Automobile windscreen rake, spectacle lenses, and effective transmittance.
Walsh, Glyn
2009-12-01
To investigate the effect of windscreen rake angle on effective transmittance and the contribution of spectacle lenses to the total transmittance of the system. Theoretical analysis has been carried out using the Fresnel reflectance equations. Windscreen rake can reduce effective transmittance significantly at angles present on modern aerodynamic vehicles. Spectacle lenses reduce the total transmittance still further, often to below the minimum level permissible in current international standards for windscreens. Drivers should always be supplied antireflection-coated lenses where there is a chance of their spectacles being used for night-time driving, if current International standards for windscreen transmittance are to be met by the spectacle-windscreen combination. Windscreen rake angle should be accounted for both in the International Organization for Standardization transmittance standards and in roadside testing devices.
Nesmith, Jonathan C. B.; O'Hara, Kevin L.; van Mantgem, Phillip J.; de Valpine, Perry
2010-01-01
Prescribed fire is an important tool for fuel reduction, the control of competing vegetation, and forest restoration. The accumulated fuels associated with historical fire exclusion can cause undesirably high tree mortality rates following prescribed fires and wildfires. This is especially true for sugar pine (Pinus lambertiana Douglas), which is already negatively affected by the introduced pathogen white pine blister rust (Cronartium ribicola J.C. Fisch. ex Rabenh). We tested the efficacy of raking away fuels around the base of sugar pine to reduce mortality following prescribed fire in Sequoia and Kings Canyon national parks, California, USA. This study was conducted in three prescribed fires and included 457 trees, half of which had the fuels around their bases raked away to mineral soil to 0.5 m away from the stem. Fire effects were assessed and tree mortality was recorded for three years after prescribed fires. Overall, raking had no detectable effect on mortality: raked trees averaged 30% mortality compared to 36% for unraked trees. There was a significant effect, however, between the interaction of raking and average pre-treatment forest floor fuel depth: the predicted probability of survival of a 50 cm dbh tree was 0.94 vs. 0.96 when average pre-treatment fuel depth was 0 cm for a raked and unraked tree, respectively. When average pre-treatment forest floor fuel depth was 30 cm, the predicted probability of survival for a raked 50 cm dbh tree was 0.60 compared to only 0.07 for an unraked tree. Raking did not affect mortality when fire intensity, measured as percent crown volume scorched, was very low (0% scorch) or very high (>80% scorch), but the raking treatment significantly increased the proportion of trees that survived by 9.6% for trees that burned under moderate fire intensity (1% to 80% scorch). Raking significantly reduced the likelihood of bole charring and bark beetle activity three years post fire. Fuel depth and anticipated fire intensity need
William B. Patterson; Michael A. Blazier; Steven L. Holtard
2010-01-01
Frequent pinestraw raking and removal in pine plantations has led to concerns about nutrient removal from the stand. While soil chemistry of raked stands has been studied, little attention has been placed on potential compaction from raking operations. Four treatments were applied to a 16-year-old loblolly pine plantation at the Louisiana State University AgCenter...
Guo, Wensong; Jian, Jianming; San, Yunlong; Lui, Rui; Li, Gang; Hou, Shulin
2017-08-01
Traditional rake type mulching film recycling machine has the problem of difficulty in unloading and packing film, poor continuity of the work. In order to solve such problems, this paper designs a kind of chain rake type mulching film recycling machine which can realize continuous raking film, collecting film, transporting film, shaking off soil, unloading film. Rake teeth is the basic part of chain rake mulching recycling machine. The stability of rake teeth's inserting soil is an important factor to ensure recovery efficiency of the plastic film recovery. By virtual prototype simulation, this paper study the influence of different factors on the stability of rake teeth inserting soil. The results are as follows: The speed of chain rake has no significant effect on the stability of rake teeth inserting soil; Reducing resistance of rake teeth in the process of working, is conducive to improve the stability of rake teeth inserting soil; Appropriate increasing elastic modulus of chain rake, is helpful to enhance the stability of rake teeth inserting soil.
Does raking basal duff affect tree growth rates or mortality?
Erin Noonan-Wright; Sharon M. Hood; Danny R. Cluck
2010-01-01
Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure...
Rake task management essentials
Koleshko, Andrey
2014-01-01
A step-by-step and interactive approach explaining the Rake essentials along with code examples and advanced features. If you are a developer who is acquainted with the Ruby language and want to speed up writing the code concerned with files, then this book is for you. To start reading this book, basic Ruby knowledge is required; however, a huge amount of experience with the language is not necessary.
Productivity and costs of stump rake and stump harvester
Energy Technology Data Exchange (ETDEWEB)
Jouhiaho, A.; Rieppo, K.; Mutikainen, A. (TTS Research, Rajamaeki (Finland)), e-mail: aki.jouhiaho@tts.fi, e-mail: kaarlo.rieppo@tts.fi, e-mail: arto.mutikainen@tts.fi
2010-07-01
The cost-effectiveness of the two most common stump extraction equipment used in Finland was investigated in the work study: stump rake and stump harvester. The productivity of stump extraction with the stump rake was on average 12,7 m3 / effective hour and with the stump harvester 12,0 m3 /effective hour. Soil preparation performed during the stump extraction decreased the productivity of stump extraction by 1,9-3,1 m3 / effective hour. Considering the work methods adapted by the drivers, the different revolutions of the engines (RPM) used in the excavators and speed of movement, it is not possible to draw a general conclusion that there would be differences in productivity between stump extraction methods at issue. Even though the acquisition price of the stump harvester was almost double that of the acquisition price of the stump rake with bucket tilt mechanism, the operating costs of the stump harvester were lower due to its lower fuel consumption. The hourly operating costs of the stump rake were 4 per cent or EUR 2,0 / hour higher than the operating costs of the stump harvester. Due to the 6 per cent higher productivity of the stump rake, the unit cost of the stump rake was 2 per cent or EUR 0,09 / m3 lower than that of the stump harvester. (orig.)
Pursuing Automated Classification of Historic Photographic Papers from Raking Light Photomicrographs
Johnson, C Richard Jr; Messier, Paul; Sethares, William A.; Klein, Andrew G; Brown, Christopher; Do, Anh Hoang; Klausmeter, Philip; Abry, Patrice; Jaffard, Stéphane; Wendt, Herwig; Roux, Stephane; Pustelnik, Nelly; van Noord, Nanne; van der Maaten, L.J.P.; Postma, E.O.; Coddington, James; Daffner, Lee Ann; Murata, Hanako; Wilhelm, Henry; Wood, Sally; Messier, Mark
2014-01-01
Surface texture is a critical feature in the manufacture, marketing, and use of photographic paper. Raking light reveals texture through a stark rendering of highlights and shadows. Though close-up raking light images effectively document surface features of photographic paper, the sheer number and
LOFT DTT rake pin stress analysis
Energy Technology Data Exchange (ETDEWEB)
Mosby, W.R.
1979-01-23
A stress analysis of the 3/8-inch and 1/4-inch pins which hold the rake assembly to the flange was performed and shows stresses to be lower than the Class 1 allowables of the ASME Boiler and Pressure Vessel Code. The alternating pin stresses were found to be below the endurance limit and fatigue failure will not occur. The rake assembly was assumed to be loaded by steady drag and lift forces and alternating vortex shedding forces.
Development of a Rotating Rake Array for Boundary-Layer-Ingesting Fan-Stage Measurements
Wolter, John D.; Arend, David J.; Hirt, Stefanie M.; Gazzaniga, John A.
2017-01-01
The recent Boundary-Layer-Ingesting Inlet/Distortion Tolerant Fan wind tunnel experiment at NASA Glenn Research Center's 8-foot by 6-foot supersonic wind tunnel examined the performance of a novel inlet and fan stage that was designed to ingest the vehicle boundary layer in order to take advantage of a predicted overall propulsive efficiency benefit. A key piece of the experiment's instrumentation was a pair of rotating rake arrays located upstream and downstream of the fan stage. This paper examines the development of these rake arrays. Pre-test numerical solutions were sampled to determine placement and spacing for rake pressure and temperature probes. The effects of probe spacing and survey density on the repeatability of survey measurements was examined. These data were then used to estimate measurement uncertainty for the adiabatic efficiency.
Bottom Raking Damage to High-Speed Craft
DEFF Research Database (Denmark)
Simonsen, Bo Cerup
1998-01-01
This paper presents a comparative study of the raking damage to high speed craft (HSC) and conventional ships. The analysis is based on a detailed theoretical model for the raking resistance of an assembled ship bottom structure and on the idea that the impact conditions for various ship types have...
Further Development of Rotating Rake Mode Measurement Data Analysis
Dahl, Milo D.; Hixon, Ray; Sutliff, Daniel L.
2013-01-01
The Rotating Rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. After analysis of the measured data, the mode amplitudes and phases were quantified. For low-speed fans within axisymmetric ducts, mode power levels computed from rotating rake measured data would agree with the far-field power levels on a tone by tone basis. However, this agreement required that the sound from the noise sources within the duct propagated outward from the duct exit without reflection at the exit and previous studies suggested conditions could exist where significant reflections could occur. To directly measure the modes propagating in both directions within a duct, a second rake was mounted to the rotating system with an offset in both the axial and the azimuthal directions. The rotating rake data analysis technique was extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode levels at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode amplitudes for the modes propagating in both directions within the duct. The fit equations were also modified to allow evanescent mode amplitudes to be computed. This extension of the rotating rake data analysis technique was tested using simulated data, numerical code produced data, and preliminary in-duct measured data.
Astronaut Harrison Schmitt collects lunar rake samples during EVA
1972-01-01
Scientist-Astronaut Harrison H. Schmitt collects lunar rake samples at Station 1 during the first Apollo 17 extravehicular activity (EVA-1) at the Taurus-Littrow landing site. This picture was taken by Astronatu Eugene Cernan, Apollo 17 commander. Schmitt is the lunar module pilot. The lunar rake, An Apollo lunar geology hand tool, is used to collect discrete samples of rocks and rock chips ranging in size from one-half inch (1.3 cm) to one inch (2.5 cm).
Influence of Physical Raking and Biological Process in the Mud ...
African Journals Online (AJOL)
Experiment was conducted in the laboratory using radioactive 32P for ascertaining the dynamics and quantifying the exchangeable amount of P between sediment and water phase under the influence of physical raking and biological processes. Collected sediment (100 g) was dispensed in a glass beaker and treated with ...
Holographic effective field theories
Energy Technology Data Exchange (ETDEWEB)
Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)
2016-06-28
We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.
Reproductive ecology of American Oystercatchers nesting on shell rakes
Jodice, Patrick G.R.; Thibault, Janet M.; Collins, S.A.; Spinks, Mark D.; Sanders, Felicia J.
2014-01-01
Degradation of nesting habitat for coastal birds has led to the use of nontraditional nesting habitat. The American Oystercatcher (Haematopus palliatus) is listed as a "Species of High Concern'' by the U. S. Shorebird Conservation Plan and is declining in the southern portion of its U. S. breeding range, where ~ 50% of breeding oystercatchers nest on shell substrate instead of beachfront habitat. We measured daily survival rates during incubation and chick rearing in shell rake habitats over five breeding seasons in the Cape Romain region of South Carolina, USA. Of 354 nesting attempts monitored, 16.1% hatched at least one egg. During incubation, daily survival rate was 0.938, corresponding to 22.8% success to hatching (nest success). For broods, daily survival was 0.991, or 74.0% success from hatching to fledging. Productivity in the Cape Romain region is primarily being lost during the incubation phase, when nests are exposed to overwash and predation. Mobile chicks may, however, be able to avoid flood events or predators by relocating to higher or more protected portions of a shell rake. Based on comparative data for American Oystercatchers from elsewhere in their range, it does not appear that shell rakes in the Cape Romain region are inferior breeding habitat. Our data suggest that conservation actions targeting nest and chick loss from flooding and predation have the greatest opportunity to enhance reproductive success in this core breeding area, and that an assessment of the availability, structure, avian use, and protection status of shell rakes is warranted.
An ergonomic assessment of the long handle blueberry harvesting rake.
May, Elizabeth; Scribani, Melissa; Wyckoff, Sherry; Bauer, Robert; May, John; Wyckoff, Lynae; Jenkins, Paul
2012-11-01
Previous work shows the superiority of the long-handled blueberry harvesting rake (LHR) for worker preference and productivity compared to the short-handle rake (SHR). Post-shift interviews on occurrence, location, and severity of pain, and video-based observation of body postures enabled ergonomic assessment of Maine workers harvesting blueberries. Workers randomly crossed between LHR and SHR on consecutive work days. Wilcoxon tests compared proportions of specific body postures between LHR and SHR. Subjects used SHR for shorter work periods than LHR. Thirty workers provided interviews for both one LHR and one SHR shift. Assessment of these matched pairs suggested a trend toward less frequent overall pain (P = 0.07) and back pain (P = 0.11) with the LHR versus the SHR. Video tape analysis included 17 sets of observations (8 SHR and 9 LHR) on 12 individuals. Posture assessment showed more severe forward bend and squatting with the SHR and more moderate/neutral postures with the LHR. Harvesting with the traditional SHR is likely to be associated with increased frequency of pain in general, and mid-low back pain in particular, when compared to the newer LHR. This may well relate to the work postures associated with each rake. Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.
About the best value of rake angle for cutting tools
Directory of Open Access Journals (Sweden)
Pămîntaş Eugen
2017-01-01
Full Text Available Regardless of whether the case of processing through methods of cutting metal, wood, plastics, stone, composite materials etc., the rake angle (γ is of major importance for energy efficiency and dynamic behaviour of cutting process, dimensional accuracy, work surface quality and pieces made cost. The paper examines the possibility of establishing the best value for the rake angle supposing two idealizations: one regarding the conditions in which cutting process takes place, and the second related to the simplifications aiming to facilitate a first stage of theoretical development of mathematical description for the chip forming process. Both idealizations are intended to individualize the influence that has the value of rake angle of the cutting tools on the process of chip forming in order to perceive the meaning of the link between the geometry of the cutting tool with other parameters of chips and by default with the work parameters set to machine-tool. While both validity and applicability of the mathematical relations obtained are negatively marked by the simplifying assumption which was appealed in achieving the approach, the highlighted findings may be good starting points for further research on the kinematics cutting depth and in the structure of the material being processed.
The evaluation of a rake method to quantify submersed vegetation in the Upper Mississippi River
Yin, Yao; Kreiling, Rebecca M.
2011-01-01
A long-handled, double-headed garden rake was used to collect submersed aquatic vegetation (SAV) and compared to in-boat visual inspection to record species presence at 67 individual sites. Six rake subsamples were taken at each site and a rake density rating was given to each species collected in the subsamples. Presence at the site, frequency of occurrence in the six rake samples, and additive density rating (the sum of the six rake density ratings) were quantified for each species at each site. The validity of the indices was tested against biomass data collected by clipping all remaining vegetation from the 67 sites. In the turbid water of the Mississippi River, visual inspection of SAV from boats was ineffective with only 27% of the species detected, while raking retrieved on average 70% of the total number of submersed species in the 67 sites. Presence of species at individual sites was correlated with biomass from Stuckenia pectinata, while frequency of occurrence and additive density rating were correlated with biomass for species with greater than 21 g of total biomass from all sites. The efficiency of the rake to collect biomass varied among species; only 18% of total biomass was captured via raking the site six times. Additive density rating as an index of abundance can be used to detect temporal changes in the same water body; however, cross-species comparison is not encouraged unless the efficiency of the rake has been determined for each species being compared.
Higgs Effective Field Theories
2016-01-01
The main focus of this meeting is to present new theoretical advancements related to effective field theories, evaluate the impact of initial results from the LHC Run2, and discuss proposals for data interpretation/presentation during Run2. A crucial role of the meeting is to bring together theorists from different backgrounds and with different viewpoints and to extend bridges towards the experimental community. To this end, we would like to achieve a good balance between senior and junior speakers, enhancing the visibility of younger scientists while keeping some overview talks.
Directory of Open Access Journals (Sweden)
Elena MAFTEI-GOLOPENȚIA
2015-11-01
Full Text Available The complexity of the world and the various existing points of view play sometimes the role of barriers to understanding the events that take place around us or in which we are directly involved, that we may find overwhelming sometimes. In this context, we have no choice but to find instruments that can help us find a meaning beyond ”raw” information. Frames and other media effects theories can be this instrument, that can help us understand ”the stories” about the surrounding world. Frames are useful to us because our mind can’t simply process each new situation from scratch. This paper aims mainly at analysing frames, their function, their types, their roles and the levels at which they manifest themselves. It also represents the theoretical background of a future case study about the way in which the academic world is symbolically seen by the press.
Kim Ludovici; Robert Eaton; Stanley Zarnoch
2018-01-01
Removal of forest floor litter by pine needle raking and prescribed burning is a common practice in longleaf pine (Pinus palustris Mill.) stands on Coastal Plain sites in the Southeastern United States. Repeated removal of litter by raking and the loss of surface organic matter from controlled burns can affect the...
The emergence of use of a rake-like tool: a longitudinal study in human infants
Directory of Open Access Journals (Sweden)
Jacqueline eFagard
2014-05-01
Full Text Available We describe the results of a longitudinal study on five infants from age 12 to 20 months, presented with an out of reach toy and a rake-like tool within reach. Five conditions of spatial relationship between toy and rake were tested. Outcomes and types of behavior were analyzed. There were successes observed around 12 months in the condition of spatial contiguity between rake and toy, but these could not be interpreted as corresponding to full understanding of the use of the rake. At this age and for the following months, in the conditions involving spatial separation between rake and toy, infants’ strategies fluctuated between paying attention to the toy only, exploring the rake for its own sake, and connecting rake and toy but with no apparent attempt to bring the toy closer. Only between 16 and 20 months did infants fairly suddenly start to intentionally try to bring the toy closer with the tool: at this stage the infants also became able to learn from their failures and to correct their actions, as well as to benefit from demonstration from an adult. We examine the individual differences in the pattern of change in behaviors leading to tool use in the five infants, and find no increase in any one type of behaviour that systematically precedes success. We conclude that sudden success at 18 months probably corresponds to the coming together of a variety of capacities.
Media Effects: Theory and Research.
Valkenburg, Patti M; Peter, Jochen; Walther, Joseph B
2016-01-01
This review analyzes trends and commonalities among prominent theories of media effects. On the basis of exemplary meta-analyses of media effects and bibliometric studies of well-cited theories, we identify and discuss five features of media effects theories as well as their empirical support. Each of these features specifies the conditions under which media may produce effects on certain types of individuals. Our review ends with a discussion of media effects in newer media environments. This includes theories of computer-mediated communication, the development of which appears to share a similar pattern of reformulation from unidirectional, receiver-oriented views, to theories that recognize the transactional nature of communication. We conclude by outlining challenges and promising avenues for future research.
Theory of Effectiveness Measurement
2006-09-01
1997. Geisler, Eliezer, The Metrics of Science and Technology, Quorum Books, Westport, CT, 2000. Geller, Daniel S. and J. David Singer , Nations...Perret, Geoffrey, There’s a War to Be Won: The United States Army in World War II, Random House, New York, 1991. Pfanzagl, Johann , Theory of
Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
Lü, Ping; Narteau, Clément; Dong, Zhibao; Rozier, Olivier; Courrech du Pont, Sylvain
2017-01-01
Raked linear dunes keep a constant orientation for considerable distances with a marked asymmetry between a periodic pattern of semi-crescentic structures on one side and a continuous slope on the other. Here we show that this shape is associated with a steady-state dune type arising from the coexistence of two dune growth mechanisms. Primary ridges elongate in the direction of the resultant sand flux. Semi-crescentic structures result from the development of superimposed dunes growing perpendicularly to the maximum gross bedform-normal transport. In the particular case of raked linear dunes, these two mechanisms produces primary and secondary ridges with similar height but with different orientations, which are oblique to each other. The raked pattern develops preferentially on the leeward side of the primary ridges according to the direction of propagation of the superimposed bedforms. As shown by numerical modelling, raked linear dunes occur where both these oblique orientations and dynamics are met. PMID:28128195
Design and Calibration of a Flowfield Survey Rake for Inlet Flight Research
Flynn, Darin C.; Ratnayake, Nalin A.; Frederick, Michael
2009-01-01
Flowfield rake was designed to quantify the flowfield for inlet research underneath NASA DFRC s F-15B airplane. Detailed loads and stress analysis performed using CFD and empirical methods to assure structural integrity. Calibration data were generated through wind tunnel testing of the rake. Calibration algorithm was developed to determine the local Mach and flow angularity at each probe. RAGE was flown November, 2008. Data is currently being analyzed.
Renormalization and effective field theory
Costello, Kevin
2011-01-01
This book tells mathematicians about an amazing subject invented by physicists and it tells physicists how a master mathematician must proceed in order to understand it. Physicists who know quantum field theory can learn the powerful methodology of mathematical structure, while mathematicians can position themselves to use the magical ideas of quantum field theory in "mathematics" itself. The retelling of the tale mathematically by Kevin Costello is a beautiful tour de force. --Dennis Sullivan This book is quite a remarkable contribution. It should make perturbative quantum field theory accessible to mathematicians. There is a lot of insight in the way the author uses the renormalization group and effective field theory to analyze perturbative renormalization; this may serve as a springboard to a wider use of those topics, hopefully to an eventual nonperturbative understanding. --Edward Witten Quantum field theory has had a profound influence on mathematics, and on geometry in particular. However, the notorio...
DEFF Research Database (Denmark)
Del Nobile, Eugenio; Sannino, Francesco
2012-01-01
We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff...... scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties....
Coherent RAKE Receiver for CPM-Based Direct Sequence Spread Spectrum
Directory of Open Access Journals (Sweden)
Ke Zhou
2016-01-01
Full Text Available Direct sequence spread spectrum (DSSS using continuous phase modulation (CPM inherits the techniques’ benefits, constant envelope, anti-interference, and spectral efficiency. To get diversity gains over a Rayleigh-fading multipath channel as in conventional direct sequence spread-spectrum binary phase shift keying (DSSS-BPSK system, a new class of coherent RAKE receivers is proposed in this work. By introducing chip branch metric to the receiver scheme, despreading and data detection can be done meanwhile based on Maximum Likelihood Sequence Detection (MLSD. Compared to the conventional RAKE receiver which sums decision metrics symbol-by-symbol, the proposed DSSS-CPM RAKE receiver accumulates symbol branch metric increments over every phase state of multiple paths after chip phase synchronization. Numerical results show that DSSS-CPM using the synchronous despreading and demodulation algorithm has no performance loss compared to CPM system that employs MLSD algorithm under the same test conditions. Moreover, the proposed RAKE receiver outperforms conventional RAKE receiver and achieves a remarkable diversity gain of bit error rate (BER under the Rayleigh-fading multipath channel.
Soft-Collinear Effective Theory
CERN. Geneva
2017-01-01
I will review the basic principles about Soft-Collinear Effective Theory. I will focus on how it can be used to understand factorization properties and how one can resum large logarithms arising from infrared physics using the renormalization group evolution.
Blind Adaptive Decorrelating RAKE (DRAKE Downlink Receiver for Space-Time Block Coded Multipath CDMA
Directory of Open Access Journals (Sweden)
Jayaweera Sudharman K
2002-01-01
Full Text Available A downlink receiver is proposed for space-time block coded CDMA systems operating in multipath channels. By combining the powerful RAKE receiver concept for a frequency selective channel with space-time decoding, it is shown that the performance of mobile receivers operating in the presence of channel fading can be improved significantly. The proposed receiver consists of a bank of decorrelating filters designed to suppress the multiple access interference embedded in the received signal before the space-time decoding. The new receiver performs the space-time decoding along each resolvable multipath component and then the outputs are diversity combined to obtain the final decision statistic. The proposed receiver relies on a key constraint imposed on the output of each filter in the bank of decorrelating filters in order to maintain the space-time block code structure embedded in the signal. The proposed receiver can easily be adapted blindly, requiring only the desired user′s signature sequence, which is also attractive in the context of wireless mobile communications. Simulation results are provided to confirm the effectiveness of the proposed receiver in multipath CDMA systems.
Tradeoffs between Spreading Factor, Symbol Constellation Size and Rake Fingers in UMTS
Potman, J.; Hoeksema, F.W.; Slump, Cornelis H.
2003-01-01
As an example of a systematic procedure for evaluating UMTS downlink DSP functions for adaptivity we study bit-error-rate performance tradeoffs between the spreading factor, the symbol constellation size and the number of used Rake fingers in UMTS despreading and demodulation. After an overview of
William F. Laudenslayer; George N. Steger; Jonathan. Arnold
2008-01-01
Large diameter, old trees are an important component of functioning forests, as they provide habitat for many wildlife species and add value to the scenery along roads and trails that cross our National Forests and Parks. Tree mortality, from prescribed or wild fire, is of great concern to forests managers, especially mortality of those of large diameter. Raking away...
Wilsonian effective action of superstring theory
Sen, Ashoke
2017-01-01
By integrating out the heavy fields in type II or heterotic string field theory one can construct the effective action for the light fields. This effective theory inherits all the algebraic structures of the parent theory and the effective action automatically satisfies the Batalin-Vilkovisky quantum master equation. This theory is manifestly ultraviolet finite, has only light fields as its explicit degrees of freedom, and the Feynman diagrams of this theory reproduce the exact scattering amplitudes of light states in string theory to any arbitrary order in perturbation theory. Furthermore in this theory the degrees of freedom of light fields above certain energy scale are also implicitly integrated out. This energy scale is determined by a particular parameter labelling a family of equivalent actions, and can be made arbitrarily low, leading to the interpretation of the effective action as the Wilsonian effective action.
Effective kinetic theory for high temperature gauge theories
Arnold, Peter B.; Moore, Guy D.; Yaffe, Laurence G.
2003-01-01
Quasiparticle dynamics in relativistic plasmas associated with hot, weakly-coupled gauge theories (such as QCD at asymptotically high temperature T) can be described by an effective kinetic theory, valid on sufficiently large time and distance scales. The appropriate Boltzmann equations depend on effective scattering rates for various types of collisions that can occur in the plasma. The resulting effective kinetic theory may be used to evaluate observables which are dominantly sensitive to the dynamics of typical ultrarelativistic excitations. This includes transport coefficients (viscosities and diffusion constants) and energy loss rates. In this paper, we show how to formulate effective Boltzmann equations which will be adequate to compute such observables to leading order in the running coupling g(T) of high-temperature gauge theories [and all orders in 1/log g(T)-1]. As previously proposed in the literature, a leading-order treatment requires including both 2leftrightarrow2 particle scattering processes as well as effective ``1leftrightarrow2'' collinear splitting processes in the Boltzmann equations. The latter account for nearly collinear bremsstrahlung and pair production/annihilation processes which take place in the presence of fluctuations in the background gauge field. Our effective kinetic theory is applicable not only to near-equilibrium systems (relevant for the calculation of transport coefficients), but also to highly non-equilibrium situations, provided some simple conditions on distribution functions are satisfied.
Effective medium theory principles and applications
Choy, Tuck C
2015-01-01
Effective medium theory dates back to the early days of the theory of electricity. Faraday in 1837 proposed one of the earliest models for a composite metal-insulator dielectric and around 1870 Maxwell and later Garnett (1904) developed models to describe a composite or mixed material medium. The subject has been developed considerably since and while the results are useful for predicting materials performance, the theory can also be used in a wide range of problems in physics and materials engineering. This book develops the topic of effective medium theory by bringing together the essentials of both the static and the dynamical theory. Electromagnetic systems are thoroughly dealt with, as well as related areas such as the CPA theory of alloys, liquids, the density functional theory etc., with applications to ultrasonics, hydrodynamics, superconductors, porous media and others, where the unifying aspects of the effective medium concept are emphasized. In this new second edition two further chapters have been...
Comparative Performance Analysis of G-RAKE Receivers with Suboptimal Finger Placement
Directory of Open Access Journals (Sweden)
K. B. Baltzis
2014-07-01
Full Text Available Generalized RAKE (G-RAKE reception reduces the total amount of interference and provides enhanced diversity by comprising extra fingers to collect information about interference and further using channel and impairment correlation estimates for fingers allocation. However, the hardware complexity and the excessive computational requirements of GRAKE receivers may restrict their application in real systems; thus, suboptimal solutions are commonly used. In this paper, we propose and evaluate three maximum likelihood G-RAKE structures for colored noise with suboptimal finger placement. In all implementations, the fingers are optimally distributed within a time window that spans from several chip periods before the first arriving multipath to several chip periods after the latest one. The first receiver has its fingers at integer multiples of the chip period while in the rest two structures the search window is segmented in halves and tenths of the chip duration. This work also extends earlier studies by thoroughly investigating the impact of fractionally spaced finger placement on system performance. Our analysis shows that a suboptimal finger allocation reduces hardware complexity with negligible performance loss. The impact of channel delay spread and processing gain on system performance is also investigated and gives interesting results.
Nam, Sungsik
2011-08-01
Spread spectrum receivers with generalized selection combining (GSC) RAKE reception were proposed and have been studied as alternatives to the classical two fundamental schemes: maximal ratio combining and selection combining because the number of diversity paths increases with the transmission bandwidth. Previous work on performance analyses of GSC RAKE receivers based on the signal to noise ratio focused on the development of methodologies to derive exact closed-form expressions for various performance measures. However, some open problems related to the performance evaluation of GSC RAKE receivers still remain to be solved such as the exact performance analysis of the capture probability and an exact assessment of the impact of self-interference on GSC RAKE receivers. The major difficulty in these problems is to derive some joint statistics of ordered exponential variates. With this motivation in mind, we capitalize in this paper on some new order statistics results to derive exact closed-form expressions for the capture probability and outage probability of GSC RAKE receivers subject to self-interference over independent and identically distributed Rayleigh fading channels, and compare it to that of partial RAKE receivers. © 2011 IEEE.
Dahl, Milo D.; Sutliff, Daniel L.
2014-01-01
The Rotating Rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. Initially, the mode amplitudes and phases were quantified from a single rake measurement at one axial location. To directly measure the modes propagating in both directions within a duct, a second rake was mounted to the rotating system with an offset in both the axial and the azimuthal directions. The rotating rake data analysis technique was then extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode levels at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode amplitudes for the modes propagating in both directions within the duct. Validation experiments have been conducted using artificial acoustic sources. Results are shown for the measurement of the standing waves in the duct from sound generated by one and two acoustic sources that are separated into the component modes propagating in both directions within the duct. Measured reflection coefficients from the open end of the duct are compared to analytical predictions.
