_n = 885.3 \\pm 2.0 \\rm{sec}$. The following physical effects were included in the calculation: the zero and finite-temperature radiative, Coulomb and finite-nucleon mass corrections to the weak rates; order-$\\alpha$ quantum-electrodynamic correction to the plasma density, electron mass, and neutrino temperature; and incomplete neutrino decoupling. New results for the finite-temperature radiative correction and the QED plasma correction were used. In addition, we wrote a new and independent nucleosynthesis code to control numerical errors to less than 0.1\\pct. Our predictions for the \\EL[4]{He} abundance are summarized with an accurate fitting formula. Summarizing our work...

  2. Implication of the proton-deuteron radiative capture for Big Bang Nucleosynthesis

    CERN Document Server

    Marcucci, L E; Kievsky, A; Viviani, M

    2015-01-01

    The astrophysical $S$-factor for the radiative capture $d(p,\\gamma)^3$He in the energy-range of interest for Big Bang Nucleosynthesis (BBN) is calculated using an {\\it ab-initio} approach. The nuclear Hamiltonian retains both two- and three-nucleon interactions - the Argonne $v_{18}$ and the Urbana IX, respectively. Both one- and many-body contributions to the nuclear current operator are included. The former retain for the first time, besides the $1/m$ leading order contribution ($m$ is the nucleon mass), also the next-to-leading order term, proportional to $1/m^3$. The many-body currents are constructed in order to satisfy the current conservation relation with the adopted Hamiltonian model. The hyperspherical harmonics technique is applied to solve the $A=3$ bound and scattering states. A particular attention is used in this second case in order to obtain, in the energy range of BBN, an uncertainty on the astrophysical $S$-factor of the order or below $\\sim$1 %. Then, in this energy range, the $S$-factor i...

  3. General neutralino NLSP with gravitino dark matter vs. big bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Hasenkamp, Jasper

    2009-08-15

    We study the scenario of gravitino dark matter with a general neutralino being the next-to-lightest supersymmetric particle (NLSP). Therefore, we compute analytically all 2- and 3-body decays of the neutralino NLSP to determine the lifetime and the electromagnetic and hadronic branching ratio of the neutralino decaying into the gravitino and Standard Model particles. We constrain the gravitino and neutralino NLSP mass via big bang nucleosynthesis and see how those bounds are relaxed for a Higgsino or a wino NLSP in comparison to the bino neutralino case. At neutralino masses >or similar 1 TeV, a wino NLSP is favoured, since it decays rapidly via a newly found 4-vertex. The Higgsino component becomes important, when resonant annihilation via heavy Higgses can occur. We provide the full analytic results for the decay widths and the complete set of Feynman rules necessary for these computations. This thesis closes any gap in the study of gravitino dark matter scenarios with neutralino NLSP coming from approximations in the calculation of the neutralino decay rates and its hadronic branching ratio. (orig.)

  4. Studies of nuclear reactions relevant to stellar or Big-Bang Nucleosynthesis using ICF plasmas at OMEGA

    Science.gov (United States)

    Zylstra, Alex; Herrmann, Hans; Kim, Yongho; Hale, Gerry; Paris, Mark; McEvoy, Aaron; Gatu Johnson, Maria; Frenje, Johan; Li, Chikang; Seguin, Fredrick; Sio, Hong; Petrasso, Richard; McNabb, Dennis; Sayre, Dan; Pino, Jesse; Brune, Carl; Bacher, Andy; Forrest, Chad; Glebov, Vladimir; Stoeckl, Christian; Janezic, Roger; Sangster, Craig

    2015-11-01

    The 3He+3He, T+3He, and p +D reactions directly relevant to Stellar or Big-Bang Nucleosynthesis (BBN) have been studied at the OMEGA laser facility using high-temperature low-density `exploding pusher' implosions. The advantage of using these plasmas is that they better mimic astrophysical systems than cold-target accelerator experiments. Measured proton spectra from the 3He3He reaction are used to constrain nuclear R-matrix modeling. The resulting T+3He gamma-ray data rule out an anomalously-high 6Li production during the Big Bang as an explanation to the high observed values in metal poor first generation stars. The proton spectrum from the T+3He reaction is also being used to constrain the R-matrix model. Recent experiments have probed the p +D reaction for the first time in a plasma; this reaction is relevant to energy production in protostars, brown dwarfs and at higher CM energies to BBN. This work was partially supported by the US DOE, NLUF, LLE, and GA.

  5. Where Are the Logical Errors in the Theory of Big Bang?

    Science.gov (United States)

    Kalanov, Temur Z.

    2015-04-01

    The critical analysis of the foundations of the theory of Big Bang is proposed. The unity of formal logic and of rational dialectics is methodological basis of the analysis. It is argued that the starting point of the theory of Big Bang contains three fundamental logical errors. The first error is the assumption that a macroscopic object (having qualitative determinacy) can have an arbitrarily small size and can be in the singular state (i.e., in the state that has no qualitative determinacy). This assumption implies that the transition, (macroscopic object having the qualitative determinacy) --> (singular state of matter that has no qualitative determinacy), leads to loss of information contained in the macroscopic object. The second error is the assumption that there are the void and the boundary between matter and void. But if such boundary existed, then it would mean that the void has dimensions and can be measured. The third error is the assumption that the singular state of matter can make a transition into the normal state without the existence of the program of qualitative and quantitative development of the matter, without controlling influence of other (independent) object. However, these assumptions conflict with the practice and, consequently, formal logic, rational dialectics, and cybernetics. Indeed, from the point of view of cybernetics, the transition, (singular state of the Universe) -->(normal state of the Universe),would be possible only in the case if there was the Managed Object that is outside the Universe and have full, complete, and detailed information about the Universe. Thus, the theory of Big Bang is a scientific fiction.

  6. Enigmatic Aspects of the Early Universe: Possibility of a 'Pre-Big Bang Phase'!

    OpenAIRE

    Sivaram, C; Arun, Kenath

    2010-01-01

    In this paper it is suggested that inclusion of mutual gravitational interactions among the particles in the early dense universe can lead to a 'pre-big bang' scenario, with particle masses greater than the Planck mass implying an accelerating phase of the universe, which then goes into the radiation phase when the masses fall below the Planck mass. The existence of towers of states of such massive particles (i.e. multiples of Planck mass) as implied in various unified theories, provides rapi...

  7. Emergence of a Big Bang singularity in an exact string background

    OpenAIRE

    Hirano, Shinji; mazumdar, Anupam

    2007-01-01

    The origin of Big Bang singularity in 3+1 dimensions can be understood in an exact string theory background obtained by an analytic continuation of a cigar like geometry with a nontrivial dilaton. In a T-dual conformal field theory picture there exists a closed string tachyon potential which excises the singular space-time of a strongly coupled regime to ensure that a higher dimensional universe has no curvature singularity. However in 3+1 dimensions the universe exhibits all the pathology of...

  8. Low-Energy Photodisintegration of the Deuteron and Big-Bang Nucleosynthesis

    OpenAIRE

    W. Tornow; Czakon, N. G.; Howell, C.R.; Hutcheson, A.; Kelley, J.H.; Litvinenko, V. N.; Mikhailov, S.; Pinayev, I. V.; Weisel, G.J.; Witala, H

    2003-01-01

    The photon analyzing power for the photodisintegration of the deuteron was measured for seven gamma-ray energies between 2.39 and 4.05 MeV using the linearly polarized gamma-ray beam of the High-Intensity Gamma-ray Source at the Duke Free-Electron Laser Laboratory. The data provide a stringent test of theoretical calculations for the inverse reaction, the neutron-proton radiative capture reaction at energies important for Big-Bang Nucleosynthesis. Our data are in excellent agreement with pote...

  9. On Big Bang Relics, the Neutrino Mass and the Cosmic Ray Spectrum

    OpenAIRE

    Wigmans, Richard

    1998-01-01

    It is shown that high-energy features of the cosmic ray spectrum, in particular the kink around 4 PeV and the corresponding change in spectral index, may be explained from interactions between highly energetic cosmic protons and relic Big Bang antineutrinos, if the latter have a rest mass of about 0.4 eV/$c^2$. This explanation is supported by experimental data from extensive air-shower experiments, and in particular by the observation (Fly's Eye) of a second kink around 300 PeV, and by the a...

  10. Quantum mechanics before the big bang in heterotic-M-theory

    OpenAIRE

    Zanzi, Andrea

    2016-01-01

    In this letter we investigate the role played by quantum mechanics before the big-bang in heterotic-M-theory assuming an orbifold compactification of time. As we will see particles are localized around a black hole but only in regions where a constructive quantum interference takes place. We infer that the creation of this interference pattern is interesting for many reasons: (A) it is a mechanism to localize particles on $S^4$ branes; (B) the Casimir potential for the dilaton can be interpre...

  11. Constraint on Heavy Element Production in Inhomogeneous Big-Bang Nucleosynthesis from the Light Element Observations

    Directory of Open Access Journals (Sweden)

    Riou Nakamura

    2013-01-01

    Full Text Available We investigate the observational constraints on the inhomogeneous big-bang nucleosynthesis that Matsuura et al. (2005 suggested that states the possibility of the heavy element production beyond 7Li in the early universe. From the observational constraints on light elements of 4He and D, possible regions are found on the plane of the volume fraction of the high-density region against the ratio between high- and low-density regions. In these allowed regions, we have confirmed that the heavy elements beyond Ni can be produced appreciably, where p- and/or r-process elements are produced well simultaneously.

  12. Majorana Neutrino Magnetic Moment and Neutrino Decoupling in Big Bang Nucleosynthesis

    CERN Document Server

    Vassh, N; Balantekin, A B; Fuller, G M

    2015-01-01

    We examine the physics of the early universe when neutrinos (electron neutrino, muon neutrino, tau neutrino) possess transition magnetic moments. These extra couplings beyond the usual weak interaction couplings alter the way neutrinos decouple from the plasma of electrons/positrons and photons. We calculate how transition magnetic moment couplings modify neutrino decoupling temperatures, and then use a full weak, strong, and electromagnetic reaction network to compute corresponding changes in Big Bang Nucleosynthesis abundance yields. We find that light element observational constraints and other cosmological constraints may allow probes of neutrino transition magnetic moments which are not directly available in the laboratory.

  13. Should price reform proceed gradually or in a"big bang?"

    OpenAIRE

    van Wijnbergen, Sweder

    1991-01-01

    Should countries such as Poland or the USSR move toward more flexible prices gradually or in a"big bang?"Why is it that governments committed to eventual price flexibility so often seem to be unable to let go of"temporary"controls? Why, after price increases early in a program of price controls, does output often rise at the same time that shortages seem to increase? Theauthor argues that intertemporal speculation, hoarding, and the political economy of price control help explain these puzzle...

  14. Determination of Dark Energy and Dark Matter from the values of Redshift for the present time, Planck and Trans-Planck epochs of the Big-Bang model

    OpenAIRE

    Gasanalizade, Asger G.; Hasanalizade, Ramin A.

    2011-01-01

    As an alternative to the Standard cosmology model we have developed a new modified Freundlich's (quantum relativity) redshift (MFRS) mechanisms, which provide a precise solutions of the Dark Energy and Dark Matter problems. We apply the joint solution of three MFRS equations for concordances quantize bounce Planck hierarchy steps. Simultaneous scaling solutions of MFRS equations in logarithmic scale appropriate to three cosmological epoch's, yields a currently testable predictions regarding t...

  15. Stable Emergent Universe -- A Creation without Big-Bang

    CERN Document Server

    Guendelman, Eduardo; Labrana, Pedro; Nissimov, Emil; Pacheva, Svetlana

    2015-01-01

    Based on an earlier introduced new class of generalized gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold, we derive an effective "Einstein-frame" theory featuring the following remarkable properties: (i) We obtain effective potential for the cosmological scalar field possessing two infinitely large flat regions which allows for a unified description of both early universe inflation as well as of present dark energy epoch; (ii) For a specific parameter range the model possesses a non-singular stable "emergent universe" solution which describes an initial phase of evolution that precedes the inflationary phase.

  16. Stable emergent Universe - a creation without Big-Bang

    Science.gov (United States)

    Guendelman, E.; Herrera, R.; Labrana, P.; Nissimov, E.; Pacheva, S.

    2015-11-01

    Based on an earlier introduced new class of generalized gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold, we derive an effective ``Einstein-frame'' theory featuring the following remarkable properties: (i) We obtain effective potential for the cosmological scalar field possessing two infinitely large flat regions which allows for a unified description of both early Universe inflation as well as of present dark energy epoch; (ii) for a specific parameter range the model possesses a non-singular stable ``emergent Universe'' solution which describes an initial phase of evolution that precedes the inflationary phase.

  17. Researchers Develop Method to Identify Sparticles in Big Bang Conditions

    CERN Multimedia

    2008-01-01

    Three Northeastern University researchers have proposed a new approach for the highly anticipated discovery of supersymmetric particles, often called sparticles. The methodology, which was published in the December 21 issue of the Physical Review Letters, is based on identifying the hierarchical mass patterns of sparticles, which are assumed to exist in a new class of particle physics theories beyond the Standard Model.

  18. The big bang of genome editing technology: development and application of the CRISPR/Cas9 system in disease animal models.

    Science.gov (United States)

    Shao, Ming; Xu, Tian-Rui; Chen, Ce-Shi

    2016-07-18

    Targeted genome editing technology has been widely used in biomedical studies. The CRISPR-associated RNA-guided endonuclease Cas9 has become a versatile genome editing tool. The CRISPR/Cas9 system is useful for studying gene function through efficient knock-out, knock-in or chromatin modification of the targeted gene loci in various cell types and organisms. It can be applied in a number of fields, such as genetic breeding, disease treatment and gene functional investigation. In this review, we introduce the most recent developments and applications, the challenges, and future directions of Cas9 in generating disease animal model. Derived from the CRISPR adaptive immune system of bacteria, the development trend of Cas9 will inevitably fuel the vital applications from basic research to biotechnology and bio-medicine. PMID:27469250

  19. The big bang of genome editing technology: development and application of the CRISPR/Cas9 system in disease animal models

    Science.gov (United States)

    SHAO, Ming; XU, Tian-Rui; CHEN, Ce-Shi

    2016-01-01

    Targeted genome editing technology has been widely used in biomedical studies. The CRISPR-associated RNA-guided endonuclease Cas9 has become a versatile genome editing tool. The CRISPR/Cas9 system is useful for studying gene function through efficient knock-out, knock-in or chromatin modification of the targeted gene loci in various cell types and organisms. It can be applied in a number of fields, such as genetic breeding, disease treatment and gene functional investigation. In this review, we introduce the most recent developments and applications, the challenges, and future directions of Cas9 in generating disease animal model. Derived from the CRISPR adaptive immune system of bacteria, the development trend of Cas9 will inevitably fuel the vital applications from basic research to biotechnology and biomedicine. PMID:27469250

  20. The critical geometry of a thermal big bang

    CERN Document Server

    Afshordi, Niayesh

    2016-01-01

    We explore the space of scalar-tensor theories containing two disformally related metrics, and find a discontinuity pointing to a special "critical" cosmological solution. This solution has a simple geometrical interpretation based on the action of a probe 3-brane embedded in an $EAdS_2\\times E_3$ geometry. Due to the different maximal speeds of propagation for matter and gravity, the cosmological fluctuations start off inside the horizon even without inflation, and will more naturally have a thermal origin (since there is never vacuum domination). The critical model makes an unambiguous, non-tuned prediction for the spectral index of the scalar fluctuations left outside the horizon: $n_s= 0.96478(64)$. Adding to this that no gravitational waves are produced, we have unveiled the most predictive model on offer.

  1. Big Bang Nucleosynthesis in Visible and Hidden-Mirror Sectors

    Directory of Open Access Journals (Sweden)

    Paolo Ciarcelluti

    2014-01-01

    dark matter. The production of ordinary nuclides shows differences from the standard model for a ratio of the temperatures between mirror and ordinary sectors x=T′/T≳0.3, and they present an interesting decrease of the abundance of Li7. For the mirror nuclides, instead, one observes an enhanced production of He4, which becomes the dominant element for x≲0.5, and much larger abundances of heavier elements.

  2. Big Bang Day: 5 Particles - 1. The Electron

    CERN Multimedia

    Simon Singh

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 1. The Electron Just over a century ago, British physicist J.J. Thompson experimenting with electric currents and charged particles inside empty glass tubes, showed that atoms are divisible into indivisible elementary particles. But how could atoms be built up of these so called "corpuscles"? An exciting 30 year race ensued, to grasp the planetary model of the atom with its orbiting electrons, and the view inside the atom was born. Whilst the number of electrons around the nucleus of an atom determines their the chemistry of all elements, the power of electrons themselves have been harnessed for everyday use: electron beams for welding,cathode ray tubes and radiation therapy.

  3. On initial conditions for the Hot Big Bang

    CERN Document Server

    Bezrukov, F; Shaposhnikov, M

    2008-01-01

    We analyse the process of reheating the Universe in the electroweak theory where the Higgs field plays a role of the inflaton. We estimate the maximal temperature of the Universe and fix the initial conditions for radiation-dominated phase of the Universe expansion in the framework of the nuMSM--the minimal extension of the Standard Model (SM) by three right-handed singlet fermions. We show that the inflationary epoch is followed by a matter dominated stage related to the Higgs field oscillations. We investigate the energy transfer from higgs-inflaton to the SM particles and show that the radiation dominated phase of the Universe expansion starts at temperature T_r ~ (3-8)*10^{13} GeV. We estimate the production rate of singlet fermions at preheating and find that their concentrations at T_r are negligibly small. This suggests that the sterile neutrino Dark Matter (DM) production and baryogenesis in the nuMSM with higgs driven inflation are low energy phenomena, having nothing to do with inflation. We study t...

  4. Big Bang Models in String Theory

    OpenAIRE

    Craps, Ben

    2006-01-01

    These proceedings are based on lectures delivered at the "RTN Winter School on Strings, Supergravity and Gauge Theories", CERN, January 16 - January 20, 2006. The school was mainly aimed at Ph.D. students and young postdocs. The lectures start with a brief introduction to spacetime singularities and the string theory resolution of certain static singularities. Then they discuss attempts to resolve cosmological singularities in string theory, mainly focusing on two specific examples: the Milne...

  5. A large neutral fraction of cosmic hydrogen a billion years after the Big Bang.

    Science.gov (United States)

    Wyithe, J Stuart B; Loeb, Abraham

    2004-02-26

    The fraction of ionized hydrogen left over from the Big Bang provides evidence for the time of formation of the first stars and quasar black holes in the early Universe; such objects provide the high-energy photons necessary to ionize hydrogen. Spectra of the two most distant known quasars show nearly complete absorption of photons with wavelengths shorter than the Lyman alpha transition of neutral hydrogen, indicating that hydrogen in the intergalactic medium (IGM) had not been completely ionized at a redshift of z approximately 6.3, about one billion years after the Big Bang. Here we show that the IGM surrounding these quasars had a neutral hydrogen fraction of tens of per cent before the quasar activity started, much higher than the previous lower limits of approximately 0.1 per cent. Our results, when combined with the recent inference of a large cumulative optical depth to electron scattering after cosmological recombination therefore suggest the presence of a second peak in the mean ionization history of the Universe. PMID:14985754

  6. Pre-Big Bang, fundamental Physics and noncyclic cosmologies. Possible alternatives to standard concepts and laws

    Science.gov (United States)

    Gonzalez-Mestres, L.

    2014-04-01

    Detailed analyses of WMAP and Planck data can have significant implications for noncyclic pre-Big Bang approaches incorporating a new fundamental scale beyond the Planck scale and, potentially, new ultimate constituents of matter with unconventional basic properties as compared to standard particles. Cosmic-ray experiments at the highest energies can also yield relevant information. Hopefully, future studies will be able to deal with alternatives: i) to standard physics for the structure of the physical vacuum, the nature of space-time, the validity of quantum field theory and conventional symmetries, the interpretation of string-like theories...; ii) to standard cosmology concerning the origin and evolution of our Universe, unconventional solutions to the cosmological constant problem, the validity of inflationary scenarios, the need for dark matter and dark energy... Lorentz-like symmetries for the properties of matter can then be naturally stable space-time configurations resulting from more general primordial scenarios that incorporate physics beyond the Planck scale and describe the formation and evolution of the physical vacuum. A possible answer to the question of the origin of half-integer spins can be provided by a primordial spinorial space-time with two complex coordinates instead of the conventional four real ones, leading to a really new cosmology. We discuss basic questions and phenomenological topics concerning noncyclic pre-Big Bang cosmologies and potentially related physics.

  7. Could there have been a single origin of life in a big bang universe?

    Science.gov (United States)

    Gordon, Richard; Hoover, Richard B.

    2007-09-01

    Frank Tipler, in The Physics of Immortality, wrote about how to spread a form of traveling artificial life throughout the known, expanding universe, prior to collapse. The key is to make the ALife self-reproducing, permitting exponential growth, like life itself, but faster. We ask whether microbial extremophiles could have originated in a single location at an early phase of a big bang universe, and spread throughout the cosmos, as is commonly assumed in discussions of the panspermia hypothesis? Since the universe was much smaller when the first condensed matter appeared, this hypothesis merits consideration. In comparing particle horizons with biohorizons, we find that the answer is no: at our earliest estimated time for the origin of life, 500x10 6 years after the big bang, if life started everywhere it could, there would have had to have been at least 50,000 origins of life. In the course of our rough calculations, we introduce the concepts of the generations of life (from microorganisms to consciousness), the Biocosmological Principle that life is spread throughout the universe, life as a wave in an active medium, and the speed of life, i.e., the speed of ejecta from galaxies and lesser bodies on which life could be transported.

  8. The amazing unity of the Universe and its origin in the Big Bang

    CERN Document Server

    van den Heuvel, Edward

    2016-01-01

    In the first chapters the author describes how our knowledge of the position of Earth in space and time has developed, thanks to the work of many generations of astronomers and physicists. He discusses how our position in the Galaxy was discovered, and how in 1929, Hubble uncovered the fact that the Universe is expanding, leading to the picture of the Big Bang. He then explains how astronomers have found that the laws of physics that were discovered here on Earth and in the Solar System (the laws of mechanics, gravity, atomic physics, electromagnetism, etc.) are valid throughout the Universe. This is illustrated by the fact that all matter in the Universe consists of atoms of the same chemical elements that we know on Earth. This unity is all the more surprising when one realizes that in the original Big Bang theory, different parts of the Universe could never have communicated with each other. It then is a mystery how they could have shared the same physical laws. This problem was solved by the introduction ...

  9. Don’t miss the Passport to the Big Bang event this Sunday!

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Word has been going around for weeks now about the inauguration of the Passport to the Big Bang on Sunday 2 June. Ideal for a family day out or a day with friends, this is a CERN event not to be missed!   The Passport to the Big Bang is a 54-km scientific tourist trail comprising ten exhibition platforms in front of ten CERN sites in the Pays de Gex and the Canton of Geneva. Linked by cycle routes, these ten platforms will mark the same number of stages in the rally for competitive cyclists and the bicycle tour for families taking place this Sunday from 9 a.m. to 12 p.m. But that’s not all: from 2 p.m., you will also have the chance to take part in a huge range of activities provided by clubs and associations from CERN and the local region. Watch an oriental dance show, have a go at building detectors out of Kapla blocks and Lego, meet different reptile species, learn about wind instruments, try your hand at Nordic walking or Zumba fitness, get a better understanding of road safety...

  10. Implication of the Proton-Deuteron Radiative Capture for Big Bang Nucleosynthesis

    Science.gov (United States)

    Marcucci, L. E.; Mangano, G.; Kievsky, A.; Viviani, M.

    2016-03-01

    The astrophysical S factor for the radiative capture d (p ,γ ) 3He in the energy range of interest for big bang nucleosynthesis (BBN) is calculated using an ab initio approach. The nuclear Hamiltonian retains both two- and three-nucleon interactions—the Argonne v18 and the Urbana IX, respectively. Both one- and many-body contributions to the nuclear current operator are included. The former retain for the first time, besides the 1 /m leading order contribution (m is the nucleon mass), also the next-to-leading order term, proportional to 1 /m3. The many-body currents are constructed in order to satisfy the current conservation relation with the adopted Hamiltonian model. The hyperspherical harmonics technique is applied to solve the A =3 bound and scattering states. Particular attention is paid in this second case in order to obtain, in the energy range of BBN, an uncertainty on the astrophysical S factor of the order or below ˜1 %. Then, in this energy range, the S factor is found to be ˜10 % larger than the currently adopted values. Part of this increase (1%-3%) is due to the 1 /m3 one-body operator, while the remaining is due to the new more accurate scattering wave functions. We have studied the implication of this new determination for the d (p ,γ )3He S factor on the deuterium primordial abundance. We find that the predicted theoretical value for 2H/H is in excellent agreement with its experimental determination, using the most recent determination of the baryon density of the Planck experiment, and with a standard number of relativistic degrees of freedom Neff=3.046 during primordial nucleosynthesis. This calls for a more accurate measurement of the astrophysical S factor in order to confirm the present predictions.

  11. Big Bang

    CERN Multimedia

    Lyons, Daniel

    2006-01-01

    "It will be the world's largest machine. It could explain the origins of the universe. But first a team of engineers has the gargantuan logistic challenge of putting the Large Hadron Collider together" (2 pages)

  12. Relic gravitons from the pre-big bang: what we know and what we do not know

    OpenAIRE

    Gasperini, M.

    1996-01-01

    I discuss the status of present knowledge about a possible background of relic gravitons left by an early, pre-big bang cosmological epoch, whose existence in the past of our Universe is suggested by the duality symmetries of string theory.

  13. Geneva Festival, 2004: Opened with the Big Bang, closed with Creation

    CERN Multimedia

    2004-01-01

    In its 50th Anniversary year, CERN had the honour of opening and closing this year's Geneva Festival. The Geneva Festival traditionally opens with a bang, but this year's was the biggest yet. On 30 July, on a warm summer's evening by Lake Geneva, several tons of fireworks replayed the early history of the Universe. Starting with the Big Bang, the display had acts representing inflation, the breaking of symmetries, the clash of antimatter and matter, hadrons and nucleosynthesis, the first atoms and the Universe becoming transparent, and the formation of stars and planets. It was a challenge to translate these very abstract ideas into more than a thousand kilograms of TNT of different colour. But, set to the music of The Matrix, Alan Parsons, and Jurassic Park, one of the most spectacular physics presentations ever staged dazzled the audience of two hundred thousand spectators. CERN physicist Rolf Landua, who scripted the narrative and worked with the pyrotechnicians on the realization, said: "From the many e...

  14. From Big Crunch to Big Bang: A Quantum String Cosmology Perspective

    OpenAIRE

    Maharana, Jnanadeva

    2001-01-01

    The scenario that the Universe contracts towards a big crunch and then undergoes a transition to expanding Universe in envisaged in the quantum string cosmology approach. The Wheeler-De Witt equation is solved exactly for an exponential dilaton potential. S-duality invariant cosmological effective action, for type IIB theory, is considered to derive classical solutions and solve WDW equations.

  15. 宇舶表 Big Bang In Red-2010年绚丽登场

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2010年情人节来临之际,瑞士著名手表品牌Hublot宇舶表特别推出Big Bang In Red腕表。表款整体选用红色这一诠释浪漫经典爱情的永厘颜色,尽在绚丽、妩媚优雅。镶钻深红色表盘、白色陶瓷表壳与天然橡胶内衬的鳄鱼真皮腕带完美结合,尽显宇舶表“融合之艺术”的设计理念。

  16. “I am a rogue night elf”: Avatars, gaming and The Big Bang Theory

    Directory of Open Access Journals (Sweden)

    Theo Plothe

    2014-03-01

    Full Text Available CBS’s The Big Bang Theory (TBBT frequently exhibits elements of video games and gaming culture. The author uses subculture theory to consider the representation of video games, gamers, and their avatars within popular culture. This paper investigates the representation of avatars within the characterization of gaming subculture on the TBBT. The author performed a content analysis of the program’s six seasons, examining the relationship between the show’s video game playing characters and their avatars. This investigation found that almost half of the scenes that contained video gaming activities contained some aspect of avatars. TBBT reifies gaming as a subculture through the relationship between the characters and their avatars. Examining the representation of these relationships is essential to understanding the representation of the gaming subculture in the mass media and within culture at large.

  17. Dust production 0.7-1.5 billion years after the Big Bang

    CERN Document Server

    Michałowski, Michał J

    2015-01-01

    Cosmic dust is an important component of the Universe, and its origin, especially at high redshifts, is still unknown. I present a simple but powerful method of assessing whether dust observed in a given galaxy could in principle have been formed by asymptotic giant branch (AGB) stars or supernovae (SNe). Using this method I show that for most of the galaxies with detected dust emission between z=4 and z=7.5 (1.5-0.7 billion years after the Big Bang) AGB stars are not numerous and efficient enough to be responsible for the measured dust masses. Supernovae could account for most of the dust, but only if all of them had efficiencies close to the maximal theoretically allowed value. This suggests that a different mechanism is responsible for dust production at high redshifts, and the most likely possibility is the grain growth in the interstellar medium.

  18. 178th International School of Physics "Enrico Fermi" : From the Big Bang to the Nucleosynthesis

    CERN Document Server

    Nappi, E

    2011-01-01

    Physicists have devoted much effort to reproducing the conditions of the primordial universe in laboratory conditions in their quest to work out a comprehensive theory of the appearance and evolution of nuclear matter. Whether it be trying to recreate the predicted primordial state of high-energy density matter in which quarks and gluons are effectively deconfined - the so-called Quark Gluon Plasma (QGP) - or exploring the structure and reaction properties of very unstable nuclei in experiments using radioactive beams, they have striven to understand the events which characterized the Big Bang and the various nucleosynthesis mechanisms which occur in the stars. This book contains the proceedings of the 2010 Enrico Fermi summer school held in Varenna, Italy, in July 2010, and devoted to the present understanding of the primordial universe and the origin of the elements, as achieved by studying nuclei and their constituents in extreme regimes of energy and composition. Subjects covered include: QGP formation; e...

  19. Quantum mechanics before the big bang in heterotic-M-theory

    CERN Document Server

    Zanzi, Andrea

    2016-01-01

    In this letter we investigate the role played by quantum mechanics before the big-bang in heterotic-M-theory assuming an orbifold compactification of time. As we will see particles are localized around a black hole but only in regions where a constructive quantum interference takes place. We infer that the creation of this interference pattern is interesting for many reasons: (A) it is a mechanism to localize particles on $S^4$ branes; (B) the Casimir potential for the dilaton can be interpreted as a gravitational effective potential for a two-body problem; (C) the quantum interference is a new way to define the branes in heterotic-M-theory. Remarkably, a modified Schroedinger equation is obtained. The stabilization of the branes' position is related to the absence of a cosmological singularity.

  20. From the Big Bang to the Nobel Prize and the JWST

    Science.gov (United States)

    Mather, John C.

    2007-01-01

    I will describe the history of the universe, from the Big Bang to 2013, when the JWST is to be launched to look back towards our beginnings. I will discuss how the COBE results led to the Nobel Prize, how the COBE results have been confirmed and extended, and their implications for future observations. The James Webb Space Telescope will be used to examine every part of our history from the first stars and galaxies to the formation of individual stars and planets and the delivery of life-supporting materials to the Earth. I will describe the plans for the JWST and how observers may use it. With luck, the JWST may produce a Nobel Prize for some discovery we can only guess today.

  1. Toward a self-consistent and unitary reaction network for big bang nucleosynthesis

    International Nuclear Information System (INIS)

    Unitarity, the mathematical expression of the conservation of probability in multichannel reactions, is an essential ingredient in the development of accurate nuclear reaction networks appropriate for nucleosynthesis in a variety of environments. We describe our ongoing program to develop a 'unitary reaction network' for the big-bang nucleosynthesis environment and look at an example of the need and power of unitary parametrizations of nuclear scattering and reaction data. Recent attention has been focused on the possible role of the 9B compound nuclear system in the resonant destruction of 7Li during primordial nucleosynthesis. We have studied reactions in the 9B compound system with a multichannel, two-body unitary R-matrix code (EDA) using the known elastic and reaction data, in a four-channel treatment. The data include elastic 6Li(3He,3He)6Li differential cross sections from 0.7 to 2.0 MeV, integrated reaction cross sections for energies from 0.7 to 5.0 MeV for 6Li(3He,p)8Be* and from 0.4 to 5.0 MeV for the 6Li(3He,γ)7Be reaction. Capture data have been added to the previous analysis with integrated cross section measurements from 0.7 to 0.825 MeV for 6Li(3He,γ)9B. The resulting resonance parameters are compared with tabulated values from TUNL Nuclear Data Group analyses. Previously unidentified resonances are noted and the relevance of this analysis and a unitary reaction network for big-bang nucleosynthesis are emphasized. (author)

  2. Nobel Lecture: From the Big Bang to the Nobel Prize and beyond

    Science.gov (United States)

    Mather, John C.

    NASA’s Cosmic Background Explorer satellite mission, the COBE, laid the foundations for modern cosmology by measuring the spectrum and anisotropy of the cosmic microwave background radiation and discovering the cosmic infrared background radiation. I describe the history of the COBE project, its scientific context, the people who built it, and the scientific results. The COBE observed the universe on the largest scales possible by mapping the cosmic microwave and infrared background radiation fields and determining their spectra. It produced conclusive evidence that the hot Big Bang theory of the early universe is correct, showed that the early universe was very uniform but not perfectly so, and that the total luminosity of post Big Bang objects is twice as great as previously believed. The COBE concept was developed by a Mission Definition Study Team appointed by NASA in 1976, based on three competing proposals submitted in 1974. The COBE was built in-house by Goddard Space Flight Center, with a helium cryostat provided by Ball Aerospace, and was launched on a Delta rocket built by McDonnell Douglas. It is in a circular orbit 900km above the Earth, in a plane inclined 99° to the equator and roughly perpendicular to the line to the Sun. It carried three instruments, a far infrared absolute spectrophotometer (FIRAS), a differential microwave radiometer with three channels (DMR), and a diffuse infrared background experiment (DIRBE). The helium cryostat cooled the FIRAS and DIRBE for 10months until the helium was exhausted, but operations continued for a total of 4years . Subsequent observations have confirmed the COBE results and led to measurements of the main cosmological parameters with a precision of a few percent.

  3. Toward a self-consistent and unitary reaction network for big-bang nucleosynthesis

    Directory of Open Access Journals (Sweden)

    Paris Mark W.

    2014-04-01

    Full Text Available Unitarity, the mathematical expression of the conservation of probability in multichannel reactions, is an essential ingredient in the development of accurate nuclear reaction networks appropriate for nucleosynthesis in a variety of environments. We describe our ongoing program to develop a “unitary reaction network” for the big-bang nucleosynthesis environment and look at an example of the need and power of unitary parametrizations of nuclear scattering and reaction data. Recent attention has been focused on the possible role of the 9B compound nuclear system in the resonant destruction of 7Li during primordial nucleosynthesis. We have studied reactions in the 9B compound system with a multichannel, two-body unitary R-matrix code (EDA using the known elastic and reaction data, in a four-channel treatment. The data include elastic 6Li(3He,3He6Li differential cross sections from 0.7 to 2.0 MeV, integrated reaction cross sections for energies from 0.7 to 5.0 MeV for 6Li(3He,p8Be* and from 0.4 to 5.0 MeV for the 6Li(3He,d7Be reaction. Capture data have been added to the previous analysis with integrated cross section measurements from 0.7 to 0.825 MeV for 6Li(3He,γ9B. The resulting resonance parameters are compared with tabulated values from TUNL Nuclear Data Group analyses. Previously unidentified resonances are noted and the relevance of this analysis and a unitary reaction network for big-bang nucleosynthesis are emphasized.

  4. Big Bang-Big Crunch Algorithm for Voltage Stability Limit Improvement by Coordinated Control of SVC Settings

    Directory of Open Access Journals (Sweden)

    S. Sakthivel

    2013-07-01

    Full Text Available Modern power system networks are operated under highly stressed conditions and there is a risk of voltage instability problems owing to increased load demand. A power system needs to be with sufficient voltage stability margin for secured operation. In this study, SVC parameters of location and size along with generator bus voltages, transformer tap settings are considered as control parameters for voltage stability limit improvement by minimizing loss and voltage deviation. The control parameters are varied in a coordinated manner for better results. The line based LQP voltage stability indicator is used for voltage stability assessment. The nature inspired meta heuristic Big Bang-Big Crunch (BB-BC algorithm is exploited for optimization of the control variables and the performance is compared with that of PSO algorithm. The effectiveness of the proposed algorithm is tested on the standard IEEE 30 bus system under normal and N-1 line outage contingency conditions. The results obtained from the simulation encourage the performances of the new algorithm.

  5. MODEL PENGANGKUTAN SAMPAH DI KOTA BANGLI

    Directory of Open Access Journals (Sweden)

    Pande N Sari Saraswati

    2013-07-01

    Full Text Available The garbage transportation in Bangli City is currently done using a direct individual pattern (door to door. The vehicles used are dump trucks which are not covered, so they pollute the areas they pass by. Most of the vehicles are in bad condition. This study was aimed at identifying the transportation routes, the number of vehicles needed, the temporary place of garbage disposal ‘Tempat Pembuangan Sementara’ (TPS, and the rate of garbage retribution. The research method included the sample of garbage from the place of residence and the place of non residence based on SNI-19-3964-1994 used as a reference. This model used five compactor trucks for carrying garbage from 283 container bins with capacity of 0.36 m3, and one armroll truck for carrying the market garbage from four loudhaul with capacity of 6 m3 per day. The amount of retribution is analyzed based on the calculation of investment feasibility for 10 years time at 18% MARR interest rate, with an assumption that there was subsidy from the government. It was found that the value of NPV (Net Present Value was Rp. 35.673.540,99, the value of BCR (Benefit of Cost Ratio was 1.021 and the value of IRR (Internal Rate of Return was 19.11%. The monthly rates of retribution were Rp. 2,000.00/family, Rp. 20,000.00/school unit, Rp. 25,000.00/office unit, Rp. 8,000.00/shop unit, Rp. 20.000.00/restaurant unit, Rp. 2,000.00/hotel/accommodation unit, and Rp. 6,000.00/market trader.

  6. BICEP2, Planck, spinorial space-time, pre-Big Bang.

    Directory of Open Access Journals (Sweden)

    Gonzalez-Mestres Luis

    2015-01-01

    Full Text Available The field of Cosmology is currently undergoing a positive and constructive crisis. Controversies concerning inflation are not really new. But after the 2013-2014 Planck and BICEP2 announcements, and the more recent joint analysis by Planck, BICEP2 and the Keck Array (PBKA, the basic issues can involve more direct links between the Mathematical Physics aspects of cosmological patterns and the interpretation of experimental results. Open questions and new ideas on the foundations of Cosmology can emerge, while future experimental and observational programs look very promising. The BICEP2 result reporting an excess of B-mode polarization signal of the cosmic microwave background (CMB radiation was initially presented as a signature of primordial gravitational waves from cosmic inflation. But polarized dust emission can be at the origin of such a signal, and the evidence claimed by BICEP2 is no longer secure after the PBKA analysis. Furthermore, even assuming that significant CMB B-mode polarization has indeed been generated by the early Universe, its theoretical and cosmological interpretation would be far from obvious. Inflationary gravitational waves are not the only possible source of primordial CMB B-modes. Alternative cosmologies such as pre-Big Bang patterns and the spinorial space-time (SST we introduced in 1996-97 can naturally produce this polarization. Furthermore, the SST automatically generates for each comoving observer a local privileged space direction (PSD whose existence may have been confirmed by Planck data. If such a PSD exists, vector perturbations have most likely been strong in the early Universe and may have produced CMB B-modes. Pre-Big Bang cosmologies can also generate gravitational waves in the early Universe without inflation. After briefly describing detectors devoted to the study of the CMB polarization, we discuss the situation emerging from BICEP2 results, Planck results and the PBKA analysis. In particular, we

  7. Analysis of the "Big Bang" and the Resulting Outward Cosmic Expansion: Hubble - Einstein Cosmology vs. The Universal Exponential Decay

    OpenAIRE

    Ellman, Roger

    2000-01-01

    There is general agreement that the universe began with an "explosion" of matter and energy at a "singularity", the "Big Bang". This paper analyses the mechanics of that beginning and two alternative theories related to it: - The Hubble-Einstein theory that that beginning created space itself, expanding and carrying the universe's matter and energy with it, and - The Universal Decay theory that the length, (L), dimensional aspect of all quantities in the universe is exponentially decaying whi...

  8. 字幕翻译中幽默元素的翻译--以The Big Bang Theory为例

    Institute of Scientific and Technical Information of China (English)

    乐迁

    2016-01-01

    幽默可分为三类:语言幽默、文化幽默和普义幽默。每类幽默的特点决定了翻译时译员要采取不同的策略。本文通过对翻译The Big Bang Theory中幽默的讨论,探索各类幽默可行的翻译方法。

  9. A study on the Translation of Cultural Elements in TV Subtitles-A Case Study of The Big Bang Theory

    Institute of Scientific and Technical Information of China (English)

    胡亚庆

    2014-01-01

    With the growing popularity of one country’s TV series in foreign countries, subtitle translation has attracted consider-able attention in recent years. The Big Bang Theory (TBBT) is a widespread American TV series whose subtitles have been trans-lated into many foreign languages, and it also boasts its richness in cultural elements, the most typical ones including science ele-ments and religious cultural elements.

  10. Limits on Cosmological Variation of Strong Interaction and Quark Masses from Big Bang Nucleosynthesis, Cosmic, Laboratory and Oklo Data

    CERN Document Server

    Flambaum, V V

    2002-01-01

    Recent data on cosmological variation of the electromagnetic fine structure constant from distant quasar (QSO) absorption spectra have inspired a more general discussion of possible variation of other constants. We discuss variation of strong scale and quark masses. We derive the limits on their relative change from (i) primordial Big-Bang Nucleosynthesis (BBN); (ii) Oklo natural nuclear reactor, (iii) quasar absorption spectra, and (iv) laboratory measurements of hyperfine intervals.

  11. L'aventure du grand collisionneur LHC du big bang au boson de Higgs

    CERN Document Server

    Denegri, Daniel

    2014-01-01

    Qu'est-ce que la physique des particules élémentaires, le LHC, et le boson de Higgs ? Ce livre présente de manière simple le monde des quarks, des leptons et de leurs interactions, gouvernées par des symétries fondamentales de la nature, ainsi que le lien entre ce monde de l'infiniment petit et celui de l'infiniment grand. Cette conjonction entre la physique des particules élémentaires et l'évolution de la matière dans les premiers instants de l Univers qui ont suivi le Big-Bang est un des plus beaux acquis de la science de ces cinquante dernières années. Après une description du cadre théorique, le modèle standard, et de son élaboration durant la deuxième moitié du XXe siècle, l'accent est mis sur ses grands succès expérimentaux, mais aussi sur ses faiblesses ou insuffisances telles que nous les percevons aujourd'hui. La passionnante histoire du grand collisionneur de hadrons du CERN, le LHC, le plus grand projet purement scientifique jamais réalisé, est présentée à la fois sous ses...

  12. Comment on "Constraints on the strength of primordial B-fields from Big Bang nucleosynthesis reexamined"

    CERN Document Server

    Kernan, P J; Vachaspati, T; Kernan, Peter J.; Starkman, Glenn D.; Vachaspati, Tanmay

    1996-01-01

    Recently Cheng, Olinto, Schramm and Truran (COST) reexamined the constraints from big bang nucleosynthesis (BBN) on the strength of primordial magnetic fields. Their bottom line agreed with that of an earlier recent paper on the subject (Kernan, Starkman and Vachaspati (KSV)), both in its final limit on the magnetic field during BBN, and in its conclusion that for allowed values of the magnetic field the dominant factor for BBN is the increased expansion rate at a given temperature caused by the energy density of the magnetic field, $B^2/8\\pi$. However, their conclusion that weak interaction rates increased with increasing B-field at these low field values contradicted the earlier results of KSV. In this comment we point out that the Taylor series expansion of the weak interaction rate about B=0 used in COST is not well-defined, while the Euler-McLaurin expansion of KSV is well-behaved and reliable. Using the Euler-McLaurin expansion we find that the weak interaction rates decrease rather than increase with i...

  13. Revisiting constraints on small scale perturbations from big-bang nucleosynthesis

    CERN Document Server

    Inomata, Keisuke; Tada, Yuichiro

    2016-01-01

    We revisit the constraints on the small scale density perturbations ($10^4\\,\\mathrm{Mpc}^{-1}\\lesssim k \\lesssim10^5\\,\\mathrm{Mpc}^{-1}$) from the modification of the freeze-out value of the neutron-proton ratio at big-bang nucleosynthesis era. Around the freeze-out temperature $T\\sim 0.5\\,\\mathrm{MeV}$, the universe can be divided into several local patches which have different temperatures since any perturbation which enters the horizon after the neutrino decoupling has not diffused yet. Taking account of this situation, we calculate the freeze-out value in detail. We find that the small scale perturbations decrease the n-p ratio in contrast to previous works. With use of the latest observed $^4$He abundance, we obtain the constraint on the power spectrum of the curvature perturbations as $\\Delta^2_\\mathcal{R}\\lesssim 0.018$ on $10^4\\,\\mathrm{Mpc}^{-1}\\lesssim k \\lesssim 10^5\\,\\mathrm{Mpc}^{-1}$.

  14. First life in primordial-planet oceans: the biological big bang

    CERN Document Server

    Gibson, Carl H; Schild, Rudolph E

    2010-01-01

    A scenario is presented for the formation of first life in the universe based on hydro-gravitational-dynamics (HGD) cosmology. From HGD, the dark matter of galaxies is H-He gas dominated planets (primordial-fog-particle PFPs) in million solar mass clumps (protoglobularstarcluster PGCs), which formed at the plasma to gas transition temperature 3000 K. Stars result from mergers of the hot-gas-planets. Over-accretion causes stars to explode as supernovae that scatter life-chemicals (C, N, O, P, S, Ca, Fe etc.) to other planets in PGC clumps and beyond. These chemicals were first collected gravitationally by merging PFPs to form H-saturated, high-pressure, dense oceans of critical-temperature 647 K water over iron-nickel cores at ~ 2 Myr. Stardust fertilizes the formation of first life in a cosmic hot-ocean soup kitchen comprised of all planets and their moons in meteoric communication, > 10^100 kg in total. Ocean freezing slows this biological big bang at ~ 8 Myr. HGD cosmology confirms that the evolving seeds o...

  15. Conference | The Big Bang and the interfaces of knowledge: towards a common understanding? | 11 November

    CERN Multimedia

    2015-01-01

    The third in a series of conferences organised by CERN and Wilton Park, this event will once again bring together scientists, theologians and philosophers to discuss the themes of the nature and understanding of a common language, truth and logic.   Wednesday, 11 November at 4 p.m. in the Main Auditorium For more information and to register, click here. In 2012, CERN and Wilton Park hosted the pioneering international conference “The Big Bang and the interfaces of knowledge: towards a common language?”. The event was very successful and a follow-up conference was organised in June 2014 with the purpose of widening the spectrum of scientists, theologians and philosophers involved, continuing the dialogue on one of the key themes that emerged during the first meeting: the nature and the understanding of “truth”. A key theme emerging from the 2014 event was the nature and understanding of logic, and this third meeting will focu...

  16. Georges Lemaître: The Priest Who Invented the Big Bang

    Science.gov (United States)

    Lambert, Dominique

    This contribution gives a concise survey of Georges Lemaître works and life, shedding some light on less-known aspects. Lemaître is a Belgian catholic priest who gave for the first time in 1927 the explanation of the Hubble law and who proposed in 1931 the "Primeval Atom Hypothesis", considered as the first step towards the Big Bang cosmology. But the scientific work of Lemaître goes far beyond Physical Cosmology. Indeed, he contributed also to the theory of Cosmis Rays, to the Spinor theory, to Analytical mechanics (regularization of 3- Bodies problem), to Numerical Analysis (Fast Fourier Transform), to Computer Science (he introduced and programmed the first computer of Louvain),… Lemaître took part to the "Science and Faith" debate. He defended a position that has some analogy with the NOMA principle, making a sharp distinction between what he called the "two paths to Truth" (a scientific one and a theological one). In particular, he never made a confusion between the theological concept of "creation" and the scientific notion of "natural beginning" (initial singularity). Lemaître was deeply rooted in his faith and sacerdotal vocation. Remaining a secular priest, he belonged to a community of priests called "The Friends of Jesus", characterized by a deep spirituality and special vows (for example the vow of poverty). He had also an apostolic activity amongst Chinese students.

  17. On the Construction of Nonsingular Pre-Big-Bang and Ekpyrotic Cosmologies and the Resulting Density Perturbations

    CERN Document Server

    Tsujikawa, S; Finelli, F; Tsujikawa, Shinji; Brandenberger, Robert; Finelli, Fabio

    2002-01-01

    We consider the construction of nonsingular Pre-Big-Bang and Ekpyrotic type cosmological models realized by the addition to the action of specific higher-order terms stemming from quantum corrections. We study models involving general relativity coupled to a single scalar field with a potential motivated by the Ekpyrotic scenario. We find that the inclusion of the string loop and quantum correction terms in the string frame makes it possible to obtain solutions of the variational equations which are nonsingular and bouncing in the Einstein frame, even when a negative exponential potential is present, as is the case in the Ekpyrotic scenario. We analyze the spectra of perturbations produced during the bouncing phase and find that the spectrum of curvature fluctuations in the model proposed originally to implement the Ekpyrotic scenario has a large blue tilt (n_R = 3). Except for instabilities introduced on small scales, the result agrees with what is obtained by imposing continuity of the induced metric and of...