Playing with QCD I: effective field theories
Energy Technology Data Exchange (ETDEWEB)
Fraga, Eduardo S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica
2009-07-01
The building blocks of hadrons are quarks and gluons, although color is confined into singlet states. QCD is believed to be the fundamental theory of strong interactions. Its asymptotically free nature puts the vacuum out of reach for perturbation theory. The Lagrangian of QCD and the Feynman rules associated were built by using the Gauge Principle, starting from the quark matter fields and obtaining gluons as connections. A simpler, and sometimes necessary or complementary, approach is provided by effective field theories or effective models, especially when one has to deal with the nonperturbative sector of the theory. (author)
Effective Lagrangians and chiral random matrix theory
Energy Technology Data Exchange (ETDEWEB)
Halasz, M.A.; Verbaarschot, J.J.M. [Department of Physics, State University of New York, Stony Brook, New York 11794 (United States)
1995-08-15
Recently, sum rules were derived for the inverse eigenvalues of the Dirac operator. They were obtained in two different ways: (i) starting from the low-energy effective Lagrangian and (ii) starting from a random matrix theory with the symmetries of the Dirac operator. This suggests that the effective theory can be obtained directly from the random matrix theory. Previously, this was shown for three or more colors with fundamental fermions. In this paper we construct the effective theory from a random matrix theory for two colors in the fundamental representation and for an arbitrary number of colors in the adjoint representation. We construct a fermionic partition function for Majorana fermions in Euclidean spacetime. Their reality condition is formulated in terms of complex conjugation of the second kind.
THEORIES OF MANAGEMENT: TOWARDS AN EFFECTIVE ...
African Journals Online (AJOL)
Mitch
This paper then tries to explore the theories/principles of management in the light of effective theatre .... The classical theory recognises the essence of workers or labour force in an organisation and advocates the welfare .... There must be a scalar chain of authority and communication ranging from the highest to the lowest ...
Exploring CRM effectiveness: an institutional theory perspective
B. Hillebrand (Bas); J.J. Nijholt (Jurriaan); E.J. Nijssen (Edwin)
2011-01-01
textabstractThis study identifies the potential contribution that institutional theory can make to understanding the success of marketing practices. Based on institutional theory, we argue that the effectiveness of marketing practices decreases when firms are motivated to adopt such practices under
Nam, Sung Sik
2016-11-23
In this paper, we investigate the impact of self-interference on the performance of a joint partial RAKE (PRAKE) receiver and adaptive modulation over both independent and identically distributed and independent but non-identically distributed Rayleigh fading channels. To better observe the impact of self-interference, our approach starts from considering the signal to interference plus noise ratio. Specifically, we accurately analyze the outage probability, the average spectral efficiency, and the average bit error rate as performance measures in the presence of self-interference. Several numerical and simulation results are selected to present the performance of the joint PRAKE receiver and adaptive modulation subject to self-interference.
Máquinas de rastrillar y modelos de utilidad - Raking machines and utility models
Directory of Open Access Journals (Sweden)
Santos López, Pascual
2007-12-01
Full Text Available With a background and forged through hard work, Vicente Martínez Piñera, tried to improve working conditions in the esparto factories of Cieza. From "menaor" a teacher, your mechanical skills led him to invent spinning, raking and manufacture wool, always introducing innovations in this difficult and tough industry. As the inventor profession does not usually give great benefits, became industrial, manufacturing and marketing its own machines and also esparto products manufactured as large hawsers for boat
Flight Test Results from the Rake Airflow Gage Experiment on the F-15B Airplane
Frederick, Michael A.; Ratnayake, Nalin A.
2011-01-01
The Rake Airflow Gage Experiment involves a flow-field survey rake that was flown on the Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center using the Dryden F-15B research test bed airplane. The objective of this flight test was to ascertain the flow-field angularity, local Mach number profile, total pressure distortion, and dynamic pressure at the aerodynamic interface plane of the Channeled Centerbody Inlet Experiment. This new mixed-compression, supersonic inlet is planned for flight test in the near term. Knowledge of the flow-field characteristics at this location underneath the airplane is essential to flight test planning and computational modeling of the new inlet, anairplane, flying at a free-stream Mach number of 1.65 and a pressure altitude of 40,000 ft, would achieve the desired local Mach number for the future inlet flight test. Interface plane distortion levels of 2 percent and a local angle of attack of -2 deg were observed at this condition. Alternative flight conditions for future testing and an exploration of certain anomalous data also are provided.
Effective medium theory for anisotropic metamaterials
Zhang, Xiujuan
2015-01-20
Materials with anisotropic material parameters can be utilized to fabricate many fascinating devices, such as hyperlenses, metasolids, and one-way waveguides. In this study, we analyze the effects of geometric anisotropy on a two-dimensional metamaterial composed of a rectangular array of elliptic cylinders and derive an effective medium theory for such a metamaterial. We find that it is possible to obtain a closed-form analytical solution for the anisotropic effective medium parameters, provided the aspect ratio of the lattice and the eccentricity of the elliptic cylinder satisfy certain conditions. The derived effective medium theory not only recovers the well-known Maxwell-Garnett results in the quasi-static regime, but is also valid beyond the long-wavelength limit, where the wavelength in the host medium is comparable to the size of the lattice so that previous anisotropic effective medium theories fail. Such an advance greatly broadens the applicable realm of the effective medium theory and introduces many possibilities in the design of structures with desired anisotropic material characteristics. A real sample of a recently theoretically proposed anisotropic medium, with a near-zero index to control the flux, is achieved using the derived effective medium theory, and control of the electromagnetic waves in the sample is clearly demonstrated.
Satellite diversity and its implications on the RAKE receiver architecture for CDMA-based S-PCN's
Taaghol, P.; Sammut, A.; Tafazolli, R.; Evans, B. G.
1995-01-01
In this paper we examine the applicability of RAKE receivers in a mobile LEO satellite channel and identify the potential problem areas. We then proceed to investigate the possibility of a coherent combining architecture (downlink) in the presence of satellite diversity. We closely examine the path delay difference statistics of a diversity channel and propose a delay compensation scheme for the downlink in order to reduce the complexity of the user terminal. Finally, the required modifications to the conventional RAKE receiver are proposed and discussed.
Effective field theory – concepts and applications
Beneke, M
2010-01-01
Effective field theory provides the modern perspective on renormalization theory and explains why we can make meaningful and precise predictions without knowing the Theory of Everything. By separating physical effects on different distance scales it is also an efficient tool to deal with the strong interaction in various regimes and to sum large logarithms in perturbation theory. The two lectures given at the school provide an introduction and cover mostly textbook material. The write-up below is therefore only meant as a brief reminder of the topics discussed, and provides references to textbooks or other lecture notes for further reading. Further details can also be found in the slides available on-line.
Implicit leadership theories : think leader, think effective?
Schyns, B.; Schilling, J
2011-01-01
In general, although research into leadership acknowledges negative aspects of leadership, research into implicit leadership theories lags behind in this respect. Most implicit leadership theories research implies that the image of a leader in general reflects an effective leader. However, recent results in leadership research as well as headlines and reports in the popular press cast doubt on this assumption. This article reports a qualitative study, focusing on general implicit leadership t...
Globalisation theories and their effect on education
Parjanadze, Nikoloz
2009-01-01
Globalisation is a relatively new concept in social sciences, especially in educational research and there is no agreement on its essence. The article presents three stances within globalisation theory â€“ the hyperglobalist , the sceptical and the transformational, which reflect disputes concerning new global trends. The discussion highlights social, economic and political aspects globalization theory deals with. The article focuses on the effects of globalisation over education and the dema...
The Faraday effect revisited: General theory
Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm
2005-01-01
This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse conductivity can be explicitly computed and coincides with the classical result. In the general case, using magnetic perturbation theory, the conductivity tensor is expanded in powers of the strength of th...
A periodic table of effective field theories
Energy Technology Data Exchange (ETDEWEB)
Cheung, Clifford [Walter Burke Institute for Theoretical Physics,California Institute of Technology,Pasadena, CA (United States); Kampf, Karol; Novotny, Jiri [Institute of Particle and Nuclear Physics,Faculty of Mathematics and Physics, Charles University,Prague (Czech Republic); Shen, Chia-Hsien [Walter Burke Institute for Theoretical Physics,California Institute of Technology,Pasadena, CA (United States); Trnka, Jaroslav [Center for Quantum Mathematics and Physics (QMAP),Department of Physics, University of California,Davis, CA (United States)
2017-02-06
We systematically explore the space of scalar effective field theories (EFTs) consistent with a Lorentz invariant and local S-matrix. To do so we define an EFT classification based on four parameters characterizing 1) the number of derivatives per interaction, 2) the soft properties of amplitudes, 3) the leading valency of the interactions, and 4) the spacetime dimension. Carving out the allowed space of EFTs, we prove that exceptional EFTs like the non-linear sigma model, Dirac-Born-Infeld theory, and the special Galileon lie precisely on the boundary of allowed theory space. Using on-shell momentum shifts and recursion relations, we prove that EFTs with arbitrarily soft behavior are forbidden and EFTs with leading valency much greater than the spacetime dimension cannot have enhanced soft behavior. We then enumerate all single scalar EFTs in d<6 and verify that they correspond to known theories in the literature. Our results suggest that the exceptional theories are the natural EFT analogs of gauge theory and gravity because they are one-parameter theories whose interactions are strictly dictated by properties of the S-matrix.
Effective field theory of broken spatial diffeomorphisms
Energy Technology Data Exchange (ETDEWEB)
Lin, Chunshan [Yukawa Institute for Theoretical Physics, Kyoto University,Kitashirakawa Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Labun, Lance Z. [Department of Physics, University of Texas,2515 Speedway, MS #C1510, Austin, TX 78712-1068 (United States); Department of Physics, National Taiwan University,No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Leung Center for Cosmology and Particle Astrophysics (LeCosPA), National Taiwan University,No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)
2016-03-17
We study the low energy effective theory describing gravity with broken spatial diffeomorphism invariance. In the unitary gauge, the Goldstone bosons associated with broken diffeomorphisms are eaten and the graviton becomes a massive spin-2 particle with 5 well-behaved degrees of freedom. In this gauge, the most general theory is built with the lowest dimension operators invariant under only temporal diffeomorphisms. Imposing the additional shift and SO(3) internal symmetries, we analyze the perturbations on a FRW background. At linear perturbation level, the observables of this theory are characterized by five parameters, including the usual cosmological parameters and one additional coupling constant for the symmetry-breaking scalars. In the de Sitter and Minkowski limit, the three Goldstone bosons are supermassive and can be integrated out, leaving two massive tensor modes as the only propagating degrees of freedom. We discuss several examples relevant to theories of massive gravity.
Effective field theory for triaxially deformed nuclei
Chen, Q. B.; Kaiser, N.; Meißner, Ulf-G.; Meng, J.
2017-10-01
Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation.
Effective field theory for triaxially deformed nuclei
Energy Technology Data Exchange (ETDEWEB)
Chen, Q.B. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Kaiser, N. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Institute for Advanced Simulation, Institut fuer Kernphysik, Juelich Center for Hadron Physics and JARA-HPC, Forschungszentrum Juelich, Juelich (Germany); Meng, J. [Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); University of Stellenbosch, Department of Physics, Stellenbosch (South Africa)
2017-10-15
Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation. (orig.)
Probabilistic Analysis and Design of a Raked Wing Tip for a Commercial Transport
Mason Brian H.; Chen, Tzi-Kang; Padula, Sharon L.; Ransom, Jonathan B.; Stroud, W. Jefferson
2008-01-01
An approach for conducting reliability-based design and optimization (RBDO) of a Boeing 767 raked wing tip (RWT) is presented. The goal is to evaluate the benefits of RBDO for design of an aircraft substructure. A finite-element (FE) model that includes eight critical static load cases is used to evaluate the response of the wing tip. Thirteen design variables that describe the thickness of the composite skins and stiffeners are selected to minimize the weight of the wing tip. A strain-based margin of safety is used to evaluate the performance of the structure. The randomness in the load scale factor and in the strain limits is considered. Of the 13 variables, the wing-tip design was controlled primarily by the thickness of the thickest plies in the upper skins. The report includes an analysis of the optimization results and recommendations for future reliability-based studies.
Quantum Theory of the Doppler Effect
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 10. Quantum Theory of the Doppler Effect. G S Ranganath. Classroom Volume 1 Issue 10 October 1996 pp 76-78. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/10/0076-0078 ...
A Guide to Effective School Leadership Theories
Lynch, Matthew
2012-01-01
Educational administrators know that leadership requires hundreds of judgments each day that require a sensitivity and understanding of various leadership strategies. Bridging the gap between the academic and practical world, "A Guide to Effective School Leadership Theories" provides an exploration of ten dominant leadership strategies to give…
Effective field theory of dissipative fluids
Crossley, Michael; Glorioso, Paolo; Liu, Hong
2017-09-01
We develop an effective field theory for dissipative fluids which governs the dynamics of long-lived gapless modes associated with conserved quantities. The resulting theory gives a path integral formulation of fluctuating hydrodynamics which systematically incorporates nonlinear interactions of noises. The dynamical variables are mappings between a "fluid spacetime" and the physical spacetime and an essential aspect of our formulation is to identify the appropriate symmetries in the fluid spacetime. The theory applies to nonlinear disturbances around a general density matrix. For a thermal density matrix, we require an additional Z 2 symmetry, to which we refer as the local KMS condition. This leads to the standard constraints of hydrodynamics, as well as a nonlinear generalization of the Onsager relations. It also leads to an emergent supersymmetry in the classical statistical regime, and a higher derivative deformation of supersymmetry in the full quantum regime.
Introduction to soft-collinear effective theory
Becher, Thomas; Ferroglia, Andrea
2015-01-01
Among resummation techniques for perturbative QCD in the context of collider and flavor physics, soft-collinear effective theory (SCET) has emerged as both a powerful and versatile tool, having been applied to a large variety of processes, from B-meson decays to jet production at the LHC. This book provides a concise, pedagogical introduction to this technique. It discusses the expansion of Feynman diagrams around the high-energy limit, followed by the explicit construction of the effective Lagrangian - first for a scalar theory, then for QCD. The underlying concepts are illustrated with the quark vector form factor at large momentum transfer, and the formalism is applied to compute soft-gluon resummation and to perform transverse-momentum resummation for the Drell-Yan process utilizing renormalization group evolution in SCET. Finally, the infrared structure of n-point gauge-theory amplitudes is analyzed by relating them to effective-theory operators. This text is suitable for graduate students and non-spe...
Weak gravity conjecture and effective field theory
Saraswat, Prashant
2017-01-01
The weak gravity conjecture (WGC) is a proposed constraint on theories with gauge fields and gravity, requiring the existence of light charged particles and/or imposing an upper bound on the field theory cutoff Λ . If taken as a consistency requirement for effective field theories (EFTs), it rules out possibilities for model building including some models of inflation. I demonstrate simple models which satisfy all forms of the WGC, but which through Higgsing of the original gauge fields produce low-energy EFTs with gauge forces that badly violate the WGC. These models illustrate specific loopholes in arguments that motivate the WGC from a bottom-up perspective; for example the arguments based on magnetic monopoles are evaded when the magnetic confinement that occurs in a Higgs phase is accounted for. This indicates that the WGC should not be taken as a veto on EFTs, even if it turns out to be a robust property of UV quantum gravity theories. However, if the latter is true, then parametric violation of the WGC at low energy comes at the cost of nonminimal field content in the UV. I propose that only a very weak constraint is applicable to EFTs, Λ ≲(log 1/g )-1 /2Mpl , where g is the gauge coupling, motivated by entropy bounds. Remarkably, EFTs produced by Higgsing a theory that satisfies the WGC can saturate but not violate this bound.
Z(3)-symmetric effective theory for SU(3) Yang-Mills theory at high temperature
Vuorinen, A.; Yaffe, Laurence G.
2006-07-01
A three-dimensional effective theory for high temperature SU(3) gauge theory, which maintains the Z(3) center symmetry of the full theory, is constructed. Such a Z(3) invariant effective theory should be applicable to a wider temperature range than the usual effective theory, known as EQCD, which fails to respect the center symmetry. This center-symmetric effective theory can reproduce domain wall and phase transition properties that are not accessible in EQCD. After identifying a convenient class of Z(3) invariant effective theories, we constrain the coefficients of the various terms in the Lagrangian using leading-order matching to EQCD at high temperature, plus matching of domain wall properties in the full theory. We sketch the expected structure of the phase diagram of the effective theory and briefly discuss the prospects of numerical simulations and the addition of quarks.
Effective Field Theory with Two Higgs Doublets
Crivellin, Andreas; Procura, Massimiliano
2016-01-01
In this article we extend the effective field theory framework describing new physics effects to the case where the underlying low-energy theory is a Two-Higgs-Doublet model. We derive a complete set of independent operators up to dimension six assuming a $Z_2$-invariant CP-conserving Higgs potential. The effects on Higgs and gauge boson masses, mixing angles in the Higgs sector as well as couplings to fermions and gauge bosons are computed. At variance with the case of a single Higgs doublet, we find that pair production of SM-like Higgses, arising through dimension-six operators, is not fixed by fermion-fermion-Higgs couplings and can therefore be sizable.
Consistency relations in effective field theory
Munshi, Dipak; Regan, Donough
2017-06-01
The consistency relations in large scale structure relate the lower-order correlation functions with their higher-order counterparts. They are direct outcome of the underlying symmetries of a dynamical system and can be tested using data from future surveys such as Euclid. Using techniques from standard perturbation theory (SPT), previous studies of consistency relation have concentrated on continuity-momentum (Euler)-Poisson system of an ideal fluid. We investigate the consistency relations in effective field theory (EFT) which adjusts the SPT predictions to account for the departure from the ideal fluid description on small scales. We provide detailed results for the 3D density contrast δ as well as the scaled divergence of velocity bar theta. Assuming a ΛCDM background cosmology, we find the correction to SPT results becomes important at k gtrsim 0.05 h/Mpc and that the suppression from EFT to SPT results that scales as square of the wave number k, can reach 40% of the total at k ≈ 0.25 h/Mpc at z = 0. We have also investigated whether effective field theory corrections to models of primordial non-Gaussianity can alter the squeezed limit behaviour, finding the results to be rather insensitive to these counterterms. In addition, we present the EFT corrections to the squeezed limit of the bispectrum in redshift space which may be of interest for tests of theories of modified gravity.
Effective theory for electroweak doublet dark matter
Dedes, A.; Karamitros, D.; Spanos, V. C.
2016-11-01
We perform a detailed study of an effective field theory which includes the standard model particle content extended by a pair of Weyl fermionic SU(2) doublets with opposite hypercharges. A discrete symmetry guarantees that a linear combination of the doublet components is stable and can act as a candidate particle for dark matter. The dark sector fermions interact with the Higgs and gauge bosons through renormalizable d =4 operators, and nonrenormalizable d =5 operators that appear after integrating out extra degrees of freedom above the TeV scale. We study collider, cosmological and astrophysical probes for this effective theory of dark matter. We find that a weakly interacting dark matter particle with a mass nearby the electroweak scale, and thus observable at the LHC, is consistent with collider and astrophysical data only when fairly large magnetic dipole moment transition operators with the gauge bosons exist, together with moderate Yukawa interactions.
Effective Field Theory of Majorana Dark Matter
Han, Huayong; WU, HONGYAN; Zheng, Sibo
2017-01-01
Thermal Majorana dark matter is explored from the viewpoint of effective field theory. Completely analytic result for dark matter annihilation into standard model background is derived in order to account relic density. The parameter space subject to the latest LUX, PandaX-II and Xenon-1T limits is shown in a model-independent way. For illustration, applications to singlet-doublet and neutralino dark matter are work out.
Maxwell-Garnett effective medium theory: Quantum nonlocal effects
Energy Technology Data Exchange (ETDEWEB)
Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of)
2015-04-15
We develop the Maxwell-Garnett theory for the effective medium approximation of composite materials with metallic nanoparticles by taking into account the quantum spatial dispersion effects in dielectric response of nanoparticles. We derive a quantum nonlocal generalization of the standard Maxwell-Garnett formula, by means the linearized quantum hydrodynamic theory in conjunction with the Poisson equation as well as the appropriate additional quantum boundary conditions.
Effective Meson Field Theory from QCD
Hsieh, Ron-Chou
2003-01-01
We give a simple and straightforward procedure of how to construct an effective meson Lagrangian from QCD Lagrangian. We integrate the methods of Gasser, Leutwyler, Alkofer and Reinhardt and use the derivative expansion scheme to derive the low energy effective Lagrangian for meson fields to $O(p^4)$. In this paper, why the meson particle can be treated as the goldstone mode is very clear. In our calculation the result in $O(p^2)$ is the same as in the chiral perturbation theory, but the resu...
Takayama, Kei; Kamiya, Yukihiro; Fujii, Takeo; Suzuki, Yasuo
Spread Spectrum (SS) has been widely used for various wireless systems such as cellular systems, wireless local area network (LAN) and so on. Using multiple antennas at the receiver, two-dimensional (2D) RAKE is realized over the time- and the space-domain. However, it should be noted that the 2D-RAKE receiver must detect the bit timing prior to the RAKE combining. In case of deep fading, it is often difficult to detect it due to low signal-to-noise power ratio (SNR). To solve this problem, we propose a new blind 2D-RAKE receiver based on the constant modulus algorithm (CMA). Since it does not need a priori bit timing detection, it is possible to compensate frequency selective fading even in very low SNR environments. The proposed method is particularly suitable for the software defined radio (SDR) architecture. The performance of the proposed method is investigated through computer simulations.
The Faraday effect revisited General theory
Cornean, H D; Pedersen, T G
2005-01-01
This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse conductivity can be explicitly computed and coincides with the classical result. In the general case, using magnetic perturbation theory, the conductivity tensor is expanded in powers of the strength of the magnetic field $B$. Then the linear term in $B$ of this expansion is written down in terms of the zero magnetic field Green function and the zero field current operator. In the periodic case, the linear term in $B$ of the conductivity tensor is expressed in terms of zero magnetic field Bloch functions and energies. No derivatives with respect to the quasimomentum appear and thereby all ambiguities are removed, in contrast to earlier work.
Diagrammatic theory of effective hydraulic conductivity
Hristopulos, Dionissios T.; Christakos, George
1997-10-01
This work presents a stochastic diagrammatic theory for the calculation of the effective hydraulic conductivity of heterogeneous media. The theory is based on the mean-flux series expansion of a log-normal hydraulic conductivity medium in terms of diagrammatic representations and leads to certain general results for the effective hydraulic conductivity of three-dimensional media. A selective summation technique is used to improve low-order perturbation analysis by evaluating an infinite set of diagrammatic terms with a specific topological structure that dominates the perturbation series. For stochastically isotropic media the selective summation yeilds the anticipated exponential expression for the effective hydraulic conductivity. This expression is extended to stochastically anisotropic media. It is also shown that in the case of non homogeneous media the uniform effective hydraulic conductivity is replaced by a non-local tensor kernel, for which general diagrammatic expressions are obtained. The non-local kernel leads to the standard exponential behavior for the effective hydraulic conductivity at the homogeneous limit.
Effective theory approach to direct detection of dark matter
Hisano, Junji
2017-01-01
An effective field theory approach is presented for evaluation of the dark matter direct detection rate in this lecture note. This is prepared for the Les Houches Summer School Effective Field Theory in Particle Physics and Cosmology, July 2017.
A Geometrical View of Higgs Effective Theory
CERN. Geneva
2016-01-01
A geometric formulation of Higgs Effective Field Theory (HEFT) is presented. Experimental observables are given in terms of geometric invariants of the scalar sigma model sector such as the curvature of the scalar field manifold M. We show how the curvature can be measured experimentally via Higgs cross-sections, W_L scattering, and the S parameter. The one-loop action of HEFT is given in terms of geometric invariants of M. The distinction between the Standard Model (SM) and HEFT is whether M is flat or curved, with the curvature a signal of the scale of new physics.
The Effective Field Theory of nonsingular cosmology
Cai, Yong; Li, Hai-Guang; Qiu, Taotao; Piao, Yun-Song
2016-01-01
In this paper, we explore the nonsingular cosmology within the framework of the Effective Field Theory(EFT) of cosmological perturbations. Due to the recently proved no-go theorem, any nonsingular cosmological models based on the cubic Galileon suffer from pathologies. We show how the EFT could help us clarify the origin of the no-go theorem, and offer us solutions to break the no-go. Particularly, we point out that the gradient instability can be removed by using some spatial derivative operators in EFT. Based on the EFT description, we obtain a realistic healthy nonsingular cosmological model, and show the perturbation spectrum can be consistent with the observations.
Effective Higgs theories in supersymmetric grand unification
Energy Technology Data Exchange (ETDEWEB)
Zheng, Sibo [Chongqing University, Department of Physics, Chongqing (China)
2017-09-15
The effective Higgs theories at the TeV scale in supersymmetric SU(5) grand unification models are systematically derived. Restricted to extensions on 5{sub H} containing the Higgs sector we show that only two types of real (vector-like) models and one type of chiral model are found to be consistent with perturbative grand unification. While the chiral model has been excluded by the LHC data, the fate of perturbative unification will be uniquely determined by the two classes of vector-like models. (orig.)
Effective field theory analysis of Higgs naturalness
Energy Technology Data Exchange (ETDEWEB)
Bar-Shalom, Shaouly [Technion-Israel Inst. of Tech., Haifa (Israel); Soni, Amarjit [Brookhaven National Lab. (BNL), Upton, NY (United States); Wudka, Jose [Univ. of California, Riverside, CA (United States)
2015-07-20
Assuming the presence of physics beyond the Standard Model ( SM) with a characteristic scale M ~ O (10) TeV, we investigate the naturalness of the Higgs sector at scales below M using an effective field theory (EFT) approach. We obtain the leading 1 -loop EFT contributions to the Higgs mass with a Wilsonian-like hard cutoff, and determine t he constraints on the corresponding operator coefficients for these effects to alleviate the little hierarchy problem up to the scale of the effective action Λ < M , a condition we denote by “EFT-naturalness”. We also determine the types of physics that can lead to EFT-naturalness and show that these types of new physics are best probed in vector-boson and multiple-Higgs production. The current experimental constraints on these coefficients are also discussed.
The effective theory of Borel equivalence relations
DEFF Research Database (Denmark)
Fokina, E.B.; Friedman, S.-D.; Törnquist, Asger Dag
2010-01-01
equality on ω is above equality on P (ω), the power set of ω, and any Borel equivalence relation strictly above equality on the reals is above equality modulo finite on P (ω). In this article we examine the effective content of these and related results by studying effectively Borel equivalence relations......The study of Borel equivalence relations under Borel reducibility has developed into an important area of descriptive set theory. The dichotomies of Silver [20] and Harrington, Kechris and Louveau [6] show that with respect to Borel reducibility, any Borel equivalence relation strictly above...... under effectively Borel reducibility. The resulting structure is complex, even for equivalence relations with finitely many equivalence classes. However use of Kleene's O as a parameter is sufficient to restore the picture from the noneffective setting. A key lemma is that of the existence of two...
Could reggeon field theory be an effective theory for QCD in the Regge limit?
Energy Technology Data Exchange (ETDEWEB)
Bartels, Jochen [II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany); Contreras, Carlos [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Avda. España 1680, Casilla 110-V, Valparaiso (Chile); Vacca, G.P. [INFN Sezione di Bologna, DIFA, Via Irnerio 46, I-40126 Bologna (Italy)
2016-03-30
In this paper we investigate the possibility whether, in the extreme limit of high energies and large transverse distances, reggeon field theory might serve as an effective theory of high energy scattering for strong interactions. We analyse the functional renormalization group equations (flow equations) of reggeon field theory and search for fixed points in the space of (local) reggeon field theories. We study in complementary ways the candidate for the scaling solution, investigate its main properties and briefly discuss possible physical interpretations.
Higgs effective field theories. Systematics and applications
Energy Technology Data Exchange (ETDEWEB)
Krause, Claudius G.
2016-07-28
Researchers of the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) announced on July 4th, 2012, the observation of a new particle. The properties of the particle agree, within the relatively large experimental uncertainties, with the properties of the long-sought Higgs boson. Particle physicists around the globe are now wondering, ''Is it the Standard Model Higgs that we observe; or is it another particle with similar properties?'' We employ effective field theories (EFTs) for a general, model-independent description of the particle. We use a few, minimal assumptions - Standard Model (SM) particle content and a separation of scales to the new physics - which are supported by current experimental results. By construction, effective field theories describe a physical system only at a certain energy scale, in our case at the electroweak-scale v. Effects of new physics from a higher energy-scale, Λ, are described by modified interactions of the light particles. In this thesis, ''Higgs Effective Field Theories - Systematics and Applications'', we discuss effective field theories for the Higgs particle, which is not necessarily the Higgs of the Standard Model. In particular, we focus on a systematic and consistent expansion of the EFT. The systematics depends on the dynamics of the new physics. We distinguish two different consistent expansions. EFTs that describe decoupling new-physics effects and EFTs that describe non-decoupling new-physics effects. We briefly discuss the first case, the SM-EFT. The focus of this thesis, however, is on the non-decoupling EFTs. We argue that the loop expansion is the consistent expansion in the second case. We introduce the concept of chiral dimensions, equivalent to the loop expansion. Using the chiral dimensions, we expand the electroweak chiral Lagrangian up to next-to-leading order, O(f{sup 2}/Λ{sup 2})=O(1/16π{sup 2}). Further, we discuss how different
Chiral effective field theories of the strong interactions
Energy Technology Data Exchange (ETDEWEB)
Schindler, M.R. [Department of Physics and Astronomy, University of South Carolina, Columbia, SC 29208 (United States); Scherer, S. [Institut fur Kernphysik, Johannes Gutenberg-Universitat, 55099 Mainz (Germany)
2011-09-15
Effective field theories of the strong interactions based on the approximate chiral symmetry of QCD provide a model-independent approach to low-energy hadron physics. We give a brief introduction to mesonic and baryonic chiral perturbation theory and discuss a number of applications. We also consider the effective field theory including vector and axial-vector mesons. (authors)
From quantum field theory to hydrodynamics: Transport coefficients and effective kinetic theory
Energy Technology Data Exchange (ETDEWEB)
Jeon, S.; Yaffe, L.G. [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)
1996-05-01
The evaluation of hydrodynamic transport coefficients in relativistic field theory, and the emergence of an effective kinetic theory description, is examined. Even in a weakly coupled scalar field theory, interesting subtleties arise at high temperatures where thermal renormalization effects are important. In this domain, a kinetic theory description in terms of the fundamental particles ceases to be valid, but one may derive an effective kinetic theory describing excitations with temperature dependent properties. While the shear viscosity depends on the elastic scattering of typical excitations whose kinetic energies are comparable to the temperature, the bulk viscosity is sensitive to particle nonconserving processes at small energies. As a result, the shear and the bulk viscosities have very different dependence on the interaction strength and temperature, with the bulk viscosity providing an especially sensitive test of the validity of an effective kinetic theory description. {copyright} {ital 1996 The American Physical Society.}
Renormalons and the heavy quark effective theory
Martinelli, G; Martinelli, G; Sachrajda, C T
1995-01-01
We propose a non-perturbative method for defining the higher dimensional operators which appear in the Heavy Quark Effective Theory (HQET), such that their matrix elements are free of renormalon singularities, and diverge at most logarithmically with the ultra-violet cut-off. Matrix elements of these operators can be computed numerically in lattice simulations of the HQET. We illustrate our procedures by presenting physical definitions of the binding energy (\\lb) and of the kinetic energy (-\\lambda_1/2m_Q) of the heavy quark in a hadron. This allows us to define a ``subtracted pole mass", whose inverse can be used as the expansion parameter in applications of the HQET.