  18. From First Stars to the Spite Plateau: a Possible Reconciliation of Halo Stars Observations with Predictions from Big Bang Nucleosynthesis

    CERN Document Server

    Piau, L; Beers, T C; Ferguson, J W; Sivarani, T; Truran, J W

    2006-01-01

    Since the pioneering observations of Spite & Spite in 1982, the constant lithium abundance of metal-poor ([Fe/H]<-1.3) halo stars near the turnoff has been attributed a cosmological origin. Closer analysis revealed that the observed abundance lies at $\\Delta$ Li~0.4 dex below the predictions of Big Bang Nucleosynthesis. The measurements of deuterium abundances on the lines of sight toward quasars and the recent data from the Wilkinson Microwave Anisotropy Probe independently confirmed this gap. We suggest here that part of the discrepancy is explained by the first generation of stars that efficiently depleted lithium. Assuming that the models for lithium evolution in the halo turnoff stars and $\\Delta$ Li estimates are correct, we infer that between 1/3 and 1/2 of the baryonic matter of the early halo (~10^9 Mo) was processed through Population III stars. This new paradigm proposes a very economical solution to the lingering difficulty of understanding the properties of the Spite Plateau and its lack o...

  19. S-factor measurement of the 2H(α,γ)6Li reaction at energies relevant for Big-Bang nucleosynthesis

    International Nuclear Information System (INIS)

    For about 20 years now, observations of 6Li in several old metal-poor stars inside the halo of our galaxy have been reported, which are largely independent of the stars' metallicity, and which point to a possible primordial origin. The observations exceed the predictions of the Standard Big-Bang Nucleosynthesis model by a factor of 500. In the relevant energy range, no directly measured S-factors were available yet for the main production reaction 2H(α,γ)6Li, while different theoretical estimations have an uncertainty of up to two orders of magnitude. The very small cross section in the picobarn range has been measured with a deuterium gas target at the LUNA accelerator (Laboratory for Underground Nuclear Astrophysics), located deep underground inside Laboratori Nazionali del Gran Sasso in Italy. A beam-induced, neutron-caused background in the γ-detector occurred which had to be analyzed carefully and subtracted in an appropriate way, to finally infer the weak signal of the reaction. For this purpose, a method to parameterize the Compton background has been developed. The results are a contribution to the discussion about the accuracy of the recent 6Li observations, and to the question if it is necessary to include new physics into the Standard Big-Bang Nucleosynthesis model.

  20. Criticize the Big-bang Cosmology%“大爆炸宇宙学”批评

    Institute of Scientific and Technical Information of China (English)

    黄志洵

    2015-01-01

    the big-bang cosmogony was based on the Hubble’ s astro-observation,he discovered that the remote celestial bodies are leaving far from us. It is the Hubble’ s theory of expanding cosmography. But this theory lacks sufficient proof,then it should be a product of subjective idealism. Another important argument of the theory of exploded cosmogony is that measurement data on microwave background radia-tion,but the data can’ t indicate that the temperature of microwave background radiation should be the re-sult of once exploding. It is never the spread ember at once exploding of an original celestrial body. Ac-cording to the definity of cosmos,people can’ t say “the age of cosmos”,because we only can say “the age of earth”,“the age of solar system” and“the age of star system”;etc. Then,we are against these ab-surd views of big-bang cosmology categorically,because such theoretical system is full of flaws that both science and philosophy all can’ t hold. Although it seems that the universe is riddled with in explicable forces,the theory of dark matter and dark energy just are two hypothesises. Another hypothesis is the exist of gravitational waves,it is just an estimate,but the actual situation might be different. The velocity of gravity in Newton’ s universal law is infinite,but the gravity propagation speed and the velocity of gravitational waves in Einstein’ s theory are the light speed c. The General relativity( GR) explains these features by suggesting that gravitation ( un-like electromagnetic forces) is a pure geometric effect of curved space-time,not a force of nature that propagates. Moreover,now different gravity models need to be considered. For example,if gravity is once again taken to be a propagating force of nature in flat space-time with the propagation speed indicated by observational evidence and experiments:not less than 2 × 1010c(c is the speed of light in vacuum). Al-though faster-than-light force propagation speeds do

  1. Conference | The Big Bang and the interfaces of knowledge: towards a common understanding of Truth? | 25 June

    CERN Multimedia

    2014-01-01

    You are cordially invited to attend the concluding open session of the conference The Big Bang and the interfaces of knowledge: towards a common understanding of Truth?    Wednesday 25 June at 14.30 in the Main Auditorium Please register by Tuesday 24 June at: https://indico.cern.ch/event/325739/ In 2012, CERN and Wilton Park hosted the pioneering international conference “The Big Bank and the interfaces of knowledge: towards a common language?” The purpose of this conference was to enable scientists from a range of disciplines to dialogue with philosophers and theologians from the world religions about the nature of the Big Bang. What understandings might scientists and theologians share in common? How are their paradigms shaped and developed? Is it possible to develop a common framework or language. The conference gained global attention. A follow-up conference will be held on 23-25 June 2014 with the purpose of widening the spectrum of...

  2. Induced Matter Theory of gravity from a Weitzenboeck 5D vacuum and pre-big bang collapse of the universe

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Jesus Martin [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR), Mar del Plata (Argentina); Bellini, Mauricio [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR), Mar del Plata (Argentina); Universidad Nacional de Mar del Plata, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Funes 3350, C.P. 7600, Mar del Plata (Argentina)

    2013-02-15

    We extend the Induced Matter Theory of gravity (IMT) to 5D curved spacetimes by using the Weitzenboeck representation of connections on a 5D curved spacetime. In this representation the 5D curvature tensor becomes null, so that we can make a static foliation on the extra non-compact coordinate to induce in the Weitzenboeck representation the Einstein equations. Once we have done it, we can rewrite the effective 4D Einstein equations in the Levi-Civita representation. This generalization of IMT opens a huge window of possible applications for this theory. A pre-big bang collapsing scenario is explored as an example. (orig.)

  3. A Study of the Subtitle Translation in“The Big Bang Theory”from Newmark’s Communicative Translation Theory

    Institute of Scientific and Technical Information of China (English)

    甄宽; 彭念凡; 甄顺

    2015-01-01

    The subtitle translation is very different from other forms of translation.We translators should meet the particular needs of the subtitle.This study is going to analyze the subtitle translation in“The Big Bang Theory” from Newmark’s Communicative Translation Theory in three main perspectives:the information transmission,the aesthetics effect and the emotional transmission.In the information transmission the study will put emphasis on the limited circumstance.In the aesthetics effect the study will explore the expression of the sense of beauty.In the emotional transmission this study will study the use of rhetoric to express different emotions.

  4. A Study of the Subtitle Translation in “The Big Bang Theory” from Newmark’s Communicative Translation Theory

    Institute of Scientific and Technical Information of China (English)

    甄宽; 彭念凡; 甄顺

    2015-01-01

    The subtitle translation is very different from other forms of translation.We translators should meet the particular needs of the subtitle.This study is going to analyze the subtitle translation in "The Big Bang Theory" from Newmark’s Communicative Translation Theory in three main perspectives:the information transmission,the aesthetics effect and the emotional transmission.In the information transmission the study will put emphasis on the limited circumstance.In the aesthetics effect the study will explore the expression of the sense of beauty.In the emotional transmission this study will study the use of rhetoric to express different emotions.

  5. Codimension-Two Big-Bang Bifurcation in a ZAD-Controlled Boost DC-DC Converter

    Science.gov (United States)

    Amador, A.; Casanova, S.; Granada, H. A.; Olivar, G.; Hurtado, J.

    In this paper, we study some nonlinear behaviors in a two-dimensional system defined by a Boost Converter controlled by CPWM (Centered Pulse-Width Modulation) and a ZAD (Zero Average Dynamics) strategy. The dynamics was analyzed using a discrete-time map, which consists of a sampled system at each switching cycle. The structure of the two-parametric space is characterized analytically. This allows proving the existence and stability of an infinite number of codimension-one curves that intersect at the same point in the two-parametric space. This phenomenon has been called a big-bang bifurcation.

  6. Mediatiserad religion i ramen av humor : En studie av den amerikanska sitcom-serien the Big Bang Theory

    OpenAIRE

    Andersson Happe, Emma

    2015-01-01

    Since 2007 the American sitcom the Big Bang Theory has spread throughout the world. With its twenty million watchers it is one of the most popular sitcoms of our time. The starting point for this essay is that the humourus series with the more or less geeky main characters is more than just entertainment - it is a part of the mediatization of religion. This means that media is affecting the recipients’ view on religion in general and the personal religion. As we watch TV, we get socialized in...

  7. Constraint on Heavy Element Production in Inhomogeneous Big-Bang Nucleosynthesis from The Light-Element Observations

    CERN Document Server

    Nakamura, Riou; Fujimoto, Shin-ichiro; Sato, Katsuhiko

    2013-01-01

    We investigate the observational constraints on the inhomogeneous big-bang nucleosynthesis that Matsuura et al. suggested the possibility of the heavy element production beyond ${}^7$Li in the early universe. From the observational constraints on light elements of ${}^4$He and D, possible regions are found on the plane of the volume fraction of the high density region against the ratio between high-and low-density regions. In these allowed regions, we have confirmed that the heavy elements beyond Ni can be produced appreciably, where $p$- and/or $r$-process elements are produced well simultaneously.

  8. Constraining the cosmic radiation density due to lepton number with Big Bang Nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Mangano, Gianpiero; Miele, Gennaro; Pisanti, Ofelia; Sarikas, Srdjan [Istituto Nazionale di Fisica Nucleare – Sezione di Napoli, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy); Pastor, Sergio, E-mail: mangano@na.infn.it, E-mail: miele@na.infn.it, E-mail: pastor@ific.uv.es, E-mail: pisanti@na.infn.it, E-mail: sarikas@na.infn.it [Instituto de Física Corpuscular (CSIC-Universitat de València), Ed. Institutos de Investigación, Apdo. correos 22085, E-46071 Valencia (Spain)

    2011-03-01

    The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos N{sub eff}. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. In the present analysis we determine the upper bounds that BBN places on N{sub eff} from primordial neutrino-antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations. We consider quite a wide range for the total lepton number in the neutrino sector, η{sub ν} = η{sub ν{sub e}}+η{sub ν{sub μ}}+η{sub ν{sub τ}} and the initial electron neutrino asymmetry η{sub ν{sub e}{sup in}}, solving the corresponding kinetic equations which rule the dynamics of neutrino (antineutrino) distributions in phase space due to collisions, pair processes and flavor oscillations. New bounds on both the total lepton number in the neutrino sector and the ν{sub e}−ν-bar {sub e} asymmetry at the onset of BBN are obtained fully exploiting the time evolution of neutrino distributions, as well as the most recent determinations of primordial {sup 2}H/H density ratio and {sup 4}He mass fraction. Note that taking the baryon fraction as measured by WMAP, the {sup 2}H/H abundance plays a relevant role in constraining the allowed regions in the η{sub ν}−η{sub ν{sub e}{sup in}} plane. These bounds fix the maximum contribution of neutrinos with primordial asymmetries to N{sub eff} as a function of the mixing parameter θ{sub 13}, and point out the upper bound N{sub eff}∼<3.4. Comparing these results with the forthcoming measurement of N{sub eff} by the Planck satellite will likely provide insight on the nature of the radiation content of the universe.

  9. Gravitino, dark matter candidate and implications for big bang nucleosynthesis; Le gravitino, candidat a la matiere noire et les implications en nucleosynthese primordiale

    Energy Technology Data Exchange (ETDEWEB)

    Bailly, S

    2008-11-15

    The Standard Model of particle physics was developed in the seventies. Despite many experimental successes, it presents many problems that can only be solved with models beyond the Standard Model. Supersymmetry is an interesting candidate, postulating a new symmetry between fermions and bosons. This model can also have interesting applications in cosmology. It offers potentially good candidates for dark matter, what represents 25% of the energy density of the Universe, and its nature is unknown. Another cosmological problem is the lithium problems in Big Bang Nucleosynthesis describing the production of light elements in the first seconds of the Universe. The lithium abundance predicted by the theory is inconsistent with observations. I study a scenario in which a supersymmetric particle, the gravitino, is the candidate for dark matter and the production of this particle through the decay of other supersymmetric particles may solve the lithium problems. (author)

  10. "Big Bang'' as a result of first-order phase transition driven by changing scalar curvature in expanding early Universe: "hyperinflation'' scenario

    CERN Document Server

    Pashitskii, E A

    2015-01-01

    We suggest that the "Big Bang" may be a result of the first-order phase transition driven by changing scalar curvature of the 4D space-time in expanding cold Universe, filled with nonlinear scalar field $\\phi $ and neutral matter with equation of state $p=\

  11. The Big Bang and Its Proofs%宇宙大爆炸:有什么证据?

    Institute of Scientific and Technical Information of China (English)

    白杉

    2003-01-01

    @@ 大爆炸理论是关于宇宙形成的最有影响的一种学说,英文说法为Big Bang,也称为大爆炸宇宙论.大爆炸理论诞生于20世纪20年代,在40年代得到补充和发展,但一直寂寂无闻.直到50年代,人们才开始广泛注意这个理论.大爆炸理论的主要观点是认为我们的宇宙诞生于140亿年前,并曾有一段从热到冷的演化史.迄今人类已经获得的宇宙大爆炸证据有下列内容.

  12. 多模态下情景喜剧The Big Bang Theory的字幕翻译

    Institute of Scientific and Technical Information of China (English)

    王祥冰

    2010-01-01

    本文在多模态话语分析的理论框架下,探讨最近流行的美国电视情景喜剧The Big Bang Theory的字幕翻译方法,分析在新的观看方式和特殊的文化环境下,字幕与画面、音响等其他模态之问的关系比传统的辅助作用要更深入,直译的方式能更好发挥字幕的作用,使得该情景喜剧的"幽默交际"得以成功实现.

  13. Problems of antimatter after Big Bang, dark energy and dark matter. Solutions in the frame of non-local physics

    CERN Document Server

    Alexeev, Boris V

    2010-01-01

    Quantum solitons are discovered with the help of generalized quantum hydrodynamics. The solitons have the character of the stable quantum objects in the self consistent electric field. The delivered theory demonstrates the great possibilities of the generalized quantum hydrodynamics in investigation of the quantum solitons. The theory leads to solitons as typical formations in the generalized quantum hydrodynamics. The principle of universal antigravitation is considered from positions of the Newtonian theory of gravitation and non-local kinetic theory. It is found that explanation of Hubble effect in the Universe and peculiar features of the rotational speeds of galaxies need not in introduction of new essence like dark matter and dark energy. Problems of antimatter after Big Bang are considered from positions of non-local physics. The origin of difficulties consists in total Oversimplification following from principles of local physics and reflects the general shortenings of the local kinetic transport theo...

  14. Classical and quantum Big Brake cosmology for scalar field and tachyonic models

    OpenAIRE

    Kamenshchik, Alexander Y.; Manti, Serena

    2012-01-01

    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical ...

  15. Classical and quantum Big Brake cosmology for scalar field and tachyonic models

    OpenAIRE

    Kamenshchik, A.; Manti, S.

    2013-01-01

    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical ...

  16. How to analyse a Big Bang of data: the mammoth project at the Cern physics laboratory in Geneva to recreate the conditions immediately after the universe began requires computing power on an unprecedented scale

    CERN Multimedia

    Thomas, Kim

    2005-01-01

    How to analyse a Big Bang of data: the mammoth project at the Cern physics laboratory in Geneva to recreate the conditions immediately after the universe began requires computing power on an unprecedented scale

  17. Five Colors FILA春季平面广告With BigBang

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    08年就成为FILA代言人的BigBang,强烈的个性形象很适合FILA追求的理念,所以1年多来稳坐代言人的位子。因为BigBang的代言,FILA渐渐成为了全新的青少年流行运动品牌。2010年春季,主打缤纷色彩的FILA为5个男孩量身定做了各自的颜色。

  18. 基于粒子群优化的混合宇宙大爆炸算法%Hybrid Big Bang-Big Crunch Algorithm Based on Particle Swarm Optimization

    Institute of Scientific and Technical Information of China (English)

    吴伟民; 田龙; 林志毅

    2016-01-01

    宇宙大爆炸算法( Big Bang-Big Crunch,BB-BC)思想来源于宇宙大爆炸和大收缩理论。针对其在高维函数的寻优过程中,随迭代次数增加,爆炸生成的碎片解收缩速度慢,多样性快速减弱,质量变差,容易陷入局部最优解的缺点,提出一种混合型BB-BC算法( HBB-BC)。首先,将质心代入当代解中作为奇点解进行改进,提高算法收缩速度;其次,结合粒子群优化的路径优化,提高碎片解的质量;最后,引入宇宙大撕裂理论增加大爆炸阶段碎片解的多样性和跳出局部最优解的能力。通过9个新型测试函数进行测试,测试结果显示,HBB-BC算法在高维函数的寻优性能上更优于BB-BC算法和另一种改进的均匀大爆炸混沌大收缩( UBB-CBC)算法。%The Big Bang-Big Crunch ( BB-BC ) algorithm is based on the big bang and big contraction theory of the universe. With the increase of number of iterations in optimizing of high dimensional func-tions, the candidates shrink slowly, worsen in quality and weaken rapidly in diversity, as well as sink in-to a local optimal solution. In light of these features, an improved hybrid BB-BC algorithm ( HBB-BC) is proposed. This algorithm puts the center of mass into contemporary candidates computing as a singular point solution to increase the speed of contraction and improves the candidates’ quality and enhances its diversity by mean of Particle Swarm optimization (PSO). At last, Big Rip theory is introduced to in-crease the diversity of the big bang phase solutions and the ability to jump out of local optimal solution. The experimental results tested by 9 new benchmark test functions indicate that the improved algorithm performs better than the BB-BC and Uniform Big Bang-Chaotic Big Crunch ( UBB-CBC) on optimization of high dimensional functions.

  19. Big bang nucleosynthesis and the cosmic neutrino background%大爆炸核合成与宇宙背景中微子

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    We present a brief overview of the neutrino decoupling and big bang nucleosynthe-sis in the early universe. The big bang relic neutrinos formed one of the backgrounds of the universe.A few possible ways to directly detect the cosmic neutrino background are briefly introduced, and partic-ular attention is paid to the relic neutrino capture on b-decaying nuclei.%  文章基于大爆炸宇宙学描述了发生于宇宙早期的中微子退耦与轻核素合成事件。退耦后的中微子形成宇宙的背景之一。文章介绍了几种探测宇宙背景中微子的方法,侧重于利用b衰变核俘获超低动能的中微子。

  20. Bid to recreate the Big Bang and unlock the secrets of life hits a

    CERN Multimedia

    Morgan, James

    2007-01-01

    "It was not the kind of "big band" they were hopint for - but the explosion at the new £6.81 bn particle accelerator in Switzerland on Saturday, was "not a major setback", says a British scientist who is leading the project." (1 page)

  1. Large hadron collider will get us closer to the Big Bang

    CERN Multimedia

    Khadilkar, Dhananjay

    2006-01-01

    The LHC consists of a 27 km tunnel located 100 meters under the ground near Geneva in Switzerland, lined with hundreds of superconducting magnets which will accelerate protons and subsequently collide them at mind-boggling energies of 14 terra electorn Volts. The result will be conditions prevalent just microseconds after the Big Band 15 billion years ago (1/2 page)

  2. Analysis of problems in translation from the original English to the Spanish version of two American comedy series : 'Friends' and 'The big bang theory'

    OpenAIRE

    Reynès, Janie

    2015-01-01

    This research focuses on two American TV shows, Friends and The Big Bang Theory. The analysis and comparison of translation segments of both shows in the original version in English and the dubbed version in Spanish enable the translation of humor in general to be studied, and, most specifically, culture-related humor. Some translation mistakes are also described. For each translation segment considered improvable a solution has been proposed. Both shows feature cultural references although F...

  3. Historia del modelo cosmológico estándar LCDM: la cosmología física tras del modelo del big bang

    OpenAIRE

    Luis Peña, Pilar Francisca

    2015-01-01

    Desde que el big bang se asentara como modelo cosmológico estándar han pasado 50 años. En este periodo, la cosmología ha mantenido abierta la cuestión de cuál es la evolución del universo y a través de la teoría inflacionaria ha enfrentado el p

  4. Big-Bang Nucleosynthesis and Gamma-Ray Constraints on Cosmic Strings with a large Higgs condensate

    CERN Document Server

    Mota, H F Santana

    2014-01-01

    We consider constraints on cosmic strings from their emission of Higgs particles, in the case that the strings have a Higgs condensate with amplitude of order the string mass scale, assuming that a fraction of the energy of condensate can be turned into radiation near cusps. The injection of energy by the decaying Higgs particles affects the light element abundances predicted by standard Big-Bang Nucleosynthesis (BBN), and also contributes to the Diffuse Gamma-Ray Background (DGRB) in the universe today. We examine the two main string scenarios (Nambu-Goto and field theory), and find that the primordial Helium abundance strongly constrains the string tension and the efficiency of the emission process. The Fermi-LAT measurement of the DGRB constrains the field theory scenario (but not the NG scenario) even more strongly, requiring that the product of the string tension {\\mu} and Newton's constant G is bounded by G{\\mu} < 3x10^{-11}{\\beta}_{ft}^{-2}, where {\\beta}_{ft}^2 is the fraction of the strings' energ...

  5. Optimal Power flow with valve point loading effects of cost function and mixed-integer control variables using Big-Bang and Big-Crunch optimization.

    Directory of Open Access Journals (Sweden)

    Chatti venkata Gopala krishna Rao

    2012-11-01

    Full Text Available This paper  presents application of Big Bang and Big crunch(BB-BC a nature inspired optimization method which is developed from the  concepts of universal evolution to solve complex static optimal power flow (OPF  with an aim to obtain minimum cost of thermal power generating units whose cost functions  are  non-convex due to  valve point loading effects. Control variables to   optimize   cost functions by satisfying usual constraints of OPF are of continuous and discrete type (mixed- integer control variables. Mathematical programming approaches presents problem in solving non-convex OPF.Nature inspired heuristic methods can be applied to solve such non-convex optimization problems. One of the requirements of heuristic methods are numerical simplicity without trial parameters in update equation of optimization along with reliability and ease in developing computer code for implementation. Most of the nature inspired methods search efficiency and reliability depends on choice of trial parameters to update control variables as optimization advances in search of optimal control variables.BB-BC optimization has search ability on par with other popular heuristic methods but free from choice of trial parameters is applied to obtain OPF solutions on two typical power  systems networks  and results are compared with MATLAB-7.0 pattern  random search optimization tool box .Digital simulation results   indicates a promising nature of the BB-BC to deal with  non-convex optimization requirements of power system situations .

  6. Towards the study of 2H(p, γ)3He reaction in the Big Bang Nucleosynthesis energy range in LUNA

    Science.gov (United States)

    Kochanek, Izabela

    2016-04-01

    The Big Bang Nucleosynthesis began a few minutes after the Big Bang, when the Universe was sufficiently cold to allow deuterium nuclei to survive photo-disintegration. The total amount of deuterium produced in the Universe during the first minutes depends on the cosmological parameters (like the energy density in baryons, Ω bh 2, and the effective neutrino number, Neff ) and on the nuclear cross sections of the relevant reactions. The main source of uncertainty in the deuterium estimation comes from the 2H(p, γ)3He cross section. Measurements of Cosmic Microwave Background (CMB) anisotropies obtained by the Planck satellite are in very good agreement with the theoretical predictions of the minimal ΛCDM cosmological model, significantly reducing the uncertainty on its parameters. The Planck data allows to indirectly deduce with very high precision the abundances of primodial nuclides, such as the primodial deuterium fraction 2H/H = (2.65 ± 0.07) .10-5 (68% C.L.). The astrophysical observations in damped Lyman-a systems at high redshifts provide a second high accuracy measurement of the primodial abundance of deuterium 2H/H = (2.53 ± 0.04) · 10-5 (68% C.L.). The present experimental status on the astrophysical S-factor of the 2H(p, γ)3He reaction in the BBN energy range, gives a systematic uncertainties of 9%. Also the difference between ab-initio calculations and experimental values of S12 is at the level of 10%. In order to clarify the actual scenario, a measurement of 2H(p, γ)3He cross section with a precision of a few percent in the 70-400 keV energy range is planned at LUNA in 2016. A feasibility test of the measurement has been performed in October 2014, giving the preliminary results on the cross section. The experimental setup for the test and final measurement campaign will be presented.

  7. Big Bounce Singularity of a Simple Five-Dimensional Cosmological Model

    Institute of Scientific and Technical Information of China (English)

    徐立昕; 刘宏亚; 王贝利

    2003-01-01

    The big bounce singularity of a simple five-dimensional cosmological model is studied. Contrary to the standard big bang space-time singularity, this big bounce singularity is found to be an event horizon at which the scale factor and the mass density of the universe are finite, while the pressure undergoes a sudden transition from negative infinity to positive infinity. By using coordinate transformation it is also shown that before the bounce the universe contracts deflationary. According to the proper-time, the universe may have existed for an infinitely long time.

  8. Enhancing Teachers' Awareness About Relations Between Science and Religion. The Debate Between Steady State and Big Bang Theories

    Science.gov (United States)

    Bagdonas, Alexandre; Silva, Cibelle Celestino

    2015-11-01

    Educators advocate that science education can help the development of more responsible worldviews when students learn not only scientific concepts, but also about science, or "nature of science". Cosmology can help the formation of worldviews because this topic is embedded in socio-cultural and religious issues. Indeed, during the Cold War period, the cosmological controversy between Big Bang and Steady State theory was tied up with political and religious arguments. The present paper discusses a didactic sequence developed for and applied in a pre-service science teacher-training course on history of science. After studying the historical case, pre-service science teachers discussed how to deal with possible conflicts between scientific views and students' personal worldviews related to religion. The course focused on the study of primary and secondary sources about cosmology and religion written by cosmologists such as Georges Lemaître, Fred Hoyle and the Pope Pius XII. We used didactic strategies such as short seminars given by groups of pre-service teachers, videos, computer simulations, role-play, debates and preparation of written essays. Along the course, most pre-service teachers emphasized differences between science and religion and pointed out that they do not feel prepared to conduct classroom discussions about this topic. Discussing the relations between science and religion using the history of cosmology turned into an effective way to teach not only science concepts but also to stimulate reflections about nature of science. This topic may contribute to increasing students' critical stance on controversial issues, without the need to explicitly defend certain positions, or disapprove students' cultural traditions. Moreover, pre-service teachers practiced didactic strategies to deal with this kind of unusual content.

  9. A galaxy rapidly forming stars 700 million years after the Big Bang at redshift 7.51.

    Science.gov (United States)

    Finkelstein, S L; Papovich, C; Dickinson, M; Song, M; Tilvi, V; Koekemoer, A M; Finkelstein, K D; Mobasher, B; Ferguson, H C; Giavalisco, M; Reddy, N; Ashby, M L N; Dekel, A; Fazio, G G; Fontana, A; Grogin, N A; Huang, J-S; Kocevski, D; Rafelski, M; Weiner, B J; Willner, S P

    2013-10-24

    Of several dozen galaxies observed spectroscopically that are candidates for having a redshift (z) in excess of seven, only five have had their redshifts confirmed via Lyman α emission, at z = 7.008, 7.045, 7.109, 7.213 and 7.215 (refs 1-4). The small fraction of confirmed galaxies may indicate that the neutral fraction in the intergalactic medium rises quickly at z > 6.5, given that Lyman α is resonantly scattered by neutral gas. The small samples and limited depth of previous observations, however, makes these conclusions tentative. Here we report a deep near-infrared spectroscopic survey of 43 photometrically-selected galaxies with z > 6.5. We detect a near-infrared emission line from only a single galaxy, confirming that some process is making Lyman α difficult to detect. The detected emission line at a wavelength of 1.0343 micrometres is likely to be Lyman α emission, placing this galaxy at a redshift z = 7.51, an epoch 700 million years after the Big Bang. This galaxy's colours are consistent with significant metal content, implying that galaxies become enriched rapidly. We calculate a surprisingly high star-formation rate of about 330 solar masses per year, which is more than a factor of 100 greater than that seen in the Milky Way. Such a galaxy is unexpected in a survey of our size, suggesting that the early Universe may harbour a larger number of intense sites of star formation than expected. PMID:24153304

  10. The first three minutes - 1990 version. [of early universe after Big Bang

    Science.gov (United States)

    Schramm, David N.

    1991-01-01

    The present state of understanding of what occurred in the universe's first three minutes is reviewed. Emphasis is on the events that lead to potentially observable consequences and that are model-independent or at least generic to broad classes of models. Inflation, phase transitions, dark matter, and nucleosynthesis are summarized.

  11. Galaxy formation from annihilation-generated supersonic turbulence in the baryon-symmetric big-bang cosmology and the gamma ray background spectrum

    Science.gov (United States)

    Stecker, F. W.; Puget, J. L.

    1972-01-01

    Following the big-bang baryon symmetric cosmology of Omnes, the redshift was calculated to be on the order of 500-600. It is show that, at these redshifts, annihilation pressure at the boundaries between regions of matter and antimatter drives large scale supersonic turbulence which can trigger galaxy formation. This picture is consistent with the gamma-ray background observations discussed previously. Gravitational binding of galaxies then occurs at a redshift of about 70, at which time vortical turbulent velocities of about 3 x 10 to the 7th power cm/s lead to angular momenta for galaxies comparable with measured values.

  12. L'uni de Genève décolle avec Discovery pour une mission aux confins du big bang

    CERN Multimedia

    Ruetschi, P

    1998-01-01

    Discovery d\\’{e}collera mardi soir de Cap Carnaveral. Dans sa soute, les trois tonnes de l'AMS, la plus importante exp\\’{e}rience de physique des particules jamais tent\\’{e}e dans l'espace. L'Universi t\\’{e} de Gen\\ {e}ve et l'EPFZ se sont impos\\’{e}es en leader dans cette chasse \\ {a} l'antimati\\ {e}re qui pourrait revolutionner la th\\’{e}orie du big bang.

  13. The Biological Big Bang: The First Oceans of Primordial Planets at 2-8 Million Years Explain Hoyle/Wickramasinghe Cometary Panspermia

    OpenAIRE

    Gibson, Carl H.

    2011-01-01

    Hydrogravitional-dynamics (HGD) cosmology of Gibson/Schild 1996 predicts that the primordial H-He^4 gas of big bang nucleosynthesis became proto-globular-star-cluster clumps of Earth-mass planets at 300 Kyr. The first stars formed from mergers of these 3000 K gas planets. Chemicals C, N, O, Fe etc. created by stars and supernovae then seeded many of the reducing hydrogen gas planets with oxides to give them hot water oceans with metallic iron-nickel cores. Water oceans at critical temperature...

  14. Big Bang: un recurso didáctico-pedagógico en el aprendizaje de la implementación de algoritmos en pseudocódigo

    OpenAIRE

    Cortes, Eduardo; Vanoli, Verónica; Casas, Sandra

    2006-01-01

    El proceso de enseñanza y aprendizaje de los cursos iniciales de nivel superior que tienen por objeto introducir al estudiante en el diseño e implementación de algoritmos, puede ser favorecido mediante el uso de herramientas específicas que den soporten tanto a los temas conceptuales como a las técnicas utilizadas. BIG BANG es una herramienta construida y utilizada como recurso didáctico-pedagógico en estos contextos, cuyo objetivo es facilitar la complementación de las prácticas habitualm...

  15. The Structure of the Big Bang from Higher-Dimensional Embeddings

    OpenAIRE

    Seahra, Sanjeev S.; Wesson, Paul S.

    2002-01-01

    We give relations for the embedding of spatially-flat Friedmann-Robertson-Walker cosmological models of Einstein's theory in flat manifolds of the type used in Kaluza-Klein theory. We present embedding diagrams that depict different 4D universes as hypersurfaces in a higher dimensional flat manifold. The morphology of the hypersurfaces is found to depend on the equation of state of the matter. The hypersurfaces possess a line-like curvature singularity infinitesimally close to the $t = 0^+$ 3...

  16. Testing the Big Bang: Light elements, neutrinos, dark matter and large-scale structure

    Science.gov (United States)

    Schramm, David N.

    1991-01-01

    Several experimental and observational tests of the standard cosmological model are examined. In particular, a detailed discussion is presented regarding: (1) nucleosynthesis, the light element abundances, and neutrino counting; (2) the dark matter problems; and (3) the formation of galaxies and large-scale structure. Comments are made on the possible implications of the recent solar neutrino experimental results for cosmology. An appendix briefly discusses the 17 keV thing and the cosmological and astrophysical constraints on it.

  17. First direct measurement of the 2H(α,γ)6Li cross section at big bang energies and the primordial lithium problem.

    Science.gov (United States)

    Anders, M; Trezzi, D; Menegazzo, R; Aliotta, M; Bellini, A; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Davinson, T; Elekes, Z; Erhard, M; Formicola, A; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Marta, M; Mazzocchi, C; Prati, P; Rossi Alvarez, C; Scott, D A; Somorjai, E; Straniero, O; Szücs, T

    2014-07-25

    Recent observations of (6)Li in metal poor stars suggest a large production of this isotope during big bang nucleosynthesis (BBN). In standard BBN calculations, the (2)H(α,γ)(6)Li reaction dominates (6)Li production. This reaction has never been measured inside the BBN energy region because its cross section drops exponentially at low energy and because the electric dipole transition is strongly suppressed for the isoscalar particles (2)H and α at energies below the Coulomb barrier. Indirect measurements using the Coulomb dissociation of (6)Li only give upper limits owing to the dominance of nuclear breakup processes. Here, we report on the results of the first measurement of the (2)H(α,γ)(6)Li cross section at big bang energies. The experiment was performed deep underground at the LUNA 400 kV accelerator in Gran Sasso, Italy. The primordial (6)Li/(7)Li isotopic abundance ratio has been determined to be (1.5 ± 0.3) × 10(-5), from our experimental data and standard BBN theory. The much higher (6)Li/(7)Li values reported for halo stars will likely require a nonstandard physics explanation, as discussed in the literature. PMID:25105610

  18. First direct measurement of the 2H(α,γ)6Li cross section at big bang energies and the primordial lithium problem.

    Science.gov (United States)

    Anders, M; Trezzi, D; Menegazzo, R; Aliotta, M; Bellini, A; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Davinson, T; Elekes, Z; Erhard, M; Formicola, A; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Marta, M; Mazzocchi, C; Prati, P; Rossi Alvarez, C; Scott, D A; Somorjai, E; Straniero, O; Szücs, T

    2014-07-25

    Recent observations of (6)Li in metal poor stars suggest a large production of this isotope during big bang nucleosynthesis (BBN). In standard BBN calculations, the (2)H(α,γ)(6)Li reaction dominates (6)Li production. This reaction has never been measured inside the BBN energy region because its cross section drops exponentially at low energy and because the electric dipole transition is strongly suppressed for the isoscalar particles (2)H and α at energies below the Coulomb barrier. Indirect measurements using the Coulomb dissociation of (6)Li only give upper limits owing to the dominance of nuclear breakup processes. Here, we report on the results of the first measurement of the (2)H(α,γ)(6)Li cross section at big bang energies. The experiment was performed deep underground at the LUNA 400 kV accelerator in Gran Sasso, Italy. The primordial (6)Li/(7)Li isotopic abundance ratio has been determined to be (1.5 ± 0.3) × 10(-5), from our experimental data and standard BBN theory. The much higher (6)Li/(7)Li values reported for halo stars will likely require a nonstandard physics explanation, as discussed in the literature.

  19. Big-Bang-Gate Cosmic Titanic: Why Aren't Physics Journal's Editors Bringing It To The Center of Scientific Attention

    Science.gov (United States)

    Gentry, Robert

    2010-02-01

    Until now science's greatest debacle occurred when Copernicus exposed Ptolemaic cosmologists' 1300 hundred year-long fraud that it must be true because observations fit theory so well, while they ignored the untested state of its central assumption of Earth centered planetary motion. With much hubris modern physicists are confident this could never happen again, that the integrity of physics journals editors suffices to guarantee that a challenge to the reigning cosmological theory -- big bang cosmology -- would immediately be brought to the center of scientific attention for analysis and discussion. In fact a decade ago it was reported [MPLA 2619 (1997); arXiv:gr-gc/9806061] that, like Ptolemaic cosmology before it, big bang's central assumption that GR expansion effects cause in-flight expansion had never been tested and, further, that experimental testing of it using GR operation of the GPS showed it to be false. This result proves it is impossible for the 2.73 K CBR to be fireball relic radiation. These results were expanded in CERN reports EXT-2003-021;022, but have been uniformly rejected by physics journals, one of which accepted a paper similar to CERN EXT-2003-022, only to reject it a few days later with the admission not to publish it because of fearing reaction of the worldwide physics community. For update on my PRL submission see http://www.alphacosmos.net. )

  20. The Big Bang machine

    CERN Multimedia

    Cox, Brian

    2009-01-01

    "At Cern in Geneva, 10'000 scientists form all over the world have gathered to discover the secrets of the universe. We drove there in a new Volvo C30 to watch the preparations for the second switch on" (12 pages)

  1. Jupiter's Big Bang.

    Science.gov (United States)

    McDonald, Kim A.

    1994-01-01

    Collision of a comet with Jupiter beginning July 16, 1994 will be observed by astronomers worldwide, with computerized information relayed to a center at the University of Maryland, financed by the National Aeronautics and Space Administration and National Science Foundation. Geologists and paleontologists also hope to learn more about earth's…

  2. Clash over Big Bang

    CERN Multimedia

    Hawkes, N

    1999-01-01

    A recent announcement from Fermilab that they had discovered a precise value for the degree of CP Violation, has angered scientists at CERN who say the 'new' result is simply confirmation of results gained at CERN eleven years ago (1 page).

  3. Finding the Big Bang

    Science.gov (United States)

    Peebles, P. James E.; Page, Lyman A., Jr.; Partridge, R. Bruce

    2009-03-01

    1. Introduction; 2. A guide to modern cosmology; 3. Origins of the cosmology of the 1960s; 4. Recollections of the 1960s Dave Hogg, Neville Woolf, George B. Field, Patrick Thaddeus, Donald E. Osterbrock, Yuri Nikolaevich Smirnov, Igor Dmitriyevich Novikov, Andrei Georgievich Doroshkevich, Rashid Alievich Sunyaev, Malcolm S. Longair, Arno Penzias, Robert W. Wilson, Bernard F. Burke, Kenneth C. Turner, P. James E. Peebles, David T. Wilkinson, Peter G. Roll, R. Bruce Partridge, Malcolm S. Longair, John Faulkner, Robert V. Wagoner, Martin Rees, Geoffrey R. Burbidge, Jayant V. Narlikar, David Layzer, Michele Kaufman, Jasper V. Wall, John Shakeshaft, William Welch, Kazimir S. Stankevich, Paul Boynton, Robert A. Stokes, Martin Harwit, Judith L. Pipher, Kandiah Shivanandan, Rainer Weiss, Jer-tsang Yu, Rainer K. Sachs, Arthur M. Wolfe, Joe Silk, George F. R. Ellis, Ronald N. Bracewell, Edward K. Conklin, Stephen Boughn, Karl C. Davis, Paul S. Henry; 5. Cosmology and the CMBR since the 1960s Dick Bond; Appendixes; Glossary; References; Index.

  4. The analysis of irony through relevance theory in The Big Bang Theory sitcom = A análise da ironia por meio da teoria da relevância na comédia de situação The Big Bang Theory

    Directory of Open Access Journals (Sweden)

    Izaias, Karla Camila Oliveira

    2011-01-01

    Full Text Available Neste trabalho, será analisada a teoria da relevância proposta por Sperber e Wilson. Adicionalmente, a figura de linguagem ironia será descrita. Esse referencial teórico será utilizado para analisar um episódio da comédia de situação intitulado "The Big Bang Theory", em um esforço para demonstrar como enunciados são compreendidos entre os personagens e o público e como ironia é largamente utilizada como recurso humorístico

  5. The analysis of irony through relevance theory in The Big Bang Theory sitcom = A análise da ironia por meio da teoria da relevância na comédia de situação The Big Bang Theory

    OpenAIRE

    Izaias, Karla Camila Oliveira

    2011-01-01

    Neste trabalho, será analisada a teoria da relevância proposta por Sperber e Wilson. Adicionalmente, a figura de linguagem ironia será descrita. Esse referencial teórico será utilizado para analisar um episódio da comédia de situação intitulado "The Big Bang Theory", em um esforço para demonstrar como enunciados são compreendidos entre os personagens e o público e como ironia é largamente utilizada como recurso humorístico.

  6. Animal models of psychopathology: the establishment, maintenance, attenuation, and persistence of head-banging by pigeons.

    Science.gov (United States)

    Layng, T V; Andronis, P T; Goldiamond, I

    1999-03-01

    Investigators of animal models of psychopathology have typically introduced experimental conditions so that an animal's behavior progressively deviates from a baseline of routine laboratory behavior toward a pattern which resembles human psychopathological behavior in some form of S, then R relation. The present experiments report consequential contingency procedures for bringing head-to-wall head-banging by an animal under experimental control and analysis. The first two experiments examined the establishment and maintenance by reinforcement of head-banging by pigeons. The final two experiments examined the occurrence of head-banging, under conditions of extinction and limited reinforcement, when an alternative behavior, i.e., key-pecking, was reinforced under a variety of reinforcement schedules. Extinguished and infrequently reinforced head-banging was found to recur under a variety of conditions including the reinforcement of the more "normal" alternative behavior. To the extent that human patterns are governed by similar functional relations, the data may be of relevance in the analysis of the maintenance, attenuation, and recurrence of human patterns designated as pathological. Further, the permanent elimination of a disturbing pattern may be difficult, and the recurrence of a disturbing pattern might properly be considered a likely and "normal" outcome of basic behavioral processes. PMID:10365865

  7. Innovación empresarial y desarrollo económico: De la destrucción creativa al big bang social coordinado

    Directory of Open Access Journals (Sweden)

    Carmen González Marsal

    2015-09-01

    Full Text Available El presente artículo parte de la distinción de Schumpeter entre innovación e invención en función de sus consecuencias económicas y analiza su conocido concepto de destrucción creativa provocada por la innovación empresarial. A continuación, se centra en el decisivo efecto de armonización social del ejercicio de la empresarialidad, sugiriendo la superación del concepto schumpeteriano a través de la idea de la creatividad coordinadora. De esta forma, se comprende que la innovación empresarial en vez de conducir a la autodestrucción del capitalismo, hace posible el desarrollo económico y social de manera ilimitada, proceso que ha sido denominado big bang social coordinado.

  8. 功能目的论视角下情景喜剧字幕翻译研究——以The Big Bang Theory为例

    Institute of Scientific and Technical Information of China (English)

    房晶

    2011-01-01

    德国功能主义目的论在行为理论、语篇语言学和交际理论的基础上,提出了翻译目的决定翻译策略,将译者从直译还是意译的两难处境中解放出来,增加了可供选择的翻译策略,为译者灵活处理源语文本提供了理论依据。本文以美国情景喜剧The Big Bang Theory为例,分别从目的论的"目的原则"、"连贯原则"和"忠诚原则"三方面,分析了该剧字幕的翻译方法和策略。

  9. An Analysis of Humor of the Big Bang Theory (Season Six)%《生活大爆炸》第六季的幽默探析

    Institute of Scientific and Technical Information of China (English)

    邬贝贝; 潘文红

    2014-01-01

    This paper analyzes humor of The Big Bang Theory (Season Six) from the perspective of violation of the cooperative principle .The study helps enable English learners to have a better understanding of Grice ’ s cooperative principle and enhance their appreciation of English humor in situation comedies .%以《生活大爆炸》第六季的对话为语料,从违反合作原则的角度出发,探讨会话者因违反合作原则的四个准则而产生的幽默效果,从而加强英语学习者对格莱斯会话含义理论的理解,提高对情景喜剧中英语幽默的欣赏能力。

  10. The Study of Pedantic Language in the Big Bang Theory%《生活大爆炸》中学究语研究

    Institute of Scientific and Technical Information of China (English)

    王亚辉

    2014-01-01

    Variants vary via variable communities. Social dialect reflects in distinct speech communities caused by social factors. Pedantic language, a sort of academic style used by speech communities with high education background, is a language variety stylized with advanced terminologies and complex sentences. The TV The Big Bang Theory, with its unique script setting, cate-gorizes its dialogues into pedantic language. Its plays discernibly incarnate the use of pedantic language in specific registers, and dis-play the impacts of it with other varieties of speech communities to some extent. This paper tentatively studies the influence of ac-ademic style on inappropriate registers through the corpus of season two of The Big Bang Theory.%语言变体随社会网络变化而迥异。社群言语的抽象表现就是由社会因素造成的社会方言。“学究语”是受教育程度相当高的社会团体使用的学术性语体,话语中常包含高级术语和复杂长句,是语言变体的一种。美剧《生活大爆炸》中独特地剧本背景设定将角色语言划归为学究语,在不同程度上表现出学究语作为独特的语言变体在特定语域中的作用,以及与不同社群的其他语言变体的冲突。该文对该剧第二季语料中的语言变体进行分析,试解读固定语域下非恰当语体对听话人造成的影响。

  11. Empirical Determination of Bang-Bang Operations

    CERN Document Server

    Byrd, M S; Byrd, Mark S.; Lidar, Daniel A.

    2003-01-01

    Strong and fast "bang-bang" (BB) pulses have been recently proposed as a means for reducing decoherence in a quantum system. So far theoretical analysis of the BB technique relied on model Hamiltonians. Here we introduce a method for empirically determining the set of required BB pulses, that relies on quantum process tomography. In this manner an experimenter may tailor his or her BB pulses to the quantum system at hand, without having to assume a model Hamiltonian.

  12. Model Development Industrial Cluster Coffee Arabica in The District Bangli, Province of Bali

    Directory of Open Access Journals (Sweden)

    I Gusti Bagus Udayana

    2015-04-01

    Full Text Available Indonesian coffee commodity is non-oil export commodities the which contributes to the increase of in foreign exchange. The coffee agribusiness development Efforts have been undertaken by the government, but there are still many obstacles, especially in maintaining the quality of products that meet international market standards and continuity of production in accordance with market demand and to support a downstream industry of agricultural production. This research is the development of industrial clusters Earlier research arabica coffee. The results Showed that the human resources and knowledge about the importance of the coffee plant in Bangli society is still very low, this is evidenced by the many farmers replacing the coffee with citrus plants. Cluster models produced is the result of the development of the models on previous research. In the development of this models and the results of the field survey results show the need for forming FGD Control of Agro-Industry Forum Bangli. This forum Aimed to control and anticipate the development of information to replace the coffee plant with coffee other than agricultural industrial commodities like oranges. Many coffee farmers have replaced coffee with citrus plants. If this continues to Happen it is feared that coffee production has gained International recognition will Decrease. This controller Bangli Agro-Industry Forum in collaboration with Industrial Cluster Management Communication Forum Coffee Arabica and core industry of arabica coffee

  13. Big Bangs in Galaxy Clusters: Using X-ray Temperature Maps to Trace Merger Histories in Clusters with Radio Halos/Relics

    Science.gov (United States)

    Burns, Jack O.; Datta, Abhirup; Hallman, Eric J.

    2016-06-01

    Galaxy clusters are assembled through large and small mergers which are the most energetic events ("bangs") since the Big Bang. Cluster mergers "stir" the intracluster medium (ICM) creating shocks and turbulence which are illuminated by ~Mpc-sized radio features called relics and halos. These shocks heat the ICM and are detected in x-rays via thermal emission. Disturbed morphologies in x-ray surface brightness and temperatures are direct evidence for cluster mergers. In the radio, relics (in the outskirts of the clusters) and halos (located near the cluster core) are also clear signposts of recent mergers. Our recent ENZO cosmological simulations suggest that around a merger event, radio emission peaks very sharply (and briefly) while the x-ray emission rises and decays slowly. Hence, a sample of galaxy clusters that shows both luminous x-ray emission and radio relics/halos are good candidates for very recent mergers. We are in the early stages of analyzing a unique sample of 48 galaxy clusters with (i) known radio relics and/or halos and (ii) significant archival x-ray observations (>50 ksec) from Chandra and/or XMM. We have developed a new x-ray data analysis pipeline, implemented on parallel processor supercomputers, to create x-ray surface brightness, high fidelity temperature, and pressure maps of these clusters in order to study merging activity. The temperature maps are made using three different map-making techniques: Weighted Voronoi Tessellation, Adaptive Circular Binning, and Contour Binning. In this talk, we will show preliminary results for several clusters, including Abell 2744 and the Bullet cluster. This work is supported by NASA ADAP grant NNX15AE17G.

  14. 宇舶Big Bang Unico系列10周年高级珠宝手表

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    宇舶是第一个将贵金属与天然橡胶融合的手表,2005年革命性地推出BigBang系列,一经推出就囊括了业界多个大奖。距离当初的初露锋芒,已经过去十年,这是宇舶为2015年巴塞尔钟表展推出的三款Big Bang系列手表的其中一种款式。

  15. Big Bang and bucks set to collide in inner space The price of exploring inner space went up this week

    CERN Multimedia

    Overbye, Dennis

    2007-01-01

    "At a news conference in Beijing this Thursday, an international consortium of physicists released the first detailed design of what they believe will be the Next Big Thing in physics: a machine 20 miles long that will slam together electrons and their evil-twin opposites, positrons, to produce fireballs of energy recreating conditions when the universe was only a trillionth of a second old." (1.5 page)

  16. 将美剧引入高职英语课堂促进跨文化意识培养--以The Big Bang Theory为例

    Institute of Scientific and Technical Information of China (English)

    王梦君

    2015-01-01

    语言学习的最终目标是进行交际,学习者只在语言学层面学习语言,而缺乏跨文化意识,并不能够达到此目标。英语非母语国家的英语教学普遍存在的问题之一,是对英语学习者缺乏充分的跨文化意识输入和培养。传媒的全球化发展为语言教学者提供了一个很好的媒介来解决这一问题。The Big Bang Theory是广受国内大学生喜爱的美剧之一,全剧节奏明快,语言精炼地道,场景能够还原生活并有连续性,人物特征鲜明,将此剧引入课堂对学习者跨文化意识的输入和培养大有裨益。

  17. Unsolved Mysteries of Science: A Mind-Expanding Journey through a Universe of Big Bangs, Particle Waves, and Other Perplexing Concepts

    Science.gov (United States)

    Malone, John

    2001-08-01

    A LIVELY EXPLORATION OF THE BIGGEST QUESTIONS IN SCIENCE How Did the Universe Begin? The Big Bang has been the accepted theory for decades, but does it explain everything? How Did Life on Earth Get Started? What triggered the cell division that started the evolutionary chain? Did life come from outer space, buried in a chunk of rock? What is Gravity? Newton's apple just got the arguments started, Einstein made things more complicated. Just how does gravity fit in with quantum theory? What Is the Inside of the Earth Like? What exactly is happening beneath our feet, and can we learn enough to help predict earthquakes and volcanic eruptions? How Do We Learn Language? Is language acquisition an inborn biological ability, or does every child have to start from scratch? Is There a Missing Link? The story of human evolution is not complete. In addition to hoaxes such as "Piltdown Man" and extraordinary finds such as "Lucy," many puzzles remain. What, in the end, do we mean by a "missing link"?