Wrapping effects in supersymmetric gauge theories
Energy Technology Data Exchange (ETDEWEB)
Fiamberti, F. [Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); INFN-Sezione di Milano, Via Celoria 16, 20133 Milano (Italy)
2010-11-15
Several perturbative computations of finite-size effects, performed on the gauge side of the AdS/CFT correspondence by means of superspace techniques, are presented. First, wrapping effects are analyzed in the standard N = 4 theory, by means of the calculation of the four-loop anomalous dimension of the Konishi operator. Then, a similar computation at five loops is described. Afterwards, finite-size effects are studied in the {beta}-deformed case, where thanks to the reduced number of supersymmetries the simpler class of single-impurity operators can be considered, so that the leading corrections to the anomalous dimensions at generic order can be reduced to the computation of a class of integrals. Explicit results are given up to eleven loops. A further chapter is dedicated to the computation of the leading finite-size effects on operators dual to open strings. In the end, some comments are made and proposals for future developments are discussed. (Abstract Copyright [2010], Wiley Periodicals, Inc.)
Nucleon Polarisabilities and Effective Field Theories
Griesshammer, Harald W.
2017-09-01
Low-energy Compton scattering probes the nucleon's two-photon response to electric and magnetic fields at fixed photon frequency and multipolarity. It tests the symmetries and strengths of the interactions between constituents, and with photons. For convenience, this energy-dependent information is often compressed into the two scalar dipole polarisabilities αE 1 and βM 1 at zero photon energy. These are fundamental quantities, and important for the proton charge radius puzzle and the Lamb shift of muonic hydrogen. Combined with emerging lattice QCD computations, they provide stringent tests for our understanding of hadron structure. Extractions of the proton and neutron polarisabilities from all published elastic data below 300 MeV in Chiral Effective Field Theory with explicit Δ (1232) are now available. This talk emphasises χEFT as natural bridge between lattice QCD and ongoing or approved efforts at HI γS, MAMI and MAX-lab. Chiral lattice extrapolations from mπ > 200 MeV to the physical point compare well to lattice computations. Combining χEFT with high-intensity experiments with polarised targets and polarised beams will extract not only scalar polarisabilities, but in particular the four so-far poorly explored spin-polarisabilities. These parametrise the stiffness of the spin in external electro-magnetic fields (nucleonic bi-refringence/Faraday effect). New chiral predictions for proton, deuteron and 3He observables show intriguing sensitivities on spin and neutron polarisabilities. Data consistency and a model-independent quantification of residual theory uncertainties by Bayesian analysis are also discussed. Proton-neutron differences explore the interplay between chiral symmetry breaking and short-distance Physics. Finally, I address their impact on the neutron-proton mass difference, big-bang nucleosynthesis, and their relevance for anthropic arguments. Supported in part by DOE DE-SC0015393 and George Washington University.
Chiral random matrix theory and effective theories of QCD
Energy Technology Data Exchange (ETDEWEB)
Takahashi, K.; Iida, S
2000-05-08
The correlations of the QCD Dirac eigenvalues are studied with use of an extended chiral random matrix model. The inclusion of spatial dependence which the original model lacks enables us to investigate the effects of diffusion modes. We get analytical expressions of level correlation functions with non-universal behavior caused by diffusion modes which is characterized by Thouless energy. Pion mode is shown to be responsible for these diffusion effects when QCD vacuum is considered a disordered medium.
Collinear factorization violation and effective field theory
Schwartz, Matthew D.; Yan, Kai; Zhu, Hua Xing
2017-09-01
The factorization of amplitudes into hard, soft and collinear parts is known to be violated in situations where incoming particles are collinear to outgoing ones. This result was first derived by studying limits where noncollinear particles become collinear. We show that through an effective field theory framework with Glauber operators, these factorization-violating effects can be reproduced from an amplitude that is factorized before the splitting occurs. We confirm results at one loop, through single Glauber exchange, and at two loops, through double Glauber exchange. To approach the calculation, we begin by reviewing the importance of Glauber scaling for factorization. We show that for any situation where initial-state and final-state particles are not collinear, the Glauber contribution is entirely contained in the soft contribution. The contributions coming from Glauber operators are necessarily nonanalytic functions of external momentum, with the nonanalyticity arising from the rapidity regulator. The nonanalyticity is critical so that Glauber operators can both preserve factorization when it holds and produce factorization-violating effects when they are present.
Two Quantum Effects In The Theory Of Gravitation
Robinson, S P
2005-01-01
We will discuss two methods by which the formalism of quantum field theory can be included in calculating the physical effects of gravitation. In the first of these, the consequences of treating general relativity as an effective quantum field theory will be examined. The primary result will be the calculation of the first-order quantum gravity corrections to the β functions of arbitrary Yang-Mills theories. These corrections will effect the high-energy phenomenology of such theories, including the details of coupling constant unification. Following this, we will address the question of how to form effective quantum field theories in classical gravitational backgrounds. We follow the prescription that effective theories should provide a description of experimentally accessible degrees of freedom with all other degrees of freedom integrated out of the theory. We will show that this prescription appears to fail for a scalar field in a black hole background because of an anomaly generated in general cov...
Effective Medium Theory for Anisotropic Metamaterials
Zhang, Xiujuan
2017-11-12
This dissertation includes the study of effective medium theories (EMTs) and their applications in describing wave propagation in anisotropic metamaterials, which can guide the design of metamaterials. An EMT based on field averaging is proposed to describe a peculiar anisotropic dispersion relation that is linear along the symmetry line but quadratic in the perpendicular direction. This dispersion relation is associated with the topological transition of the iso-frequency contours (IFCs), suggesting interesting wave propagation behaviors from beam shaping to beam splitting. In the framework of coherent potential approximation, an analytical EMT is further developed, with the ability to build a direct connection between the microscopic structure and the macroscopic material properties, which overcomes the requirement of prior knowledge of the field distributions. The derived EMT is valid beyond the long-wavelength limit. Using the EMT, an anisotropic zero-index metamaterial is designed. Moreover, the derived EMT imposes a condition that no scattered wave is generated in the ambient medium, which suggests the input signal cannot detect any object that might exist, making it invisible. Such correspondence between the EMT and the invisibilityinspires us to explore the wave cloaking in the same framework of coherent potential approximation. To further broaden the application realm of EMT, an EMT using the parameter retrieval method is studied in the regimes where the previously-developed EMTs are no longer accurate. Based on this study, in conjunction with the EMT mentioned above, a general scheme to realize coherent perfect absorption (CPA) in anisotropic metamaterials is proposed. As an exciting area in metamaterials, the field of metasurfaces has drawn great attention recently. As an easily attainable device, a grating may be the simplest version of metasurfaces. Here, an analytical EMT for gratings made of cylinders is developed by using the multiple scattering
The Supersymmetric Effective Field Theory of Inflation
Energy Technology Data Exchange (ETDEWEB)
Delacrétaz, Luca V.; Gorbenko, Victor [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94306 (United States); Senatore, Leonardo [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94306 (United States); Kavli Institute for Particle Astrophysics and Cosmology, Stanford University and SLAC,Menlo Park, CA 94025 (United States)
2017-03-10
We construct the Supersymmetric Effective Field Theory of Inflation, that is the most general theory of inflationary fluctuations when time-translations and supersymmetry are spontaneously broken. The non-linear realization of these invariances allows us to define a complete SUGRA multiplet containing the graviton, the gravitino, the Goldstone of time translations and the Goldstino, with no auxiliary fields. Going to a unitary gauge where only the graviton and the gravitino are present, we write the most general Lagrangian built out of the fluctuations of these fields, invariant under time-dependent spatial diffeomorphisms, but softly-breaking time diffeomorphisms and gauged SUSY. With a suitable Stückelberg transformation, we introduce the Goldstone boson of time translation and the Goldstino of SUSY. No additional dynamical light field is needed. In the high energy limit, larger than the inflationary Hubble scale for the Goldstino, these fields decouple from the graviton and the gravitino, greatly simplifying the analysis in this regime. We study the phenomenology of this Lagrangian. The Goldstino can have a non-relativistic dispersion relation. Gravitino and Goldstino affect the primordial curvature perturbations at loop level. The UV modes running in the loops generate three-point functions which are degenerate with the ones coming from operators already present in the absence of supersymmetry. Their size is potentially as large as corresponding to f{sub NL}{sup equil.,orthog.}∼1 or, for particular operators, even ≫1. The non-degenerate contribution from modes of order H is estimated to be very small.
Effective interactions for light nuclei: an effective (field theory) approach
Stetcu, I.; Rotureau, J.; Barrett, B.R.; van Kolck, U.
2009-01-01
One of the central open problems in nuclear physics is the construction of effective interactions suitable for many-body calculations. We discuss a recently developed approach to this problem, where one starts with an effective field theory containing only fermion fields and formulated directly in a no-core shell-model space. We present applications to light nuclei and to systems of a few atoms in a harmonic-oscillator trap. Future applications and extensions, as well as challenges, are also ...
Directory of Open Access Journals (Sweden)
M. Cocco
2005-06-01
Full Text Available In this work we present a 3D Finite Difference numerical method to model the dynamic spontaneous propagation of an earthquake rupture on planar faults in an elastic half-space. We implement the Traction-at-Split-Nodes fault boundary condition for a system of faults, either vertical or oblique, using different constitutive laws. We can adopt both a slip-weakening law to prescribe the traction evolution within the breakdown zone or rate- and state-dependent friction laws, which involve the choice of an evolution relation for the state variable. Our numerical procedure allows the use of oblique and heterogeneous distribution of initial stress and allows the rake rotation. This implies that the two components of slip velocity and total dynamic traction are coupled together to satisfy, in norm, the adopted constitutive law. The simulations presented in this study show that the rupture acceleration to super-shear crack speeds occurs along the direction of the imposed initial stress; the rupture front velocity along the perpendicular direction is slower than that along the pre-stress direction. Depending on the position on the fault plane the orientation of instantaneous total dynamic traction can change with time with respect to the imposed initial stress direction. These temporal rake rotations depend on the amplitude of initial stress and on its distribution on the fault plane. They also depend on the curvature and direction of the rupture front with respect to the imposed initial stress direction: this explains why rake rotations are mostly located near the rupture front and within the cohesive zone.
Effective field theory approaches for tensor potentials
Energy Technology Data Exchange (ETDEWEB)
Jansen, Maximilian
2016-11-14
Effective field theories are a widely used tool to study physical systems at low energies. We apply them to systematically analyze two and three particles interacting via tensor potentials. Two examples are addressed: pion interactions for anti D{sup 0}D{sup *0} scattering to dynamically generate the X(3872) and dipole interactions for two and three bosons at low energies. For the former, the one-pion exchange and for the latter, the long-range dipole force induce a tensor-like structure of the potential. We apply perturbative as well as non-perturbative methods to determine low-energy observables. The X(3872) is of major interest in modern high-energy physics. Its exotic characteristics require approaches outside the range of the quark model for baryons and mesons. Effective field theories represent such methods and provide access to its peculiar nature. We interpret the X(3872) as a hadronic molecule consisting of neutral D and D{sup *} mesons. It is possible to apply an effective field theory with perturbative pions. Within this framework, we address chiral as well as finite volume extrapolations for low-energy observables, such as the binding energy and the scattering length. We show that the two-point correlation function for the D{sup *0} meson has to be resummed to cure infrared divergences. Moreover, next-to-leading order coupling constants, which were introduced by power counting arguments, appear to be essential to renormalize the scattering amplitude. The binding energy as well as the scattering length display a moderate dependence on the light quark masses. The X(3872) is most likely deeper bound for large light quark masses. In a finite volume on the other hand, the binding energy significantly increases. The dependence on the light quark masses and the volume size can be simultaneously obtained. For bosonic dipoles we apply a non-perturbative, numerical approach. We solve the Lippmann-Schwinger equation for the two-dipole system and the Faddeev
Effective field theory description of halo nuclei
Hammer, H.-W.; Ji, C.; Phillips, D. R.
2017-10-01
Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction. Individual nucleons inside the core are thus unresolved in the halo configuration, and the low-energy effective interactions are short-range forces between the core and the valence nucleons. Similar phenomena occur in clusters of 4He atoms, cold atomic gases near a Feshbach resonance, and some exotic hadrons. In these weakly-bound quantum systems universal scaling laws for s-wave binding emerge that are independent of the details of the interaction. Effective field theory (EFT) exposes these correlations and permits the calculation of non-universal corrections to them due to short-distance effects, as well as the extension of these ideas to systems involving the Coulomb interaction and/or binding in higher angular-momentum channels. Halo nuclei exhibit all these features. Halo EFT, the EFT for halo nuclei, has been used to compute the properties of single-neutron, two-neutron, and single-proton halos of s-wave and p-wave type. This review summarizes these results for halo binding energies, radii, Coulomb dissociation, and radiative capture, as well as the connection of these properties to scattering parameters, thereby elucidating the universal correlations between all these observables. We also discuss how Halo EFT's encoding of the long-distance physics of halo nuclei can be used to check and extend ab initio calculations that include detailed modeling of their short-distance dynamics.
Effective field theories for muonic hydrogen
Directory of Open Access Journals (Sweden)
Peset Clara
2017-01-01
Full Text Available Experimental measurements of muonic hydrogen bound states have recently started to take place and provide a powerful setting in which to study the properties of QCD. We profit from the power of effective field theories (EFTs to provide a theoretical framework in which to study muonic hydrogen in a model independent fashion. In particular, we compute expressions for the Lamb shift and the hyperfine splitting. These expressions include the leading logarithmic O(mμα6 terms, as well as the leading O(mμα5mμ2ΛQCD2${\\cal O}\\left( {{m_\\mu }{\\alpha ^5}{{m_\\mu ^2} \\over {\\Lambda _{{\\rm{QCD}}}^2}}} \\right$ hadronic effects. Most remarkably, our analyses include the determination of the spin-dependent and spin-independent structure functions of the forward virtualphoton Compton tensor of the proton to O(p3 in HBET and including the Delta particle. Using these results we obtain the leading hadronic contributions to the Wilson coeffcients of the lepton-proton four fermion operators in NRQED. The spin-independent coeffcient yields a pure prediction for the two-photon exchange contribution to the muonic hydrogen Lamb shift, which is the main source of uncertainty in our computation. The spindependent coeffcient yields the prediction of the hyperfine splitting. The use of EFTs crucially helps us organizing the computation, in such a way that we can clearly address the parametric accuracy of our result. Furthermore, we review in the context of NRQED all the contributions to the energy shift of O(mμα5, as well as those that scale like mrα6× logarithms.
Fayadh, Rashid A.; Malek, F.; Fadhil, Hilal A.; Aldhaibani, Jaafar A.; Salman, M. K.; Abdullah, Farah Salwani
2015-05-01
For high data rate propagation in wireless ultra-wideband (UWB) communication systems, the inter-symbol interference (ISI), multiple-access interference (MAI), and multiple-users interference (MUI) are influencing the performance of the wireless systems. In this paper, the rake-receiver was presented with the spread signal by direct sequence spread spectrum (DS-SS) technique. The adaptive rake-receiver structure was shown with adjusting the receiver tap weights using least mean squares (LMS), normalized least mean squares (NLMS), and affine projection algorithms (APA) to support the weak signals by noise cancellation and mitigate the interferences. To minimize the data convergence speed and to reduce the computational complexity by the previous algorithms, a well-known approach of partial-updates (PU) adaptive filters were employed with algorithms, such as sequential-partial, periodic-partial, M-max-partial, and selective-partial updates (SPU) in the proposed system. The simulation results of bit error rate (BER) versus signal-to-noise ratio (SNR) are illustrated to show the performance of partial-update algorithms that have nearly comparable performance with the full update adaptive filters. Furthermore, the SPU-partial has closed performance to the full-NLMS and full-APA while the M-max-partial has closed performance to the full-LMS updates algorithms.
The use of theory in school effectiveness research revisited
Scheerens, Jaap
2013-01-01
From an international review of 109 school effectiveness research studies, only 6 could be seen as theory driven. As the border between substantive conceptual models of educational effectiveness and theory-based models is not always very sharp, this number might be increased to 11 by including those
Applying Learning Theories and Instructional Design Models for Effective Instruction
Khalil, Mohammed K.; Elkhider, Ihsan A.
2016-01-01
Faculty members in higher education are involved in many instructional design activities without formal training in learning theories and the science of instruction. Learning theories provide the foundation for the selection of instructional strategies and allow for reliable prediction of their effectiveness. To achieve effective learning…
Heavy Quarks, QCD, and Effective Field Theory
Energy Technology Data Exchange (ETDEWEB)
Thomas Mehen
2012-10-09
The research supported by this OJI award is in the area of heavy quark and quarkonium production, especially the application Soft-Collinear E ective Theory (SCET) to the hadronic production of quarkonia. SCET is an e ffective theory which allows one to derive factorization theorems and perform all order resummations for QCD processes. Factorization theorems allow one to separate the various scales entering a QCD process, and in particular, separate perturbative scales from nonperturbative scales. The perturbative physics can then be calculated using QCD perturbation theory. Universal functions with precise fi eld theoretic de nitions describe the nonperturbative physics. In addition, higher order perturbative QCD corrections that are enhanced by large logarithms can be resummed using the renormalization group equations of SCET. The applies SCET to the physics of heavy quarks, heavy quarkonium, and similar particles.
3d N=1 effective supergravity and F-theory from M-theory on fourfolds
Energy Technology Data Exchange (ETDEWEB)
Prins, Daniël; Tsimpis, Dimitrios [Université de Lyon, UMR 5822, CNRS/IN2P3, Institut de Physique Nucléaire de Lyon,4 rue Enrico Fermi, F-69622 Villeurbanne Cedex (France)
2015-09-16
We consider 3d N=1 M-theory compactifications on Calabi-Yau fourfolds, and the effective 3d theory of light modes obtained by reduction from eleven dimensions. We study in detail the mass spectrum at the vacuum and, by decoupling the massive multiplets, we derive the effective 3d N=1 theory in the large-volume limit up to quartic fermion terms. We show that in general it is an ungauged N=1 supergravity of the form expected from 3d supersymmetry. In particular the massless bosonic fields consist of the volume modulus and the axions originating from the eleven-dimensional three-form, while the moduli-space metric is locally isometric to hyperbolic space. We consider the F-theory interpretation of the 3d N=1 M-theory vacua in the light of the F-theory effective action approach. We show that these vacua generally have F-theory duals with circle fluxes, thus breaking 4d Poincaré invariance.
Boundary effects in super-Yang-Mills theory
Energy Technology Data Exchange (ETDEWEB)
Shah, Mushtaq B.; Ganai, Prince A. [National Institute of Technology, Department of Physics, Srinagar, Kashmir (India); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Alberta (Canada); Zaz, Zaid [University of Kashmir, Department of Electronics and Communication Engineering, Srinagar, Kashmir (India); Bhat, Anha [National Institute of Technology, Department of Metallurgical and Materials Engineering, Srinagar, Kashmir (India); Masood, Syed [International Islamic University, Department of Physics, Islamabad (Pakistan)
2017-05-15
In this paper, we shall analyze a three dimensional supersymmetry theory with N = 2 supersymmetry. We will analyze the quantization of this theory, in the presence of a boundary. The effective Lagrangian used in the path integral quantization of this theory, will be given by the sum of the gauge fixing term and the ghost term with the original classical Lagrangian. Even though the supersymmetry of this effective Lagrangian will also be broken due to the presence of a boundary, it will be demonstrated that half of the supersymmetry of this theory can be preserved by adding a boundary Lagrangian to the effective bulk Lagrangian. The supersymmetric transformation of this new boundary Lagrangian will exactly cancel the boundary term generated from the supersymmetric transformation of the effective bulk Lagrangian. We will analyze the Slavnov-Taylor identity for this N = 2 Yang-Mills theory with a boundary. (orig.)
Universal Charge Diffusion and the Butterfly Effect in Holographic Theories
Blake, Mike
2016-08-01
We study charge diffusion in holographic scaling theories with a particle-hole symmetry. We show that these theories have a universal regime in which the diffusion constant is given by Dc=C vB2/(2 π T ), where vB is the velocity of the butterfly effect. The constant of proportionality C depends only on the scaling exponents of the infrared theory. Our results suggest an unexpected connection between transport at strong coupling and quantum chaos.
Towards a comprehensive theory of monadic effects
DEFF Research Database (Denmark)
Filinski, Andrzej
2011-01-01
, operational, and axiomatic characterizations of effects; principles and frameworks for combining effects; prescriptive vs. descriptive effect-type systems; specification vs. implementation of effects; and realizations of effect-related theoretical constructions in practical functional languages, both eager...
Effective Theory of Floquet Topological Transitions
Kundu, Arijit; Fertig, H. A.; Seradjeh, Babak
2014-01-01
We develop a theory of topological transitions in a Floquet topological insulator, using graphene irradiated by circularly polarized light as a concrete realization. We demonstrate that a hallmark signature of such transitions in a static system, i.e. metallic bulk transport with conductivity of order $e^2/h$, is substantially suppressed at some Floquet topological transitions in the clean system. We determine the conditions for this suppression analytically and confirm our results in numeric...
Directory of Open Access Journals (Sweden)
Andi Trimulyono
2015-06-01
Full Text Available Salah satu aspek yang paling penting dalam pembuatan kapal adalah perencanaan sistem propulsi salah satu aspek dari sistem propulsi itu sendiri adalah perencanaan desain Propeller. Propeller merupakan salah satu aspek yang harus direncanakan dengan baik agar tercapai tujuan kapal dalam hal kecepatan. Kecepatan pada kapal tidak terlepas dari desain propeller yang baik agar mendapatkan gaya dorong (Thrust optimal yang dihasilkan oleh gerak propeller.Tujuan dari penelitian ini adalah untuk mengetahui nilai thrust optimum untuk Propeller TB Ari 400 HP dari analisa model variasi sudut rake dan jumlah daun yang dibuat sehingga dapat diketahui dari variasi model tersebut manakah yang memiliki nilai thrust tinggi dan torque terendah serta untuk mengetahui perbandingan nilai thrust yang dihasilkan dari variasi model B-series dan Kaplan dengan variabel sudut rake dan jumlah daun. Hasil dari penelitian ini menunjukkan Nilai thrust tertinggi dihasilkan pada model Propeller Ka5 50 diameter 1 m sudut rake 00 dengan nilai thrust tertinggi sebesar 14608,8 N pada putaran 500 RPM. Nilai torque terendah dihasilkan pada model Propeller B4 50 Series sudut 100 diameter 0,813m dengan nilai 513,967 Nm pada putaran 500 RPM. Nilai perbandingan thrust dan torque tersebut di dapatkan dari model dengan parameter analisis dimensi yang sama dan Putaran 500 RPM. Dan mendaptkan Nilai efisiensi tertinggi diperoleh pada model propeller B4 50 sudut rake 120 diameter 0,813 m yaitu sebesar 0,6764 pada putaran 500 RPM
Dissipative Effects in the Effective Field Theory of Inflation
Energy Technology Data Exchange (ETDEWEB)
Lopez Nacir, Diana; /Buenos Aires, CONICET /Buenos Aires U.; Porto, Rafael A.; /Princeton, Inst. Advanced Study /ISCAP, New York /Columbia U.; Senatore, Leonardo; /Stanford U., ITP /SLAC /KIPAC, Menlo Park; Zaldarriaga, Matias; /Princeton, Inst. Advanced Study
2012-09-14
We generalize the effective field theory of single clock inflation to include dissipative effects. Working in unitary gauge we couple a set of composite operators, {Omicron}{sub {mu}{nu}}..., in the effective action which is constrained solely by invariance under time-dependent spatial diffeomorphisms. We restrict ourselves to situations where the degrees of freedom responsible for dissipation do not contribute to the density perturbations at late time. The dynamics of the perturbations is then modified by the appearance of 'friction' and noise terms, and assuming certain locality properties for the Green's functions of these composite operators, we show that there is a regime characterized by a large friction term {gamma} >> H in which the {zeta}-correlators are dominated by the noise and the power spectrum can be significantly enhanced. We also compute the three point function <{zeta}{zeta}{zeta}> for a wide class of models and discuss under which circumstances large friction leads to an increased level of non-Gaussianities. In particular, under our assumptions, we show that strong dissipation together with the required non-linear realization of the symmetries implies |f{sub NL}| {approx} {gamma}/c{sub s}{sup 2} H >> 1. As a paradigmatic example we work out a variation of the 'trapped inflation' scenario with local response functions and perform the matching with our effective theory. A detection of the generic type of signatures that result from incorporating dissipative effects during inflation, as we describe here, would teach us about the dynamics of the early universe and also extend the parameter space of inflationary models.
The Long and Short of Nuclear Effective Field Theory Expansions
Kaplan, D B; Kaplan, David B.; Steele, James V.
1999-01-01
Nonperturbative effective field theory calculations for NN scattering seem to break down at rather low momenta. By examining several toy models, we clarify how effective field theory expansions can in general be used to properly separate long- and short-range effects. We find that one-pion exchange has a large effect on the scattering phase shift near poles in the amplitude, but otherwise can be treated perturbatively. Analysis of a toy model that reproduces 1S0 NN scattering data rather well suggests that failures of effective field theories for momenta above the pion mass can be due to short-range physics rather than the treatment of pion exchange. We discuss the implications this has for extending the applicability of effective field theories.
Holomorphy without supersymmetry in the Standard Model Effective Field Theory
Directory of Open Access Journals (Sweden)
Rodrigo Alonso
2014-12-01
Full Text Available The anomalous dimensions of dimension-six operators in the Standard Model Effective Field Theory (SMEFT respect holomorphy to a large extent. The holomorphy conditions are reminiscent of supersymmetry, even though the SMEFT is not a supersymmetric theory.
The premotor theory of attention and the Simon effect
van der Lubbe, Robert Henricus Johannes; Abrahamse, E.L.
2011-01-01
In the paper by Hommel (2011-this issue), the roles of the theory of event coding (TEC) and the premotor theory of attention (PMTA) for the Simon effect were considered. PMTA was treated by Hommel in terms of the proposal that attentional orienting can be viewed as the preparation of a saccade
The Effects of Integrating Laboratory Work with Theory on Academic ...
African Journals Online (AJOL)
The major findings of the study showed that students taught physics by intergrating laboratory work with theory performed better than those taught by treating practical work after and separate from theory. Gender showed no significant effects. It was therefore recommended that physics teachers should adopt the method of ...
The Faraday effect revisited: General theory
DEFF Research Database (Denmark)
Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm
conductivity can be explicitly computed and coincides with the classical result. In the general case, using magnetic perturbation theory, the conductivity tensor is expanded in powers of the strength of the magnetic field B. Then the linear term in B of this expansion is written down in terms of the zero...... magnetic field Green function and the zero field current operator. In the periodic case, the linear term in B of the conductivity tensor is expressed in terms of zero magnetic field Bloch functions and energies. No derivatives with respect to the quasimomentum appear and thereby all ambiguities are removed...
Effective Theory of Floquet Topological Transitions
Kundu, Arijit; Fertig, H. A.; Seradjeh, Babak
2014-12-01
We develop a theory of topological transitions in a Floquet topological insulator, using graphene irradiated by circularly polarized light as a concrete realization. We demonstrate that a hallmark signature of such transitions in a static system, i.e., metallic bulk transport with conductivity of order e2/h , is substantially suppressed at some Floquet topological transitions in the clean system. We determine the conditions for this suppression analytically and confirm our results in numerical simulations. Remarkably, introducing disorder dramatically enhances this transport by several orders of magnitude.
Spectator Interactions in Soft-Collinear Effective Theory
Energy Technology Data Exchange (ETDEWEB)
Hill, Richard J
2002-11-08
Soft-collinear effective theory is generalized to include soft massless quarks in addition to collinear fields. This extension is necessary for the treatment of interactions with the soft spectator quark in a heavy meson. The power counting of the relevant fields and the construction of the effective Lagrangian are discussed at leading order in {Lambda}/m{sub b}. Several novel effects occur in the matching of full-theory amplitudes onto effective-theory operators containing soft light quarks, such as the appearance of an intermediate mass scale and large non-localities of operators on scales of order 1/{Lambda}. Important examples of effective-theory operators with soft light quarks are studied and their renormalization properties explored. The formalism presented here forms the basis for a systematic analysis of factorization and power corrections for any exclusive B-meson decay into light particles.
Effective Field Theories from Soft Limits of Scattering Amplitudes.
Cheung, Clifford; Kampf, Karol; Novotny, Jiri; Trnka, Jaroslav
2015-06-05
We derive scalar effective field theories-Lagrangians, symmetries, and all-from on-shell scattering amplitudes constructed purely from Lorentz invariance, factorization, a fixed power counting order in derivatives, and a fixed order at which amplitudes vanish in the soft limit. These constraints leave free parameters in the amplitude which are the coupling constants of well-known theories: Nambu-Goldstone bosons, Dirac-Born-Infeld scalars, and Galilean internal shift symmetries. Moreover, soft limits imply conditions on the Noether current which can then be inverted to derive Lagrangians for each theory. We propose a natural classification of all scalar effective field theories according to two numbers which encode the derivative power counting and soft behavior of the corresponding amplitudes. In those cases where there is no consistent amplitude, the corresponding theory does not exist.
Correlated effective field theory in transition metal compounds
Mukhopadhyay, Subhasis; Chatterjee, Ibha
2004-03-01
Mean field theory is good enough to study the physical properties at higher temperatures and in higher dimensions. It explains the critical phenomena in a restricted sense. Near the critical temperatures, when fluctuations become important, it may not give the correct results. Similarly in low dimensions, the correlations become important and the mean field theory seems to be inadequate to explain the physical phenomena. At low-temperatures too, the quantum correlations become important and these effects are to be treated in an appropriate way. In 1974, Prof. M.E. Lines of Bell Laboratories, developed a theory which goes beyond the mean field theory and is known as the correlated effective field (CEF) theory. It takes into account the fluctuations in a semiempirical way. Lines and his collaborators used this theory to explain the short-range correlations and their anisotropy in the paramagnetic phase. Later Suzuki et al., Chatterjee and Desai, Mukhopadhyay and Chatterjee applied this theory to the magnetically ordered phase and a tremendous success of the theory has been found in real systems. The success of the CEF theory is discussed in this review. In order to highlight the success of this theory, earlier effective field theories and their improvements over mean field theories e.g., Bethe-Peierls-Weiss method, reaction field approximation, etc., are also discussed in this review for completeness. The beauty of the CEF theory is that it is mean field-like, but captures the essential physics of real systems to a great extent. However, this is a weak correlated theory and as a result is inappropriate for the metallic phase when strong correlations become important. In recent times, transition metal oxides become important due to the discovery of the high-temperature superconductivity and the colossal magnetoresistance phenomena. These oxides seem to be Mott insulators and undergo an insulator to metal transition by applying magnetic field, pressure and by changing
Correlation theory of crystal field and anisotropic exchange effects
DEFF Research Database (Denmark)
Lindgård, Per-Anker
1985-01-01
A general theory for including correlation effects in static and dynamic properties is presented in terms of Raccah or Stevens operators. It is explicitly developed for general crystal fields and anisotropic interactions and systems with several sublattices, like the rare earth compounds....... The theory gives explicitly a temperature dependent renormalization of both the crystal field and the interactions, and a damping of the excitations and in addition a central park component. The general theory is illustrated by a discussion of the singlet-doublet system. The correlation effects...
Baryon non-invariant couplings in Higgs effective field theory
Energy Technology Data Exchange (ETDEWEB)
Merlo, Luca; Saa, Sara; Sacristan-Barbero, Mario [Universidad Autonoma de Madrid, Departamento de Fisica Teorica y Instituto de Fsica Teorica, IFT-UAM/CSIC, Madrid (Spain)
2017-03-15
The basis of leading operators which are not invariant under baryon number is constructed within the Higgs effective field theory. This list contains 12 dimension six operators, which preserve the combination B - L, to be compared to only 6 operators for the standard model effective field theory. The discussion of the independent flavour contractions is presented in detail for a generic number of fermion families adopting the Hilbert series technique. (orig.)
Versatility of field theory motivated nuclear effective Lagrangian approach
Energy Technology Data Exchange (ETDEWEB)
Arumugam, P. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Sharma, B.K. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India)]. E-mail: bharat@iopb.res.in; Sahu, P.K. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Patra, S.K. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Sil, Tapas [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Centelles, M. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Vinas, X. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)
2004-11-04
We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei.
Quantum field theory as effective BV theory from Chern-Simons
Energy Technology Data Exchange (ETDEWEB)
Krotov, Dmitry [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation); Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, Moscow 117259 (Russian Federation); Moscow State University, Department of Physics, Vorobjevy Gory, Moscow 119899 (Russian Federation)], E-mail: krotov@itep.ru; Losev, Andrei [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, Moscow 117259 (Russian Federation)
2009-01-11
The general procedure for obtaining explicit expressions for all cohomologies of Berkovits' operator is suggested. It is demonstrated that calculation of BV integral for the classical Chern-Simons-like theory (Witten's OSFT-like theory) reproduces BV version of two-dimensional gauge model at the level of effective action. This model contains gauge field, scalars, fermions and some other fields. We prove that this model is an example of 'singular' point from the perspective of the suggested method for cohomology evaluation. For arbitrary 'regular' point the same technique results in AKSZ (Alexandrov, Kontsevich, Schwarz, Zaboronsky) version of Chern-Simons theory (BF theory) in accord with [N. Berkovits, Covariant quantization of the superparticle using pure spinors, JHEP 0109 (2001) 016, (hep-th/0105050); N. Berkovits, ICTP lectures on covariant quantization of the superstring, (hep-th/0209059); M. Movshev, A. Schwarz, On maximally supersymmetric Yang-Mills theories, Nucl. Phys. B 681 (2004) 324, (hep-th/0311132); M. Movshev, A. Schwarz, Algebraic structure of Yang-Mills theory, (hep-th/0404183)].
Theory of the spin Seebeck effect.
Adachi, Hiroto; Uchida, Ken-ichi; Saitoh, Eiji; Maekawa, Sadamichi
2013-03-01
The spin Seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters. The inverse spin Hall effect converts the injected spin current into a transverse charge voltage, thereby producing electromotive force as in the conventional charge Seebeck device. Recent theoretical and experimental efforts have shown that the magnon and phonon degrees of freedom play crucial roles in the spin Seebeck effect. In this paper, we present the theoretical basis for understanding the spin Seebeck effect and briefly discuss other thermal spin effects.
Effective theories of single field inflation when heavy fields matter
Achucarro, Ana; Hardeman, Sjoerd; Palma, Gonzalo A; Patil, Subodh P
2012-01-01
We compute the low energy effective field theory (EFT) expansion for single-field inflationary models that descend from a parent theory containing multiple other scalar fields. By assuming that all other degrees of freedom in the parent theory are sufficiently massive relative to the inflaton, it is possible to derive an EFT valid to arbitrary order in perturbations, provided certain generalized adiabaticity conditions are respected. These conditions permit a consistent low energy EFT description even when the inflaton deviates off its adiabatic minimum along its slowly rolling trajectory. By generalizing the formalism that identifies the adiabatic mode with the Goldstone boson of this spontaneously broken time translational symmetry prior to the integration of the heavy fields, we show that this invariance of the parent theory dictates the entire non-perturbative structure of the descendent EFT. The couplings of this theory can be written entirely in terms of the reduced speed of sound of adiabatic perturbat...
Theory of the Spin Seebeck Effect
Adachi, Hiroto; Uchida, Ken-ichi; Saitoh, Eiji; Maekawa, Sadamichi
2012-01-01
The spin Seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters. The inverse spin Hall effect converts the injected spin current into a transverse charge voltage, thereby producing electromotive force as in the conventional charge Seebeck device. Recent theoretical and experimental eff...
Applying learning theories and instructional design models for effective instruction.
Khalil, Mohammed K; Elkhider, Ihsan A
2016-06-01
Faculty members in higher education are involved in many instructional design activities without formal training in learning theories and the science of instruction. Learning theories provide the foundation for the selection of instructional strategies and allow for reliable prediction of their effectiveness. To achieve effective learning outcomes, the science of instruction and instructional design models are used to guide the development of instructional design strategies that elicit appropriate cognitive processes. Here, the major learning theories are discussed and selected examples of instructional design models are explained. The main objective of this article is to present the science of learning and instruction as theoretical evidence for the design and delivery of instructional materials. In addition, this article provides a practical framework for implementing those theories in the classroom and laboratory. Copyright © 2016 The American Physiological Society.
Effective Gravitational Theories in String Theory and the AdS/CFT Correspondence
DEFF Research Database (Denmark)
Pedersen, Andreas Vigand
We consider various aspects of effective gravitational theories, including supergravity, within the framework of the blackfold approach. The thesis is naturally split into three parts. In the first part of the thesis, we explore the blackfold approach and explain how it is possible to write down...... as low/high spin. As a byproduct of our analysis, we find a new stationary dipole-charged black hole solution on the AdS S backgrounds of type IIB/M-theory. We finally consider, via a double scaling extremal limit, a novel null-wave zero-temperature giant graviton exhibiting a BPS spectrum. Finally...
Foil bearing lubrication theory including compressibility effects
Gorla, Rama Subba Reddy; Catalano, Daniel A.
1987-01-01
An analysis is presented to determine the film thickness in a foil bearing. Using the Reynolds equation and including the compressibility effects of the gas, an equation was developed applicable to the film thickness in a foil bearing. The bearing was divided into three regions, namely, the entrance region, middle region and exit region. Solutions are obtained for the film thickness in each region.
Proton–proton fusion in lattice effective field theory
Energy Technology Data Exchange (ETDEWEB)
Rupak, Gautam, E-mail: grupak@u.washington.edu; Ravi, Pranaam, E-mail: pr340@msstate.edu
2015-02-04
The proton–proton fusion rate is calculated at low energy in a lattice effective field theory (EFT) formulation. The strong and the Coulomb interactions are treated non-perturbatively at leading order in the EFT. The lattice results are shown to accurately describe the low energy cross section within the validity of the theory at energies relevant to solar physics. In prior works in the literature, Coulomb effects were generally not included in non-perturbative lattice calculations. Work presented here is of general interest in nuclear lattice EFT calculations that involve Coulomb effects at low energy. It complements recent developments of the adiabatic projection method for lattice calculations of nuclear reactions.
From information theory to quantitative description of steric effects.
Alipour, Mojtaba; Safari, Zahra
2016-07-21
Immense efforts have been made in the literature to apply the information theory descriptors for investigating the electronic structure theory of various systems. In the present study, the information theoretic quantities, such as Fisher information, Shannon entropy, Onicescu information energy, and Ghosh-Berkowitz-Parr entropy, have been used to present a quantitative description for one of the most widely used concepts in chemistry, namely the steric effects. Taking the experimental steric scales for the different compounds as benchmark sets, there are reasonable linear relationships between the experimental scales of the steric effects and theoretical values of steric energies calculated from information theory functionals. Perusing the results obtained from the information theoretic quantities with the two representations of electron density and shape function, the Shannon entropy has the best performance for the purpose. On the one hand, the usefulness of considering the contributions of functional groups steric energies and geometries, and on the other hand, dissecting the effects of both global and local information measures simultaneously have also been explored. Furthermore, the utility of the information functionals for the description of steric effects in several chemical transformations, such as electrophilic and nucleophilic reactions and host-guest chemistry, has been analyzed. The functionals of information theory correlate remarkably with the stability of systems and experimental scales. Overall, these findings show that the information theoretic quantities can be introduced as quantitative measures of steric effects and provide further evidences of the quality of information theory toward helping theoreticians and experimentalists to interpret different problems in real systems.
ALPs effective field theory and collider signatures
Energy Technology Data Exchange (ETDEWEB)
Brivio, I. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica y Instituto de Fisica Teorica, IFT-UAM/CSIC, Madrid (Spain); University of Copenhagen, Niels Bohr International Academy, Copenhagen (Denmark); Gavela, M.B.; Merlo, L.; Rey, R. del [Universidad Autonoma de Madrid, Departamento de Fisica Teorica y Instituto de Fisica Teorica, IFT-UAM/CSIC, Madrid (Spain); Mimasu, K. [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); Universite Catholique de Louvain, Centre for Cosmology, Particle Physics and Phenomenology (CP3), Louvain-la-Neuve (Belgium); No, J.M. [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); King' s College London, Department of Physics, London (United Kingdom); Sanz, V. [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)
2017-08-15
We study the leading effective interactions between the Standard Model fields and a generic singlet CP-odd (pseudo-) Goldstone boson. Two possible frameworks for electroweak symmetry breaking are considered: linear and non-linear. For the latter case, the basis of leading effective operators is determined and compared with that for the linear expansion. Associated phenomenological signals at colliders are explored for both scenarios, deriving new bounds and analyzing future prospects, including LHC and High Luminosity LHC sensitivities. Mono-Z, mono-W, W-photon plus missing energy and on-shell top final states are most promising signals expected in both frameworks. In addition, non-standard Higgs decays and mono-Higgs signatures are especially prominent and expected to be dominant in non-linear realisations. (orig.)
Acoustic Effects in Classical Nucleation Theory
Baird, J. K.; Su, C.-H.
2017-01-01
The effect of sound wave oscillations on the rate of nucleation in a parent phase can be calculated by expanding the free energy of formation of a nucleus of the second phase in powers of the acoustic pressure. Since the period of sound wave oscillation is much shorter than the time scale for nucleation, the acoustic effect can be calculated as a time average of the free energy of formation of the nucleus. The leading non-zero term in the time average of the free energy is proportional to the square of the acoustic pressure. The Young-Laplace equation for the surface tension of the nucleus can be used to link the time average of the square of the pressure in the parent phase to its time average in the nucleus of the second phase. Due to the surface tension, the pressure in the nuclear phase is higher than the pressure in the parent phase. The effect is to lower the free energy of formation of the nucleus and increase the rate of nucleation.
The effective method for investigation meridian tropism theory in rats ...
African Journals Online (AJOL)
This present work describes an effective new method for study traditional Chinese medicine (TCM) on meridian tropism (MT) theory, which plays an essential role in clinical selection of TCM according to syndromes and strengthens the therapeutic effects. The new thread included material basis foundation and its tissue ...
Analysis of General Power Counting Rules in Effective Field Theory
Gavela, B M; Manohar, A V; Merlo, L
2016-01-01
We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.
Structural properties of the lattice heavy quark effective theory
Energy Technology Data Exchange (ETDEWEB)
Mandula, J.E. [Department of Energy, Washington, DC (United States). Div. of High Energy Physics; Ogilvie, M.C. [Department of Physics, Washington University, St. Louis, MO 63130 (United States)
1995-04-01
We discuss two related aspects of the lattice version of the heavy quark effective theory (HQET). They are the effects of heavy quark modes with large momenta, near the boundary of the Brillouin zone, and the renormalization of the lattice HQET. We argue that even though large momentum modes are present, their contributions to heavy-light bound states and perturbative loop integrals are dynamically suppressed and vanish in the continuum limit. We also discuss a new feature of the renormalization of the lattice HQET not present in the continuum theory, namely that the classical velocity is finitely renormalized. ((orig.)).
Structural Properties of the Lattice Heavy Quark Effective Theory
Mandula, Jeffrey E.; Ogilvie, Michael C.
1995-04-01
We discuss two related aspects of the lattice version of the heavy quark effective theory (HQET). They are the effects of heavy quark modes with large momenta, near the boundary of the Brillouin zone, and the renormalization of the lattice HQET. We argue that even though large momentum modes are present, their contributions to heavy-light bound states and perturbative loop integrals are dynamically suppressed and vanish in the continuum limit. We also discuss a new feature of the renormalization of the lattice HQET not present in the continuum theory, namely that the classical velocity is finitely renormalized.
Heavy dark matter annihilation from effective field theory.
Ovanesyan, Grigory; Slatyer, Tracy R; Stewart, Iain W
2015-05-29
We formulate an effective field theory description for SU(2)_{L} triplet fermionic dark matter by combining nonrelativistic dark matter with gauge bosons in the soft-collinear effective theory. For a given dark matter mass, the annihilation cross section to line photons is obtained with 5% precision by simultaneously including Sommerfeld enhancement and the resummation of electroweak Sudakov logarithms at next-to-leading logarithmic order. Using these results, we present more accurate and precise predictions for the gamma-ray line signal from annihilation, updating both existing constraints and the reach of future experiments.
Directory of Open Access Journals (Sweden)
Chiang Mung
2006-01-01
Full Text Available The problem of choosing the optimal multipath components to be employed at a minimum mean square error (MMSE selective Rake receiver is considered for an impulse radio ultra-wideband system. First, the optimal finger selection problem is formulated as an integer programming problem with a nonconvex objective function. Then, the objective function is approximated by a convex function and the integer programming problem is solved by means of constraint relaxation techniques. The proposed algorithms are suboptimal due to the approximate objective function and the constraint relaxation steps. However, they perform better than the conventional finger selection algorithm, which is suboptimal since it ignores the correlation between multipath components, and they can get quite close to the optimal scheme that cannot be implemented in practice due to its complexity. In addition to the convex relaxation techniques, a genetic-algorithm- (GA- based approach is proposed, which does not need any approximations or integer relaxations. This iterative algorithm is based on the direct evaluation of the objective function, and can achieve near-optimal performance with a reasonable number of iterations. Simulation results are presented to compare the performance of the proposed finger selection algorithms with that of the conventional and the optimal schemes.
D-effects in Toroidally Compactified Type II String Theory
Pioline, B
1999-01-01
We review exact results obtained for R^4 couplings in maximally supersymmetric type II string theories. These couplings offer a privileged scene to understand the rules of semiclassical calculus in string theory. Upon expansion in weak string coupling, they reveal an infinite sum of non-perturbative e^{-1/g} effects that can be imputed to euclidean D-branes wrapped on cycles of the compactification manifolds. They also shed light on the relation between Dp-branes and D-(p-2)branes, D-strings and (p,q) strings, instanton sums and soliton loops. The latter interpretation takes over in D<=6 in order to account for the e^{-1/g^2} effects, still mysterious from the point of view of instanton calculus. [To appear in the proceedings of the conference "Quantum Aspects of Gauge Theories, Supersymmetry and Unification" held at Neuchatel University, Switzerland, 18-23 September 1997.
Ionic size effects on the Poisson-Boltzmann theory.
Colla, Thiago; Nunes Lopes, Lucas; Dos Santos, Alexandre P
2017-07-07
In this paper, we develop a simple theory to study the effects of ionic size on ionic distributions around a charged spherical particle. We include a correction to the regular Poisson-Boltzmann equation in order to take into account the size of ions in a mean-field regime. The results are compared with Monte Carlo simulations and a density functional theory based on the fundamental measure approach and a second-order bulk expansion which accounts for electrostatic correlations. The agreement is very good even for multivalent ions. Our results show that the theory can be applied with very good accuracy in the description of ions with highly effective ionic radii and low concentration, interacting with a colloid or a nanoparticle in an electrolyte solution.
Grümmer, Frank; Speth, Josef
2006-07-01
We review Migdal's theory of finite Fermi systems and its application to the structure of nuclei. The theory is an extension of Landau's theory of interacting Fermi systems. In the first part the basic formulae are derived within the many-body Green functions approach. The theory is applied to isovector electric giant resonances in medium and heavy mass nuclei. The parameterizations of the renormalized effective ph-interaction and the effective operators are discussed. It is shown that the number of free parameters is restricted by conservation laws. We also present an extension of Migdal's theory, where the low-lying phonons are considered in a consistent manner. The extended theory is again applied to the same isovector electric giant resonances and to the analysis of (α, α') reaction data. We point out that the extended theory is the appropriate framework for self-consistent nuclear structure calculations starting from effective Lagrangians and Hamiltonians.
Generalized Effective Medium Theory for Particulate Nanocomposite Materials
Directory of Open Access Journals (Sweden)
Muhammad Usama Siddiqui
2016-08-01
Full Text Available The thermal conductivity of particulate nanocomposites is strongly dependent on the size, shape, orientation and dispersion uniformity of the inclusions. To correctly estimate the effective thermal conductivity of the nanocomposite, all these factors should be included in the prediction model. In this paper, the formulation of a generalized effective medium theory for the determination of the effective thermal conductivity of particulate nanocomposites with multiple inclusions is presented. The formulated methodology takes into account all the factors mentioned above and can be used to model nanocomposites with multiple inclusions that are randomly oriented or aligned in a particular direction. The effect of inclusion dispersion non-uniformity is modeled using a two-scale approach. The applications of the formulated effective medium theory are demonstrated using previously published experimental and numerical results for several particulate nanocomposites.
Deuteron magnetic quadrupole moment from chiral effective field theory
Liu, C. -P.; de Vries, J.; Mereghetti, E.; Timmermans, R. G. E.; van Kolck, U.
2012-01-01
We calculate the magnetic quadrupole moment (MQM) of the deuteron at leading order in the systematic expansion provided by chiral effective field theory. We take into account parity (P) and time-reversal (T) violation which, at the quark-gluon level, results from the QCD vacuum angle and
Effective field theory of dark matter: a global analysis
Liem, S.; Bertone, G.; Calore, F.; Ruiz de Austri, R.; Tait, T.M.P.; Trotta, R.; Weniger, C.
We present global fits of an effective field theory description of real, and complex scalar dark matter candidates. We simultaneously take into account all possible dimension 6 operators consisting of dark matter bilinears and gauge invariant combinations of quark and gluon fields. We derive
Classical and non-classical effective medium theories: New perspectives
Energy Technology Data Exchange (ETDEWEB)
Tsukerman, Igor, E-mail: igor@uakron.edu
2017-05-18
Highlights: • Advanced non-asymptotic and nonlocal homogenization theories of metamaterials, valid in electrostatics and electrodynamics. • Classical theories (Clausius–Mossotti, Lorenz–Lorentz, Maxwell Garnett) fit well into the proposed framework. • Nonlocal effects can be included in the model, making order-of-magnitude accuracy improvements possible. • A challenging problem for future research is to determine what effective tensors are attainable for given constituents of a metamaterial. - Abstract: Future research in electrodynamics of periodic electromagnetic composites (metamaterials) can be expected to produce sophisticated homogenization theories valid for any composition and size of the lattice cell. The paper outlines a promising path in that direction, leading to non-asymptotic and nonlocal homogenization models, and highlights aspects of homogenization that are often overlooked: the finite size of the sample and the role of interface boundaries. Classical theories (e.g. Clausius–Mossotti, Maxwell Garnett), while originally derived from a very different set of ideas, fit well into the proposed framework. Nonlocal effects can be included in the model, making an order-of-magnitude accuracy improvements possible. One future challenge is to determine what effective parameters can or cannot be obtained for a given set of constituents of a metamaterial lattice cell, thereby delineating the possible from the impossible in metamaterial design.
The Effects of Integrating Laboratory Work with Theory on Academic ...
African Journals Online (AJOL)
This study was an attempt to investigate the effects of integrating laboratory work with theory on academic achievement of secondary school physics students. The study was conducted in Oron Local Government Area of Akwa Ibom State, Nigeria. A total of one hundred and sixty two (162) senior secondary two (SS2) physics ...
Effective field theory approach to LHC Higgs data
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 87; Issue 3. Effective field theory approach to LHC Higgs data. ADAM FALKOWSKI. Special Issue Volume 87 Issue 3 September 2016 Article ID 39. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/pram/087/03/0039. Keywords.
On the exotic Higgs decays in effective field theory
Energy Technology Data Exchange (ETDEWEB)
Belusca-Maito, Hermes; Falkowski, Adam [Universite Paris-Sud, Laboratoire de Physique Theorique, Orsay (France)
2016-09-15
We discuss exotic Higgs decays in an effective field theory where the Standard Model is extended by dimension-6 operators. We review and update the status of two-body lepton- and quark-flavor-violating decays involving the Higgs boson. We also comment on the possibility of observing three-body flavor-violating Higgs decays in this context. (orig.)
Alpha alpha scattering in halo effective field theory
Higa, R.; Hammer, H. -W.; van Kolck, U.
2008-01-01
We study the two-alpha-particle (alpha alpha) system in an Effective Field Theory (EFT) for halo-like systems. We propose a power Counting that incorporates the subtle interplay of strong and electromagnetic forces leading to a narrow resonance at an energy of about 0.1 MeV. We investigate the EFT
Strange two-baryon interactions using chiral effective field theory
Polinder, H.
2008-01-01
We have constructed the leading order strangeness S = −1,−2 baryon-baryon potential in a chiral effective field theory approach. The chiral potential consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon contact terms. The potential, derived using SU(3)f symmetry constraints,
The Hoyle state in nuclear lattice effective field theory
Indian Academy of Sciences (India)
2014-10-08
Oct 8, 2014 ... We review the calculation of the Hoyle state of 12C in nuclear lattice effective field theory (NLEFT) and its anthropic implications in the nucleosynthesis of 12C and 16O in red giant stars. We also analyse the extension of NLEFT to the regime of medium-mass nuclei, with emphasis on the determination of the ...
The Hoyle state in nuclear lattice effective field theory
Indian Academy of Sciences (India)
Abstract. We review the calculation of the Hoyle state of 12C in nuclear lattice effective field theory (NLEFT) and its anthropic implications in the nucleosynthesis of 12C and 16O in red giant stars. We also analyse the extension of NLEFT to the regime of medium-mass nuclei, with emphasis on the determination of the ...
Effective Biot theory and its generalization to poroviscoelastic models
Liu, Xu; Greenhalgh, Stewart; Zhou, Bing; Greenhalgh, Mark
2018-02-01
A method is suggested to express the effective bulk modulus of the solid frame of a poroelastic material as a function of the saturated bulk modulus. This method enables effective Biot theory to be described through the use of seismic dispersion measurements or other models developed for the effective saturated bulk modulus. The effective Biot theory is generalized to a poroviscoelastic model of which the moduli are represented by the relaxation functions of the generalized fractional Zener model. The latter covers the general Zener and the Cole-Cole models as special cases. A global search method is described to determine the parameters of the relaxation functions, and a simple deterministic method is also developed to find the defining parameters of the single Cole-Cole model. These methods enable poroviscoelastic models to be constructed, which are based on measured seismic attenuation functions, and ensure that the model dispersion characteristics match the observations.
String Theory Effects on Five-Dimensional Black Hole Physics
Castro, Alejandra; Kraus, Per; Larsen, Finn
2008-01-01
We review recent developments in understanding quantum/string corrections to BPS black holes and strings in five-dimensional supergravity. These objects are solutions to the effective action obtained from M-theory compactified on a Calabi-Yau threefold, including the one-loop corrections determined by anomaly cancellation and supersymmetry. We introduce the off-shell formulation of this theory obtained through the conformal supergravity method and review the methods for investigating supersymmetric solutions. This leads to quantum/string corrected attractor geometries, as well as asymptotically flat black strings and spinning black holes. With these solutions in hand, we compare our results with analogous studies in four-dimensional string-corrected supergravity, emphasizing the distinctions between the four and five dimensional theories.
Analysis of general power counting rules in effective field theory
Energy Technology Data Exchange (ETDEWEB)
Gavela, Belen; Merlo, Luca [Universidad Autonoma de Madrid, Instituto de Fisica Teorica, IFT-UAM/CSIC, Madrid (Spain); Jenkins, Elizabeth E.; Manohar, Aneesh V. [University of California at San Diego, Department of Physics, La Jolla, CA (United States); CERN TH Division, Geneva 23 (Switzerland)
2016-09-15
We derive the general counting rules for a quantum effective field theory (EFT) in d dimensions. The rules are valid for strongly and weakly coupled theories, and they predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. We show that the size of the cross sections is controlled by the Λ power counting of EFT, not by chiral counting, even for chiral perturbation theory (χPT). The relation between Λ and f is generalized to d dimensions. We show that the naive dimensional analysis 4π counting is related to ℎ counting. The EFT counting rules are applied to χPT, low-energy weak interactions, Standard Model EFT and the non-trivial case of Higgs EFT. (orig.)
Power counting and Wilsonian renormalization in nuclear effective field theory
Valderrama, Manuel Pavón
2016-05-01
Effective field theories are the most general tool for the description of low energy phenomena. They are universal and systematic: they can be formulated for any low energy systems we can think of and offer a clear guide on how to calculate predictions with reliable error estimates, a feature that is called power counting. These properties can be easily understood in Wilsonian renormalization, in which effective field theories are the low energy renormalization group evolution of a more fundamental — perhaps unknown or unsolvable — high energy theory. In nuclear physics they provide the possibility of a theoretically sound derivation of nuclear forces without having to solve quantum chromodynamics explicitly. However there is the problem of how to organize calculations within nuclear effective field theory: the traditional knowledge about power counting is perturbative but nuclear physics is not. Yet power counting can be derived in Wilsonian renormalization and there is already a fairly good understanding of how to apply these ideas to non-perturbative phenomena and in particular to nuclear physics. Here we review a few of these ideas, explain power counting in two-nucleon scattering and reactions with external probes and hint at how to extend the present analysis beyond the two-body problem.
Introduction to non-perturbative heavy quark effective theory
Energy Technology Data Exchange (ETDEWEB)
Sommer, R. [DESY, Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC
2010-08-15
My lectures on the effective field theory for heavy quarks, an expansion around the static limit, concentrate on the motivation and formulation of HQET, its renormalization and discretization. This provides the basis for understanding that and how this effective theory can be formulated fully non-perturbatively in the QCD coupling, while by the very nature of an effective field theory, it is perturbative in the expansion parameter 1/m. After the couplings in the effective theory have been determined, the result at a certain order in 1/m is unique up to higher order terms in 1/m. In particular the continuum limit of the lattice regularized theory exists and leaves no trace of how it was regularized. In other words, the theory yields an asymptotic expansion of the QCD observables in 1/m - as usual in a quantum field theory modified by powers of logarithms. None of these properties has been shown rigorously (e.g. to all orders in perturbation theory) but perturbative computations and recently also non-perturbative lattice results give strong support to this ''standard wisdom''. A subtle issue is that a theoretically consistent formulation of the theory is only possible through a non-perturbative matching of its parameters with QCD at finite values of 1/m. As a consequence one finds immediately that the splitting of a result for a certain observable into, for example, lowest order and first order is ambiguous. Depending on how the matching between effective theory and QCD is done, a first order contribution may vanish and appear instead in the lowest order. For example, the often cited phenomenological HQET parameters anti {lambda} and {lambda}{sub 1} lack a unique non-perturbative definition. But this does not affect the precision of the asymptotic expansion in 1/m. The final result for an observable is correct up to order (1/m){sup n+1} if the theory was treated including (1/m){sup n} terms. Clearly, the weakest point of HQET is that it
Ma, Zimi; Jia, Chunhua; Guo, Jin; Gu, Haorong; Miao, Yanhuan
2014-02-01
To study the Chinese ancient five-element theory, one of the philosophical foundations of Traditional Chinese Medicine (TCM) theory construction, from the perspective of comtemporary cognitive science, and to reveal the important functions of five-element theory in the construction of TCM theory. The basic effects of five-element theory in the construction of TCM theory are intensively expounded and proved from the following aspects: embodiment of five-element theory in cognizing the world, quasi axiom of five-element theory in essence, classification thery of family resemblance and deductive inference pattern of five-element theory, and the openness and expansibility of five-element theory. If five-element theory is considered a cognitive pattern or cognitive system related to culture, then there should be features of cognitive embodiment in the cognitive system. If five-element theory is regarded as a symbolic system, however, then there should be a quasi-axiom for the system, and inferential deduction. If, however, five-element theory is taken as a theoretical constructive metaphor, then there should be features of opening and expansibility for the metaphor. Based on five-element theory, this study provides a cognitive frame for the construction of TCM (a medicine that originated in China, and is characterized by holism and treatment based on pattern identification differentiation) theory with the function of constructing a concept base, thereby implying further research strategies. Useful information may be produced from the creative inferences obtained from the incorporation of five-element theory.