  18. ECM and Verbal Humor—Take Big Bang Theory as an Example%事件域认知模型与言语幽默——以美剧《生活大爆炸》为例

    Institute of Scientific and Technical Information of China (English)

    高文璐

    2012-01-01

      以王寅教授提出的事件域认知模型(ECM)为理论基础,从认知的角度对美国情景喜剧《生活大爆炸》中的言语幽默进行动态分析.ECM对言语幽默具有很强的解释力,通过ECM中的事件(Event)、行为/事体(A/B)、特征性或分类性特征(D/C)三个层面探究《生活大爆炸》中言语幽默产生的动态机制.%  Event-domain Cognitive Model (ECM), proposed by Chinese professor Wang Yin, is applied to dynamically the cog⁃nitive analysis of verbal humor in an American sitcom Big Bang Theory. It affords a strong explanatory power for the formation of verbal humor. The ECM theory tries to explore the dynamic mechanism of verbal humor on the EVENT, ACTION, BEING and D/C levels.

  19. Gabriele Veneziano : "La physique moderne doit dépasser Einstein et explorer l'avant-Big Bang"

    CERN Multimedia

    Deschamps, Pascale-Marie

    2004-01-01

    Interview with Gabriele Veneziana: in search of the infinitesimally small and infinitesimally large, the Standard Model of elementary particles and Einstein's general relativity are not enough to explain the universe. The "visible" matter predicted by the Standard Model represents only 5% of the energy of the Universe, the dark "invisible" matter constitutes 25 to 30%. Therefore 65 to 70 % of something else is missing. String theory calls into question all that one knows of the primordial universe formulated by the Standard Model (4 pages)

  20. A study on verbal humor in The Big Bang Theory from the perspective of relevance theory%从关联理论视角解读《生活大爆炸》中的言语幽默

    Institute of Scientific and Technical Information of China (English)

    陈丽玉

    2013-01-01

    本文运用关联理论解读美国情景喜剧《生活大爆炸》中的幽默对白,探讨言语幽默的产生机制,以期更好地理解和欣赏言语幽默。%The present paper aims to study verbal humor in the American sitcom The Big Bang Theory from a perspective of Relevance Theory with a purpose of summarizing the generating mechanism of verbal humor and providing suggestions for better appreciation of verbal humor.

  1. Constraint on a varying proton-electron mass ratio 1.5 billion years after the big bang.

    Science.gov (United States)

    Bagdonaite, J; Ubachs, W; Murphy, M T; Whitmore, J B

    2015-02-20

    A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10% of the age of the Universe today, is analyzed to put a constraint on a varying proton-electron mass ratio, μ. A high resolution spectrum of the J1443+2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to μ, yielding a limit on the relative deviation from the current laboratory value of Δμ/μ=(-9.5 ± 5.4(stat)± 5.3(syst))×10(-6). PMID:25763949

  2. A constraint on a varying proton--electron mass ratio 1.5 billion years after the Big Bang

    CERN Document Server

    Bagdonaite, J; Murphy, M T; Whitmore, J B

    2015-01-01

    A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10$\\%$ of the age of the universe today, is analyzed to put a constraint on a varying proton--electron mass ratio, $\\mu$. A high resolution spectrum of the J1443$+$2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to $\\mu$, yielding a limit on the relative deviation from the current laboratory value of $\\Delta\\mu/\\mu=(-9.5\\pm5.4_{\\textrm{stat}} \\pm 5.3_{\\textrm{sys}})\\times 10^{-6}$.

  3. A universal, post Big-Bang Nucleo-synthesis, pre-Galactic, origin of the Lithium (Spite) Plateau

    CERN Document Server

    Ouyed, Rachid

    2012-01-01

    (Abridged abstract) We investigate the lithium plateau in the context of primordial dual-shock quark novae (dsQNe; i.e. a QN occurring a few days to a few weeks following the preceding SN explosion) going off in the wake of Pop. III stars. The neutron-rich relativistic QN ejecta leads to spallation of 56Ni processed in the ejecta of the preceding SN ejecta and thus to "iron impoverishment" of the primordial gas swept by dsQNe. We show that the generation of stars formed from fragmentation of pristine clouds swept-up by dsQNe acquire a metallicity with -7.5 2 (and up to [C/Fe] ~ 5) can be accounted for in our model for dsQNe with t_delay 10-11 days (i.e. [Fe/H] > -3). For shorter delays the temperature of the SN shell is too hot (> 2.5x10^6 K) for the spallated 7Li to survive. We find a corresponding 6Li plateau with 6Li/7Li < 0.3.

  4. Research on the Subtitle Translation of "The Big Bang Theory" from the Perspective of Functional Equivalence Theory%功能对等视角下《生活大爆炸》字幕翻译研究

    Institute of Scientific and Technical Information of China (English)

    蒋婷婷; 高圣兵

    2014-01-01

    "The Big Bang Theory"is a popular sitcom welcomed by a large audience. The features and limitations of the subtitles are fully showed in this sitcom, so the research can be done to this sitcom. In order to find out whether the subtitle translation have met the need of equivalence with different translating skills and methods and how they meet it, this paper presents a case study of American sitcom "The Big Bang Theory" within the framework of functionalism.%《生活大爆炸》是一个广受喜欢的情景喜剧。其字幕翻译中,包含了许多影视翻译的特征和制约因素,本文从语言和文体方面选取一些比较典型的对话片段,分析说明在翻译过程中是如何做到功能对等的,进而论证奈达的功能对等理论对字幕翻译具有实践性指导作用。

  5. Big Bang Day : Physics Rocks

    CERN Multimedia

    Brian Cox; John Barrowman; Eddie Izzard

    2008-01-01

    Is particle physics the new rock 'n' roll? The fundamental questions about the nature of the universe that particle physics hopes to answer have attracted the attention of some very high profile and unusual fans. Alan Alda, Ben Miller, Eddie Izzard, Dara O'Briain and John Barrowman all have interests in this branch of physics. Brian Cox - CERN physicist, and former member of 90's band D:Ream, tracks down some very well known celebrity enthusiasts and takes a light-hearted look at why this subject can appeal to all of us.

  6. Did the big bang boil?

    CERN Multimedia

    Wilczek, Frank

    2006-01-01

    "Standard theories tell us that, at some point in the Universe's evolution, free quarks and gluons must have become bound together into the hadronic matter we see today. But was this transition abrupt or smooth?

  7. Big Bang Day: Engineering Solutions

    CERN Multimedia

    Lyn Evans; Austin Ball; Jim Virdee; Adam Hart-Davis

    2008-01-01

    CERN's Large Hadron Collider is the most complicated scientific apparatus ever built. Many of the technologies it uses hadn't even been invented when scientists started building it. Adam Hart-Davis discovers what it takes to build the world's most intricate discovery machine.

  8. Birmingham probes the Big Bang

    CERN Multimedia

    2007-01-01

    "The world's largest particle accelerator in Geneva is gearing up to begin work again. BBC Midlands Today science correspondent David Gregory went to see how scientists from the University of Birmingham are at the heart of trying to understand what makes our universe tick." (1 page)

  9. Retour vers le Big Bang

    CERN Multimedia

    Pentier, Olivier

    2007-01-01

    A laboratory from Grenoble participated in the building of LHC (Large Hadron Collider) at CERN. This particle accelerator, operational at the end of 2007, will help to understand how the universe was born. (1 page)

  10. Scientists recreating the Big Bang

    CERN Multimedia

    Bagla, Pallava

    2007-01-01

    "Beneath the breathtaking alpine vineyards, work is on at a feverish pace to complete a machine nickmamed the "Lord of Rings". Otherwise called a particle accelerator, it will be switched on next summer." (1/2 page)

  11. Matrix Big Brunch

    OpenAIRE

    Bedford, J; Papageorgakis, C.; Rodriguez-Gomez, D.; Ward, J.

    2007-01-01

    Following the holographic description of linear dilaton null Cosmologies with a Big Bang in terms of Matrix String Theory put forward by Craps, Sethi and Verlinde, we propose an extended background describing a Universe including both Big Bang and Big Crunch singularities. This belongs to a class of exact string backgrounds and is perturbative in the string coupling far away from the singularities, both of which can be resolved using Matrix String Theory. We provide a simple theory capable of...

  12. 从英汉文化差异角度看2012年热播美剧Gossip Girl和The Big Bang Theory的字幕翻译

    Institute of Scientific and Technical Information of China (English)

    孟芸

    2013-01-01

    如今.不论电视剧还是电影领域,从美国引进的作品都占有重要一席。然而目前大部分中国人还不具备不依赖字幕直接欣赏英语片的能力,因此字幕翻译正日益受到影视爱好者和语言学习者的高度重视。本文主要从英汉文化差异看2012年热播关剧Gossip Girl和The Big Bang Theory的字幕翻译以及其对翻译策略选择的影响。

  13. Interpretation of Irony in the Big Bang Theory from the Perspective of Relevance%关联理论视角下《生活大爆炸》中的反语阐释

    Institute of Scientific and Technical Information of China (English)

    郑燕

    2013-01-01

    Irony study is drawing more and more attention from linguists. The basic claim in this article will be illustrated with these three prototypical cases by analyzing ironic utterances in the Big Bang Theory. The aim is to show how the relevance-theoret⁃ic framework of verbal irony describe and explain ironic communication in this comedy.%  反语研究正在受到越来越多语言学家的关注。此文将通过《生活大爆炸》里的三个典型的案例分析来阐释反语,其研究目的是研究关联理论如何描述和解释这部喜剧里的反语。

  14. From God's particle to the world formula. Big Bang, Higgs, antimatter, and the mysterious shadow world; Vom Gottesteilchen zur Weltformel. Urknall, Higgs, Antimaterie und die raetselhafte Schattenwelt

    Energy Technology Data Exchange (ETDEWEB)

    Vaas, Ruediger

    2013-07-01

    Our knowledge about the elementary particles stands before a revolution: With the biggest machine of mankind the legendary Higgs boson was discovered - and for its prediction the Nobel prize awarded. Other researchers search for antiparticles from the universe and the shadow regime of the dark matter. What has be happened after the big bang? How the components of the universe have been arised? Of which consists the world - and why it exists at all? Science reporter and cosmology specialist Ruediger Vaas bends the bow from the smallest of all to the largest of all. He analyzes the actual state of knowledge and reports about the search for a ''world formula'', which explains, what holds the universe together in the innermost. A unique excursion to the fronts of research.

  15. Modeling and Management of Big Data: Challenges and opportunities

    OpenAIRE

    Gil Méndez, David; Song, Il-Yeol

    2016-01-01

    The term Big Data denotes huge-volume, complex, rapid growing datasets with numerous, autonomous and independent sources. In these new circumstances Big Data bring many attractive opportunities; however, good opportunities are always followed by challenges, such as modelling, new paradigms, novel architectures that require original approaches to address data complexities. The purpose of this special issue on Modeling and Management of Big Data is to discuss research and experience in modellin...

  16. The big bang as a result of the first-order phase transition driven by a change of the scalar curvature in an expanding early Universe: The "hyperinflation" scenario

    Science.gov (United States)

    Pashitskii, E. A.; Pentegov, V. I.

    2016-01-01

    We suggest that the Big Bang could be a result of the first-order phase transition driven by a change in the scalar curvature of the 4D spacetime in an expanding cold Universe filled with a nonlinear scalar field φ and neutral matter with an equation of state p = νɛ (where p and ɛ are the pressure and energy density of the matter, respectively). We consider the Lagrangian of a scalar field with nonlinearity φ4 in a curved spacetime that, along with the term-ξ R|φ|2 quadratic in φ (where ξ is the interaction constant between the scalar and gravitational fields and R is the scalar curvature), contains the term ξ Rφ0(φ + φ+) linear in φ, where φ0 is the vacuum mean of the scalar field amplitude. As a consequence, the condition for the existence of extrema of the scalar-field potential energy is reduced to an equation cubic in φ. Provided that ν > 1/3, the scalar curvature R = [κ(3ν-1)ɛ-4Λ] (where κ and Λ are Einstein's gravitational and cosmological constants, respectively) decreases with decreasing ɛ as the Universe expands, and a first-order phase transition in variable "external field" parameter proportional to R occurs at some critical value R c hyperinflation." After the passage through the phase-transition point, the scalar-field potential energy should be rapidly released, which must lead to strong heating of the Universe, playing the role of the Big Bang.

  17. Modelling the low-tar BIG process; Modellering af low-tar BIG processen

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Lars Henrik

    2002-09-15

    This report describes the possibilities of integrating a biomass gasifier in a combined heat and power plant. The purpose of the study is, among others, to see if the gasification technology can challenge existing heat and power production methods. A research programme dealing with the construction of a low far gasifier (LT-BIG), which easily can be scaled to large gasification plants, is in progress. This report also contains a model formulation and implementation for this suggested low tar gasifier. All the models are created by the use of the energy simulation tool DNA. For some cases it has been necessary to develop new components or to alter existing components in DNA. Three different systems are considered; Gas Engine, Simple Cycle Gas Turbine and Combined Cycle. When biomass with and lower heating value of 19 MJ/kg and a moisture content of 50% is employed the subsequent results and designs are achieved: 1) The Engine plant utilizes the hot flue-gas to dry the biomass, but has difficulties taking advantage of the potential energy from the cooling of the syngas. An engine with a net electric efficiency of 40% at full load is computed to convert 38,5% of the energy content in the biomass to electricity. 2) The Simple Cycle Gas Turbine plant has good potential for integration with a gasifier. It dries the biomass by means of the flue-gas and recuperates the energy from the hot syngas to preheat the pressurised gas before it enters the combustion chamber. With an isentropic efficiency of 89% and a pressure ratio of 20, an electric efficiency of 38% is computed. 3) The Combined Cycle plant almost reach a computed efficiency of 45%. It utilises the cooling of the hot syngas to produce extra steam for the cycle, which results in a very steady efficiency, even when the moisture content of the fuel is changed. A grand parametric and sensitivity study of the LT-BIG model is carried out. The study includes estimates of the air demand for the gasifier and the partial

  18. Cosmological Models and Renormalization Group Flow

    OpenAIRE

    Kristjansson, K. R.; Thorlacius, L.

    2002-01-01

    We study cosmological solutions of Einstein gravity with a positive cosmological constant in diverse dimensions. These include big-bang models that re-collapse, big-bang models that approach de Sitter acceleration at late times, and bounce models that are both past and future asymptotically de Sitter. The re-collapsing and the bounce geometries are all tall in the sense that entire spatial slices become visible to a comoving observer before the end of conformal time, while the accelerating bi...

  19. Modeling and Analysis in Marine Big Data: Advances and Challenges

    Directory of Open Access Journals (Sweden)

    Dongmei Huang

    2015-01-01

    Full Text Available It is aware that big data has gathered tremendous attentions from academic research institutes, governments, and enterprises in all aspects of information sciences. With the development of diversity of marine data acquisition techniques, marine data grow exponentially in last decade, which forms marine big data. As an innovation, marine big data is a double-edged sword. On the one hand, there are many potential and highly useful values hidden in the huge volume of marine data, which is widely used in marine-related fields, such as tsunami and red-tide warning, prevention, and forecasting, disaster inversion, and visualization modeling after disasters. There is no doubt that the future competitions in marine sciences and technologies will surely converge into the marine data explorations. On the other hand, marine big data also brings about many new challenges in data management, such as the difficulties in data capture, storage, analysis, and applications, as well as data quality control and data security. To highlight theoretical methodologies and practical applications of marine big data, this paper illustrates a broad view about marine big data and its management, makes a survey on key methods and models, introduces an engineering instance that demonstrates the management architecture, and discusses the existing challenges.

  20. Model of a Negatively Curved Two-Dimensional Space.

    Science.gov (United States)

    Eckroth, Charles A.

    1995-01-01

    Describes the construction of models of two-dimensional surfaces with negative curvature that are used to illustrate differences in the triangle sum rule for the various Big Bang Theories of the universe. (JRH)

  1. SEPHIROT: SCENARIO for CREATION AUTOMATICALLY from DIGITS AVERAGED-PROBABILITY Newcomb-Benford Log-Law: Inflation, BosonS, a Maxwell-Boltzmann Big-Bang Fireball, FermionS, HDE, HDM, CMB; UTTER-SIMPLICITY PURPOSELY SANS ANYthing!!!: It's a Jack-in-the-Box Univers: A Consciousness? EMET/TRUTH!!!

    Science.gov (United States)

    Siegel, Edward Carl-Ludwig; Marvin Antonoff/Albert Overhauser(RIP)/Frederic Young/Adolph Smith/Irwin Wunderman(RIP/Janis Wignall Team

    2013-03-01

    Siegel[http://fqxi.org/community/forum/topic/1553]: TEN-DIGITS[0,...,9] PROBABILITY AVERAGE LOG-Law SCALE-INVARIANCE; Utter-Simplicity: ``Complexity'' (Versus ``Complicatedness'') Zipf-law/ Hyperbolicity/ Inevitability (Archimedes), vs, Pareto-law, SCENARIO AUTOMATICALLY CREATES a UNIVERSE: inflation, a big-bang, bosons(E) ->Mellin-(c⌃2)-tranform -> fermions (m) , hidden - dark - energy (HDE) , hidden - dark - matter (HDM) , cosmic-microwave-background(CMB), supersymmetry(SUSY) PURPOSELY SANS ANY: theories, models, mechanisms, processes, parameters, assumptions,...WHATSOEVER: It's a'' Jack-in-the-Box'' Universe!!! ONLY VIA: Bose-{Euler[(1732)] sum =product over-reals R-Riemann[Monats. Akad.,(1859)] sum =product over-complexs)-Bernoulli-Kummer}-Newcomb[Am. J. Math. 4(1), 39(1881) THE discovery of the QUANTUM!!!]-{Planck(1901)]-Einstein(1905)]-Sommerfeld}-Poincare[Calcul des Probabilités, 313 (1912)]-Weyl[Goett. Nach.(1914); Math. Ann. 77, 313(1916)]-(Bose(1924)-Einstein(1925)]-VS.

  2. An Analysis of Humorous Effects of Turn-taking---A Case Study of The Big Bang Theory%以《生活大爆炸》为例分析话轮转换的幽默效果

    Institute of Scientific and Technical Information of China (English)

    刘馨林

    2014-01-01

    In daily conversation , turn-taking is a very common phenomenon .Turn-taking is first proposed by the founders of conversational analysis ,Harvey Sacks , Emanuel Schegolff and Gail Jefferson .They summarize the turn-taking rules in personal communication so that the rules can help people to analyze different effects as a result of turn-taking mechanism , such as humorous effects of expressions .This paper attempts to expound what turn-taking is, what turn-taking strategies are , and analyze how to use turn-taking strategies to produce humorous conversations by taking the sitcom , The Big Bang Theory , as an example .%在日常会话中,话轮转换是一种普遍现象。话轮转换最初是由话语分析学派的开创者Harvey Sacks ,Emanuel Schegolff和Gail Jefferson提出的。他们总结了在交流中话轮转换的规则,从而帮助人们分析由话轮转换机制产生的不同表达效果,例如通过话轮转换产生幽默的会话效果。主要阐述话轮转换概念,话轮转换策略,并以《生活大爆炸》为例,揭示如何利用话轮转换策略表达出幽默的会话效果。

  3. 从语境角度分析《生活大爆炸》中的幽默言语%Analysis of the Humorous Discourse in The Big Bang Theory from the Perspective of Cognitive Environment

    Institute of Scientific and Technical Information of China (English)

    张黎

    2014-01-01

    该文以关联理论为基础,从认知语境的角度对《生活大爆炸》中幽默话语进行了分析,阐述了认知语境产生幽默所应具备的条件,以及影响个人认知语境的几个因素。以往的幽默研究着重强调交流双方在具有共同的认知语境之下产生的幽默,这篇文章指出交际双方在认知语境方面存在的差异很多时候是幽默制造的必需品;研究突破了传统的对语境的研究,从不同的角度阐述了认知语境与幽默之间存在着的的关系。%Based on Relevance Theory, This paper analyzed the humorous dialogues in American sitcom The Big Bang Theory from the perspective of cognitive environment to elaborate the necessary conditions of cognitive environment for humor genera-tion as well as the factors which influence people’s cognitive environment. Previous studies of humor always emphasize the hu-mor generated when two parties of communication have the same cognitive environment. This paper pointed out that the differ-ences of cognitive environment between both sides of communication are often the necessities for humor manufacturing;besides, the research broken through the traditional single general study of cognitive environment, and fully elaborated the varied and complicated relationship between cognitive environment and humor from a new perspective.

  4. Past Eras In Cyclic Cosmological Models

    CERN Document Server

    Frampton, Paul H

    2009-01-01

    In infinitely cyclic cosmology past eras are discussed using set theory and transfinite numbers. One consistent scenario, already in the literature, is where there is always a countably infinite number, $\\aleph_0$, of universes and no big bang. I describe here an alternative where the present number of universes is $\\aleph_0$ and in the infinite past there was only a finite number of universes. In this alternative model it is also possible that there was no big bang.

  5. Reheating the Standard Model from a Hidden Sector

    OpenAIRE

    Tenkanen, Tommi; Vaskonen, Ville

    2016-01-01

    We consider a scenario where the inflaton decays to a hidden sector thermally decoupled from the visible Standard Model sector. A tiny portal coupling between the hidden and the visible sectors later heats the visible sector so that the Standard Model degrees of freedom come to dominate the energy density of the Universe before Big Bang Nucleosynthesis. We find that this scenario is viable, although obtaining the correct dark matter abundance and retaining successful Big Bang Nucleosynthesis ...

  6. Changing the personality of a face: Perceived Big Two and Big Five personality factors modeled in real photographs.

    Science.gov (United States)

    Walker, Mirella; Vetter, Thomas

    2016-04-01

    General, spontaneous evaluations of strangers based on their faces have been shown to reflect judgments of these persons' intention and ability to harm. These evaluations can be mapped onto a 2D space defined by the dimensions trustworthiness (intention) and dominance (ability). Here we go beyond general evaluations and focus on more specific personality judgments derived from the Big Two and Big Five personality concepts. In particular, we investigate whether Big Two/Big Five personality judgments can be mapped onto the 2D space defined by the dimensions trustworthiness and dominance. Results indicate that judgments of the Big Two personality dimensions almost perfectly map onto the 2D space. In contrast, at least 3 of the Big Five dimensions (i.e., neuroticism, extraversion, and conscientiousness) go beyond the 2D space, indicating that additional dimensions are necessary to describe more specific face-based personality judgments accurately. Building on this evidence, we model the Big Two/Big Five personality dimensions in real facial photographs. Results from 2 validation studies show that the Big Two/Big Five are perceived reliably across different samples of faces and participants. Moreover, results reveal that participants differentiate reliably between the different Big Two/Big Five dimensions. Importantly, this high level of agreement and differentiation in personality judgments from faces likely creates a subjective reality which may have serious consequences for those being perceived-notably, these consequences ensue because the subjective reality is socially shared, irrespective of the judgments' validity. The methodological approach introduced here might prove useful in various psychological disciplines. (PsycINFO Database Record

  7. Changing the personality of a face: Perceived Big Two and Big Five personality factors modeled in real photographs.

    Science.gov (United States)

    Walker, Mirella; Vetter, Thomas

    2016-04-01

    General, spontaneous evaluations of strangers based on their faces have been shown to reflect judgments of these persons' intention and ability to harm. These evaluations can be mapped onto a 2D space defined by the dimensions trustworthiness (intention) and dominance (ability). Here we go beyond general evaluations and focus on more specific personality judgments derived from the Big Two and Big Five personality concepts. In particular, we investigate whether Big Two/Big Five personality judgments can be mapped onto the 2D space defined by the dimensions trustworthiness and dominance. Results indicate that judgments of the Big Two personality dimensions almost perfectly map onto the 2D space. In contrast, at least 3 of the Big Five dimensions (i.e., neuroticism, extraversion, and conscientiousness) go beyond the 2D space, indicating that additional dimensions are necessary to describe more specific face-based personality judgments accurately. Building on this evidence, we model the Big Two/Big Five personality dimensions in real facial photographs. Results from 2 validation studies show that the Big Two/Big Five are perceived reliably across different samples of faces and participants. Moreover, results reveal that participants differentiate reliably between the different Big Two/Big Five dimensions. Importantly, this high level of agreement and differentiation in personality judgments from faces likely creates a subjective reality which may have serious consequences for those being perceived-notably, these consequences ensue because the subjective reality is socially shared, irrespective of the judgments' validity. The methodological approach introduced here might prove useful in various psychological disciplines. (PsycINFO Database Record PMID:26348599

  8. Translating strategy of cultural defaults of subtitles ---Taking The Big Bang Theory for example%影视字幕中文化缺省的翻译策略——以《生活大爆炸》为例

    Institute of Scientific and Technical Information of China (English)

    章程

    2012-01-01

    Many cultural defauhs exist in audiovisuals. Subtitle translation, as a new kind of art translation, has its own characteristics. This paper, taking American audiovisual The Big Bang Theory for example, explores translation strategies of cultural defaults.%在影视作品中存在大量的文化缺省现象。字幕翻译作为一种新的文学翻译形式有着它自身的特点。以美剧《生活大爆炸》为例,探讨影视作品中文化缺省的翻译策略。

  9. 范畴层次视域下的美国情景剧《生活大爆炸》中的言语幽默%Interpretation of Verbal Humor in Sitcom the Big Bang Theory from the Perspective of Categorization Levels

    Institute of Scientific and Technical Information of China (English)

    雷丽岚; 周蓓

    2011-01-01

    《生活大爆炸》是最近热播的情景喜剧,讲述四个情商极低的科学家和一个美女邻居之间的故事。试图运用范畴层次理论来阐释其特有的言语幽默。%The big bang theory is a very popular sitcom telling what happened between four scientists with a low EQ and a neighbor beauty.The paper tries to interpret its special verbal humor from the perspective of categorization levels.

  10. Statistical model selection with “Big Data”

    Directory of Open Access Journals (Sweden)

    Jurgen A. Doornik

    2015-12-01

    Full Text Available Big Data offer potential benefits for statistical modelling, but confront problems including an excess of false positives, mistaking correlations for causes, ignoring sampling biases and selecting by inappropriate methods. We consider the many important requirements when searching for a data-based relationship using Big Data, and the possible role of Autometrics in that context. Paramount considerations include embedding relationships in general initial models, possibly restricting the number of variables to be selected over by non-statistical criteria (the formulation problem, using good quality data on all variables, analyzed with tight significance levels by a powerful selection procedure, retaining available theory insights (the selection problem while testing for relationships being well specified and invariant to shifts in explanatory variables (the evaluation problem, using a viable approach that resolves the computational problem of immense numbers of possible models.

  11. Small Area Model-Based Estimators Using Big Data Sources

    Directory of Open Access Journals (Sweden)

    Marchetti Stefano

    2015-06-01

    Full Text Available The timely, accurate monitoring of social indicators, such as poverty or inequality, on a finegrained spatial and temporal scale is a crucial tool for understanding social phenomena and policymaking, but poses a great challenge to official statistics. This article argues that an interdisciplinary approach, combining the body of statistical research in small area estimation with the body of research in social data mining based on Big Data, can provide novel means to tackle this problem successfully. Big Data derived from the digital crumbs that humans leave behind in their daily activities are in fact providing ever more accurate proxies of social life. Social data mining from these data, coupled with advanced model-based techniques for fine-grained estimates, have the potential to provide a novel microscope through which to view and understand social complexity. This article suggests three ways to use Big Data together with small area estimation techniques, and shows how Big Data has the potential to mirror aspects of well-being and other socioeconomic phenomena.

  12. Online Knowledge-Based Model for Big Data Topic Extraction

    Science.gov (United States)

    Khan, Muhammad Taimoor; Durrani, Mehr; Khalid, Shehzad; Aziz, Furqan

    2016-01-01

    Lifelong machine learning (LML) models learn with experience maintaining a knowledge-base, without user intervention. Unlike traditional single-domain models they can easily scale up to explore big data. The existing LML models have high data dependency, consume more resources, and do not support streaming data. This paper proposes online LML model (OAMC) to support streaming data with reduced data dependency. With engineering the knowledge-base and introducing new knowledge features the learning pattern of the model is improved for data arriving in pieces. OAMC improves accuracy as topic coherence by 7% for streaming data while reducing the processing cost to half. PMID:27195004

  13. Multidimensional Big Spatial Data Modeling Through A Case Study: Lte Rf Subsystem Power Consumption Modeling

    DEFF Research Database (Denmark)

    Antón Castro, Francesc/François; Musiige, Deogratius; Mioc, Darka;

    2016-01-01

    This paper presents a case study for comparing different multidimensional mathematical modeling methodologies used in multidimensional spatial big data modeling and proposing a new technique. An analysis of multidimensional modeling approaches (neural networks, polynomial interpolation and homotopy...

  14. Personality correlates of pathological gambling derived from Big Three and Big Five personality models.

    Science.gov (United States)

    Miller, Joshua D; Mackillop, James; Fortune, Erica E; Maples, Jessica; Lance, Charles E; Keith Campbell, W; Goodie, Adam S

    2013-03-30

    Personality traits have proved to be consistent and important factors in a variety of externalizing behaviors including addiction, aggression, and antisocial behavior. Given the comorbidity of these behaviors with pathological gambling (PG), it is important to test the degree to which PG shares these trait correlates. In a large community sample of regular gamblers (N=354; 111 with diagnoses of pathological gambling), the relations between measures of two major models of personality - Big Three and Big Five - were examined in relation to PG symptoms derived from a semi-structured diagnostic interview. Across measures, traits related to the experience of strong negative emotions were the most consistent correlates of PG, regardless of whether they were analyzed using bivariate or multivariate analyses. In several instances, however, the relations between personality and PG were moderated by demographic variable such as gender, race, and age. It will be important for future empirical work of this nature to pay closer attention to potentially important moderators of these relations.

  15. Personality correlates of pathological gambling derived from Big Three and Big Five personality models.

    Science.gov (United States)

    Miller, Joshua D; Mackillop, James; Fortune, Erica E; Maples, Jessica; Lance, Charles E; Keith Campbell, W; Goodie, Adam S

    2013-03-30

    Personality traits have proved to be consistent and important factors in a variety of externalizing behaviors including addiction, aggression, and antisocial behavior. Given the comorbidity of these behaviors with pathological gambling (PG), it is important to test the degree to which PG shares these trait correlates. In a large community sample of regular gamblers (N=354; 111 with diagnoses of pathological gambling), the relations between measures of two major models of personality - Big Three and Big Five - were examined in relation to PG symptoms derived from a semi-structured diagnostic interview. Across measures, traits related to the experience of strong negative emotions were the most consistent correlates of PG, regardless of whether they were analyzed using bivariate or multivariate analyses. In several instances, however, the relations between personality and PG were moderated by demographic variable such as gender, race, and age. It will be important for future empirical work of this nature to pay closer attention to potentially important moderators of these relations. PMID:23078872

  16. GALAXY EVOLUTION. An over-massive black hole in a typical star-forming galaxy, 2 billion years after the Big Bang.

    Science.gov (United States)

    Trakhtenbrot, Benny; Urry, C Megan; Civano, Francesca; Rosario, David J; Elvis, Martin; Schawinski, Kevin; Suh, Hyewon; Bongiorno, Angela; Simmons, Brooke D

    2015-07-10

    Supermassive black holes (SMBHs) and their host galaxies are generally thought to coevolve, so that the SMBH achieves up to about 0.2 to 0.5% of the host galaxy mass in the present day. The radiation emitted from the growing SMBH is expected to affect star formation throughout the host galaxy. The relevance of this scenario at early cosmic epochs is not yet established. We present spectroscopic observations of a galaxy at redshift z = 3.328, which hosts an actively accreting, extremely massive BH, in its final stages of growth. The SMBH mass is roughly one-tenth the mass of the entire host galaxy, suggesting that it has grown much more efficiently than the host, contrary to models of synchronized coevolution. The host galaxy is forming stars at an intense rate, despite the presence of a SMBH-driven gas outflow. PMID:26160942

  17. GRAMMAR RULE BASED INFORMATION RETRIEVAL MODEL FOR BIG DATA

    Directory of Open Access Journals (Sweden)

    T. Nadana Ravishankar

    2015-07-01

    Full Text Available Though Information Retrieval (IR in big data has been an active field of research for past few years; the popularity of the native languages presents a unique challenge in big data information retrieval systems. There is a need to retrieve information which is present in English and display it in the native language for users. This aim of cross language information retrieval is complicated by unique features of the native languages such as: morphology, compound word formations, word spelling variations, ambiguity, word synonym, other language influence and etc. To overcome some of these issues, the native language is modeled using a grammar rule based approach in this work. The advantage of this approach is that the native language is modeled and its unique features are encoded using a set of inference rules. This rule base coupled with the customized ontological system shows considerable potential and is found to show better precision and recall.

  18. Modeling genomic regulatory networks with big data.

    Science.gov (United States)

    Bolouri, Hamid

    2014-05-01

    High-throughput sequencing, large-scale data generation projects, and web-based cloud computing are changing how computational biology is performed, who performs it, and what biological insights it can deliver. I review here the latest developments in available data, methods, and software, focusing on the modeling and analysis of the gene regulatory interactions in cells. Three key findings are: (i) although sophisticated computational resources are increasingly available to bench biologists, tailored ongoing education is necessary to avoid the erroneous use of these resources. (ii) Current models of the regulation of gene expression are far too simplistic and need updating. (iii) Integrative computational analysis of large-scale datasets is becoming a fundamental component of molecular biology. I discuss current and near-term opportunities and challenges related to these three points.

  19. ALMA observations of the host galaxy of GRB 090423 at z = 8.23: deep limits on obscured star formation 630 million years after the big bang

    International Nuclear Information System (INIS)

    We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3σ limits of F ν(222 GHz) ≲ 33 μJy and F ν(3.6 μm) ≲ 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M 82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L IR(8-1000 μm) ≲ 3 × 1010 L ☉, corresponding to a limit on the obscured star formation rate of SFRIR≲5 M ☉ yr–1. For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFRUV ≲ 1 M ☉ yr–1. We also place a limit on the host galaxy stellar mass of M * ≲ 5 × 107 M ☉ (for a stellar population age of 100 Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z ≳ 4 (Lyman break galaxies, Lyα emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z ≳ 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

  20. ALMA observations of the host galaxy of GRB 090423 at z = 8.23: deep limits on obscured star formation 630 million years after the big bang

    Energy Technology Data Exchange (ETDEWEB)

    Berger, E.; Zauderer, B. A.; Chary, R.-R.; Laskar, T.; Chornock, R.; Davies, J. E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Stanway, E. R.; Levan, A. J. [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Levesque, E. M. [CASA, University of Colorado UCB 389, Boulder, CO 80309 (United States)

    2014-12-01

    We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3σ limits of F {sub ν}(222 GHz) ≲ 33 μJy and F {sub ν}(3.6 μm) ≲ 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M 82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L {sub IR}(8-1000 μm) ≲ 3 × 10{sup 10} L {sub ☉}, corresponding to a limit on the obscured star formation rate of SFR{sub IR}≲5 M {sub ☉} yr{sup –1}. For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFR{sub UV} ≲ 1 M {sub ☉} yr{sup –1}. We also place a limit on the host galaxy stellar mass of M {sub *} ≲ 5 × 10{sup 7} M {sub ☉} (for a stellar population age of 100 Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z ≳ 4 (Lyman break galaxies, Lyα emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z ≳ 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

  1. Analysis of The Big Bang Theory's Subtitle Translationfrom the Perspective of Eco-translatology%生态翻译学视角下情景喜剧字幕翻译的研究--以《生活大爆炸》为例

    Institute of Scientific and Technical Information of China (English)

    杨喆

    2014-01-01

    生态翻译学是近年来兴起的一个根植于中国的翻译理论,它是一个完整的理论系统,解决了“何为译”、“如何译”、“为何译”等一系列问题。而《生活大爆炸》作为一部吸引了无数中国人眼球的情景喜剧,其成功的字幕翻译无疑为其在中国的传播起到了举足轻重的作用。本文试从生态翻译学“如何译”的角度,即“三维”转换角度来分析《生活大爆炸》中的字幕翻译。%Eco-translatology is a newly developed translation theory that rooted in China. It's a comprehensive theory system which deals with many important translation questions such as what is translation, how to translate, why do people translate and so on. The Big Bang Theory is a popular sitcom among Chinese. And its success is closely related to its subtitle translation. This paper will mainly analyze the subtitle translation of The Big Bang Theory with three-dimensional transformations.

  2. On the Cold Big Bang Cosmology

    Directory of Open Access Journals (Sweden)

    Assis A. V. D. B.

    2011-04-01

    Full Text Available We solve the general relativity (GR field equations under the cosmological scope via one extra postulate. The plausibility of the postulate resides within the Heisenberg in- determinacy principle, being heuristically analysed throughout the appendix. Under this approach, a negative energy density may provide the positive energy content of the universe via fluctuation, since the question of conservation of energy in cosmol- ogy is weakened, supported by the known lack of scope of the Noether’s theorem in cosmology. The initial condition of the primordial universe turns out to have a natural cuto such that the temperature of the cosmological substratum converges to the ab- solute zero, instead of the established divergence at the very beginning. The adopted postulate provides an explanation for the cosmological dark energy open question. The solution agrees with cosmological observations, including a 2.7K CMBT prediction.

  3. Seeking nature of God in Big Bang

    CERN Multimedia

    2008-01-01

    ""The most exciting thing of all," says Professor Peter Watkins with a smile, "is we have absolutely no idea what will happen until we switch it on." When you realise that the University of Birmingham academic is referring to the world's largest particle physics experiment, it is a little disconcerting. After 13 years of planning and construction, the Large Hadron Collider (LHC), is due to begin its work in the spring of 2008."

  4. Further Holographic Investigations of Big Bang Singularities

    OpenAIRE

    Engelhardt, Netta; Hertog, Thomas; Horowitz, Gary T.

    2015-01-01

    We further explore the quantum dynamics near past cosmological singularities in anisotropic Kasner-AdS solutions using gauge/gravity duality. The dual description of the bulk evolution involves N=4 super Yang-Mills on the contracting branch of an anisotropic de Sitter space and is well defined. We compute two-point correlators of Yang-Mills operators of large dimensions using spacelike geodesics anchored on the boundary. The correlator between two points separated in a direction with negative...

  5. Testing out the Big bang theory

    CERN Multimedia

    Rumford, Alex

    2007-01-01

    "Bristol University academics are among some of the finest minds in the world toiling in a mind-blowingly massive laboratory to find answers to some of the biggest questions that can be asked - about life, the universe and everything. Lucy Parkinson travelled to Switzerland to find out what they are doing there." (2 pages)

  6. Inside the big-bang machine

    CERN Multimedia

    Boyle, Alan

    2007-01-01

    "The future of particle physics is being built below ground, in a setting that's more appropriate for construction hardhats than lab coats. To get to the caverns where the world's most powerful particle collider is taking shape, you have to take an industrial-issue elevator down just one floor. But that floor is a doozy: it's about 100 meters below ground, roughly as deep as a 30-story building is tall." (2 pages)

  7. From pop to the Big Bang

    CERN Multimedia

    Sutherland, Paul

    2007-01-01

    "An amazing new movie takes us to the brink of the end of the world. Sunshine whisks us to a moment 50 years in the future when the sun is about to die, attacked by rogue particles made at the start of time." (2 pages)

  8. Motivating Reluctant Learners with a Big Bang

    Science.gov (United States)

    Lochner, James C.; Cvetic, Geraldine A.; Hall, Jonathan B.

    2007-01-01

    We present results of a collaboration between a media specialist, a science teacher, and an astronomer to bring a modern astronomy topic to at-risk, emotionally disabled students who have experienced little success. These normally unengaged students became highly motivated because they were given an authentic task of presenting research on an intriguing science topic, and because they witnessed a collaboration brought together on their behalf This experience demonstrates that sophisticated astronomy topics can be used to motivate at-risk students.

  9. Oceanic turbulence - Big bangs or continuous creation?

    Science.gov (United States)

    Caldwell, D. R.

    1983-01-01

    A hypothesis concerning the turbulence characteristics of 'microstructure' patches in the ocean is proposed in which a turbulence field is driven at the same time and scale at which it is observed. The driving energy is converted into turbulence kinetic energy in such a way that the observed overturning thickness scale is linearly related to the length scale. This hypothesis is contrasted with that of Gibson (1982), in which the 'patches' are produced by rare, powerful turbulence generators that have 'fossilized' prior to their observation. Careful attention is given to the sampling process and its assumptions.

  10. Big Bang and context-driven collapse.

    Science.gov (United States)

    Robertson-Tessi, Mark; Anderson, Alexander R A

    2015-03-01

    Heterogeneity is the single most important factor driving cancer progression and treatment failure, yet little is understood about how and when this heterogeneity arises. A new study shows that colorectal cancers acquire their dominant mutations early in development and that subsequent mutations, even if they confer greater fitness, are unlikely to sweep through the tumor. PMID:25711865

  11. Tracking Back to the Big Bang.

    Science.gov (United States)

    Peat, David

    1983-01-01

    Traces some astronomical history and considers how astronomers have arrived at their current knowledge of distance, size, and time as it applies to objects in the night sky. The information is provided as background to a discussion of the Hubble constant and its relationship to the age of the universe. (JN)

  12. UH team expands big-bang theory

    CERN Document Server

    Creamer, B

    2002-01-01

    After six months of research at a new underground neutrino detector near the central Japan city of Toyama, an international research team announced yesterday that neutrinos have mass and are capable of morphing from one type to another (1 page).

  13. Re-creating the big bang

    CERN Document Server

    Mung, Adrienne

    2007-01-01

    "Deep beneath the Swiss-French border near Geneva, thousands of physicists rushed to build the world's largest and most expensive science experiment that they hope will bring them one step closer toward unlocking some of the universe's oldest secrets." (1,5 page)

  14. Still waiting for that Big Bang...

    CERN Multimedia

    2009-01-01

    "It has been called the greatest and most ambitious science experiment ever built by man. When operating at full power, the Large Hadron Collider - Europe's 3.2 billion (pounds) particle accelerator - will hurl beams of protons around its rings at a fraction of a per cent less than the speed of light" (2 pages)

  15. A la poursuite du Big Bang

    CERN Multimedia

    Bois, Jérome

    2008-01-01

    Hundred meters under the Pays de Gex, at the end of July, billions of particles are going to be throwed at 99,99% of the speed of the light to recreate the conditions having existed at the origin of the Universe. (1 page)

  16. Dal Big Bang infiniti universi nascosti

    CERN Multimedia

    Valsecchi, Maria Cristina

    2005-01-01

    The intensity of the gravitational force, the speed with which the universe expands, the electric power of the electron, the speed of the light. That's some fundamental constants, some values which determine the characteristics of the universe surrounding us (½ page)

  17. Scientists hope collider makes a big bang

    CERN Multimedia

    Nickerson, Colin

    2007-01-01

    "In a 17-ile circular tunnel curving beneath the Swiss-French border, scientists are poised to recreate the universe's first trillionth of a second. The aim of the audacious undertaking is to solve one of the most perturbing puzzles of physics: How did matter attain mass and form the cosmos? (2 pages)

  18. Museum makes room for the Big Bang

    CERN Multimedia

    Pinnell, Heather

    2007-01-01

    "Heather Pinnell discovers that a small exhibition about the Large Hadron Collider scored very highly for its impact." The museum has plans to add a spark chamber into the gallery to show that the experiments done at CERM are safe. (2/3 page)

  19. Pa spaning efter Big Bang i underjorden

    CERN Multimedia

    Granström, Helena

    2008-01-01

    The LHC will start this summer; an accelerator placed in a 27km long annel. The machine will collide particles in order to test the theory of dark matter, dark energy and supersymmetry. We will get to know much more, but maybe understand even less. (4 pages)

  20. Big Bang machine could destroy the earth

    CERN Multimedia

    Leake, J

    1999-01-01

    BNL have set up a committee to investigate the possibility that operation of RHIC will create a 'strangelets' chain reaction whereby the strange particles formed in the accelerator go on to convert anything they touch into more strange matter. The committee will also consider the alternative possibility that colliding particles could achieve such high density they form a mini black hole. Both scenarios are considered extremely unlikely (1 page).

  1. Pooling resources to decypher the Big Bang

    CERN Multimedia

    Harvey, F

    2003-01-01

    "Work has started on a "virtual supercomputer" that will be the world's second most powerful data processor. The virtual computer will take the form of a "grid", a technology that links many smaller computers to make one huge computing resource" (1/2 page)

  2. Pooling resources to decypher the Big Bang

    CERN Multimedia

    Harvey, Fiona

    2003-01-01

    " Work has started on a "virtual supercomputer" that will be the world's second most powerful data processor. The virtual computer will take the form of a "grid", a technology that links many smaller computers to make one huge computing resource" (1/2 page.

  3. Special Issue: Big data and predictive computational modeling

    Science.gov (United States)

    Koutsourelakis, P. S.; Zabaras, N.; Girolami, M.

    2016-09-01

    The motivation for this special issue stems from the symposium on "Big Data and Predictive Computational Modeling" that took place at the Institute for Advanced Study, Technical University of Munich, during May 18-21, 2015. With a mindset firmly grounded in computational discovery, but a polychromatic set of viewpoints, several leading scientists, from physics and chemistry, biology, engineering, applied mathematics, scientific computing, neuroscience, statistics and machine learning, engaged in discussions and exchanged ideas for four days. This special issue contains a subset of the presentations. Video and slides of all the presentations are available on the TUM-IAS website http://www.tum-ias.de/bigdata2015/.

  4. Bianchi Type-I Massive String Magnetized Barotropic Perfect Fluid Cosmological Model in the Bimetric Theory of Gravitation

    Institute of Scientific and Technical Information of China (English)

    N. P. Gaikwad; M. S. Borkar; S. S. Charjan

    2011-01-01

    @@ We investigate the Bianchi type-I massive string magnetized barotropic perfect fluid cosmological model in Rosen's bimetric theory of gravitation with and without a magnetic field by applying the techniques used by Latelier(1979,1980) and Stachel(1983).To obtain a deterministic model of the universe, it is assumed that the universe is filled with barotropic perfect fluid distribution.The physical and geometrical significance of the model are discussed.By comparing our model with the model of Bali et al.(2007), it is realized that there are no big-bang and big-crunch singularities in our model and T=0 is not the time of the big bang, whereas the model of Bali et al.starts with a big bang at T=0.Further, our model is in agreement with Bali et al.(2007) as time increases in the presence, as well as in the absence, of a magnetic field.

  5. Big Bang Day : The Great Big Particle Adventure - 1. Atom

    CERN Multimedia

    Steven Weinberg; Terry White; John Ellis; Jim Virdee

    2008-01-01

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The notion of atoms dates back to Greek philosophers who sought a natural mechanical explanation of the Universe, as opposed to a divine one. The existence what we call chemical atoms, the constituents of all we see around us, wasn't proved until a hundred years ago, but almost simultaneously it was realised these weren't the indivisible constituents the Greeks envisaged. Much of the story of physics since then has been the ever-deeper probing of matter until, at the end of the 20th century, a complete list of fundamental ingredients had been identified, apart from one, the much discussed Higgs particle. In this programme, Ben finds out why this last particle is so pivotal, not just to atomic theory, but to our very existence - and how hopeful the scientists are of proving its existence.