Proton–proton fusion in lattice effective field theory
Directory of Open Access Journals (Sweden)
Gautam Rupak
2015-02-01
Full Text Available The proton–proton fusion rate is calculated at low energy in a lattice effective field theory (EFT formulation. The strong and the Coulomb interactions are treated non-perturbatively at leading order in the EFT. The lattice results are shown to accurately describe the low energy cross section within the validity of the theory at energies relevant to solar physics. In prior works in the literature, Coulomb effects were generally not included in non-perturbative lattice calculations. Work presented here is of general interest in nuclear lattice EFT calculations that involve Coulomb effects at low energy. It complements recent developments of the adiabatic projection method for lattice calculations of nuclear reactions.
Effective Gravitational Theories in String Theory and the AdS/CFT Correspondence
DEFF Research Database (Denmark)
Pedersen, Andreas Vigand
We consider various aspects of effective gravitational theories, including supergravity, within the framework of the blackfold approach. The thesis is naturally split into three parts. In the first part of the thesis, we explore the blackfold approach and explain how it is possible to write down......, in the third part of the thesis, we switch focus and consider long-wavelength perturbations of charged black branes. More specically, we consider hydrodynamic uctuations of the black p-brane solution of Einstein/Maxwell gravity in D = p + n + 3 dimensions. We extract the first order dissipative transport...
The effective field theory of cosmological large scale structures
Energy Technology Data Exchange (ETDEWEB)
Carrasco, John Joseph M. [Stanford Univ., Stanford, CA (United States); Hertzberg, Mark P. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Senatore, Leonardo [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
2012-09-20
Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c^{2}_{s} ≈ 10^{–6}c^{2} and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)^{4}. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc^{–1}.
The effective field theory of dark matter direct detection
Energy Technology Data Exchange (ETDEWEB)
Fitzpatrick, A. Liam; Haxton, Wick; Katz, Emanuel; Lubbers, Nicholas; Xu, Yiming
2013-02-01
We extend and explore the general non-relativistic effective theory of dark matter (DM) direct detection. We describe the basic non-relativistic building blocks of operators and discuss their symmetry properties, writing down all Galilean-invariant operators up to quadratic order in momentum transfer arising from exchange of particles of spin 1 or less. Any DM particle theory can be translated into the coefficients of an effective operator and any effective operator can be simply related to most general description of the nuclear response. We find several operators which lead to novel nuclear responses. These responses differ significantly from the standard minimal WIMP cases in their relative coupling strengths to various elements, changing how the results from different experiments should be compared against each other. Response functions are evaluated for common DM targets — F, Na, Ge, I, and Xe — using standard shell model techniques. We point out that each of the nuclear responses is familiar from past studies of semi-leptonic electroweak interactions, and thus potentially testable in weak interaction studies. We provide tables of the full set of required matrix elements at finite momentum transfer for a range of common elements, making a careful and fully model-independent analysis possible. Finally, we discuss embedding non-relativistic effective theory operators into UV models of dark matter.
Special theory of relativity through the Doppler effect
Energy Technology Data Exchange (ETDEWEB)
Moriconi, M [Departamento de Fisica, Universidade Federal Fluminense, Av. Litoranea s/n, Boa Viagem-CEP 24210-340, Niteroi, Rio de Janeiro (Brazil)
2006-11-01
We present the special theory of relativity taking the Doppler effect as the starting point, and derive several of its main effects, such as time dilation, length contraction, addition of velocities and the mass-energy relation, and assuming energy and momentum conservation, we discuss how to introduce the 4-momentum in a natural way. We also use the Doppler effect to explain the 'twin paradox', and its version on a cylinder. As a by-product we discuss Bell's spaceship paradox, and the Lorentz transformation for arbitrary velocities in one dimension.
DsixTools: the standard model effective field theory toolkit
Energy Technology Data Exchange (ETDEWEB)
Celis, Alejandro [Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Arnold Sommerfeld Center for Theoretical Physics, Munich (Germany); Fuentes-Martin, Javier; Vicente, Avelino [Universitat de Valencia-CSIC, Instituto de Fisica Corpuscular, Valencia (Spain); Virto, Javier [University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland)
2017-06-15
We present DsixTools, a Mathematica package for the handling of the dimension-six standard model effective field theory. Among other features, DsixTools allows the user to perform the full one-loop renormalization group evolution of the Wilson coefficients in the Warsaw basis. This is achieved thanks to the SMEFTrunner module, which implements the full one-loop anomalous dimension matrix previously derived in the literature. In addition, DsixTools also contains modules devoted to the matching to the ΔB = ΔS = 1, 2 and ΔB = ΔC = 1 operators of the Weak Effective Theory at the electroweak scale, and their QCD and QED Renormalization group evolution below the electroweak scale. (orig.)
Hadronic parity violation in pionless effective field theory
Energy Technology Data Exchange (ETDEWEB)
Schindler, Matthias R., E-mail: schindle@gwu.edu [George Washington University, Department of Physics (United States)
2011-11-15
We present results for two-body observables that are sensitive to the parity-violating component of nucleon-nucleon interactions. These interactions are studied using an effective field theory in which the only dynamic degrees of freedom are nucleon fields. The observables we study are cross-section asymmetries in nucleon-nucleon scattering and asymmetries and induced polarizations in the process np{yields}d{gamma}.
Born-Oppenheimer approximation in an effective field theory language
Brambilla, Nora; Krein, Gastão; Tarrús Castellà, Jaume; Vairo, Antonio
2018-01-01
The Born-Oppenheimer approximation is the standard tool for the study of molecular systems. It is founded on the observation that the energy scale of the electron dynamics in a molecule is larger than that of the nuclei. A very similar physical picture can be used to describe QCD states containing heavy quarks as well as light-quarks or gluonic excitations. In this work, we derive the Born-Oppenheimer approximation for QED molecular systems in an effective field theory framework by sequentially integrating out degrees of freedom living at energies above the typical energy scale where the dynamics of the heavy degrees of freedom occurs. In particular, we compute the matching coefficients of the effective field theory for the case of the H2+ diatomic molecule that are relevant to compute its spectrum up to O (m α5). Ultrasoft photon loops contribute at this order, being ultimately responsible for the molecular Lamb shift. In the effective field theory the scaling of all the operators is homogeneous, which facilitates the determination of all the relevant contributions, an observation that may become useful for high-precision calculations. Using the above case as a guidance, we construct under some conditions an effective field theory for QCD states formed by a color-octet heavy quark-antiquark pair bound with a color-octet light-quark pair or excited gluonic state, highlighting the similarities and differences between the QED and QCD systems. Assuming that the multipole expansion is applicable, we construct the heavy-quark potential up to next-to-leading order in the multipole expansion in terms of nonperturbative matching coefficients to be obtained from lattice QCD.
Effective binary theory of multi-component nucleation
Energy Technology Data Exchange (ETDEWEB)
Kalikmanov, V. I., E-mail: Vitaly.Kalikmanov@twisterbv.com [Twister Supersonic Gas Solutions, Einsteinlaan 20, 2289 CC Rijswijk, Netherlands and Department of Geoscience and Engineering, Delft University of Technology, Stevinweg 1, 2628 CN Delft (Netherlands)
2015-03-28
Classical theory of multi-component nucleation [O. Hirschfelder, J. Chem. Phys. 61, 2690 (1974)] belongs to the class of the so-called intractable problems: it requires computational time which is an exponential function of the number of components N. For a number of systems of practical interest with N > 10, the brute-force use of the classical theory becomes virtually impossible and one has to resort to an effective medium approach. We present an effective binary model which captures important physics of multi-component nucleation. The distinction between two effective species is based on the observation that while all N components contribute to the cluster thermodynamic properties, there is only a part of them which trigger the nucleation process. The proposed 2D-theory takes into account adsorption by means of the Gibbs dividing surface formalism and uses statistical mechanical considerations for the treatment of small clusters. Theoretical predictions for binary-, ternary-, and 14-component mixtures are compared with available experimental data and other models.
A referential theory of the repetition-induced truth effect.
Unkelbach, Christian; Rom, Sarah C
2017-03-01
People are more likely to judge repeated statements as true compared to new statements, a phenomenon known as the illusory truth effect. The currently dominant explanation is an increase in processing fluency caused by prior presentation. We present a new theory to explain this effect. We assume that people judge truth based on coherent references for statements in memory. Due to prior presentation, repeated statements have more coherently linked references; thus, a repetition-induced truth effect follows. Five experiments test this theory. Experiment 1-3 show that both the amount and the coherence of references for a repeated statement influence judged truth. Experiment 4 shows that people also judge new statements more likely "true" when they share references with previously presented statements. Experiment 5 realizes theoretically predicted conditions under which repetition should not influence judged truth. Based on these data, we discuss how the theory relates to other explanations of repetition-induced truth and how it may integrate other truth-related phenomena and belief biases. Copyright © 2016 Elsevier B.V. All rights reserved.
Effective field theories for van der Waals interactions
Brambilla, Nora; Shtabovenko, Vladyslav; Tarrús Castellà, Jaume; Vairo, Antonio
2017-06-01
Van der Waals interactions between two neutral but polarizable systems at a separation R much larger than the typical size of the systems are at the core of a broad sweep of contemporary problems in settings ranging from atomic, molecular and condensed matter physics to strong interactions and gravity. In this paper, we reexamine the dispersive van der Waals interactions between two hydrogen atoms. The novelty of the analysis resides in the usage of nonrelativistic effective field theories of quantum electrodynamics. In this framework, the van der Waals potential acquires the meaning of a matching coefficient in an effective field theory, dubbed van der Waals effective field theory, suited to describe the low-energy dynamics of an atom pair. It may be computed systematically as a series in R times some typical atomic scale and in the fine-structure constant α . The van der Waals potential gets short-range contributions and radiative corrections, which we compute in dimensional regularization and renormalize here for the first time. Results are given in d space-time dimensions. One can distinguish among different regimes depending on the relative size between 1 /R and the typical atomic bound-state energy, which is of order m α2. Each regime is characterized by a specific hierarchy of scales and a corresponding tower of effective field theories. The short-distance regime is characterized by 1 /R ≫m α2 and the leading-order van der Waals potential is the London potential. We also compute next-to-next-to-next-to-leading-order corrections. In the long-distance regime we have 1 /R ≪m α2. In this regime, the van der Waals potential contains contact terms, which are parametrically larger than the Casimir-Polder potential that describes the potential at large distances. In the effective field theory, the Casimir-Polder potential counts as a next-to-next-to-next-to-leading-order effect. In the intermediate-distance regime, 1 /R ˜m α2, a significantly more complex
Viscosity and dissipative hydrodynamics from effective field theory
Grozdanov, Sašo; Polonyi, Janos
2015-05-01
With the goal of deriving dissipative hydrodynamics from an action, we study classical actions for open systems, which follow from the generic structure of effective actions in the Schwinger-Keldysh closed-time-path (CTP) formalism with two time axes and a doubling of degrees of freedom. The central structural feature of such effective actions is the coupling between degrees of freedom on the two time axes. This reflects the fact that from an effective field theory point of view, dissipation is the loss of energy of the low-energy hydrodynamical degrees of freedom to the integrated-out, UV degrees of freedom of the environment. The dynamics of only the hydrodynamical modes may therefore not possess a conserved stress-energy tensor. After a general discussion of the CTP effective actions, we use the variational principle to derive the energy-momentum balance equation for a dissipative fluid from an effective Goldstone action of the long-range hydrodynamical modes. Despite the absence of conserved energy and momentum, we show that we can construct the first-order dissipative stress-energy tensor and derive the Navier-Stokes equations near hydrodynamical equilibrium. The shear viscosity is shown to vanish in the classical theory under consideration, while the bulk viscosity is determined by the form of the effective action. We also discuss the thermodynamics of the system and analyze the entropy production.
Equivalent Theory and Retrieval of Effective Metamaterials Parameters
Feng, Simin
2010-01-01
Currently widely used retrieval method often suffers from unreal resonant-antiresonant coupling in extracted permittivity and permeability of metamaterals; and the retrieved material parameters are length-dependent. Here, we apply equivalent theory to discuss a general unit-cell design criterion for length-independent retrieval of effective metamaterial parameters from a single layer of unit cells. We introduce a graphical method which directly retrieves the effective ordinary and extraordinary permittivities and permeabilities without computing refractive index and impedance as middle steps. Our method resolves the longstanding resonant-antiresonant mystery.
Purposeful Program Theory: Effective Use of Theories of Change and Logic Models
Funnell, Sue C.; Rogers, Patricia J.
2011-01-01
Between good intentions and great results lies a program theory--not just a list of tasks but a vision of what needs to happen, and how. Now widely used in government and not-for-profit organizations, program theory provides a coherent picture of how change occurs and how to improve performance. "Purposeful Program Theory" shows how to develop,…
Perturbation theory and nonperturbative effects: A happy marriage ?
Chýla, J.
1992-03-01
Perturbation expansions in renormalized quantum field theories are reformulated in a way that permits a straightforward handling of situations when in the conventional approach, i.e. in fixed renormalization scheme, these expansions are factorially divergent and even of asymptotically constant sign. The result takes the form of convergent (under certain circumstances) expansions in a set of functions Z k(a, χ) of the couplant and the free parameter χ which specifies the procedure involved. The value of χ is shown to be correlated to the basic properties of nonperturbative effects as embodied in power corrections. Close connection of this procedure to Borel summation technique is demonstrated and its relation to conventional perturbation theory in fixed renormalization schemes elucidated.
Inclusion of Dispersion Effects in Density Functional Theory
DEFF Research Database (Denmark)
Møgelhøj, Andreas
on fitting to high-level ab initio and experimental results. The fitting scheme, based on Baysian theory, focuses on the three aspects: a) model space, b) datasets, and c) model selection. The model space consists of a flexible expansion of the exchange enhancement factor in the generalized gradient...... approximation plus local density approximation, and the non-local Rutgers-Chalmers correlations. The datasets are chosen to represent gas phase chemistry, surface chemistry, solid state physics, and non-covalently bound systems in order to produce a generally applicable functional that is particularly useful......In this thesis, applications and development will be presented within the field of van der Waals interactions in density functional theory. The thesis is based on the three projects: i) van der Waals interactions effect on the structure of liquid water at ambient conditions, ii) development...
Chiral effective theory with a light scalar and lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Soto, J., E-mail: joan.soto@ub.edu [Departament d' Estructura i Constituents de la Materia, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia (Spain); Institut de Ciencies del Cosmos, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia (Spain); Talavera, P., E-mail: pere.talavera@icc.ub.edu [Institut de Ciencies del Cosmos, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia (Spain); Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Comte Urgell 187, E-08036 Barcelona (Spain); Tarrus, J., E-mail: tarrus@ecm.ub.es [Departament d' Estructura i Constituents de la Materia, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia (Spain); Institut de Ciencies del Cosmos, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia (Spain)
2013-01-21
We extend the usual chiral perturbation theory framework ({chi}PT) to allow the inclusion of a light dynamical isosinglet scalar. Using lattice QCD results, and a few phenomenological inputs, we explore the parameter space of the effective theory. We discuss the S-wave pion-pion scattering lengths, extract the average value of the two light quark masses and evaluate the impact of the dynamical singlet field in the low-energy constants l{sup Macron }{sub 1}, l{sup Macron }{sub 3} and l{sup Macron }{sub 4} of {chi}PT. We also show how to extract the mass and width of the sigma resonance from chiral extrapolations of lattice QCD data.
Perturbation theory of nuclear matter with a microscopic effective interaction
Benhar, Omar; Lovato, Alessandro
2017-11-01
An updated and improved version of the effective interaction based on the Argonne-Urbana nuclear Hamiltonian, derived using the formalism of correlated basis functions and the cluster expansion technique, is employed to obtain a number of properties of cold nuclear matter at arbitrary neutron excess within the formalism of many-body perturbation theory. The numerical results, including the ground-state energy per nucleon, the symmetry energy, the pressure, the compressibility, and the single-particle spectrum, are discussed in the context of the available empirical information, obtained from measured nuclear properties and heavy-ion collisions.
Effective Field Theory and the Gamow Shell Model
Rotureau, J.; van Kolck, U.
2013-01-01
We combine Halo/Cluster Effective Field Theory (H/CEFT) and the Gamow Shell Model (GSM) to describe the $0^+$ ground state of $\\rm{^6He}$ as a three-body halo system. We use two-body interactions for the neutron-alpha particle and two-neutron pairs obtained from H/CEFT at leading order, with parameters determined from scattering in the p$_{3/2}$ and s$_0$ channels, respectively. The three-body dynamics of the system is solved using the GSM formalism, where the continuum states are incorporate...
The effective field theory of nonsingular cosmology: II
Cai, Yong; Li, Hai-Guang; Qiu, Taotao; Piao, Yun-Song
2017-06-01
Based on the effective field theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT operators that are capable to avoid instabilities in nonsingular cosmologies, we construct a nonsingular model dubbed the Genesis-inflation model, in which a slowly expanding phase (namely, Genesis) with increasing energy density is followed by slow-roll inflation. The spectrum of the primordial perturbation may be simulated numerically, which shows itself a large-scale cutoff, as the large-scale anomalies in CMB might be a hint for.
The effective field theory of nonsingular cosmology: II
Energy Technology Data Exchange (ETDEWEB)
Cai, Yong; Li, Hai-Guang [University of Chinese Academy of Sciences, School of Physics, Beijing (China); Qiu, Taotao [Central China Normal University, Institute of Astrophysics, Wuhan (China); Piao, Yun-Song [University of Chinese Academy of Sciences, School of Physics, Beijing (China); Chinese Academy of Sciences, Institute of Theoretical Physics, P.O. Box 2735, Beijing (China)
2017-06-15
Based on the effective field theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT operators that are capable to avoid instabilities in nonsingular cosmologies, we construct a nonsingular model dubbed the Genesis-inflation model, in which a slowly expanding phase (namely, Genesis) with increasing energy density is followed by slow-roll inflation. The spectrum of the primordial perturbation may be simulated numerically, which shows itself a large-scale cutoff, as the large-scale anomalies in CMB might be a hint for. (orig.)
Perturbative Pions in Effective Field Theory for Nucleon Interactions
Mehen, Thomas
2001-12-01
I discuss pions in effective field theory (EFT) for the nucleon interaction within the power counting scheme proposed by Kaplan-Savage-Wise (KSW). After explaining why KSW power counting demands perturbative treatment of pions, I present results of next-to-next-to-leading order (NNLO) calculations of nucleon-nucleon scattering in S-,P-, and D-wave channels. Perturbative treatment of pions fails in spin-triplet channels. The origin of large perturbative corrections is the piece of the spin-tensor force which survives in the chiral limit.
Nuclear surface properties in relativistic effective field theory
Energy Technology Data Exchange (ETDEWEB)
Del Estal, M.; Centelles, M.; Vinas, X
1999-04-26
We perform Hartree calculations of symmetric and asymmetric semi-infinite nuclear matter in the framework of relativistic models based on effective hadronic field theories as recently proposed in the literature. In addition to the conventional cubic and quartic scalar self-interactions, the extended models incorporate a quartic vector self-interaction, scalar-vector non-linearities and tensor couplings of the vector mesons. We investigate the implications of these terms on nuclear surface properties such as the surface energy coefficient, surface thickness, surface stiffness coefficient, neutron skin thickness and the spin-orbit force.
Effective theory of black holes in the 1/D expansion
Energy Technology Data Exchange (ETDEWEB)
Emparan, Roberto [Institució Catalana de Recerca i Estudis Avançats (ICREA),Passeig Lluís Companys 23, E-08010 Barcelona (Spain); Departament de Física Fonamental, Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona (Spain); Shiromizu, Tetsuya [Department of Mathematics, Nagoya University,Nagoya 464-8602 (Japan); Kobayashi-Maskawa Institute, Nagoya University,Nagoya 464-8602 (Japan); Suzuki, Ryotaku [Department of Physics, Osaka City University,Osaka 558-8585 (Japan); Tanabe, Kentaro [Theory Center, Institute of Particles and Nuclear Studies, KEK,Tsukuba, Ibaraki, 305-0801 (Japan); Tanaka, Takahiro [Department of Physics, Kyoto University,Kyoto, 606-8502 (Japan); Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto, 606-8502 (Japan)
2015-06-23
The gravitational field of a black hole is strongly localized near its horizon when the number of dimensions D is very large. In this limit, we can effectively replace the black hole with a surface in a background geometry (e.g. Minkowski or Anti-deSitter space). The Einstein equations determine the effective equations that this ‘black hole surface’ (or membrane) must satisfy. We obtain them up to next-to-leading order in 1/D for static black holes of the Einstein-(A)dS theory. To leading order, and also to next order in Minkowski backgrounds, the equations of the effective theory are the same as soap-film equations, possibly up to a redshift factor. In particular, the Schwarzschild black hole is recovered as a spherical soap bubble. Less trivially, we find solutions for ‘black droplets’, i.e. black holes localized at the boundary of AdS, and for non-uniform black strings.
Universal dimer–dimer scattering in lattice effective field theory
Directory of Open Access Journals (Sweden)
Serdar Elhatisari
2017-05-01
Full Text Available We consider two-component fermions with short-range interactions and large scattering length. This system has universal properties that are realized in several different fields of physics. In the limit of large fermion–fermion scattering length aff and zero-range interaction, all properties of the system scale proportionally with aff. For the case with shallow bound dimers, we calculate the dimer–dimer scattering phase shifts using lattice effective field theory. We extract the universal dimer–dimer scattering length add/aff=0.618(30 and effective range rdd/aff=−0.431(48. This result for the effective range is the first calculation with quantified and controlled systematic errors. We also benchmark our methods by computing the fermion–dimer scattering parameters and testing some predictions of conformal scaling of irrelevant operators near the unitarity limit.
Lattice effective field theory for medium-mass nuclei
Energy Technology Data Exchange (ETDEWEB)
Lähde, Timo A., E-mail: t.laehde@fz-juelich.de [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Epelbaum, Evgeny; Krebs, Hermann [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44870 Bochum (Germany); Lee, Dean [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Meißner, Ulf-G. [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn (Germany); JARA – High Performance Computing, Forschungszentrum Jülich, D-52425 Jülich (Germany); Rupak, Gautam [Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS 39762 (United States)
2014-05-01
We extend Nuclear Lattice Effective Field Theory (NLEFT) to medium-mass nuclei, and present results for the ground states of alpha nuclei from {sup 4}He to {sup 28}Si, calculated up to next-to-next-to-leading order (NNLO) in the EFT expansion. This computational advance is made possible by extrapolations of lattice data using multiple initial and final states. For our soft two-nucleon interaction, we find that the overall contribution from multi-nucleon forces must change sign from attractive to repulsive with increasing nucleon number. This effect is not produced by three-nucleon forces at NNLO, but it can be approximated by an effective four-nucleon interaction. We discuss the convergence of the EFT expansion and the broad significance of our findings for future ab initio calculations.
The scharnhorst effect: Superluminality and causality in effective field theories
de Clark, Sybil Gertrude
We present two re-derivations of the Scharnhorst effect. The latter was first obtained in 1990 by Klaus Scharnhorst, soon followed by Gabriel Barton, and consists in the theoretical prediction that the phase velocity of photons propagating in a Casimir vacuum normal to the plates would be larger than c. (Abstract shortened by ProQuest.).
Energy Technology Data Exchange (ETDEWEB)
Gruemmer, Frank; Speth, Josef [Institut fuer Kernphysik (Theorie) FZ-Juelich, D52425 Juelich (Germany)
2006-07-15
We review Migdal's theory of finite Fermi systems and its application to the structure of nuclei. The theory is an extension of Landau's theory of interacting Fermi systems. In the first part the basic formulae are derived within the many-body Green functions approach. The theory is applied to isovector electric giant resonances in medium and heavy mass nuclei. The parameterizations of the renormalized effective ph-interaction and the effective operators are discussed. It is shown that the number of free parameters is restricted by conservation laws. We also present an extension of Migdal's theory, where the low-lying phonons are considered in a consistent manner. The extended theory is again applied to the same isovector electric giant resonances and to the analysis of ({alpha}, {alpha}') reaction data. We point out that the extended theory is the appropriate framework for self-consistent nuclear structure calculations starting from effective Lagrangians and Hamiltonians. (topical review)
Toward a general theory of momentum-like effects.
Hubbard, Timothy L
2017-08-01
The future actions, behaviors, and outcomes of objects, individuals, and processes can often be anticipated, and some of these anticipations have been hypothesized to result from momentum-like effects. Five types of momentum-like effects (representational momentum, operational momentum, attentional momentum, behavioral momentum, psychological momentum) are briefly described. Potential similarities involving properties of momentum-like effects (continuation, coherence, role of chance or guessing, role of sensory processing, imperviousness to practice or error feedback, shifts in memory for position, effects of changes in velocity, rapid occurrence, effects of retention interval, attachment to an object rather than an abstract frame of reference, nonrigid transformation) are described, and potential constraints on a future theory of momentum-like effects (dynamic representation, nature of extrapolation, sensitivity to environmental contingencies, bridging gaps between stimulus and response, increasing adaptiveness to the environment, serving as a heuristic for perception and action, insensitivity to stimulus format, importance of subjective consequences, role of knowledge and belief, automaticity of occurrence, properties of functional architecture) are discussed. The similarity and ubiquity of momentum-like effects suggests such effects might result from a single or small number of mechanisms that operate over different dimensions, modalities, and time-scales and provide a fundamental adaptation for perception and action. Copyright © 2017. Published by Elsevier B.V.
Quantum Monte Carlo calculations with chiral effective field theory interactions
Energy Technology Data Exchange (ETDEWEB)
Tews, Ingo
2015-10-12
The neutron-matter equation of state connects several physical systems over a wide density range, from cold atomic gases in the unitary limit at low densities, to neutron-rich nuclei at intermediate densities, up to neutron stars which reach supranuclear densities in their core. An accurate description of the neutron-matter equation of state is therefore crucial to describe these systems. To calculate the neutron-matter equation of state reliably, precise many-body methods in combination with a systematic theory for nuclear forces are needed. Chiral effective field theory (EFT) is such a theory. It provides a systematic framework for the description of low-energy hadronic interactions and enables calculations with controlled theoretical uncertainties. Chiral EFT makes use of a momentum-space expansion of nuclear forces based on the symmetries of Quantum Chromodynamics, which is the fundamental theory of strong interactions. In chiral EFT, the description of nuclear forces can be systematically improved by going to higher orders in the chiral expansion. On the other hand, continuum Quantum Monte Carlo (QMC) methods are among the most precise many-body methods available to study strongly interacting systems at finite densities. They treat the Schroedinger equation as a diffusion equation in imaginary time and project out the ground-state wave function of the system starting from a trial wave function by propagating the system in imaginary time. To perform this propagation, continuum QMC methods require as input local interactions. However, chiral EFT, which is naturally formulated in momentum space, contains several sources of nonlocality. In this Thesis, we show how to construct local chiral two-nucleon (NN) and three-nucleon (3N) interactions and discuss results of first QMC calculations for pure neutron systems. We have performed systematic auxiliary-field diffusion Monte Carlo (AFDMC) calculations for neutron matter using local chiral NN interactions. By
Minimal flavour violation an effective field theory approach
D'Ambrosio, G.; Isidori, G.; Strumia, A.
2002-01-01
We present a general analysis of extensions of the Standard Model which satisfy the criterion of Minimal Flavour Violation (MFV). We define this general framework by constructing a low-energy effective theory containing the Standard Model fields, with one or two Higgs doublets and, as the only source of SU(3)^5 flavour symmetry breaking, the background values of fields transforming under the flavour group as the ordinary Yukawa couplings. We analyse present bounds on the effective scale of dimension-six operators, which range between 1 and 10 TeV, with the most stringent constraints imposed by B -> X_s gamma. In this class of theories, it is possible to relate predictions for FCNC processes in B physics to those in K physics. We compare the sensitivity of various experimental searches in probing the hypothesis of MFV. Within the two-Higgs-doublet scenario, we develop a general procedure to obtain all tan(beta)-enhanced Higgs-mediated FCNC amplitudes, discussing in particular their impact in B -> l^+l^-, Delta...
The Last Gasp of Dark Matter Effective Theory
Bruggisser, Sebastian; Urbano, Alfredo
2016-01-01
We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.
Vortex precession in trapped superfluids from effective field theory
Esposito, Angelo; Krichevsky, Rafael; Nicolis, Alberto
2017-09-01
We apply a recently developed effective string theory for vortex lines to the case of two-dimensional trapped superfluids. We do not assume a perturbative microscopic description for the superfluid, but only a gradient expansion for the long-distance hydrodynamical description and for the trapping potential. For any regular trapping potential, we compute the spatial dependence of the superfluid density and the orbital frequency and trajectory of an off-center vortex. Our results are fully relativistic and in the nonrelativistic limit reduce to known results based on the Gross-Pitaevskii model. In our formalism, the leading effect in the nonrelativistic limit arises from two simple Feynman diagrams in which the vortex interacts with the trapping potential through the exchange of hydrodynamical modes.
Radiative capture reactions in lattice effective field theory.
Rupak, Gautam; Lee, Dean
2013-07-19
We outline a general method for computing nuclear capture reactions on the lattice. The method consists of two major parts. In this study we detail the second part which consists of calculating an effective two-body capture reaction on the lattice at finite volume. We solve this problem by calculating the two-point Green's function using an infrared regulator and the capture amplitude to a two-body bound state. We demonstrate the details of this method by calculating on the lattice the leading M1 contribution to the radiative neutron capture on proton at low energies using pionless effective field theory. We find good agreement with exact continuum results. The approach we outline here can be used in a wide range of applications including few-body reactions in cold atomic systems and hadronic reactions in lattice quantum chromodynamics.
FCNC Effects in a Minimal Theory of Fermion Masses
Buras, Andrzej J; Pokorski, Stefan; Ziegler, Robert
2011-01-01
As a minimal theory of fermion masses we extend the SM by heavy vectorlike fermions, with flavor-anarchical Yukawa couplings, that mix with chiral fermions such that small SM Yukawa couplings arise from small mixing angles. This model can be regarded as an effective description of the fermionic sector of a large class of existing flavor models and thus might serve as a useful reference frame for a further understanding of flavor hierarchies in the SM. Already such a minimal framework gives rise to FCNC effects through exchange of massive SM bosons whose couplings to the light fermions get modified by the mixing. We derive general formulae for these corrections and discuss the bounds on the heavy fermion masses. Particularly stringent bounds, in a few TeV range, come from the corrections to the Z couplings.