  6. On Comic Effect of The Big Bang Theory from the Perspective of Violating Politeness Maxim%从违反礼貌原则的角度浅析《生活大爆炸》对白的幽默效果

    Institute of Scientific and Technical Information of China (English)

    章丹

    2014-01-01

    Humor is a key feature of the sitcoms. The Big Bang Theory is recently hitting ratings high in America. The sitcom is well written and features an endearing cast who provides viewers with lots of humorous moments. This essay focuses on pragmatic analysis of the dialogues in Season 6 which have comic effect emerged by violating the six maxims of politeness principles.%幽默是情景喜剧的精髓所在。《生活大爆炸》是近几年热播的一美剧。剧情幽默风趣,经常让观众捧腹大笑。本文以本片第六季为蓝本分别从违反礼貌原则的六个准则角度分析其对白的幽默效果。

  7. ExpIanation of the Humorous Utterances Based on the ReIevance Theory---Take The Big Bang Theory for ExampIe%从关联理论角度解释话语幽默--以美剧《生活大爆炸》为例

    Institute of Scientific and Technical Information of China (English)

    史岩

    2015-01-01

    Selecting large quantities of humorous utterances from the American TV series The Big Bang Theory,this paper aims to explore how the humor is produced and understood based on the Relevance Theory. The fact proved that the Relevance Theory can ex-plain the humorous utterances forcefully and it paves a new way for the research on humorous utterances.%选取《生活大爆炸》中大量幽默言语,从关联理论出发,探究幽默是如何产生的,又是怎样被理解的。事实证明关联理论对幽默言语具有很强的解释力,为幽默话语研究开拓了新领域。

  8. Reviews Book: Nucleus Book: The Wonderful World of Relativity Book: Head Shot Book: Cosmos Close-Up Places to Visit: Physics DemoLab Book: Quarks, Leptons and the Big Bang EBook: Shooting Stars Equipment: Victor 70C USB Digital Multimeter Web Watch

    Science.gov (United States)

    2012-09-01

    WE RECOMMEND Nucleus: A Trip into the Heart of Matter A coffee-table book for everyone to dip into and learn from The Wonderful World of Relativity A charming, stand-out introduction to relativity The Physics DemoLab, National University of Singapore A treasure trove of physics for hands-on science experiences Quarks, Leptons and the Big Bang Perfect to polish up on particle physics for older students Victor 70C USB Digital Multimeter Equipment impresses for usability and value WORTH A LOOK Cosmos Close-Up Weighty tour of the galaxy that would make a good display Shooting Stars Encourage students to try astrophotography with this ebook HANDLE WITH CARE Head Shot: The Science Behind the JKF Assassination Exploration of the science behind the crime fails to impress WEB WATCH App-lied science for education: a selection of free Android apps are reviewed and iPhone app options are listed

  9. 从文化翻译论看美剧《生活大爆炸》的字幕翻译策略%On the Subtitle Translation of the US TV series The Big Bang Theory, with Reference to the Cultural Translation Theory

    Institute of Scientific and Technical Information of China (English)

    齐佳宁; 田翠芸; 刘颖

    2014-01-01

    随着国际化的逐步加深,影视作品作为一种文化传播媒介在人们的日常生活中扮演着越来越重要的角色。而字幕翻译作为国际交流的工具,在国际影视作品传播过程中发挥着关键的作用。运用文化翻译论分析了美剧《生活大爆炸》的字幕翻译,并结合其制造的视听效果,初步总结了影视字幕的翻译方法和翻译策略,为影视字幕翻译提供一些借鉴。%with the general deepening of the current trend towards internationalization , films and TV programs have become increasingly more important in cultural communication .Subtitle translation , which is an important tool of international communication , is quite crucial in the world-wide spread of films and TV programs .Referring to the Cultural Translation Theory , the US TV series The Big Bang Theory is analyzed in this thesis .With a comprehen-sive consideration of the visual and sound effects projected by the Big Bang Theory program , some subtitle transla-tion methods and strategies have been summarized , which, it is hoped, will provide some guidance for effective subtitle translation .

  10. 科学与影视娱乐交融的科普模式——以美国电视剧《生活大爆炸》为案例%Science and Entertainment: A Case Study on the American TV Series The Big Bang Theory

    Institute of Scientific and Technical Information of China (English)

    王一鸣

    2012-01-01

    随着当代科学与社会及公众的联系更加紧密,借助于资讯与传媒的发达,产生了科学与影视娱乐交融的科普模式。美国电视剧《生活大爆炸》即是一部成功实践这种模式的生活情景喜剧,在娱乐中传播与普及科学知识,获得较大社会反响。分析了《生活大爆炸》的成功的运行机制和特点,并与中国现状进行了对比,同时在此基础上对科学传播与影视娱乐结合的科普方式进行了思考。%With the connection between contemporary science, society and people, and also by the progress of information and communication, the new method of science popularization through the integration of science and entertainment was generated. The American TV series The Big Bang Theory was one of that and obtained great social responding by communicating and popularizing the science through entertainment. The operating mechanism and features of The Big Bang Theory are analyzed. The current status of China is also discussed. Furthermore, the method of science popularization through the integration of science and entertainment is pondered.

  11. Modeling and Analysis in Marine Big Data: Advances and Challenges

    OpenAIRE

    Dongmei Huang; Danfeng Zhao; Lifei Wei; Zhenhua Wang; Yanling Du

    2015-01-01

    It is aware that big data has gathered tremendous attentions from academic research institutes, governments, and enterprises in all aspects of information sciences. With the development of diversity of marine data acquisition techniques, marine data grow exponentially in last decade, which forms marine big data. As an innovation, marine big data is a double-edged sword. On the one hand, there are many potential and highly useful values hidden in the huge volume of marine data, which is widely...

  12. Building Simulation Modelers are we big-data ready?

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, Jibonananda [ORNL; New, Joshua Ryan [ORNL

    2014-01-01

    Recent advances in computing and sensor technologies have pushed the amount of data we collect or generate to limits previously unheard of. Sub-minute resolution data from dozens of channels is becoming increasingly common and is expected to increase with the prevalence of non-intrusive load monitoring. Experts are running larger building simulation experiments and are faced with an increasingly complex data set to analyze and derive meaningful insight. This paper focuses on the data management challenges that building modeling experts may face in data collected from a large array of sensors, or generated from running a large number of building energy/performance simulations. The paper highlights the technical difficulties that were encountered and overcome in order to run 3.5 million EnergyPlus simulations on supercomputers and generating over 200 TBs of simulation output. This extreme case involved development of technologies and insights that will be beneficial to modelers in the immediate future. The paper discusses different database technologies (including relational databases, columnar storage, and schema-less Hadoop) in order to contrast the advantages and disadvantages of employing each for storage of EnergyPlus output. Scalability, analysis requirements, and the adaptability of these database technologies are discussed. Additionally, unique attributes of EnergyPlus output are highlighted which make data-entry non-trivial for multiple simulations. Practical experience regarding cost-effective strategies for big-data storage is provided. The paper also discusses network performance issues when transferring large amounts of data across a network to different computing devices. Practical issues involving lag, bandwidth, and methods for synchronizing or transferring logical portions of the data are presented. A cornerstone of big-data is its use for analytics; data is useless unless information can be meaningfully derived from it. In addition to technical

  13. More than the Big Five: egoism and the HEXACO model of personality

    NARCIS (Netherlands)

    R.E. de Vries; A. de Vries; A. de Hoogh; J. Feij

    2009-01-01

    Egoism is a personality trait that is associated with self-enriching and self-centred behaviours. Research has suggested that egoism lies beyond the Big Five personality factors. Recently, the HEXACO model of personality has been proposed as an alternative to the Big Five model. In three studies, th

  14. Ontology-Based Big Dimension Modeling in Data Warehouse Schema Design

    DEFF Research Database (Denmark)

    Xiufeng, Liu; Iftikhar, Nadeem

    2013-01-01

    During data warehouse schema design, designers often encounter how to model big dimensions that typically contain a large number of attributes and records. To investigate effective approaches for modeling big dimensions is necessary in order to achieve better query performance, with respect...

  15. Unleashing spatially distributed ecohydrology modeling using Big Data tools

    Science.gov (United States)

    Miles, B.; Idaszak, R.

    2015-12-01

    Physically based spatially distributed ecohydrology models are useful for answering science and management questions related to the hydrology and biogeochemistry of prairie, savanna, forested, as well as urbanized ecosystems. However, these models can produce hundreds of gigabytes of spatial output for a single model run over decadal time scales when run at regional spatial scales and moderate spatial resolutions (~100-km2+ at 30-m spatial resolution) or when run for small watersheds at high spatial resolutions (~1-km2 at 3-m spatial resolution). Numerical data formats such as HDF5 can store arbitrarily large datasets. However even in HPC environments, there are practical limits on the size of single files that can be stored and reliably backed up. Even when such large datasets can be stored, querying and analyzing these data can suffer from poor performance due to memory limitations and I/O bottlenecks, for example on single workstations where memory and bandwidth are limited, or in HPC environments where data are stored separately from computational nodes. The difficulty of storing and analyzing spatial data from ecohydrology models limits our ability to harness these powerful tools. Big Data tools such as distributed databases have the potential to surmount the data storage and analysis challenges inherent to large spatial datasets. Distributed databases solve these problems by storing data close to computational nodes while enabling horizontal scalability and fault tolerance. Here we present the architecture of and preliminary results from PatchDB, a distributed datastore for managing spatial output from the Regional Hydro-Ecological Simulation System (RHESSys). The initial version of PatchDB uses message queueing to asynchronously write RHESSys model output to an Apache Cassandra cluster. Once stored in the cluster, these data can be efficiently queried to quickly produce both spatial visualizations for a particular variable (e.g. maps and animations), as well

  16. Cosmological Models and Renormalization Group Flow

    CERN Document Server

    Kristjansson, K R

    2002-01-01

    We study cosmological solutions of Einstein gravity with a positive cosmological constant and perfect fluid matter in diverse dimensions. These include big-bang models that re-collaspse, big-bang models that approach de Sitter acceleration at late times, and bounce models that are both past and future asymptotically de Sitter. The re-collapsing and the bounce geometries are all tall in the sense that entire spatial slices become visible to a comoving observer before the end of conformal time, while the accelerating big-bang geometries can be either short or tall. We consider the interpretation of these cosmological solutions as renormalization group flows in a dual field theory and give a geometric interpretation of the associated c-function as the area of the apparent cosmological horizon in Planck units. We find that the covariant entropy bound is violated in certain of our solutions and thus holography may be used to restrict the model parameters.

  17. Big Data and Data Models for Climate System Energetics

    Science.gov (United States)

    Fillmore, D. W.; Habermann, T.; Goedecke, W. B.

    2015-12-01

    Multi-decade satellite missions, such as the NASA CERES mission designed to place observational constraints on the distribution of reflected solar radiation and emitted thermal radiation, present a significant challenge both in the analysis of heterogeneous Big Data and in data continuity. The NASA CERES EBAF dataset is a part of a broader effort to increase the usability of satellite observational data for the climate modeling community. Issues of accessibility, consistency, and reproducibility are paramount. Here we describe the transformation of CERES measurements from source to high level data products intended for direct use by the climate community. At each stage we examine data storage and processing patterns, metadata and potential challenges in reproducibility. The spatial distribution of net energy uptake and transport in the climate system, and its evolution over interannual and decadal time scales, is fundamental to the development of Earth system models. The workflow begins with the CERES footprint radiance seen by a polar orbiter, to the conversion of radiance to radiometric fluxes based on scene identification from MODIS and VIIRS imagery, followed by diurnal interpolation through the use of geostationary satellite imagery and eventually to the creation of high level gridded data products, the ultimate being the Energy Balanced and Filled flux product for direct comparison to climate models. Based on this CERES case study we try to anticipate future questions the may arise in the context of these massive satellite data collections, and what new data models may facilitate future data analysis.

  18. Predictive Modeling With Big Data: Is Bigger Really Better?

    Science.gov (United States)

    Junqué de Fortuny, Enric; Martens, David; Provost, Foster

    2013-12-01

    With the increasingly widespread collection and processing of "big data," there is natural interest in using these data assets to improve decision making. One of the best understood ways to use data to improve decision making is via predictive analytics. An important, open question is: to what extent do larger data actually lead to better predictive models? In this article we empirically demonstrate that when predictive models are built from sparse, fine-grained data-such as data on low-level human behavior-we continue to see marginal increases in predictive performance even to very large scale. The empirical results are based on data drawn from nine different predictive modeling applications, from book reviews to banking transactions. This study provides a clear illustration that larger data indeed can be more valuable assets for predictive analytics. This implies that institutions with larger data assets-plus the skill to take advantage of them-potentially can obtain substantial competitive advantage over institutions without such access or skill. Moreover, the results suggest that it is worthwhile for companies with access to such fine-grained data, in the context of a key predictive task, to gather both more data instances and more possible data features. As an additional contribution, we introduce an implementation of the multivariate Bernoulli Naïve Bayes algorithm that can scale to massive, sparse data. PMID:27447254

  19. Transforming Healthcare Delivery: Integrating Dynamic Simulation Modelling and Big Data in Health Economics and Outcomes Research.

    Science.gov (United States)

    Marshall, Deborah A; Burgos-Liz, Lina; Pasupathy, Kalyan S; Padula, William V; IJzerman, Maarten J; Wong, Peter K; Higashi, Mitchell K; Engbers, Jordan; Wiebe, Samuel; Crown, William; Osgood, Nathaniel D

    2016-02-01

    In the era of the Information Age and personalized medicine, healthcare delivery systems need to be efficient and patient-centred. The health system must be responsive to individual patient choices and preferences about their care, while considering the system consequences. While dynamic simulation modelling (DSM) and big data share characteristics, they present distinct and complementary value in healthcare. Big data and DSM are synergistic-big data offer support to enhance the application of dynamic models, but DSM also can greatly enhance the value conferred by big data. Big data can inform patient-centred care with its high velocity, volume, and variety (the three Vs) over traditional data analytics; however, big data are not sufficient to extract meaningful insights to inform approaches to improve healthcare delivery. DSM can serve as a natural bridge between the wealth of evidence offered by big data and informed decision making as a means of faster, deeper, more consistent learning from that evidence. We discuss the synergies between big data and DSM, practical considerations and challenges, and how integrating big data and DSM can be useful to decision makers to address complex, systemic health economics and outcomes questions and to transform healthcare delivery. PMID:26497003

  20. Transforming Healthcare Delivery: Integrating Dynamic Simulation Modelling and Big Data in Health Economics and Outcomes Research.

    Science.gov (United States)

    Marshall, Deborah A; Burgos-Liz, Lina; Pasupathy, Kalyan S; Padula, William V; IJzerman, Maarten J; Wong, Peter K; Higashi, Mitchell K; Engbers, Jordan; Wiebe, Samuel; Crown, William; Osgood, Nathaniel D

    2016-02-01

    In the era of the Information Age and personalized medicine, healthcare delivery systems need to be efficient and patient-centred. The health system must be responsive to individual patient choices and preferences about their care, while considering the system consequences. While dynamic simulation modelling (DSM) and big data share characteristics, they present distinct and complementary value in healthcare. Big data and DSM are synergistic-big data offer support to enhance the application of dynamic models, but DSM also can greatly enhance the value conferred by big data. Big data can inform patient-centred care with its high velocity, volume, and variety (the three Vs) over traditional data analytics; however, big data are not sufficient to extract meaningful insights to inform approaches to improve healthcare delivery. DSM can serve as a natural bridge between the wealth of evidence offered by big data and informed decision making as a means of faster, deeper, more consistent learning from that evidence. We discuss the synergies between big data and DSM, practical considerations and challenges, and how integrating big data and DSM can be useful to decision makers to address complex, systemic health economics and outcomes questions and to transform healthcare delivery.

  1. The Relationship between the Big-Five Model of Personality and Self-Regulated Learning Strategies

    Science.gov (United States)

    Bidjerano, Temi; Dai, David Yun

    2007-01-01

    The study examined the relationship between the big-five model of personality and the use of self-regulated learning strategies. Measures of self-regulated learning strategies and big-five personality traits were administered to a sample of undergraduate students. Results from canonical correlation analysis indicated an overlap between the…

  2. Information Literacy for Health Professionals: Teaching Essential Information Skills with the Big6 Information Literacy Model

    Science.gov (United States)

    Santana Arroyo, Sonia

    2013-01-01

    Health professionals frequently do not possess the necessary information-seeking abilities to conduct an effective search in databases and Internet sources. Reference librarians may teach health professionals these information and technology skills through the Big6 information literacy model (Big6). This article aims to address this issue. It also…

  3. Crowdsourcing Big Trace Data Filtering: a Partition-And Model

    Science.gov (United States)

    Yang, X.; Tang, L.

    2016-06-01

    GPS traces collected via crowdsourcing way are low-cost and informative and being as a kind of new big data source for urban geographic information extraction. However, the precision of crowdsourcing traces in urban area is very low because of low-end GPS data devices and urban canyons with tall buildings, thus making it difficult to mine high-precision geographic information such as lane-level road information. In this paper, we propose an efficient partition-and-filter model to filter trajectories, which includes trajectory partitioning and trajectory filtering. For the partition part, the partition with position and angle constrain algorithm is used to partition a trajectory into a set of sub-trajectories based on distance and angle constrains. Then, the trajectory filtering with expected accuracy method is used to filter the sub-trajectories according to the similarity between GPS tracking points and GPS baselines constructed by random sample consensus algorithm. Experimental results demonstrate that the proposed partition-and-filtering model can effectively filter the high quality GPS data from various crowdsourcing trace data sets with the expected accuracy.

  4. Comment on "a simple inflationary quintessential model"

    CERN Document Server

    Fernandez-Jambrina, L

    2016-01-01

    In [1] a new cosmological model is proposed with no big bang singularity in the past. This model starts with an inflationary era, follows with a stiff matter dominated period and evolves to accelerated expansion in an asymptotically de Sitter regime. We argue that the initial singularity is in fact no big bang but a directional singularity which cannot be reached by comoving observers but by observers with nonzero linear momentum. Hence, the time lapse from the initial singularity can be as long as desired depending on the linear momentum of the observer. This conclusion applies to similar inflationary models. This sort of cosmological singularities have been postulated also in other scenarios.

  5. Dot-Product Join: An Array-Relation Join Operator for Big Model Analytics

    OpenAIRE

    Qin, Chengjie; Rusu, Florin

    2016-01-01

    Big Data analytics has been approached exclusively from a data-parallel perspective, where data are partitioned to multiple workers -- threads or separate servers -- and model training is executed concurrently over different partitions, under various synchronization schemes that guarantee speedup and/or convergence. The dual -- Big Model -- problem that, surprisingly, has received no attention in database analytics, is how to manage models with millions if not billions of parameters that do n...

  6. Sketch of Big Data Real-Time Analytics Model

    OpenAIRE

    Amen, Bakhtiar; Lu, Joan

    2015-01-01

    Big Data has drawn huge attention from researchers in information sciences, decision makers in governments and enterprises. However, there is a lot of potential and highly useful value hidden in the huge volume of data. Data is the new oil, but unlike oil data can be refined further to create even more value. Therefore, a new scientific paradigm is born as data-intensive scientific discovery, also known as Big Data. The growth volume of real-time data requires new techniques and technologies ...

  7. The Study of Humor Utterance Translation in The Big Bang Theory from the Perspective of Relevance Theory%关联理论视角下美国情景喜剧《生活大爆炸》中幽默言语的翻译

    Institute of Scientific and Technical Information of China (English)

    俞娜莎

    2014-01-01

    《生活大爆炸》这一情景喜剧目前在美国深得人心。幽默诙谐的语言造就了该剧的成功。该文详细探讨了关联理论视角下情景喜剧《生活大爆炸》中的幽默言语翻译。该文首先论述了在关联理论视角下其幽默言语的产生机制;其次探究关联理论对幽默言语翻译的适用性;最后提出了关联理论视角下的可行的影视幽默言语翻译策略:格特的直接翻译策略和间接翻译策略,并详细例证了直接翻译的直译法、注释法和间接翻译的补充法、替代法和省译法等具体的翻译方法。%s:The Big Bang Theory has been a popular American sitcom. Humorous utterance greatly contributes to its success. This paper tries to discuss the humorous utterance translation from the perspective of Relevance Theory in detail. The paper firstly in⁃troduces the generative mechanism of humorous utterance from the perspective of Relevance Theory;then it discusses the appli⁃cability of Relevance Theory on humor translation;at last, it points out some subtitling translation strategies in The Big Bang The⁃ory from the perspective of Relevance Theory, namely, Gutt’s direct translation and indirect translation, and illustrates the specif⁃ic translation methods, that is, literal translation and annotation that belong to direct translation as well as supplement, replace⁃ment and omission that belong to indirect translation.

  8. Modeling and processing for next-generation big-data technologies with applications and case studies

    CERN Document Server

    Barolli, Leonard; Barolli, Admir; Papajorgji, Petraq

    2015-01-01

    This book covers the latest advances in Big Data technologies and provides the readers with a comprehensive review of the state-of-the-art in Big Data processing, analysis, analytics, and other related topics. It presents new models, algorithms, software solutions and methodologies, covering the full data cycle, from data gathering to their visualization and interaction, and includes a set of case studies and best practices. New research issues, challenges and opportunities shaping the future agenda in the field of Big Data are also identified and presented throughout the book, which is intended for researchers, scholars, advanced students, software developers and practitioners working at the forefront in their field.

  9. Reheating the Standard Model from a Hidden Sector

    CERN Document Server

    Tenkanen, Tommi

    2016-01-01

    We consider a scenario where the inflaton decays to a hidden sector thermally decoupled from the visible Standard Model sector. A tiny portal coupling between the hidden and the visible sectors later heats the visible sector so that the Standard Model degrees of freedom come to dominate the energy density of the Universe before Big Bang Nucleosynthesis. We find that this scenario is viable, although obtaining the correct dark matter abundance and retaining successful Big Bang Nucleosynthesis is not obvious. We also show that the isocurvature perturbations constituted by a primordial Higgs condensate are not problematic for the viability of the scenario.

  10. Primordial alchemy: a test of the standard model

    International Nuclear Information System (INIS)

    Big Bang Nucleosynthesis provides the only probe of the early evolution of the Universe constrained by observational data. The standard, hot, big bang model predicts the synthesis of the light elements (D, 3He, 4He, 7Li) in astrophysically interesting abundances during the first few minutes in the evolution of the Universe. A quantitative comparison of the predicted abundances with those observed astronomically confirms the consistency of the standard model and yields valuable constraints on the parameters of cosmology and elementary particle physics. The current status of the comparison between theory and observation will be reviewed and the opportunities for future advances outlined

  11. 修辞在人物性格刻画中的作用──以《生活大爆炸》中的对白为例%The Function of Rhetoric in Character Depiction——Taking Dialogues from The Big Bang Theory as an Example

    Institute of Scientific and Technical Information of China (English)

    陈大方

    2011-01-01

    《:生活大爆炸》是时下非常风靡的一部以"科学天才"为背景的情景喜剧,该片荣获了包括TCA奖和艾美奖在内的多个奖项。本文尝试从修辞的视域出发,分析人物对白中的修辞手法,如反语、曲解、反问、用典等,从而剖析其在人物性格刻画中的作用。%The Big Bang Theory is a very popular situation comedy nowadays with "science talent" as its background.This play has won several honors including TCA and Emmy.This paper intends to analyze from the perspective of rhetoric,analyzing the rhetorical devices of character's dialogues,such as irony,perversion,rhetorical questions,allusion,etc.as a way to anatomize character personality.

  12. 情景喜剧会话修正特征研究--基于《生活大爆炸》中的会话分析%Sitcom Session Correction Characteristic Research---Based on the Conversation Analysis of"The Big Bang Theory"

    Institute of Scientific and Technical Information of China (English)

    岳淑英; 党小玲

    2016-01-01

    There must be some spelling mistakes in the session,the pronunciation errors or misunderstanding and that can make the conversation go smoothly.The most effective way is to the session correction.Taking the 8th session in the sitcom of"The Big Bang Theory"as the corpus,based on the theory of Schegloff etc.,this paper make analysis on the characteristic of the session correction.%会话中必然存在一些拼写错误、发音错误或理解错误,而能够让会话顺利进行的最有效的方式即为会话修正。以情景喜剧《生活大爆炸》第八季中的会话为语料,基于Schegloff等人的理论,分析其中的会话修正特征。

  13. 从关联理论阐释话语标记语you know的语用功能--以美剧《生活大爆炸》为例%A Study on Pragmatic Functions of Discourse Marker You Know in The Big Bang Theory from the Perspective of Relevance Theory

    Institute of Scientific and Technical Information of China (English)

    李恒

    2016-01-01

    话语标记语,作为一种被广泛使用的语言现象,在过去40年来得到了国内外学者的关注。语言学家们大多就其定义及功能对其进行研究。本文以《生活大爆炸》第三季对白为语料,从关联理论对其中出现的话语标记语 you know的五种语用功能进行分析,帮助交际者更好地理解和生成话语,继而获得交际成功。%Discourse marker,as a widely used linguistic phenomenon,has gained the attention of scholars from home and abroad in the past 40 years.Linguists have been mostly focusing on its definition and functions.This paper tries to analyze the five pragmatic functions of discourse marker“you know”from the perspective of Relevance Theory based on the dialogues of Season 3 in The Big Bang Theory,in order to help communicators understand and produce utterances better and then achieve successful communication.

  14. A Brief Review on Leading Big Data Models

    OpenAIRE

    Sharma, Sugam; Tim, Udoyara S; Wong, Johnny; Gadia, Shashi; Sharma, Subhash

    2014-01-01

    Today, science is passing through an era of transformation, where the inundation of data, dubbed data deluge is influencing the decision making process. The science is driven by the data and is being termed as data science. In this internet age, the volume of the data has grown up to petabytes, and this large, complex, structured or unstructured, and heterogeneous data in the form of “Big Data” has gained significant attention. The rapid pace of data growth through various disparate sources, ...

  15. Big Think: A Model for Critical Inquiry in Economics Courses

    OpenAIRE

    Robert Garnett; John Reardon

    2011-01-01

    This paper outlines a concrete strategy for addressing the critical inquiry gap in undergraduate economics education, building on the work of Colander and McGoldrick, who argue that economics students currently do not receive sufficient exposure to ‘big think’ questions: ill-structured questions that invite students and instructors to interrogate arguments, evaluate assumptions, and discover serendipitous connections across courses and disciplines (2009b: 5-6). Our goal is to operationalize t...