Effective field theory and unitarity in vector boson scattering
Energy Technology Data Exchange (ETDEWEB)
Sekulla, Marco [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany); Kilian, Wolfgang [Siegen Univ. (Germany); Ohl, Thorsten [Wuerzburg Univ. (Germany); Reuter, Juergen [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group
2016-10-15
Weak vector boson scattering at high energies will be one of the key measurements in current and upcoming LHC runs. It is most sensitive to any new physics associated with electroweak symmetry breaking. However, a conventional EFT analysis will fail at high energies. To address this problem, we present a parameter-free prescription valid for arbitrary perturbative and non-perturbative models: the T-matrix unitarization. We describe its implementation as an asymptotically consistent reference model matched to the low-energy effective theory. We show examples of typical observables of vector-boson scattering at the LHC in our unitarized framework. For many strongly-coupled models like composite Higgs models, dimension-8 operators might be actually the leading operators. In addition to those longitudinal and transversal dimension eight EFT operators, the effects of generic tensor and scalar resonances within simplified models are considered.
The last gasp of dark matter effective theory
Energy Technology Data Exchange (ETDEWEB)
Bruggisser, Sebastian [DESY,Notkestrasse 85, D-22607 Hamburg (Germany); Riva, Francesco; Urbano, Alfredo [CERN, Theoretical Physics Department,Geneva (Switzerland)
2016-11-10
We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.
The last gasp of Dark Matter effective theory
Energy Technology Data Exchange (ETDEWEB)
Bruggisser, Sebastian [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Riva, Francesco; Urbano, Alfredo [CERN, Geneva (Switzerland). Theoretical Physics Dept.
2016-07-15
We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.
Directory of Open Access Journals (Sweden)
Jeffrey S. Harrison
2015-09-01
Full Text Available Objective – This article provides a brief overview of stakeholder theory, clears up some widely held misconceptions, explains the importance of examining stakeholder theory from a variety of international perspectives and how this type of research will advance management theory, and introduces the other articles in the special issue. Design/methodology/approach – Some of the foundational ideas of stakeholder theory are discussed, leading to arguments about the importance of the theory to management research, especially in an international context. Findings – Stakeholder theory is found to be a particularly useful perspective for addressing some of the important issues in business from an international perspective. It offers an opportunity to reinterpret a variety of concepts, models and phenomena across may different disciplines. Practical implications – The concepts explored in this article may be applied in many contexts, domestically and internationally, and across business disciplines as diverse as economics, public administration, finance, philosophy, marketing, law, and management. Originality/value – Research on stakeholder theory in an international context is both lacking and sorely needed. This article and the others in this special issue aim to help fill that void.
Khakzad Rostami, N.; Landucci, G; Reniers, G.L.L.M.E.
2016-01-01
In the present study, we have introduced a methodology based on graph theory and multicriteria decision analysis for cost-effective fire protection of chemical plants subject to fire-induced domino effects. By modeling domino effects in chemical plants as a directed graph, the graph centrality
Electron scattering from neon via effective range theory
Energy Technology Data Exchange (ETDEWEB)
Fedus, Kamil, E-mail: kamil@fizyka.umk.pl [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun (Poland)
2014-07-01
Elastic cross-sections for electron scattering on neon from 0 energy up to 16 eV are analyzed by an analytical approach to the modified effective range theory (MERT). It is shown that energy and angular variations of elastic differential, integral and momentum transfer cross sections can be accurately parameterized by six MERT coefficients up to the energy threshold for the first Feshbach resonance. MERT parameters are determined empirically by numerical comparison with large collection of available experimental data of elastic total (integral) cross-sections. The present analysis is validated against numerous electron beams and swarm experiments. The comparison of derived MERT parameters with those found for other noble gases, helium, argon and krypton, is done. The derived scattering length (for the s-partial wave) in neon, 0.227a0, agrees well with recent theories; it is small but, differently from Ar and Kr, still positive. Analogue parameters for the p-wave and the d-wave are negative and positive respectively for all the four gases compared. (author)
Applications of Effective Field Theory Techniques to Jet Physics
Freedman, Simon M.
In this thesis we study jet production at large energies from leptonic collisions. We use the framework of effective theories of Quantum Chromodynamics (QCD) to examine the properties of jets and systematically improve calculations. We first develop a new formulation of soft-collinear effective theory (SCET), the appropriate effective theory for jets. In this formulation, soft and collinear degrees of freedom are described using QCD fields that interact with each other through light-like Wilson lines in external currents. This formulation gives a more intuitive picture of jet processes than the traditional formulation of SCET. In particular, we show how the decoupling of soft and collinear degrees of freedom that occurs at leading order in power counting is explicit to next-to-leading order and likely beyond. We then use this formulation to write the thrust rate in a factorized form at next-to-leading order in the thrust parameter. The rate involves an incomplete sum over final states due to phase space cuts that is enforced by a measurement operator. Subleading corrections require matching onto not only the next-to-next-to leading order SCET operators, but also matching onto subleading measurement operators. We derive the appropriate hard, jet, and soft functions and show they reproduce the expected subleading thrust rate. Next, we renormalize the next-to-leading order dijet operators used for the subleading thrust rate. Constraints on matching coefficients from current conservation and reparametrization invariance are shown. We also discuss the subtleties involved in regulating the infrared divergences of the individual loop diagrams in order to extract the ultraviolet divergences. The results can be used to increase the theoretical precision of the thrust rate. Finally, we study the (exclusive) k⊥ and C/A jet algorithms in SCET. Regularizing the virtualities and rapidities of the individual graphs, we are able to write the O(alpha s) dijet cross section as the
National Research Council Canada - National Science Library
Weiner, Bryan J; Lewis, Megan A; Linnan, Laura A
.... However, no integrated theory of implementation has emerged from this research. This article describes a theory of the organizational determinants of effective implementation of comprehensive worksite health promotion programs...
Dark matter effective field theory scattering in direct detection experiments
Energy Technology Data Exchange (ETDEWEB)
Schneck, K.; Cabrera, B.; Cerdeno, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, Priscilla B.; Daal, M.; Di Stefano, P. C.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, Jeter C.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, W.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.
2015-05-01
We examine the consequences of the effective eld theory (EFT) of dark matter-nucleon scattering or current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral di*erences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.
Dark matter effective field theory scattering in direct detection experiments
Energy Technology Data Exchange (ETDEWEB)
Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.
2015-05-18
We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. Here. we demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. In conclusion, we discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.
Nuclear Parity-Violation in Effective Field Theory
Energy Technology Data Exchange (ETDEWEB)
Shi-Lin Zhu; C.M. Maekawa; B.R. Holstein; M.J. Ramsey-Musolf; U van Kolck
2005-02-21
We reformulate the analysis of nuclear parity-violation (PV) within the framework of effective field theory (EFT). To order Q, the PV nucleon-nucleon (NN) interaction depends on five a priori unknown constants that parameterize the leading-order, short-range four-nucleon operators. When pions are included as explicit degrees of freedom, the potential contains additional medium- and long-range components parameterized by PV piNN couplings. We derive the form of the corresponding one- and two-pion-exchange potentials. We apply these considerations to a set of existing and prospective PV few-body measurements that may be used to determine the five independent low-energy constants relevant to the pionless EFT and the additional constants associated with dynamical pions. We also discuss the relationship between the conventional meson-exchange framework and the EFT formulation, and argue that the latter provides a more general and systematic basis for analyzing nuclear PV.
Dark matter effective field theory scattering in direct detection experiments
Energy Technology Data Exchange (ETDEWEB)
Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.
2015-05-18
We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.
Dynamical 3-Space Gravity Theory: Effects on Polytropic Solar Models
Directory of Open Access Journals (Sweden)
May R. D.
2011-01-01
Full Text Available Numerous experiments and observations have confirmed the existence of a dynamical 3-space, detectable directly by light-speed anisotropy experiments, and indirectly by means of novel gravitational effects, such as bore hole g anomalies, predictable black hole masses, flat spiral-galaxy rotation curves, and the expansion of the universe, all without dark matter and dark energy. The dynamics for this 3-space follows from a unique generalisation of Newtonian gravity, once that is cast into a velocity formalism. This new theory of gravity is applied to the solar model of the sun to compute new density, pressure and temperature profiles, using polytrope modelling of the equation of state for the matter. These results should be applied to a re-analysis of solar neutrino production, and to stellar evolution in general.
Dynamical 3-Space Gravity Theory: Effects on Polytropic Solar Models
Directory of Open Access Journals (Sweden)
Cahill R. T.
2011-01-01
Full Text Available Numerous experiments and observations have confirmed the existence of a dynamical 3-space, detectable directly by light-speed anisotropy experiments, and indirectly by means of novel gravitational effects, such as bore hole g-anomalies, predictable black hole masses, flat spiral-galaxy rotation curves, and the expansion of the universe, all without dark matter and dark energy. The dynamics for this 3-space follows from a unique generalisation of Newtonian gravity, once that is cast into a velocity formalism. This new theory of gravity is applied to the solar model of the sun to compute new density, pressure and temperature profiles, using polytrope modelling of the equation of state for the matter. These results should be applied to a re-analysis of solar neutrino production, and to stellar evolution in general.
Effective gravitational couplings for cosmological perturbations in generalized Proca theories
De Felice, Antonio; Kase, Ryotaro; Mukohyama, Shinji; Tsujikawa, Shinji; Zhang, Ying-li
2016-01-01
We consider the finite interactions of the generalized Proca theory including the sixth-order Lagrangian and derive the full linear perturbation equations of motion on the flat Friedmann-Lema\\^{i}tre-Robertson-Walker background in the presence of a matter perfect fluid. By construction, the propagating degrees of freedom (besides the matter perfect fluid) are two transverse vector perturbations, one longitudinal scalar, and two tensor polarizations. The Lagrangians associated with intrinsic vector modes neither affect the background equations of motion nor the second-order action of tensor perturbations, but they do give rise to non-trivial modifications to the no-ghost condition of vector perturbations and to the propagation speeds of vector and scalar perturbations. We derive the effective gravitational coupling $G_{\\rm eff}$ with matter density perturbations under a quasi-static approximation on scales deep inside the sound horizon. We find that the existence of intrinsic vector modes allows a possibility ...
Breaking discrete symmetries in the effective field theory of inflation
Energy Technology Data Exchange (ETDEWEB)
Cannone, Dario [Dipartimento di Fisica e Astronomia “G. Galilei”, Università degli Studi di Padova,Padova, I-35131 (Italy); INFN, Sezione di Padova,Padova, I-35131 (Italy); Gong, Jinn-Ouk [Asia Pacific Center for Theoretical Physics,Pohang, 790-784 (Korea, Republic of); Department of Physics,Postech, Pohang, 790-784 (Korea, Republic of); Tasinato, Gianmassimo [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)
2015-08-03
We study the phenomenon of discrete symmetry breaking during the inflationary epoch, using a model-independent approach based on the effective field theory of inflation. We work in a context where both time reparameterization symmetry and spatial diffeomorphism invariance can be broken during inflation. We determine the leading derivative operators in the quadratic action for fluctuations that break parity and time-reversal. Within suitable approximations, we study their consequences for the dynamics of linearized fluctuations. Both in the scalar and tensor sectors, we show that such operators can lead to new direction-dependent phases for the modes involved. They do not affect the power spectra, but can have consequences for higher correlation functions. Moreover, a small quadrupole contribution to the sound speed can be generated.
Effective field theory for long-range properties of bottomonium
Krein, Gastão
2017-03-01
In this communication we present selected results from a recent study [N. Brambilla, G. Krein, J. Tarrús Castellà and A. Vairo, Phys. Rev. D 93, 054002 (2016)] of long-range properties of bottomonium. An analytical expression for the chromopolarizability of 1S bottomonium states is derived within the framework of potential nonrelativistic QCD (pNRQCD). Next, after integrating out the ultrasoft scale associated with the binding energy of bottomonium, the QCD trace anomaly is used to obtain the two-pion production amplitude for the chromopolarizability operator and the result is matched to a chiral effective field theory having bottomonium states and pions as degrees of freedom. We present results for the leading chiral logarithm correction to the mass of the 1S bottomonium and the van der Waals potential between two bottomonium states.
Instanton effects in ABJM theory from Fermi gas approach
Energy Technology Data Exchange (ETDEWEB)
Hatsuda, Yasuyuki [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst.; Nagoya Univ. (Japan). Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics
2012-11-19
We study the instanton effects of the ABJM partition function using the Fermi gas formalism. We compute the exact values of the partition function at the Chern-Simons levels k=1, 2, 3, 4, 6 up to N=44, 20, 18, 16, 14 respectively, and extract non-perturbative corrections from these exact results. Fitting the resulting non-perturbative corrections by their expected forms from the Fermi gas, we determine unknown parameters in them. After separating the oscillating behavior of the grand potential, which originates in the periodicity of the grand partition function, and the worldsheet instanton contribution, which is computed from the topological string theory, we succeed in proposing an analytical expression for the leading D2-instanton correction. Just as the perturbative result, the instanton corrections to the partition function are expressed in terms of the Airy function.
Towards an Effective THeory Of Structure formation (ETHOS)
CERN. Geneva
2016-01-01
Although there is substantial gravitational evidence for the existence of dark matter, its particle nature remains one of the biggest mysteries in modern physics. The favourite theoretical model, Cold Dark Matter (CDM), assumes that non-gravitational dark matter interactions are irrelevant for galaxy formation and evolution. Surprisingly, current astronomical observations allow significant departures from the CDM hypothesis that have a relevant impact on our understanding of how galaxies form and evolve. Moreover, the observed properties of the smallest galaxies have been a consistent challenge for the CDM model. In this talk, I will argue that to explain galaxy formation and evolution in the broadest sense, an effective dark matter theory must contain a wider range of dark matter particle physics. I will describe the first steps we have taken towards developing ETHOS and present some of its applications.
Does theory influence the effectiveness of health behavior interventions? Meta-analysis.
Prestwich, Andrew; Sniehotta, Falko F; Whittington, Craig; Dombrowski, Stephan U; Rogers, Lizzie; Michie, Susan
2014-05-01
To systematically investigate the extent and type of theory use in physical activity and dietary interventions, as well as associations between extent and type of theory use with intervention effectiveness. An in-depth analysis of studies included in two systematic reviews of physical activity and healthy eating interventions (k = 190). Extent and type of theory use was assessed using the Theory Coding Scheme (TCS) and intervention effectiveness was calculated using Hedges's g. Metaregressions assessed the relationships between these measures. Fifty-six percent of interventions reported a theory base. Of these, 90% did not report links between all of their behavior change techniques (BCTs) with specific theoretical constructs and 91% did not report links between all the specified constructs with BCTs. The associations between a composite score or specific items on the TCS and intervention effectiveness were inconsistent. Interventions based on Social Cognitive Theory or the Transtheoretical Model were similarly effective and no more effective than interventions not reporting a theory base. The coding of theory in these studies suggested that theory was not often used extensively in the development of interventions. Moreover, the relationships between type of theory used and the extent of theory use with effectiveness were generally weak. The findings suggest that attempts to apply the two theories commonly used in this review more extensively are unlikely to increase intervention effectiveness. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Idris, Fazilah; Abdullah, Mohd Richard Neles; Ahmad, Abdul Razak; Mansor, Ahmad Zamri
2016-01-01
There has been little research done on explaining the ethnic tolerance behavior from the perspective of sociological theories. The authors chose rational choice theory and the theory of planned behavior as they are widely used in explaining the human social behaviour. In this article, the theories are used to explain the effects of religion on…
Three-body halo nuclei in an effective theory framework
Energy Technology Data Exchange (ETDEWEB)
Canham, David L.
2009-05-20
The universal properties and structure of halo nuclei composed of two neutrons (2n) and a core are investigated within an effective quantum mechanics framework. We construct an effective interaction potential that exploits the separation of scales in halo nuclei and treat the nucleus as an effective three-body system, which to leading order is described by the large S-wave scattering lengths in the underlying two-body subsystems. The uncertainty from higher orders in the expansion is quantified through theoretical error bands. First, we investigate the possibility to observe excited Efimov states in 2n halo nuclei. Based on the experimental data, {sup 20}C is the only halo nucleus candidate to possibly have an Efimov excited state, with an energy less than 7 keV below the scattering threshold. Second, we study the structure of {sup 20}C and other 2n halo nuclei. In particular, we calculate their matter density form factors, radii, and two-neutron opening angles. We then make a systematic improvement upon these calculations by extending the effective potential to the next-to-leading order. To this order, we require an additional two-body parameter, which we tune to the effective range of the interaction. In addition to range corrections to the 2n halo nuclei results, we show corrections to the Efimov effect in the three-boson system. Furthermore, we explore universality in the linear range corrections to the Efimov spectrum. Finally, we study the scattering of D{sup 0} and D{sup *0} mesons and their antiparticles off the X(3872) in an effective field theory for short-range interactions. We present results for the S-wave scattering amplitude, total interaction cross section and S-wave scattering length. (orig.)
Theory of nitrogen doping of carbon nanoribbons: edge effects.
Jiang, Jie; Turnbull, Joseph; Lu, Wenchang; Boguslawski, Piotr; Bernholc, J
2012-01-07
Nitrogen doping of a carbon nanoribbon is profoundly affected by its one-dimensional character, symmetry, and interaction with edge states. Using state-of-the-art ab initio calculations, including hybrid exact-exchange density functional theory, we find that, for N-doped zigzag ribbons, the electronic properties are strongly dependent upon sublattice effects due to the non-equivalence of the two sublattices. For armchair ribbons, N-doping effects are different depending upon the ribbon family: for families 2 and 0, the N-induced levels are in the conduction band, while for family 1 the N levels are in the gap. In zigzag nanoribbons, nitrogen close to the edge is a deep center, while in armchair nanoribbons its behavior is close to an effective-mass-like donor with the ionization energy dependent on the value of the band gap. In chiral nanoribbons, we find strong dependence of the impurity level and formation energy upon the edge position of the dopant, while such site-specificity is not manifested in the magnitude of the magnetization.
Effects of collisions on conservation laws in gyrokinetic field theory
Energy Technology Data Exchange (ETDEWEB)
Sugama, H.; Nunami, M. [National Institute for Fusion Science, Toki 509-5292 (Japan); Department of Fusion Science, SOKENDAI (The Graduate University for Advanced Studies), Toki 509-5292 (Japan); Watanabe, T.-H. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)
2015-08-15
Effects of collisions on conservation laws for toroidal plasmas are investigated based on the gyrokinetic field theory. Associating the collisional system with a corresponding collisionless system at a given time such that the two systems have the same distribution functions and electromagnetic fields instantaneously, it is shown how the collisionless conservation laws derived from Noether's theorem are modified by the collision term. Effects of the external source term added into the gyrokinetic equation can be formulated similarly with the collisional effects. Particle, energy, and toroidal momentum balance equations including collisional and turbulent transport fluxes are systematically derived using a novel gyrokinetic collision operator, by which the collisional change rates of energy and canonical toroidal angular momentum per unit volume in the gyrocenter space can be given in the conservative forms. The ensemble-averaged transport equations of particles, energy, and toroidal momentum given in the present work are shown to include classical, neoclassical, and turbulent transport fluxes which agree with those derived from conventional recursive formulations.
Cognitive Load Theory and the Effects of Transient Information on the Modality Effect
Leahy, Wayne; Sweller, John
2016-01-01
Based on cognitive load theory and the "transient information effect," this paper investigated the "modality effect" while interpreting a contour map. The length and complexity of auditory and visual text instructions were manipulated. Experiment 1 indicated that longer audio text information within a presentation was inferior…
Nam, Sung Sik
2017-06-12
A new finger replacement technique which is applicable for RAKE receivers in the soft handover region has been proposed and studied under the ideal assumption that the fading is both independent and identically distributed from path to path. To supplement our previous work, we present a general comprehensive framework for the performance assessment of the proposed finger replacement schemes operating over independent but non-identically distributed (i.n.d.) faded paths. To accomplish this object, we derive new closed-form expressions for the target key statistics which are composed of i.n.d. exponential random variables. With these new expressions, the performance analysis of various wireless communication systems over more practical channel environments can be possible.
Exploring Bayesian model selection methods for effective field theory expansions
Schaffner, Taylor; Yamauchi, Yukari; Furnstahl, Richard
2017-09-01
A fundamental understanding of the microscopic properties and interactions of nuclei has long evaded physicists due to the complex nature of quantum chromodynamics (QCD). One approach to modeling nuclear interactions is known as chiral effective field theory (EFT). Today, the method's greatest limitation lies in the approximation of interaction potentials and their corresponding uncertainties. Computing EFT expansion coefficients, known as Low-Energy Constants (LECs), from experimental data reduces to a problem of statistics and fitting. In the conventional approach, the fitting is done using frequentist methods that fail to evaluate the quality of the model itself (e.g., how many orders to use) in addition to its fit to the data. By utilizing Bayesian statistical methods for model selection, the model's quality can be taken into account, providing a more controlled and robust EFT expansion. My research involves probing different Bayesian model checking techniques to determine the most effective means for use with estimating the values of LECs. In particular, we are using model problems to explore the Bayesian calculation of an EFT expansion's evidence and an approximation to this value known as the WAIC (Widely Applicable Information Criterion). This work was supported in part by the National Science Foundation under Grant No. PHY-1306250.
Directory of Open Access Journals (Sweden)
Ali Hoseini Soorand
2015-10-01
Full Text Available Background and Aim: Hypertension is one of the most common and important non-communicable diseases and health problems in the world today nevertheless, it is preventable and controllable. Theory of Planned Behavior is one of the major theories that explains the process of adopting healthy behaviors. The present study aimed atat determining the effect of the theory on components of theory in patients with hypertension. Materials and Methods:. This randomized controlled field trial study was done on 110 patients with hypertension in Zirkouh city who were divided into two equal groups. Validity and reliability of the questionnaire used were determined through face and content validity and through Cronbach’s alpha and test-retest, respectively. The obtained data was analyzed by means of SPSS software (V: 16 using statistical t-test and repeated analysis of variance. Results: Both groups were similar regarding mean score of the theory components before intervention, but after the intervention the average scores of the experimental group increased. The attitude increased from 48.7 to 64.1, subjective norm from 34.9 to 43.1, perceived behavioral control from 33.8 to 43, intention behavior from 33.9 to 41.09 and behavior from 65.6 to 82.45 and these differences were statistically significant (P<0.001. However, nosignificant difference was observed in the control group. Conclusion: Regarding the positive effect of education based on The Theory of Planned Behavior in controlling hypertension, planning of a curriculum based on this theory is recommended.
Inadequate Evidence for Multiple Intelligences, Mozart Effect, and Emotional Intelligence Theories
Waterhouse, Lynn
2006-01-01
I (Waterhouse, 2006) argued that, because multiple intelligences, the Mozart effect, and emotional intelligence theories have inadequate empirical support and are not consistent with cognitive neuroscience findings, these theories should not be applied in education. Proponents countered that their theories had sufficient empirical support, were…
A renormalizable effective theory for leading logarithms in ChPT
Bissegger, Moritz; Fuhrer, Andreas
2007-01-01
We argue that the linear sigma model at small external momenta is an effective theory for the leading logarithms of chiral perturbation theory. Based on this assumption an attempt is made to sum these leading logarithms using the standard renormalization group techniques, which are valid in renormalizable quantum field theories.
The Validity of Hersey and Blanchard's Theory of Leader Effectiveness.
Hambleton, Ronald K.; Gumpert, Ray
1982-01-01
Examined the use and validity of Hersey and Blanchard's Situational Leadership Theory. Results supported the validity of the theory. Found a definite and significant relationship between the leadership style of a manager in particular situations and managers' perceptions of subordinate job performance. No causal relationship was found. (Author/RC)
Generalized uncertainty principle as a consequence of the effective field theory
Energy Technology Data Exchange (ETDEWEB)
Faizal, Mir, E-mail: mirfaizalmir@gmail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia – Okanagan, Kelowna, British Columbia V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Ali, Ahmed Farag, E-mail: ahmed.ali@fsc.bu.edu.eg [Department of Physics, Faculty of Science, Benha University, Benha, 13518 (Egypt); Netherlands Institute for Advanced Study, Korte Spinhuissteeg 3, 1012 CG Amsterdam (Netherlands); Nassar, Ali, E-mail: anassar@zewailcity.edu.eg [Department of Physics, Zewail City of Science and Technology, 12588, Giza (Egypt)
2017-02-10
We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counter terms for this scalar field theory deformed by generalized uncertainty principle, and show that the generalized uncertainty principle contributes to the matter conformal anomaly.
Kählerian effective potentials for Chern–Simons-matter theories
Directory of Open Access Journals (Sweden)
J.M. Queiruga
2016-01-01
Full Text Available In this paper, we will calculate the effective potential for a theory of multiple M2-branes. As the theory of multiple M2-branes can be described by a Chern–Simons-matter theory, this will be done by calculating the Kählerian effective potential for a Chern–Simons-matter theory. This calculation will be performed in N=1 superspace formalism. We will initially study an Abelian Chern–Simons-matter theory, and then generalize those results to the full non-Abelian Chern–Simons-matter theory. We will obtain explicit expressions for the superpropagators for this theory. These superpropagators will be used to calculate the one-loop effective potential.
Type IIA flux compactifications. Vacua, effective theories and cosmological challenges
Energy Technology Data Exchange (ETDEWEB)
Koers, Simon
2009-07-30
In this thesis, we studied a number of type IIA SU(3)-structure compactifications with 06-planes on nilmanifolds and cosets, which are tractable enough to allow for an explicit derivation of the low energy effective theory. In particular we calculated the mass spectrum of the light scalar modes, using N = 1 supergravity techniques. For the torus and the Iwasawa solution, we have also performed an explicit Kaluza-Klein reduction, which led to the same result. For the nilmanifold examples we have found that there are always three unstabilized moduli corresponding to axions in the RR sector. On the other hand, in the coset models, except for SU(2) x SU(2), all moduli are stabilized. We discussed the Kaluza-Klein decoupling for the supersymmetric AdS vacua and found that it requires going to the Nearly-Calabi Yau limited. We searched for non-trivial de Sitter minima in the original flux potential away from the AdS vacuum. Finally, in chapter 7, we focused on a family of three coset spaces and constructed non-supersymmetric vacua on them. (orig.)
Effective field theory, electric dipole moments and electroweak baryogenesis
Balazs, Csaba; White, Graham; Yue, Jason
2017-03-01
Negative searches for permanent electric dipole moments (EDMs) heavily constrain models of baryogenesis utilising various higher dimensional charge and parity violating (CPV) operators. Using effective field theory, we create a model independent connection between these EDM constraints and the baryon asymmetry of the universe (BAU) produced during a strongly first order electroweak phase transition. The thermal aspects of the high scale physics driving the phase transition are paramaterised by the usual kink solution for the bubble wall profile. We find that operators involving derivatives of the Higgs field yield CPV contributions to the BAU containing derivatives of the Higgs vacuum expectation value (vev), while non-derivative operators lack such contributions. Consequently, derivative operators cannot be eliminated in terms of non-derivative operators (via the equations of motion) if one is agnostic to the new physics that leads to the phase transition. Thus, we re-classify the independent dimension six operators, restricting ourselves to third generation quarks, gauge bosons and the Higgs. Finally, we calculate the BAU (as a function of the bubble wall width and the cutoff) for a derivative and a non-derivative operator, and relate it to the EDM constraints.
Effective Field Theory of Fractional Quantized Hall Nematics
Energy Technology Data Exchange (ETDEWEB)
Mulligan, Michael; /MIT, LNS; Nayak, Chetan; /Station Q, UCSB; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC
2012-06-06
We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state wave function in the symmetry-broken phase. In such a state of matter, the Hall resistance remains quantized while the longitudinal DC resistivity due to thermally-excited quasiparticles is anisotropic. We interpret recent experiments at Landau level filling factor {nu} = 7/3 in terms of our theory.
Thickness and camber effects in slender wing theory
Plotkin, A.
1983-01-01
It is noted that the flow past thin slender wings with round leading edges can remain attached up to moderate values of angle of attack. In the low aspect ratio limit, the slender wing theory of Jones (1946) can therefore provide a simple analytical tool for studying this flow. First-order corrections to slender wing theory due to spanwise thickness and camber are developed. For wings of general planform, the validity and applicability of slender wing theory have recently been extended with the addition of chordwise and compressibility corrections by Levin and Seginer (1982). It is believed that similar corrections can be applied to the present results.
Critical properties of effective gauge theories for novel quantum fluids
Energy Technology Data Exchange (ETDEWEB)
Smoergrav, Eivind
2005-07-01
Critical properties of U(1) symmetric gauge theories are studied in 2+1 dimensions, analytically through duality transformations and numerically through Monte Carlo simulations. Physical applications range from quantum phase transitions in two dimensional insulating materials to superfluid and superconducting properties of light atoms such as hydrogen under extreme pressure. A novel finite size scaling method, utilizing the third moment M{sub 3} of the action, is developed. Finite size scaling analysis of M{sub 3} yields the ratio (1 + alpha)/ny and 1/ny separately, so that critical exponents alpha and ny can be obtained independently without invoking hyperscaling. This thesis contains eight research papers and an introductory part covering some basic concepts and techniques. Paper 1: The novel M{sub 3} method is introduced and employed together with Monte Carlo simulations to study the compact Abelian Higgs model in the adjoint representation with q = 2. Paper 2: We study phase transitions in the compact Abelian Higgs model for fundamental charge q = 2; 3; 4; 5. Various other models are studied to benchmark the M{sub 3} method. Paper 3: This is a proceeding paper based on a talk given by F. S. Nogueira at the Aachen EPS HEP 2003 conference. A review of the results from Paper 1 and Paper 2 on the compact Abelian Higgs model together with some results on q = 1 obtained by F. S. Nogueira, H. Kleinert, and A. Sudboe is given. Paper 4: The effect of a Chern-Simons (CS) term in the phase structure of two Abelian gauge theories is studied. Paper 5: We study the critical properties of the N-component Ginzburg-Landau theory. Paper 6: We consider the vortices in the 2-component Ginzburg-Landau model in a finite but low magnetic field. The ground state is a lattice of co centered vortices in both order parameters. We find two novel phase transitions. i) A 'vortex sub-lattice melting' transition where vortices in the field with lowest phase stiffness (&apos
Towards Working Technicolor: Effective Theories and Dark Matter
DEFF Research Database (Denmark)
Bjarke Gudnason, Sven; Kouvaris, Christoforos; Sannino, Francesco
2006-01-01
A fifth force, of technicolor type, responsible for breaking the electroweak theory is an intriguing extension of the Standard Model. Recently new theories have been shown to feature walking dynamics for a very low number of techniflavors and are not ruled out by electroweak precision measurement...... technicolor interactions. There are hypercharge assignments for the techniquarks which renders one of the technibaryons electrically neutral. We investigate the cosmological implications of this scenario and provide a component of dark matter....