  16. Big Bang–Big Crunch Optimization Algorithm for Linear Phase Fir Digital Filter Design

    OpenAIRE

    Ms. Rashmi Singh Dr. H. K. Verma

    2012-01-01

    The Big Bang–Big Crunch (BB–BC) optimization algorithm is a new optimization method that relies on the Big Bang and Big Crunch theory, one of the theories of the evolution of the universe. In this paper, a Big Bang–Big Crunch algorithm has been used here for the design of linear phase finite impulse response (FIR) filters. Here the experimented fitness function based on the mean squared error between the actual and the ideal filter response. This paper presents the plot of magnitude response ...

  17. SETI as a part of Big History

    Science.gov (United States)

    Maccone, Claudio

    2014-08-01

    Big History is an emerging academic discipline which examines history scientifically from the Big Bang to the present. It uses a multidisciplinary approach based on combining numerous disciplines from science and the humanities, and explores human existence in the context of this bigger picture. It is taught at some universities. In a series of recent papers ([11] through [15] and [17] through [18]) and in a book [16], we developed a new mathematical model embracing Darwinian Evolution (RNA to Humans, see, in particular, [17] and Human History (Aztecs to USA, see [16]) and then we extrapolated even that into the future up to ten million years (see 18), the minimum time requested for a civilization to expand to the whole Milky Way (Fermi paradox). In this paper, we further extend that model in the past so as to let it start at the Big Bang (13.8 billion years ago) thus merging Big History, Evolution on Earth and SETI (the modern Search for ExtraTerrestrial Intelligence) into a single body of knowledge of a statistical type. Our idea is that the Geometric Brownian Motion (GBM), so far used as the key stochastic process of financial mathematics (Black-Sholes models and related 1997 Nobel Prize in Economics!) may be successfully applied to the whole of Big History. In particular, in this paper we derive Big History Theory based on GBMs: just as the GBM is the “movie” unfolding in time, so the Statistical Drake Equation is its “still picture”, static in time, and the GBM is the time-extension of the Drake Equation. Darwinian Evolution on Earth may be easily described as an increasing GBM in the number of living species on Earth over the last 3.5 billion years. The first of them was RNA 3.5 billion years ago, and now 50

  18. Worms Propagation Modeling and Analysis in Big Data Environment

    OpenAIRE

    Song He; Can Zhang; Wei Guo; Li-Dong Zhai

    2015-01-01

    The integration of the Internet and Mobile networks results in huge amount of data, as well as security threat. With the fragile capacity of security protection, worms can propagate in the integration network and undermine the stability and integrity of data. The propagation of worm is a great security risk to massive amounts of data in the integration network. We propose a kind of worm propagating in big data environment named BD-Worm. BD-Worm consumes computing resources and gets privacy in...

  19. The changing model of big pharma: impact of key trends.

    Science.gov (United States)

    Gautam, Ajay; Pan, Xiaogang

    2016-03-01

    Recent years have seen exciting breakthroughs in biomedical sciences that are producing truly novel therapeutics for unmet patient needs. However, the pharmaceutical industry is also facing significant barriers in the form of pricing and reimbursement, continued patent expirations and challenging market dynamics. In this article, we have analyzed data from the 1995-2015 period, on key aspects such as revenue distribution, research units, portfolio mix and emerging markets to identify four key trends that help to understand the change in strategic focus, realignment of R&D footprint, the shift from primary care toward specialty drugs and biologics and the growth of emerging markets as major revenue drivers for big pharma.

  20. Big Egos in Big Science

    DEFF Research Database (Denmark)

    Jeppesen, Jacob; Vaarst Andersen, Kristina; Lauto, Giancarlo;

    and locations, having a diverse knowledge set and capable of tackling more and more complex problems. This prose the question if Big Egos continues to dominate in this rising paradigm of big science. Using a dataset consisting of full bibliometric coverage from a Large Scale Research Facility, we utilize...... a stochastic actor oriented model (SAOM) to analyze both network endogeneous mechanisms and individual agency driving the collaboration network and further if being a Big Ego in Big Science translates to increasing performance. Our findings suggest that the selection of collaborators is not based...... on preferentialattachment, but more of an assortativity effect creating not merely a rich-gets-richer effect but an elitist network with high entry barriers. In this acclaimed democratic and collaborative environment of Big Science, the elite closes in on itself. We propose this tendency to be even more explicit in other...

  1. HADOOP+Big Data: Analytics Using Series Queue with Blocking Model

    Directory of Open Access Journals (Sweden)

    S. Koteeswaran

    2014-07-01

    Full Text Available Big data deals with large volumes of tons and tons of data. Since managing this much amount of data is not in the mere way for the traditional data mining techniques. Technology is in the world of pervasive environment i.e., technology follows up with its tremendous growth. Hence coordinating these amount of data in a linear way is mere little difficult, hence we proposed a new scheme in order to draw the data and data transformation in large data base. We extended our work in HADOOP (one of the big data managing tool. Our model is fully based on aggregation of data and data modelling. Our proposed model leads to high end data transformation for big data processing. We achieved our analytical result by applying our model with 2 HADOOP clusters, 4 nodes and with 25 jobs in MR functionality.

  2. Ontology-Based Big Dimension Modeling in Data Warehouse Schema Design

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem

    2013-01-01

    During data warehouse schema design, designers often encounter how to model big dimensions that typically contain a large number of attributes and records. To investigate effective approaches for modeling big dimensions is necessary in order to achieve better query performance, with respect to...... partitioning, vertical partitioning and their hybrid. We formalize the design methods and propose an algorithm that describes the modeling process from an OWL ontology to a data warehouse schema. In addition, this paper also presents an effective ontology-based tool to automate the modeling process. The tool...... can automatically generate the data warehouse schema from the ontology of describing the terms and business semantics for the big dimension. In case of any change in the requirements, we only need to modify the ontology, and re-generate the schema using the tool. This paper also evaluates the proposed...

  3. Modeling regeneration responses of big sagebrush (Artemisia tridentata) to abiotic conditions

    Science.gov (United States)

    Schlaepfer, Daniel R.; Lauenroth, William K.; Bradford, John B.

    2014-01-01

    Ecosystems dominated by big sagebrush, Artemisia tridentata Nuttall (Asteraceae), which are the most widespread ecosystems in semiarid western North America, have been affected by land use practices and invasive species. Loss of big sagebrush and the decline of associated species, such as greater sage-grouse, are a concern to land managers and conservationists. However, big sagebrush regeneration remains difficult to achieve by restoration and reclamation efforts and there is no regeneration simulation model available. We present here the first process-based, daily time-step, simulation model to predict yearly big sagebrush regeneration including relevant germination and seedling responses to abiotic factors. We estimated values, uncertainty, and importance of 27 model parameters using a total of 1435 site-years of observation. Our model explained 74% of variability of number of years with successful regeneration at 46 sites. It also achieved 60% overall accuracy predicting yearly regeneration success/failure. Our results identify specific future research needed to improve our understanding of big sagebrush regeneration, including data at the subspecies level and improved parameter estimates for start of seed dispersal, modified wet thermal-time model of germination, and soil water potential influences. We found that relationships between big sagebrush regeneration and climate conditions were site specific, varying across the distribution of big sagebrush. This indicates that statistical models based on climate are unsuitable for understanding range-wide regeneration patterns or for assessing the potential consequences of changing climate on sagebrush regeneration and underscores the value of this process-based model. We used our model to predict potential regeneration across the range of sagebrush ecosystems in the western United States, which confirmed that seedling survival is a limiting factor, whereas germination is not. Our results also suggested that modeled

  4. A Fourier dimensionality reduction model for big data interferometric imaging

    CERN Document Server

    Kartik, S Vijay; Thiran, Jean-Philippe; Wiaux, Yves

    2016-01-01

    Data dimensionality reduction in radio interferometry can provide critical savings of computational resources for image reconstruction, which is of paramount importance for the scalability of imaging methods to the big data setting of the next-generation telescopes. This article sheds new light on dimensionality reduction from the perspective of the compressed sensing theory and studies its interplay with imaging algorithms designed in the context of convex optimization. We propose a post-gridding linear data embedding to the space spanned by the left singular vectors of the measurement operator, providing a dimensionality reduction below image size. This embedding preserves the null space of the measurement operator and hence its sampling properties are also preserved in light of the compressed sensing theory. We show that this can be approximated by first computing the dirty image and then applying a weighted subsampled discrete Fourier transform to obtain the final reduced data vector. This Fourier dimensi...

  5. On Subtitle Translation Strategies From the Perspective of Relevance Theory:A Case Study of The Big Bang Theory%关联理论视角下的字幕翻译策略--以《生活大爆炸》为例

    Institute of Scientific and Technical Information of China (English)

    张文珍

    2013-01-01

    Since the international dissemination of movie and TV plays relies on subtitle translation, it is essential for us to make a dedicated research into the related translation strategies , considering the unique particularities of the language of such translation versions .Relevance Theory argues that a successful communication allows the audience to achieve maximum con-textual effects with minimum processing efforts, which is exactly the expected result of subtitle translation.Hence, guiding un-der the Relevance Theory, the paper explores the translation strategies embodied in the subtitles of the blockbuster The Big Bang Theory, hoping to facilitate the future translation of subtitles.%  影视作品的跨国界传播有赖于字幕翻译,影视语言又具有其特殊性,这就给字幕翻译提出了特殊要求,有必要就此展开专门研究。关联理论认为,判断交际行为成功与否取决于听话者是否通过付出最小努力获得最大语境效果,这正是字幕翻译所应追求的。故笔者以关联理论为指导,从“双关语翻译”、“情绪表达翻译”、“文化词语翻译”三个维度,探索热播美剧《生活大爆炸》中的字幕翻译策略,以期有助于日后的字幕翻译工作。

  6. Bang-bang control of feeding: role of hypothalamic and satiety signals.

    Directory of Open Access Journals (Sweden)

    B Silvano Zanutto

    2007-05-01

    Full Text Available Rats, people, and many other omnivores eat in meals rather than continuously. We show by experimental test that eating in meals is regulated by a simple bang-bang control system, an idea foreshadowed by Le Magnen and many others, shown by us to account for a wide range of behavioral data, but never explicitly tested or tied to neurophysiological facts. The hypothesis is simply that the tendency to eat rises with time at a rate determined by satiety signals. When these signals fall below a set point, eating begins, in on-off fashion. The delayed sequelae of eating increment the satiety signals, which eventually turn eating off. Thus, under free conditions, the organism eats in bouts separated by noneating activities. We report an experiment with rats to test novel predictions about meal patterns that are not explained by existing homeostatic approaches. Access to food was systematically but unpredictably interrupted just as the animal tried to start a new meal. A simple bang-bang model fits the resulting meal-pattern data well, and its elements can be identified with neurophysiological processes. Hypothalamic inputs can provide the set point for longer-term regulation carried out by a comparator in the hindbrain. Delayed gustatory and gastrointestinal aftereffects of eating act via the nucleus of the solitary tract and other hindbrain regions as neural feedback governing short-term regulation. In this way, the model forges real links between a functioning feedback mechanism, neuro-hormonal data, and both short-term (meals and long-term (eating-rate regulation behavioral data.

  7. Gossip Management at Universities Using Big Data Warehouse Model Integrated with a Decision Support System

    Directory of Open Access Journals (Sweden)

    Pelin Vardarlier

    2016-01-01

    Full Text Available Big Data has recently been used for many purposes like medicine, marketing and sports. It has helped improve management decisions. However, for almost each case a unique data warehouse should be built to benefit from the merits of data mining and Big Data. Hence, each time we start from scratch to form and build a Big Data Warehouse. In this study, we propose a Big Data Warehouse and a model for universities to be used for information management, to be more specific gossip management. The overall model is a decision support system that may help university administraitons when they are making decisions and also provide them with information or gossips being circulated among students and staff. In the model, unsupervised machine learning algorithms have been employed. A prototype of the proposed system has also been presented in the study. User generated data has been collected from students in order to learn gossips and students’ problems related to school, classes, staff and instructors. The findings and results of the pilot study suggest that social media messages among students may give important clues for the happenings at school and this information may be used for management purposes.The model may be developed and implemented by not only universities but also some other organisations.

  8. A New Look at the Big Five Factor Structure through Exploratory Structural Equation Modeling

    Science.gov (United States)

    Marsh, Herbert W.; Ludtke, Oliver; Muthen, Bengt; Asparouhov, Tihomir; Morin, Alexandre J. S.; Trautwein, Ulrich; Nagengast, Benjamin

    2010-01-01

    NEO instruments are widely used to assess Big Five personality factors, but confirmatory factor analyses (CFAs) conducted at the item level do not support their a priori structure due, in part, to the overly restrictive CFA assumptions. We demonstrate that exploratory structural equation modeling (ESEM), an integration of CFA and exploratory…

  9. Thermodynamics of apparent horizon and Friedmann equations in big bounce universe

    Science.gov (United States)

    Liu, Molin; Yang, Yuling; Lu, Jianbo; Xu, Lixin

    2016-05-01

    In this paper, we study a big bounce universe typified by a non-singular big bounce, as opposed to a singular big bang. This cosmological model can describe radiation dominated early universe and matter dominated late universe in FRW model. The connections between thermodynamics and gravity are observed here. In the early stage of both cold and hot universes, we find there is only one geometry containing a 4D de Sitter universe with a general state parameter. We also find the form of the apparent horizon in the early universe strongly depends on the extra dimension, which suggests that the influence of the extra dimension could in principle be found in the early universe. Moreover, we show that in the late stages of both cold and hot universes, the moment when the apparent horizon begins to bounce keeps essentially in step with the behavior of the cosmological scalar factor.

  10. Methodological challenges and analytic opportunities for modeling and interpreting Big Healthcare Data.

    Science.gov (United States)

    Dinov, Ivo D

    2016-01-01

    Managing, processing and understanding big healthcare data is challenging, costly and demanding. Without a robust fundamental theory for representation, analysis and inference, a roadmap for uniform handling and analyzing of such complex data remains elusive. In this article, we outline various big data challenges, opportunities, modeling methods and software techniques for blending complex healthcare data, advanced analytic tools, and distributed scientific computing. Using imaging, genetic and healthcare data we provide examples of processing heterogeneous datasets using distributed cloud services, automated and semi-automated classification techniques, and open-science protocols. Despite substantial advances, new innovative technologies need to be developed that enhance, scale and optimize the management and processing of large, complex and heterogeneous data. Stakeholder investments in data acquisition, research and development, computational infrastructure and education will be critical to realize the huge potential of big data, to reap the expected information benefits and to build lasting knowledge assets. Multi-faceted proprietary, open-source, and community developments will be essential to enable broad, reliable, sustainable and efficient data-driven discovery and analytics. Big data will affect every sector of the economy and their hallmark will be 'team science'.

  11. Methodological challenges and analytic opportunities for modeling and interpreting Big Healthcare Data.

    Science.gov (United States)

    Dinov, Ivo D

    2016-01-01

    Managing, processing and understanding big healthcare data is challenging, costly and demanding. Without a robust fundamental theory for representation, analysis and inference, a roadmap for uniform handling and analyzing of such complex data remains elusive. In this article, we outline various big data challenges, opportunities, modeling methods and software techniques for blending complex healthcare data, advanced analytic tools, and distributed scientific computing. Using imaging, genetic and healthcare data we provide examples of processing heterogeneous datasets using distributed cloud services, automated and semi-automated classification techniques, and open-science protocols. Despite substantial advances, new innovative technologies need to be developed that enhance, scale and optimize the management and processing of large, complex and heterogeneous data. Stakeholder investments in data acquisition, research and development, computational infrastructure and education will be critical to realize the huge potential of big data, to reap the expected information benefits and to build lasting knowledge assets. Multi-faceted proprietary, open-source, and community developments will be essential to enable broad, reliable, sustainable and efficient data-driven discovery and analytics. Big data will affect every sector of the economy and their hallmark will be 'team science'. PMID:26918190

  12. omniClassifier: a Desktop Grid Computing System for Big Data Prediction Modeling

    Science.gov (United States)

    Phan, John H.; Kothari, Sonal; Wang, May D.

    2016-01-01

    Robust prediction models are important for numerous science, engineering, and biomedical applications. However, best-practice procedures for optimizing prediction models can be computationally complex, especially when choosing models from among hundreds or thousands of parameter choices. Computational complexity has further increased with the growth of data in these fields, concurrent with the era of “Big Data”. Grid computing is a potential solution to the computational challenges of Big Data. Desktop grid computing, which uses idle CPU cycles of commodity desktop machines, coupled with commercial cloud computing resources can enable research labs to gain easier and more cost effective access to vast computing resources. We have developed omniClassifier, a multi-purpose prediction modeling application that provides researchers with a tool for conducting machine learning research within the guidelines of recommended best-practices. omniClassifier is implemented as a desktop grid computing system using the Berkeley Open Infrastructure for Network Computing (BOINC) middleware. In addition to describing implementation details, we use various gene expression datasets to demonstrate the potential scalability of omniClassifier for efficient and robust Big Data prediction modeling. A prototype of omniClassifier can be accessed at http://omniclassifier.bme.gatech.edu/.

  13. A critical review of lexical analysis and Big Five model

    Directory of Open Access Journals (Sweden)

    María Cristina Richaud de Minzi

    2002-06-01

    Full Text Available In the last years the idea has resurfaced that traits can be measured in a reliable and valid and this can be useful inthe prediction of human behavior. The five-factor model appears to represent a conceptual and empirical advances in the field of personality theory. Necessary orthogonal factors (Goldberg, 1992, p. 26 to show the relationships between the descriptors of the features in English is five, and its nature can be summarized through the broad concepts of Surgency, Agreeableness, Responsibility, Emotional Stability versus neuroticism and openness to experience (John, 1990, p96 Furthermore, despite the criticisms that have been given to the model, represents a breakthrough in the field of personality assessment. This approach means a contribution to the study of personality, without being the integrative model of personality.

  14. Metabolic modeling with Big Data and the gut microbiome.

    Science.gov (United States)

    Sung, Jaeyun; Hale, Vanessa; Merkel, Annette C; Kim, Pan-Jun; Chia, Nicholas

    2016-09-01

    The recent advances in high-throughput omics technologies have enabled researchers to explore the intricacies of the human microbiome. On the clinical front, the gut microbial community has been the focus of many biomarker-discovery studies. While the recent deluge of high-throughput data in microbiome research has been vastly informative and groundbreaking, we have yet to capture the full potential of omics-based approaches. Realizing the promise of multi-omics data will require integration of disparate omics data, as well as a biologically relevant, mechanistic framework - or metabolic model - on which to overlay these data. Also, a new paradigm for metabolic model evaluation is necessary. Herein, we outline the need for multi-omics data integration, as well as the accompanying challenges. Furthermore, we present a framework for characterizing the ecology of the gut microbiome based on metabolic network modeling. PMID:27668170

  15. Metabolic modeling with Big Data and the gut microbiome.

    Science.gov (United States)

    Sung, Jaeyun; Hale, Vanessa; Merkel, Annette C; Kim, Pan-Jun; Chia, Nicholas

    2016-09-01

    The recent advances in high-throughput omics technologies have enabled researchers to explore the intricacies of the human microbiome. On the clinical front, the gut microbial community has been the focus of many biomarker-discovery studies. While the recent deluge of high-throughput data in microbiome research has been vastly informative and groundbreaking, we have yet to capture the full potential of omics-based approaches. Realizing the promise of multi-omics data will require integration of disparate omics data, as well as a biologically relevant, mechanistic framework - or metabolic model - on which to overlay these data. Also, a new paradigm for metabolic model evaluation is necessary. Herein, we outline the need for multi-omics data integration, as well as the accompanying challenges. Furthermore, we present a framework for characterizing the ecology of the gut microbiome based on metabolic network modeling.

  16. Teaching the Big Ideas of Biology with Operon Models

    Science.gov (United States)

    Cooper, Robert A.

    2015-01-01

    This paper presents an activity that engages students in model-based reasoning, requiring them to predict the behavior of the trp and lac operons under different environmental conditions. Students are presented six scenarios for the "trp" operon and five for the "lac" operon. In most of the scenarios, specific mutations have…

  17. 科学情景喜剧人物设置特性分析--以《生活大爆炸》为例%Characteristics of the Character Establishment of Science Sitcom:A Case Study on The Big Bang Theory

    Institute of Scientific and Technical Information of China (English)

    卿婉莹

    2013-01-01

    Since it was presented, Ameri can science sitcom The Big Bang Theory has been widely appreciated by the audience,including critics and real scientists. Focused on young scientists,the TV play has created an individual style of science sitcom through the integration of science and daily life. Compared with ordinary themes, the science sitcom sets three particular kinds of character relations to advance the story on the background of science. By presenting the differences of the understanding of science,differences and contradictions among scientists and connections with science fiction,the particular character establishment of science sitcom could be enlightenment for science communication.%美国科学情景喜剧《生活大爆炸》自推出以来,受到了观众及电视界、科学界的各方好评。该剧以青年科学家为人物核心,将深奥的科学理论、晦涩的科学语言、独特的科学场景与日常生活有机结合,开创出独特的科学情景喜剧风格。相较于一般体裁的情景喜剧,关注“科学”题材的《生活大爆炸》为了解决如何让“呆板、严肃的科学”吸引人而又保证其品质格调的问题,主创人员在影视剧常规创作的基础上精心设置了三组人物关系,紧扣“科学”话题,通过科学家与其他人物之间的各种冲突推动幽默剧情不断发展。构建知识差异的矛盾、讲述科学家之间的分歧、用科幻架起沟通的桥梁,科学情景喜剧中独特的人物设置对科学传播具有启发意义。

  18. Big Surveys, Big Data Centres

    Science.gov (United States)

    Schade, D.

    2016-06-01

    Well-designed astronomical surveys are powerful and have consistently been keystones of scientific progress. The Byurakan Surveys using a Schmidt telescope with an objective prism produced a list of about 3000 UV-excess Markarian galaxies but these objects have stimulated an enormous amount of further study and appear in over 16,000 publications. The CFHT Legacy Surveys used a wide-field imager to cover thousands of square degrees and those surveys are mentioned in over 1100 publications since 2002. Both ground and space-based astronomy have been increasing their investments in survey work. Survey instrumentation strives toward fair samples and large sky coverage and therefore strives to produce massive datasets. Thus we are faced with the "big data" problem in astronomy. Survey datasets require specialized approaches to data management. Big data places additional challenging requirements for data management. If the term "big data" is defined as data collections that are too large to move then there are profound implications for the infrastructure that supports big data science. The current model of data centres is obsolete. In the era of big data the central problem is how to create architectures that effectively manage the relationship between data collections, networks, processing capabilities, and software, given the science requirements of the projects that need to be executed. A stand alone data silo cannot support big data science. I'll describe the current efforts of the Canadian community to deal with this situation and our successes and failures. I'll talk about how we are planning in the next decade to try to create a workable and adaptable solution to support big data science.

  19. 《生活大爆炸》中艺术语言的陌生化%Defamiliar Language and its Translation in "The big bang Theory"

    Institute of Scientific and Technical Information of China (English)

    王馥沁; 张璘

    2012-01-01

    陌生化是俄国形式主义理论关于艺术创作的重要思想。在形式主义看来,艺术的过程就是使事物"陌生化",打破常识常规,延长审美,使人产生新鲜陌生感。《生活大爆炸》作为一部另类的情景喜剧,其艺术语言的运用独辟蹊径,别具匠心。本文从陌生化角度分析影片中的幽默语言、视听语言、造型语言等影视艺术语言的运用,深入探析其独特创新之处,阐释其偏离生活常态而产生的另类美感。%Defamiliarization is an important theory of Russian formalism. In the formalism, the process of " Defamiliarization " is to make the object strange . Therefore , Situational comedy, as a form of the art, is lacking in the analysis of Defamiliar Language use . From the aspect of defamiliarization ,this article analyses the humorous language,visual language, the model language and other artistic language film, deeply to improve the subsequent TV development trend and to provide a reasonable conception and prediction.

  20. A model of self-actualization:A Psychobiography Study of Liu Bang's Personality T raits%自我实现者的典范--刘邦自我实现人格的心理传记分析

    Institute of Scientific and Technical Information of China (English)

    舒跃育

    2015-01-01

    Liu Bang is a model of self‐actualization among the political figures . Through analysis and comparison of the nine founding emperors' family backgrounds , birth order , childhood and experiences of education ,and the way to power and ruling time , this paper finds that under limited circumstances Liu Bang achieved his self‐potential to the greatest extent . He not only went beyond himself and changed history ,but also surpassed the limits of human nature .These can be attributed to his personality traits of self‐actualization .%刘邦是政治人物中的自我实现者的典范。研究通过对九位开国帝王的出身、家庭排行、幼年经历与教育情况、获得政权方式、登基时间、在位时间的分析比较发现,相对其他八位开国帝王而言,刘邦是在各方面条件极其受限的情况下,实现了自己潜能最大程度的发挥,他不仅超越了自我、改变了历史,同时也突破了人性的限制。而他对这些限制的突破,源自他诸多自我实现的人格特征。