Quantum optical effective-medium theory and transformation quantum optics for metamaterials
DEFF Research Database (Denmark)
Wubs, Martijn; Amooghorban, Ehsan; Zhang, Jingjing
2016-01-01
While typically designed to manipulate classical light, metamaterials have many potential applications for quantum optics as well. We argue why a quantum optical effective-medium theory is needed. We present such a theory for layered metamaterials that is valid for light propagation in all spatial...... directions, thereby generalizing earlier work for one-dimensional propagation. In contrast to classical effective-medium theory there is an additional effective parameter that describes quantum noise. Our results for metamaterials are based on a rather general Lagrangian theory for the quantum...
Psychological theory and pedagogical effectiveness: the learning promotion potential framework.
Tomlinson, Peter
2008-12-01
After a century of educational psychology, eminent commentators are still lamenting problems besetting the appropriate relating of psychological insights to teaching design, a situation not helped by the persistence of crude assumptions concerning the nature of pedagogical effectiveness. To propose an analytical or meta-theoretical framework based on the concept of learning promotion potential (LPP) as a basis for understanding the basic relationship between psychological insights and teaching strategies, and to draw out implications for psychology-based pedagogical design, development and research. This is a theoretical and meta-theoretical paper relying mainly on conceptual analysis, though also calling on psychological theory and research. Since teaching consists essentially in activity designed to promote learning, it follows that a teaching strategy has the potential in principle to achieve particular kinds of learning gains (LPP) to the extent that it embodies or stimulates the relevant learning processes on the part of learners and enables the teacher's functions of on-line monitoring and assistance for such learning processes. Whether a teaching strategy actually does realize its LPP by way of achieving its intended learning goals depends also on the quality of its implementation, in conjunction with other factors in the situated interaction that teaching always involves. The core role of psychology is to provide well-grounded indication of the nature of such learning processes and the teaching functions that support them, rather than to directly generate particular ways of teaching. A critically eclectic stance towards potential sources of psychological insight is argued for. Applying this framework, the paper proposes five kinds of issue to be attended to in the design and evaluation of psychology-based pedagogy. Other work proposing comparable ideas is briefly reviewed, with particular attention to similarities and a key difference with the ideas of Oser
Effects of conformational distributions on sigma profiles in COSMO theories.
Wang, Shu; Stubbs, John M; Siepmann, J Ilja; Sandler, Stanley I
2005-12-15
The charge density or sigma profile of a solute molecule is an essential component in COSMO (conductor-like screen model) based solvation theories, and its generation depends on the molecular conformation used. The usual procedure is to determine the conformation of an isolated molecule, and assume that this is unchanged when the molecule is placed in solution. In this paper, the conformations of 1-hexanol and 2-methoxy-ethanol in both the liquid and vapor phases obtained from Gibbs ensemble simulation and from an isolated-molecule quantum DFT optimization are used to determine the effect of realistic conformation differences on COSMO-based properties predictions. In particular, the vapor pressure at the normal boiling temperature and the binary mixture VLE (vapor-liquid equilibrium) predictions obtained using different conformations are investigated. The results show that the sigma profile for 1-hexanol varies only slightly using the different conformations, while the sigma profile of 2-methoxy-ethanol shows a significant difference between the liquid and vapor phases. Consequently, the vapor pressure predictions for 1-hexanol are similar regardless of the manner in which the conformation population was obtained, while there is a larger difference for 2-methoxy-ethanol depending on whether the liquid or vapor conformations from simulation or the DFT-optimized structure is used. These differences in predictions are seen to be largely due to differences in the ideal solvation energy term. In mixture VLE calculations involving 1-hexanol, we again see that there is little difference in the phase equilibrium predictions among the different conformations, while for the mixture with 2-methoxy-ethanol, the differences in the sigma profiles lead to a more noticeable, though not significant, difference in the phase equilibrium predictions.
Classical theory of atom-surface scattering: The rainbow effect
Miret-Artés, Salvador; Pollak, Eli
2012-07-01
The scattering of heavy atoms and molecules from surfaces is oftentimes dominated by classical mechanics. A large body of experiments have gathered data on the angular distributions of the scattered species, their energy loss distribution, sticking probability, dependence on surface temperature and more. For many years these phenomena have been considered theoretically in the framework of the “washboard model” in which the interaction of the incident particle with the surface is described in terms of hard wall potentials. Although this class of models has helped in elucidating some of the features it left open many questions such as: true potentials are clearly not hard wall potentials, it does not provide a realistic framework for phonon scattering, and it cannot explain the incident angle and incident energy dependence of rainbow scattering, nor can it provide a consistent theory for sticking. In recent years we have been developing a classical perturbation theory approach which has provided new insight into the dynamics of atom-surface scattering. The theory includes both surface corrugation as well as interaction with surface phonons in terms of harmonic baths which are linearly coupled to the system coordinates. This model has been successful in elucidating many new features of rainbow scattering in terms of frictions and bath fluctuations or noise. It has also given new insight into the origins of asymmetry in atomic scattering from surfaces. New phenomena deduced from the theory include friction induced rainbows, energy loss rainbows, a theory of super-rainbows, and more. In this review we present the classical theory of atom-surface scattering as well as extensions and implications for semiclassical scattering and the further development of a quantum theory of surface scattering. Special emphasis is given to the inversion of scattering data into information on the particle-surface interactions.
Hořava-Lifshitz gravity and effective theory of the fractional quantum Hall effect
Energy Technology Data Exchange (ETDEWEB)
Wu, Chaolun [Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States); Wu, Shao-Feng [Department of Physics, Shanghai University,Shanghai 200444 (China); Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States)
2015-01-22
We show that Hořava-Lifshitz gravity theory can be employed as a covariant framework to build an effective field theory for the fractional quantum Hall effect that respects all the spacetime symmetries such as non-relativistic diffeomorphism invariance and anisotropic Weyl invariance as well as the gauge symmetry. The key to this formalism is a set of correspondence relations that maps all the field degrees of freedom in the Hořava-Lifshitz gravity theory to external background (source) fields among others in the effective action of the quantum Hall effect, according to their symmetry transformation properties. We originally derive the map as a holographic dictionary, but its form is independent of the existence of holographic duality. This paves the way for the application of Hořava-Lifshitz holography on fractional quantum Hall effect. Using the simplest holographic Chern-Simons model, we compute the low energy effective action at leading orders and show that it captures universal electromagnetic and geometric properties of quantum Hall states, including the Wen-Zee shift, Hall viscosity, angular momentum density and their relations. We identify the shift function in Hořava-Lifshitz gravity theory as minus of guiding center velocity and conjugate to guiding center momentum. This enables us to distinguish guiding center angular momentum density from the internal one, which is the sum of Landau orbit spin and intrinsic (topological) spin of the composite particles. Our effective action shows that Hall viscosity is minus half of the internal angular momentum density and proportional to Wen-Zee shift, and Hall bulk viscosity is half of the guiding center angular momentum density.
Cultural effects on the neural basis of theory of mind.
Kobayashi Frank, Chiyoko; Temple, Elise
2009-01-01
"Theory of mind" has been described as the ability to attribute and understand other people's desires and intentions as distinct from one's own. It has been found to develop as early as between 3 and 4 years old, with precursor abilities possibly developing much earlier. There has been debate about the extent to which the developmental trajectory of theory of mind may differ across cultures or language systems. Although very few neuroimaging studies have directly compared different groups from different culture and language systems, across studies of a number of cultural/language groups have been used to explore the neural correlates of theory of mind. A summary of these findings suggests that there may be both universal and culture or language-specific neural correlates related to theory of mind. These studies, while still preliminary in many ways, illustrate the importance of taking into account the cultural background of participants. Furthermore these results suggest that there may be important cultural influence on theory of mind and the neural correlates associated with this ability.
A THEORY OF LEADERSHIP EFFECTIVENESS. MCGRAW-HILL SERIES IN MANAGEMENT.
FIEDLER, FRED E.
CENTRAL TO THE THEORY OF LEADERSHIP EFFECTIVENESS OUTLINED HERE IS A CONTINGENCY MODEL, ACCORDING TO WHICH GROUP EFFECTIVENESS DEPENDS ON INTERACTION BETWEEN LEADERSHIP STYLES AND THE DEGREE TO WHICH SITUATIONS ENABLE LEADERS TO EXERT INFLUENCE. THE THEORY PREDICTS THAT A TASK-ORIENTED STYLE WILL BE THE BEST STYLE IN FAVORABLE LEADERSHIP…
Effective mass theory of a two-dimensional quantum dot in the ...
Indian Academy of Sciences (India)
Effective mass theory; BenDaniel–Duke; quantum dot; electron; magnetic field. PACS Nos 73.21.La; 73.21. ... tronic structure is often understood on the basis of effective mass theory (EMT). In this paper, we use EMT to study the ..... [2] R C Ashoori, Nature (London) 379, 413 (1996). [3] Vijay A Singh and Luv Kumar, Am. J.
Effects of Actor-Network Theory in Accounting Research
DEFF Research Database (Denmark)
Justesen, Lise Nederland; Mouritsen, Jan
2011-01-01
of a critical literature review and discussion. Findings – Since the early 1990s, actor-network theory, particularly the work of Bruno Latour, has inspired accounting researchers and led to a number of innovative studies of accounting phenomena. In particular, Latour's book, Science in Action, has been...... number of accounting papers that apply actor-network theory. A different sample might have given a somewhat different picture. Furthermore, it focuses on the influence of Latour's work and refrains from discussing how the writings of Michel Callon, John Law or other thinkers within the actor......Purpose – This paper aims to discuss how Bruno Latour's version of actor-network theory has influenced accounting research. It also seeks to show that Latour's writings contain unexplored potential that may inspire future accounting research. Design/methodology/approach – The paper takes the form...
Time dependent density matrix theory and effective interaction
Energy Technology Data Exchange (ETDEWEB)
Tohyama, Mitsuru [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine
1998-07-01
A correlated ground state of {sup 16}O and an E2 giant resonance built on it are calculated using an extended version of the time-dependent Hartree-Fock theory called the time-dependent density-matrix theory (TDDM). The Skyrme force is used in the calculation of both a mean field and two-body correlations. It is found that TDDM gives reasonable ground-state correlations and a large spreading width of the E2 giant resonance when single-particle states in the continuum are treated appropriately. (author)
Classroom Management: Sound Theory and Effective Practice. Fourth Edition
Tauber, Robert T.
2007-01-01
Educators need a balance between discipline theory and its practice in the classroom. This is especially important in today's educational climate, with its increased demands for teacher accountability. Tauber has designed this book for both those who are new to teaching and those who are already seasoned teachers, but who have had little, if any,…
Bilingual Education Theory and Practice: Its Effectiveness and Parental Opinions.
Chavez, Linda; Amselle, Jorge
1997-01-01
Research studies fail to support bilingual education theory, despite Hispanic parents' extensive lobbying to have their children taught in Spanish. Many Hispanic parents now realize that bilingual education has not served their best interests. The vast majority of limited-English-proficiency students receive English-as-a-Second Language…
412 The Effects of Integrating Laboratory Work with Theory on ...
African Journals Online (AJOL)
User
2010-10-17
Oct 17, 2010 ... researcher-made instruments, Physics Practical Achievement Test (PPAT) and Physics Theory ... The Research Design used was the pre-test, post-test control group design. The design is structurally ... Achievement Test (PTAT). The instruments, PTAT and PPAT were given face-validation by four.
Experiential Learning Theory as a Guide for Effective Teaching.
Murrell, Patricia H.; Claxton, Charles S.
1987-01-01
David Kolb's experiential learning theory involves a framework useful in designing courses that meet needs of diverse learners. Course designs providing systematic activities in concrete experience, reflective observations, abstract conceptualization, and active experimentation will be sensitive to students' learning styles while challenging…
Effective Contraceptive Use: An Exploration of Theory-Based Influences
Peyman, N.; Oakley, D.
2009-01-01
The purpose of this study was to explore factors that influence oral contraceptive (OC) use among women in Iran using the Theory of Planned Behavior (TPB) and concept of self-efficacy (SE). The study sample consisted of 360 married OC users, aged 18-49 years recruited at public health centers of Mashhad, 900 km east of Tehran. SE had the strongest…
Particle Production and Effective Thermalization in Inhomogeneous Mean Field Theory
Aarts, G.; Smit, J.
2000-01-01
As a toy model for dynamics in nonequilibrium quantum field theory we consider the abelian Higgs model in 1+1 dimensions with fermions. In the approximate dynamical equations, inhomogeneous classical (mean) Bose fields are coupled to quantized fermion fields, which are treated with a mode function
Effective Learning Environments in Relation to Different Learning Theories
Guney, A.; Al, S.
2012-01-01
There are diverse learning theories which explain learning processes which are discussed within this paper, through cognitive structure of learning process. Learning environments are usually described in terms of pedagogical philosophy, curriculum design and social climate. There have been only just
QCD on the Lattice: The Central Role of Effective Field Theory
El-Khadra, Aida X.
Nonperturbative QCD effects are ubiquitous and affect not just processes studied in particle and nuclear physics, but also in astrophysics and cosmology. Lattice field theory is a general quantitative tool for the study of nonperturbative phenomena and has provided us with much insight into nonperturbative QCD effects. In these lectures I present an introduction to lattice QCD with emphasis on the methods used for calculations relevant to quark flavor physics. In lattice QCD, quantitative control over systematic errors is made possible with the use of effective field theories. I briefly review how the effective field theories arise and their relation to the sources of systematic error in lattice QCD.
Momentum dissipation and effective theories of coherent and incoherent transport
Davison, Richard A.; Goutéraux, Blaise
2015-01-01
We study heat transport in two systems without momentum conservation: a hydrodynamic system, and a holographic system with spatially dependent, massless scalar fields. When momentum dissipates slowly, there is a well-defined, coherent collective excitation in the AC heat conductivity, and a crossover between sound-like and diffusive transport at small and large distance scales. When momentum dissipates quickly, there is no such excitation in the incoherent AC heat conductivity, and diffusion dominates at all distance scales. For a critical value of the momentum dissipation rate, we compute exact expressions for the Green's functions of our holographic system due to an emergent gravitational self-duality, similar to electric/magnetic duality, and SL(2, ) symmetries. We extend the coherent/incoherent classification to examples of charge transport in other holographic systems: probe brane theories and neutral theories with non-Maxwell actions.
A review of the findings and theories on surface size effects on visual attention
DEFF Research Database (Denmark)
Peschel, Anne Odile; Orquin, Jacob Lund
2013-01-01
that large objects are more likely to be fixated, receive more fixations, and are fixated faster than small objects, a comprehensive explanation of this effect is still lacking. To bridge the theoretical gap, we relate the findings from this review to three theories of surface size effects suggested...... in the literature: a linear model based on the assumption of random fixations (Lohse, 1997), a theory of surface size as visual saliency (Pieters et al., 2007), and a theory based on competition for attention (CA; Janiszewski, 1998). We furthermore suggest a fourth model – demand for attention – which we derive...... from the theory of CA by revising the underlying model assumptions. In order to test the models against each other, we reanalyze data from an eye tracking study investigating surface size and saliency effects on attention. The reanalysis revealed little support for the first three theories while...
Effective spacetime understanding emergence in effective field theory and quantum gravity
Crowther, Karen
2016-01-01
This book discusses the notion that quantum gravity may represent the "breakdown" of spacetime at extremely high energy scales. If spacetime does not exist at the fundamental level, then it has to be considered "emergent", in other words an effective structure, valid at low energy scales. The author develops a conception of emergence appropriate to effective theories in physics, and shows how it applies (or could apply) in various approaches to quantum gravity, including condensed matter approaches, discrete approaches, and loop quantum gravity.
Role of Instructional Theory in Authoring Effective and Efficient Learning Technologies.
Scandura, Joseph M.
1996-01-01
Major issues in instructional theory and the advantages of structural analysis for building instructional systems are discussed. Building on core technology and the structural learning theory, a research program is proposed which will enable efficient development of effective learning systems for industry and schools. Contains 66 references. (AEF)
Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory.
Burgess, Cliff P
2004-01-01
This article is meant as a summary and introduction to the ideas of effective field theory as applied to gravitational systems, ideas which provide the theoretical foundations for the modern use of general relativity as a theory from which precise predictions are possible.
Oral, I.; Dogan, O.
2007-04-01
The aim of this study is to find out the effect of the course materials based on Multiple Intelligence Theory upon the intelligence groups' learning process. In conclusion, the results proved that the materials prepared according to Multiple Intelligence Theory have a considerable effect on the students' learning process. This effect was particularly seen on the student groups of the musical-rhythmic, verbal-linguistic, interpersonal-social and naturalist intelligence.
Diep, Cassandra S; Chen, Tzu-An; Davies, Vanessa F; Baranowski, Janice C; Baranowski, Tom
2014-01-01
To test the hypotheses that interventions clearly based on theory, multiple theories, or a formal intervention planning process will be more effective in changing fruit and vegetable consumption among children than interventions with no behavioral theoretical foundation. Systematic review and meta-analysis. Identification of articles in PubMed, PsycInfo, Medline, Cochrane Collaborative database, and existing literature reviews and meta-analyses. Children aged 2-18 years. Change in fruit and/or vegetable consumption in dietary change interventions. Meta-analysis, meta-regression analysis, and summary reporting for articles. Predicating an intervention on behavioral theory had a small to moderate enhancement (P theory and non-theory interventions were 0.232 for fruit, 0.043 for vegetables, and 0.333 for fruit and vegetables combined. There was mixed support, however, for enhanced dietary change with multiple theories or a formal planning process. After controlling for study quality, theory use was related only to vegetable consumption (β = 0.373; P theory's influences on dietary behaviors to guide future interventions among children. More research is also needed to identify what may be effective practical- or experience-based procedures that complement theory, to incorporate into interventions. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.
An effective field theory approach to two trapped particles
Stetcu, I.; Rotureau, J.; Barrett, B.R.; van Kolck, U.
2010-01-01
We discuss the problem of two particles interacting via short-range interactions within a harmonic-oscillator trap. The interactions are organized according to their number of derivatives and defined in truncated model spaces made from a bound-state basis. Leading-order (LO) interactions are iterated to all orders, while corrections are treated in perturbation theory. We show explicitly that next-to-LO and next-to-next-to-LO interactions improve convergence as the model space increases. In th...
Alien calculus and non perturbative effects in Quantum Field Theory
Bellon, Marc P.
2016-12-01
In many domains of physics, methods for dealing with non-perturbative aspects are required. Here, I want to argue that a good approach for this is to work on the Borel transforms of the quantities of interest, the singularities of which give non-perturbative contributions. These singularities in many cases can be largely determined by using the alien calculus developed by Jean Écalle. My main example will be the two point function of a massless theory given as a solution of a renormalization group equation.
Quantum Theory of Conducting Matter Superconductivity and Quantum Hall Effect
Fujita, Shigeji; Godoy, Salvador
2009-01-01
Explains major superconducting properties including zero resistance, Meissner effect, sharp phase change, flux quantization, excitation energy gap, and Josephson effects using quantum statistical mechanical calculations. This book covers the 2D superconductivity and the quantum Hall effects
Color constancy effects measurement of the Retinex theory
Marini, Daniele; Rizzi, Alessandro; Carati, Caterina
1998-12-01
Understanding chromatic adaptation is a necessary step to solve the color constancy problem for a variety of application purposes. Retinex theory justifies chromatic adaptation, as well as other color illusions, on visual perception principles. Based on the above theory, we have derived an algorithm to solve the color constancy problem and to simulate chromatic adaption. The evaluation of the result depends on the kind of applications considered. Since our purpose is to contribute to the problem of color rendering on computer system display for photorealistic image synthesis, we have devised a specific test approach. A virtual 'Mondrian' patchwork has been created by applying a rendering algorithm with a photorealistic light model to generate images under different light sources. Trichromatic values of the computer generated patches are the input data for the Retinex algorithm, which computes new color corrected patches. The Euclidean distance in CIELAB space, between the original and Retinex color corrected trichromatic values, has been calculated, showing that the Retinex computational model is very well suited to solve the color constancy problem without any information on the illuminant spectral distribution.
Radiation reaction for spinning bodies in effective field theory. II. Spin-spin effects
Maia, Natália T.; Galley, Chad R.; Leibovich, Adam K.; Porto, Rafael A.
2017-10-01
We compute the leading post-Newtonian (PN) contributions at quadratic order in the spins to the radiation-reaction acceleration and spin evolution for binary systems, entering at four-and-a-half PN order. Our calculation includes the backreaction from finite-size spin effects, which is presented for the first time. The computation is carried out, from first principles, using the effective field theory framework for spinning extended objects. At this order, nonconservative effects in the spin-spin sector are independent of the spin supplementary conditions. A nontrivial consistency check is performed by showing that the energy loss induced by the resulting radiation-reaction force is equivalent to the total emitted power in the far zone. We find that, in contrast to the spin-orbit contributions (reported in a companion paper), the radiation reaction affects the evolution of the spin vectors once spin-spin effects are incorporated.
DEFF Research Database (Denmark)
Wæver, Ole
2009-01-01
Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism and refle......Kenneth N. Waltz's 1979 book, Theory of International Politics, is the most influential in the history of the discipline. It worked its effects to a large extent through raising the bar for what counted as theoretical work, in effect reshaping not only realism but rivals like liberalism...... and reflectivism. Yet, ironically, there has been little attention to Waltz's very explicit and original arguments about the nature of theory. This article explores and explicates Waltz's theory of theory. Central attention is paid to his definition of theory as ‘a picture, mentally formed' and to the radical anti......-empiricism and anti-positivism of his position. Followers and critics alike have treated Waltzian neorealism as if it was at bottom a formal proposition about cause-effect relations. The extreme case of Waltz being so victorious in the discipline, and yet being consistently mis-interpreted on the question of theory...
Becoming a CEO: an exploration of the theory and practice of effective organisational leadership
O'Keeffe, Niall
2012-01-01
This Thesis is an exploration of potential enhancement in effectiveness, personally, professionally and organisationally through the use of Theory as an Apparatus of Thought. Enhanced effectiveness was sought by the practitioner (Subject), while in transition to becoming Chief Executive of his organization. The introduction outlines the content and the structure of the University College Cork DBA. Essay One outlines what Theory is, what Adult Mental Development is and an exploration of Theo...
Tackling non-linearities with the effective field theory of dark energy and modified gravity
Frusciante, Noemi; Papadomanolakis, Georgios
2017-12-01
We present the extension of the effective field theory framework to the mildly non-linear scales. The effective field theory approach has been successfully applied to the late time cosmic acceleration phenomenon and it has been shown to be a powerful method to obtain predictions about cosmological observables on linear scales. However, mildly non-linear scales need to be consistently considered when testing gravity theories because a large part of the data comes from those scales. Thus, non-linear corrections to predictions on observables coming from the linear analysis can help in discriminating among different gravity theories. We proceed firstly by identifying the necessary operators which need to be included in the effective field theory Lagrangian in order to go beyond the linear order in perturbations and then we construct the corresponding non-linear action. Moreover, we present the complete recipe to map any single field dark energy and modified gravity models into the non-linear effective field theory framework by considering a general action in the Arnowitt-Deser-Misner formalism. In order to illustrate this recipe we proceed to map the beyond-Horndeski theory and low-energy Hořava gravity into the effective field theory formalism. As a final step we derived the 4th order action in term of the curvature perturbation. This allowed us to identify the non-linear contributions coming from the linear order perturbations which at the next order act like source terms. Moreover, we confirm that the stability requirements, ensuring the positivity of the kinetic term and the speed of propagation for scalar mode, are automatically satisfied once the viability of the theory is demanded at linear level. The approach we present here will allow to construct, in a model independent way, all the relevant predictions on observables at mildly non-linear scales.
Framing anomaly in the effective theory of the fractional quantum Hall effect.
Gromov, Andrey; Cho, Gil Young; You, Yizhi; Abanov, Alexander G; Fradkin, Eduardo
2015-01-09
We consider the geometric part of the effective action for the fractional quantum Hall effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to obtain the correct gravitational linear response functions. In the lowest order in gradients, the linear response generating functional includes Chern-Simons, Wen-Zee, and gravitational Chern-Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states.
Theory of magnon-driven spin Seebeck effect
Xiao, J.; Bauer, G.E.W.; Uchida, K.; Saitoh, E.; Maekawa, S.
2010-01-01
The spin Seebeck effect is a spin-motive force generated by a temperature gradient in a ferromagnet that can be detected via normal metal contacts through the inverse spin Hall effect [K. Uchida et al., Nature (London) 455, 778 (2008)]. We explain this effect by spin pumping at the contact that is
arXiv Chiral Effective Theory of Dark Matter Direct Detection
Bishara, Fady
2017-02-03
We present the effective field theory for dark matter interactions with the visible sector that is valid at scales of O(1 GeV). Starting with an effective theory describing the interactions of fermionic and scalar dark matter with quarks, gluons and photons via higher dimension operators that would arise from dimension-five and dimension-six operators above electroweak scale, we perform a nonperturbative matching onto a heavy baryon chiral perturbation theory that describes dark matter interactions with light mesons and nucleons. This is then used to obtain the coefficients of the nuclear response functions using a chiral effective theory description of nuclear forces. Our results consistently keep the leading contributions in chiral counting for each of the initial Wilson coefficients.
Theory of tunneling ionization of molecules: Weak-field asymptotics including dipole effects
DEFF Research Database (Denmark)
Tolstikhin, Oleg I.; Morishita, Toru; Madsen, Lars Bojer
2011-01-01
The formulation of the parabolic adiabatic expansion approach to the problem of ionization of atomic systems in a static electric field, originally developed for the axially symmetric case [ Phys. Rev. A 82 023416 (2010)], is generalized to arbitrary potentials. This approach is used to rederive...... the asymptotic theory of tunneling ionization in the weak-field limit. In the atomic case, the resulting formulas for the ionization rate coincide with previously known results. In addition, the present theory accounts for the possible existence of a permanent dipole moment of the unperturbed system and, hence......, applies to polar molecules. Accounting for dipole effects constitutes an important difference of the present theory from the so-called molecular Ammosov-Delone-Krainov theory. The theory is illustrated by comparing exact and asymptotic results for a set of model polar molecules and a realistic molecular...
I can do that: the impact of implicit theories on leadership role model effectiveness.
Hoyt, Crystal L; Burnette, Jeni L; Innella, Audrey N
2012-02-01
This research investigates the role of implicit theories in influencing the effectiveness of successful role models in the leadership domain. Across two studies, the authors test the prediction that incremental theorists ("leaders are made") compared to entity theorists ("leaders are born") will respond more positively to being presented with a role model before undertaking a leadership task. In Study 1, measuring people's naturally occurring implicit theories of leadership, the authors showed that after being primed with a role model, incremental theorists reported greater leadership confidence and less anxious-depressed affect than entity theorists following the leadership task. In Study 2, the authors demonstrated the causal role of implicit theories by manipulating participants' theory of leadership ability. They replicated the findings from Study 1 and demonstrated that identification with the role model mediated the relationship between implicit theories and both confidence and affect. In addition, incremental theorists outperformed entity theorists on the leadership task.
Khakzad, Nima; Landucci, Gabriele; Reniers, Genserik
2017-09-01
In the present study, we have introduced a methodology based on graph theory and multicriteria decision analysis for cost-effective fire protection of chemical plants subject to fire-induced domino effects. By modeling domino effects in chemical plants as a directed graph, the graph centrality measures such as out-closeness and betweenness scores can be used to identify the installations playing a key role in initiating and propagating potential domino effects. It is demonstrated that active fire protection of installations with the highest out-closeness score and passive fire protection of installations with the highest betweenness score are the most effective strategies for reducing the vulnerability of chemical plants to fire-induced domino effects. We have employed a dynamic graph analysis to investigate the impact of both the availability and the degradation of fire protection measures over time on the vulnerability of chemical plants. The results obtained from the graph analysis can further be prioritized using multicriteria decision analysis techniques such as the method of reference point to find the most cost-effective fire protection strategy. © 2016 Society for Risk Analysis.
Mediatization:Critical Theory Approaches to Media Effects
Hjarvard, Stig
2017-01-01
Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exp...
Linguistic Effects on the Neural Basis of Theory of Mind
Frank, C. Kobayashi
2010-01-01
“Theory of mind” (ToM) has been described as the ability to attribute and understand other people’s desires and intentions as distinct from one’s own. There has been a debate about the extent to which language influences ToM development. Although very few studies directly examined linguistic influence on the neural basis of ToM, results from these studies indicate at least moderate influence of language on ToM. In this review both behavioral and neurological studies that examined the relationship between language and ToM are selectively discussed. This review focuses on cross-linguistic / cultural studies (especially Japanese vs. American / English) since my colleagues and I found evidence of significant linguistic influence on the neural basis of ToM through a series of functional brain imaging experiments. Evidence from both behavioral and neurological studies of ToM (including ours) suggests that the pragmatic (not the constitutive) aspects of language influence ToM understanding more significantly. PMID:21113278
DEFF Research Database (Denmark)
Popov, Vladislav; Lavrinenko, Andrei; Novitsky, Andrey
2016-01-01
We elaborate on an operator approach to effective medium theory for homogenization of the periodic multilayered structures composed of nonmagnetic isotropic materials, which is based on equating the spatial evolution operators for the original structure and its effective alternative. We show...... that the zeroth-, first-, and second-order approximations of the operator effective medium theory correspond to electric dipoles, chirality, and magnetic dipoles plus electric quadrupoles, respectively. We discover that the spatially dispersive bianisotropic effective medium obtained in the second......-order approximation perfectly replaces a multilayered composite and does not suffer from the effective medium approximation breakdown that happened near the critical angle of total internal reflection found previously in the conventional effective medium theory. We establish the criterion of the validity...
Facilitative Social Change Leadership Theory: 10 Recommendations toward Effective Leadership
Watt, Willis M.
2009-01-01
In the fast pace of the 21st century there is a demand for effective leaders capable of handling the internal and external changes occurring in our organizations. This paper seeks to inform the reader because change is natural; it is constant; it is inevitable. But, what constitutes effective leadership is the question. The main purpose of this…
Effects of a Theory-Based, Peer-Focused Drug Education Course.
Gonzalez, Gerardo M.
1990-01-01
Describes innovative, theory-based, peer-focused college drug education academic course and its effect on perceived levels of risk associated with the use of alcohol, marijuana, and cocaine. Evaluation of the effects of the course indicated the significant effect on perceived risk of cocaine, but not alcohol or marijuana. (Author/ABL)
Effective Field Theories for Hot and Dense Matter
Directory of Open Access Journals (Sweden)
Blaschke D.
2010-10-01
Full Text Available The lecture is divided in two parts. The ﬁrst one deals with an introduction to the physics of hot, dense many-particle systems in quantum ﬁeld theory [1, 2]. The basics of the path integral approach to the partition function are explained for the example of chiral quark models. The QCD phase diagram is discussed in the meanﬁeld approximation while QCD bound states in the medium are treated in the rainbow-ladder approximation (Gaussian ﬂuctuations. Special emphasis is devoted to the discussion of the Mott eﬀect, i.e. the transition of bound states to unbound, but resonant scattering states in the continnum under the inﬂuence of compression and heating of the system. Three examples are given: (1 the QCD model phase diagram with chiral symmetry ¨ restoration and color superconductivity [3], (2 the Schrodinger equation for heavy-quarkonia [4], and (2 Pions [5] as well as Kaons and D-mesons in the ﬁnite-temperature Bethe-Salpeter equation [6]. We discuss recent applications of this quantum ﬁeld theoretical approach to hot and dense quark matter for a description of anomalous J/ψ supression in heavy-ion collisions [7] and for the structure and cooling of compact stars with quark matter interiors [8]. The second part provides a detailed introduction to the Polyakov-loop Nambu–Jona-Lasinio model [9] for thermodynamics and mesonic correlations [10] in the phase diagram of quark matter. Important relationships of low-energy QCD like the Gell-Mann–Oakes–Renner relation are generalized to ﬁnite temperatures. The eﬀect of including the coupling to the Polyakov-loop potential on the phase diagram and mesonic correlations is discussed. An outlook is given to eﬀects of nonlocality of the interactions [11] and of mesonic correlations in the medium [12] which go beyond the meanﬁeld description.
von Lilienfeld, O Anatole; Tavernelli, Ivano; Rothlisberger, Ursula; Sebastiani, Daniel
2004-10-08
We add an effective atom-centered nonlocal term to the exchange-correlation potential in order to cure the lack of London dispersion forces in standard density functional theory. Calibration of this long-range correction is performed using density functional perturbation theory and an arbitrary reference. Without any prior assignment of types and structures of molecular fragments, our corrected generalized gradient approximation density functional theory calculations yield correct equilibrium geometries and dissociation energies of argon-argon, benzene-benzene, graphite-graphite, and argon-benzene complexes.
Effective Theory of Dark Energy at Redshift Survey Scales
Gleyzes, Jérôme; Mancarella, Michele; Vernizzi, Filippo
2016-01-01
We explore the phenomenological consequences of general late-time modifications of gravity in the quasi-static approximation, in the case where cold dark matter is non-minimally coupled to the gravitational sector. Assuming spectroscopic and photometric surveys with configuration parameters similar to those of the Euclid mission, we derive constraints on our effective description from three observables: the galaxy power spectrum in redshift space, tomographic weak-lensing shear power spectrum and the correlation spectrum between the integrated Sachs-Wolfe effect and the galaxy distribution. In particular, with $\\Lambda$CDM as fiducial model and a specific choice for the time dependence of our effective functions, we perform a Fisher matrix analysis and find that the unmarginalized $68\\%$ CL errors on the parameters describing the modifications of gravity are of order $\\sigma\\sim10^{-2}$--$10^{-3}$. We also consider two other fiducial models. A nonminimal coupling of CDM enhances the effects of modified gravit...
Nucleon effective masses in field theories of dense matter
Energy Technology Data Exchange (ETDEWEB)
Lee, C.H.; Reddy, S.; Prakash, M. [Dept. of Physics and Astronomy, Stony Brook, NY (United States)
1998-06-01
We point out some generic trends of effective masses in commonly used field-theoretical descriptions of stellar matter in which several species of strongly interacting particles of dissimilar masses may be present. (orig.)
Organizational Friction: Urban Crime Control Diminish Effect Theory
2010-12-10
its neighbors, due to its healthy tourism industry , it has not managed to escape the challenges that confront much of the rest of Latin America. The...employment in the tourism industry . Paul is 27 years old, single, and is currently unemployed. The substantive part of the study began by examining the...use of an aspirin for a toothache, which after prolong use loses its effect. In the final analysis perhaps the greatest testimony to the effect that
Theory of Spin Seebeck Effects in a Quantum Wire
Ogata, Masao; Fukuyama, Hidetoshi
2017-09-01
Spin Seebeck coefficient in a quantum wire is microscopically derived using the Kubo formula and thermal Green’s functions, taking account of the effects of disorder in a self-consistent t-matrix approximation. It is found that the induced spin current to be detected through the inverse spin Hall effect will be in the range of experimental detectability when the chemical potential for electrons in the quantum wire is close to the band edge.
Linear-response theory of the longitudinal spin Seebeck effect
Adachi, Hiroto; Maekawa, Sadamichi
2012-01-01
We theoretically investigate the longitudinal spin Seebeck effect, in which the spin current is injected from a ferromagnet into an attached nonmagnetic metal in a direction parallel to the temperature gradient. Using the fact that the phonon heat current flows intensely into the attached nonmagnetic metal in this particular configuration, we show that the sign of the spin injection signal in the longitudinal spin Seebeck effect can be opposite to that in the conventional transverse spin Seeb...
Extended Soliton Solutions in an Effective Action for SU(2 Yang-Mills Theory
Directory of Open Access Journals (Sweden)
Nobuyuki Sawado
2006-01-01
Full Text Available The Skyrme-Faddeev-Niemi (SFN model which is an O(3 σ model in three dimensional space up to fourth-order in the first derivative is regarded as a low-energy effective theory of SU(2 Yang-Mills theory. One can show from the Wilsonian renormalization group argument that the effective action of Yang-Mills theory recovers the SFN in the infrared region. However, the theory contains an additional fourth-order term which destabilizes the soliton solution. We apply the perturbative treatment to the second derivative term in order to exclude (or reduce the ill behavior of the original action and show that the SFN model with the second derivative term possesses soliton solutions.
Effective theories for 2+1 dimensional non-Abelian topological spin liquids
Hernaski, Carlos A.; Gomes, Pedro R. S.
2017-10-01
In this work we propose an effective low-energy theory for a large class of 2+1 dimensional non-Abelian topological spin liquids whose edge states are conformal degrees of freedom with central charges corresponding to the coset structure su(2) k ⊕ su(2) k ' /su(2) k+ k ' . For particular values of k ' it furnishes the series for unitary minimal and superconformal models. These gapped phases were recently suggested to be obtained from an array of one-dimensional coupled quantum wires. In doing so we provide an explicit relationship between two distinct approaches: quantum wires and Chern-Simons bulk theory. We firstly make a direct connection between the interacting quantum wires and the corresponding conformal field theory at the edges, which turns out to be given in terms of chiral gauged WZW models. Relying on the bulk-edge correspondence we are able to construct the underlying non-Abelian Chern-Simons effective field theory.
Confidence Intervals for Standardized Effect Sizes: Theory, Application, and Implementation
Directory of Open Access Journals (Sweden)
Ken Kelley
2007-02-01
Full Text Available The behavioral, educational, and social sciences are undergoing a paradigmatic shift in methodology, from disciplines that focus on the dichotomous outcome of null hypothesis significance tests to disciplines that report and interpret effect sizes and their corresponding confidence intervals. Due to the arbitrariness of many measurement instruments used in the behavioral, educational, and social sciences, some of the most widely reported effect sizes are standardized. Although forming confidence intervals for standardized effect sizes can be very beneficial, such confidence interval procedures are generally difficult to implement because they depend on noncentral t, F, and x2 distributions. At present, no main-stream statistical package provides exact confidence intervals for standardized effects without the use of specialized programming scripts. Methods for the Behavioral, Educational, and Social Sciences (MBESS is an R package that has routines for calculating confidence intervals for noncentral t, F, and x2 distributions, which are then used in the calculation of exact confidence intervals for standardized effect sizes by using the confidence interval transformation and inversion principles. The present article discusses the way in which confidence intervals are formed for standardized effect sizes and illustrates how such confidence intervals can be easily formed using MBESS in R.
Effective medium theory of thin-plate acoustic metamaterials.
Li, Pei; Yao, Shanshan; Zhou, Xiaoming; Huang, Guoliang; Hu, Gengkai
2014-04-01
Effective dynamic properties of acoustic metamaterials made of multilayered flexible thin-plates with periodically attached mass-spring resonators are studied. By using the transfer matrix method, the thin-plate acoustic metamaterial under the plane wave incidence is characterized by a homogeneous effective medium with anisotropic mass density. An approximate analytic expression of effective mass density is derived for a single-layer metamaterial in the normally incident case, and it is shown that the effective mass density can follow either Lorentz or Drude medium models. For the obliquely incident case, it is found that effective mass density is dependent on the lateral wave number of incident waves. Such spatial dispersion comes from the coincidence effect between the incident acoustic wave and flexural wave in the thin plate, and it occurs at much lower frequencies than that for a uniform plate without resonators. Based on the observed spatial dispersion, an acoustic device made of thin-plate metamaterials is designed for frequency-controlled acoustic directive radiation in the low-frequency regime.
Trepte, Sabine; Krämer, Nicole
2007-01-01
"In this paper we propose that Tajfel’s (1979) social identity theory (SIT) and self-categorization theory (SCT, Turner, Brown & Tajfel, 1987) is a relevant and helpful theoretical groundwork to explain selective exposure to media content in general and to entertainment media in particular. It is hypothesized that gender and national identity have a significant effect on selective exposure to entertainment series when being salient. Two international quasi-experimental studies have been condu...
Lower limit to the scale of an effective quantum theory of gravitation.
Caldwell, R R; Grin, Daniel
2008-01-25
An effective quantum theory of gravitation in which gravity weakens at energies higher than approximately 10(-3) eV is one way to accommodate the apparent smallness of the cosmological constant. Such a theory predicts departures from the Newtonian inverse-square force law on distances below approximately 0.05 mm. However, it is shown that this modification also leads to changes in the long-range behavior of gravity and is inconsistent with observed gravitational lenses.
Effective dynamics along given reaction coordinates, and reaction rate theory.
Zhang, Wei; Hartmann, Carsten; Schütte, Christof
2016-12-22
In molecular dynamics and related fields one considers dynamical descriptions of complex systems in full (atomic) detail. In order to reduce the overwhelming complexity of realistic systems (high dimension, large timescale spread, limited computational resources) the projection of the full dynamics onto some reaction coordinates is examined in order to extract statistical information like free energies or reaction rates. In this context, the effective dynamics that is induced by the full dynamics on the reaction coordinate space has attracted considerable attention in the literature. In this article, we contribute to this discussion: we first show that if we start with an ergodic diffusion process whose invariant measure is unique then these properties are inherited by the effective dynamics. Then, we give equations for the effective dynamics, discuss whether the dominant timescales and reaction rates inferred from the effective dynamics are accurate approximations of such quantities for the full dynamics, and compare our findings to results from approaches like Mori-Zwanzig, averaging, or homogenization. Finally, by discussing the algorithmic realization of the effective dynamics, we demonstrate that recent algorithmic techniques like the "equation-free" approach and the "heterogeneous multiscale method" can be seen as special cases of our approach.
Local thermodynamic mapping for effective liquid density-functional theory
Kyrlidis, Agathagelos; Brown, Robert A.
1992-01-01
The structural-mapping approximation introduced by Lutsko and Baus (1990) in the generalized effective-liquid approximation is extended to include a local thermodynamic mapping based on a spatially dependent effective density for approximating the solid phase in terms of the uniform liquid. This latter approximation, called the local generalized effective-liquid approximation (LGELA) yields excellent predictions for the free energy of hard-sphere solids and for the conditions of coexistence of a hard-sphere fcc solid with a liquid. Moreover, the predicted free energy remains single valued for calculations with more loosely packed crystalline structures, such as the diamond lattice. The spatial dependence of the weighted density makes the LGELA useful in the study of inhomogeneous solids.
The Hippocratic Oath, effect size, and utility theory.
Bordley, Robert F
2009-01-01
To be consistent with the Hippocratic Oath, this article proposes that a physician choose that treatment that has the greatest chance of giving the patient an outcome no worse than the uncertain outcome an untreated patient would experience. As this article shows, this specifies the utility function that the physician should use in choosing among treatments. This utility function, although varying with the life circumstances of the patient, need not reflect the patient's utility function. This Hippocratic utility function can be estimated with an effect size measure similar to the stochastic superiority and common language effect size measures used in the statistical analysis of experiments.
Employment Effects of Dispersal Policies. Part I: Theory
DEFF Research Database (Denmark)
Damm, Anna Piil; Rosholm, Michael
2003-01-01
and the transition rate into employment outside the local labour market, but decreases the transition rate into local employment. Thus, a decrease in current place utility decreases the overall job-finding rate if the local reservation wage effect dominates. We argue that dispersal policies on refugee immigrants...... are characterised by low average values of current place utility. Hence, the model predicts that dispersal policies increase the geographical mobility rates of refugees and, for a sufficiently large local reservation wage effect, decrease their job-finding rates....
Partially massless higher-spin theory II: one-loop effective actions
Brust, Christopher; Hinterbichler, Kurt
2017-01-01
We continue our study of a generalization of the D-dimensional linearized Vasiliev higher-spin equations to include a tower of partially massless (PM) fields. We compute one-loop effective actions by evaluating zeta functions for both the "minimal" and "non-minimal" parity-even versions of the theory. Specifically, we compute the log-divergent part of the effective action in odd-dimensional Euclidean AdS spaces for D = 7 through 19 (dual to the a-type conformal anomaly of the dual boundary theory), and the finite part of the effective action in even-dimensional Euclidean AdS spaces for D = 4 through 8 (dual to the free energy on a sphere of the dual boundary theory). We pay special attention to the case D = 4, where module mixings occur in the dual field theory and subtlety arises in the one-loop computation. The results provide evidence that the theory is UV complete and one-loop exact, and we conjecture and provide evidence for a map between the inverse Newton's constant of the partially massless higher-spin theory and the number of colors in the dual CFT.
Effectiveness of Interactive Video to Teach CPR Theory and Skills.
Lyness, Ann L.
This study investigated whether an interactive video system of instruction taught cardiopulmonary resuscitation (CPR) as effectively as traditional instruction. Using standards of the American Heart Association, the study was designed with two randomized groups to be taught either by live instruction or by interactive video. Subjects were 100…
Psychological Theory and Pedagogical Effectiveness: The Learning Promotion Potential Framework
Tomlinson, Peter
2008-01-01
Background: After a century of educational psychology, eminent commentators are still lamenting problems besetting the appropriate relating of psychological insights to teaching design, a situation not helped by the persistence of crude assumptions concerning the nature of pedagogical effectiveness. Aims: To propose an analytical or…
Percolation theory to predict effective properties of solid oxide fuel-cell composite electrodes
Chen, Daifen; Lin, Zijing; Zhu, Huayang; Kee, Robert J.
A micromodel based upon percolation theory is developed to predict effective properties in composite electrodes for solid oxide fuel-cell (SOFC) applications. The theory considers binary and multi-component mixtures of particles that are either ion or electron conductors. The model predicts effective ionic and electronic conductivities, three-phase boundary lengths, and hydraulic pore radii. The effective properties depend upon primary physical characteristics, including average particle-radii, volumetric packing densities, particle contact angles, and porosity. All results are presented in nondimensional form, which provides considerable generality in their practical application.
Resummation and renormalization in effective theories of particle physics
Jakovac, Antal
2015-01-01
Effective models of strong and electroweak interactions are extensively applied in particle physics phenomenology, and in many instances can compete with large-scale numerical simulations of Standard Model physics. These contexts include but are not limited to providing indications for phase transitions and the nature of elementary excitations of strong and electroweak matter. A precondition for obtaining high-precision predictions is the application of some advanced functional techniques to the effective models, where the sensitivity of the results to the accurate choice of the input parameters is under control and the insensitivity to the actual choice of ultraviolet regulators is ensured. The credibility of such attempts ultimately requires a clean renormalization procedure and an error estimation due to a necessary truncation in the resummation procedure. In this concise primer we discuss systematically and in sufficient technical depth the features of a number of approximate methods, as applied to vario...
On quantum effects in a theory of biological evolution.
Martin-Delgado, M A
2012-01-01
We construct a descriptive toy model that considers quantum effects on biological evolution starting from Chaitin's classical framework. There are smart evolution scenarios in which a quantum world is as favorable as classical worlds for evolution to take place. However, in more natural scenarios, the rate of evolution depends on the degree of entanglement present in quantum organisms with respect to classical organisms. If the entanglement is maximal, classical evolution turns out to be more favorable.
The theory behind the age-related positivity effect
Directory of Open Access Journals (Sweden)
Andrew E Reed
2012-09-01
Full Text Available The positivity effect refers to an age-related trend that favors positive over negative stimuli in cognitive processing. Relative to their younger counterparts, older people attend to and remember more positive than negative information. Since the effect was initially identified and the conceptual basis articulated (Mather & Carstensen, 2005 scores of independent replications and related findings have appeared in the literature. Over the same period, a number of investigations have failed to observe age differences in the cognitive processing of emotional material. When findings are considered in theoretical context, a reliable pattern of evidence emerges that helps to refine conceptual tenets. In this article we articulate the operational definition and theoretical foundations of the positivity effect and review the empirical evidence based on studies of visual attention, memory, decision-making, and neural activation. We conclude with a discussion of future research directions with emphasis on the conditions where a focus on positive information may benefit and/or impair cognitive performance in older people.
Constraining Dark Sectors at Colliders: Beyond the Effective Theory Approach
Harris, Philip; Spannowsky, Michael; Williams, Ciaran
2015-01-01
We outline and investigate a set of benchmark simplified models with the aim of providing a minimal simple framework for an interpretation of the existing and forthcoming searches of dark matter particles at the LHC. The simplified models we consider provide microscopic QFT descriptions of interactions between the Standard Model partons and the dark sector particles mediated by the four basic types of messenger fields: scalar, pseudo-scalar, vector or axial-vector. Our benchmark models are characterised by four to five parameters, including the mediator mass and width, the dark matter mass and an effective coupling(s). In the gluon fusion production channel we resolve the top-quark in the loop and compute full top-mass effects for scalar and pseudo-scalar messengers. We show the LHC limits and reach at 8 and 14 TeV for models with all four messenger types. We also outline the complementarity of direct detection, indirect detection and LHC bounds for dark matter searches. Finally, we investigate the effects wh...
Using Expectancy Effects Theory To Analyze the Groups Who Supported Senator McCarthy.
Corder, Lloyd E.
In this essay, Festinger's cognitive dissonance theory (which seeks to explain how individuals try to reconcile holding two inconsistent beliefs at the same time) is used to explore the nature of expectancy effects and what possible roles they play in the thinking of the radical right. The paper first defines expectancy effects and explains how…
Curry, Steven P.
2016-01-01
The purpose of this qualitative study was to explore how faculty members, teaching in the virtual environment of higher education, perceived the effectiveness of leader actions to understand how principles of existing leadership theory in critical areas such as communication effectiveness, development of trust, and ability to motivate faculty…
Toker, Betül; Avci, Rasit
2015-01-01
This study examined the effectiveness of a cognitive-behavioral theory (CBT) psycho-educational group program on the academic procrastination behaviors of university students and the persistence of any training effect. This was a quasi-experimental research based on an experimental and control group pretest, posttest, and followup test model.…
Thermoelectric and Thermomagnetic Effects in Kaluza's Kinetic Theory
Sagaceta-Mejía, Alma R.; Sandoval-Villalbazo, Alfredo; García-Perciante, Ana L.
2017-10-01
A five-dimensional treatment of the Boltzmann equation is used to establish the constitutive equations that relate thermodynamic fluxes and forces up to first order in the gradients for simple charged fluids in the presence of electromagnetic fields. The formalism uses the ansatz first introduced by Kaluza back in 1921, proposing that the particle charge-mass ratio is proportional to the fifth component of its velocity field. It is shown that in this approach, space-time curvature yields thermodynamic forces leading to generalizations of the well-known cross-effects present in linear irreversible thermodynamics.
Theory of Crowding Effects on Bimolecular Reaction Rates.
Berezhkovskii, Alexander M; Szabo, Attila
2016-07-07
An analytical expression for the rate constant of a diffusion-influenced bimolecular reaction in a crowded environment is derived in the framework of a microscopic model that accounts for: (1) the slowdown of diffusion due to crowding and the dependence of the diffusivity on the distance between the reactants, (2) a crowding-induced attractive short-range potential of mean force, and (3) nonspecific reversible binding to the crowders. This expression spans the range from reaction to diffusion control. Crowding can increase the reaction-controlled rate by inducing an effective attraction between reactants but decrease the diffusion-controlled rate by reducing their relative diffusivity.
The challenge of video games to media effect theory
Malliet, Steven
2007-01-01
Research on the effects of video game play has mainly been focusing on topics such as agression, violence and hostility. This is undoubtedly related to the countless social and political debates that have been held on the harmful impact of this new medium. From a social-psychological point of view, researchers have frequently observed that, up to 15 minutes after having played a game of action, one is more excited or aroused than in the case one had not played that game. Concerning the long-t...
Effects of a social cognitive theory-based hip fracture prevention web site for older adults.
Nahm, Eun-Shim; Barker, Bausell; Resnick, Barbara; Covington, Barbara; Magaziner, Jay; Brennan, Patricia Flatley
2010-01-01
The purposes of this study were to develop a Social Cognitive Theory-based, structured Hip Fracture Prevention Web site for older adults and conduct a preliminary evaluation of its effectiveness. The Theory-based, structured Hip Fracture Prevention Web site is composed of learning modules and a moderated discussion board. A total of 245 older adults recruited from two Web sites and a newspaper advertisement were randomized into the Theory-based, structured Hip Fracture Prevention Web site and the conventional Web sites groups. Outcomes included (1) knowledge (hip fractures and osteoporosis), (2) self-efficacy and outcome expectations, and (3) calcium intake and exercise and were assessed at baseline, end of treatment (2 weeks), and follow-up (3 months). Both groups showed significant improvement in most outcomes. For calcium intake, only the Theory-based, structured Hip Fracture Prevention Web site group showed improvement. None of the group and time interactions were significant. The Theory-based, structured Hip Fracture Prevention Web site group, however, was more satisfied with the intervention. The discussion board usage was significantly correlated with outcome gains. Despite several limitations, the findings showed some preliminary effectiveness of Web-based health interventions for older adults and the use of a Theory-based, structured Hip Fracture Prevention Web site as a sustainable Web structure for online health behavior change interventions.
Chiral symmetry and effective field theories for hadronic, nuclear and stellar matter
Energy Technology Data Exchange (ETDEWEB)
Holt, Jeremy W., E-mail: jwholt.phys@gmail.com [Department of Physics, University of Washington, Seattle, 98195 (United States); Rho, Mannque [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Institut de Physique Théorique, CEA Saclay, 91191 Gif-sur-Yvette (France); Weise, Wolfram [Physik Department, Technische Universität München, D-85747 Garching (Germany); ECT*, Villa Tambosi, I-38123 Villazzano (Italy)
2016-03-21
Chiral symmetry, first entering in nuclear physics in the 1970s for which Gerry Brown played a seminal role, has led to a stunningly successful framework for describing strongly-correlated nuclear dynamics both in finite and infinite systems. We review how the early, germinal idea conceived with the soft-pion theorems in the pre-QCD era has evolved into a highly predictive theoretical framework for nuclear physics, aptly assessed by Steven Weinberg: “it (chiral effective field theory) allows one to show in a fairly convincing way that what they (nuclear physicists) have been doing all along... is the correct first step in a consistent approximation scheme”. Our review recounts both how the theory presently fares in confronting Nature and how one can understand its extremely intricate workings in terms of the multifaceted aspects of chiral symmetry, namely, chiral perturbation theory, skyrmions, Landau Fermi-liquid theory, the Cheshire cat phenomenon, and hidden local and mended symmetries.
Quasiclassical theory for the superconducting proximity effect in Dirac materials
Hugdal, Henning G.; Linder, Jacob; Jacobsen, Sol H.
2017-06-01
We derive the quasiclassical nonequilibrium Eilenberger and Usadel equations to first order in quantities small compared to the Fermi energy, valid for Dirac edge and surface electrons with spin-momentum locking p .σ ¯ , as relevant for topological insulators. We discuss in detail several of the key technical points and assumptions of the derivation, and provide a Riccati parametrization of the equations. Solving first the equilibrium equations for S/N and S/F bilayers and Josephson junctions, we study the superconducting proximity effect in Dirac materials. Similarly to related works, we find that the effect of an exchange field depends strongly on the direction of the field. Only components normal to the transport direction lead to attenuation of the Cooper pair wave function inside the F. Fields parallel to the transport direction lead to phase shifts in the dependence on the superconducting phase difference for both the charge current and density of states in an S/F/S junction. Moreover, we compute the differential conductance in S/N and S/F bilayers with an applied voltage bias and determine the dependence on the length of the N and F regions and the exchange field.
DEFF Research Database (Denmark)
Codello, Alessandro; Jain, Rajeev Kumar
2017-01-01
Following our previous work wherein the leading order effective action was computed in the covariant effective field theory of gravity, here we specialize the effective action to the FRW spacetime and obtain the effective Friedmann equations. In particular, we focus our attention on studying...... expansion of the universe at the present epoch even in the absence of a cosmological constant. We briefly discuss some phenomenological consequences of our results....
Playing with QCD I: effective field theories. Fourth lecture
Energy Technology Data Exchange (ETDEWEB)
Fraga, Eduardo S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica
2009-07-01
Lattice QCD is just starting to explore the finite density region, still far away from the high-density low-temperature sector. pQCD at finite density seems to provide sensible results, even for not so large values of {mu}. Mass and gap effects provide important contributions to the EoS near the critical region. The phase diagram can be very rich in the high-{mu} sector, with different possibilities for pairing and color superconductivity. Astrophysical measurements are becoming increasingly precise, and will start killing models soon. Some signatures (for strange, quark or hybrid neutron stars) are still very similar, though. The interior of compact stars is a very rich and intricate medium, which may contain all sorts of condensates as well as deconfined quark matter. (author)
Using the Theory of Constraints for Effective Supply Chain Management
Directory of Open Access Journals (Sweden)
Archie Lockhamy III
1999-08-01
Full Text Available This article provides methodology and guidelines for employing a 'constraint-based approach for effective supply chain management. The article explores the shortcomings of using a traditional supply chain management as well as an Activity Based Management (ABM approach in the managing of supply chains. In addition, the article introduces a supply chain management methodology based on achieving a global optimum for the entire chain. Examples are provided on how constraint-based techniques are currently being applied to the management of certain subsets of the supply chain. Guidelines are presented for managing supply chains using a constraint-based approach. Finally, the article ends with the discussion of the implications regarding the use of a constraint-based approach to the management of supply chains along with the need for future research in this area.
Thermal and viscous effects on sound waves: revised classical theory.
Davis, Anthony M J; Brenner, Howard
2012-11-01
In this paper the recently developed, bi-velocity model of fluid mechanics based on the principles of linear irreversible thermodynamics (LIT) is applied to sound propagation in gases taking account of first-order thermal and viscous dissipation effects. The results are compared and contrasted with the classical Navier-Stokes-Fourier results of Pierce for this same situation cited in his textbook. Comparisons are also made with the recent analyses of Dadzie and Reese, whose molecularly based sound propagation calculations furnish results virtually identical with the purely macroscopic LIT-based bi-velocity results below, as well as being well-supported by experimental data. Illustrative dissipative sound propagation examples involving application of the bi-velocity model to several elementary situations are also provided, showing the disjoint entropy mode and the additional, evanescent viscous mode.
Z boson mediated dark matter beyond the effective theory
Kearney, John; Orlofsky, Nicholas; Pierce, Aaron
2017-02-01
Direct detection bounds are beginning to constrain a very simple model of weakly interacting dark matter—a Majorana fermion with a coupling to the Z boson. In a particularly straightforward gauge-invariant realization, this coupling is introduced via a higher-dimensional operator. While attractive in its simplicity, this model generically induces a large ρ parameter. An ultraviolet completion that avoids an overly large contribution to ρ is the singlet-doublet model. We revisit this model, focusing on the Higgs blind spot region of parameter space where spin-independent interactions are absent. This model successfully reproduces dark matter with direct detection mediated by the Z boson but whose cosmology may depend on additional couplings and states. Future direct detection experiments should effectively probe a significant portion of this parameter space, aside from a small coannihilating region. As such, Z -mediated thermal dark matter as realized in the singlet-doublet model represents an interesting target for future searches.
Can chaos theory be used to increase preventive maintenance effectiveness?
Rice, W P
1996-01-01
Clinical engineering programs typically establish the content and frequency of a device's inspection and preventive maintenance procedures at the time of implementation. In some programs, these are not altered throughout the device's useful life. In others, history data and traditional statistical methods are used to adapt procedures to change in risk measures. Such methods are essentially reactive in that they are based upon past trends and do not readily consider potentialities for future change in the performance and utilization environments. Chaos theoretical concepts and related measures, when implemented in artificial intelligence programs such as neural networks and genetic algorithms, and used as an adjunct with computerized technology management programs, can assist in asking and answering the more dynamic, proactive questions necessary for effective inspection and preventive maintenance optimization. Today's healthcare environment is ideal for exploring their utilization.
Quantum Theory of SASE-FEL with Propagation Effects
Bonifacio, R
2005-01-01
We present a proof of principle of the novel regime of quantum SASE with propagation effects. Using a self-consistent system of Schrodinger-Maxwell equations, we show that the dynamics of the system is determined by a properly defined "quantum FEL-parameter", ρ', which rules the number of photons emitted per electron, as well as the electron recoil in units of ћk. In the limit ρ'>>1 the quantum model reproduces the classical SASE regime with random spiking behavior and broad spectrum. In this limit we show that the equation for the Wigner function reduces to the classical Vlasov equation. In the opposite limit, ρ'<1, we demonstrate "quantum purification" of SASE: the classical spiking behavior disappears and the power spectrum becomes very narrow so that the temporal coherence of the SASE spectrum is dramatically improved. Photon statistics, electron-photon entangled states, minimum uncertainty states and quantum limitations on bunching and energy spre...
Distinguishing f( R) theories from general relativity by gravitational lensing effect
Liu, Hongguang; Wang, Xin; Li, Haida; Ma, Yongge
2017-11-01
The post-Newtonian formulation of a general class of f( R) theories is set up in a third-order approximation. It turns out that the information of a specific form of f( R) gravity is encoded in the Yukawa potential, which is contained in the perturbative expansion of the metric components. Although the Yukawa potential is canceled in the second-order expression of the effective refraction index of light, detailed analysis shows that the difference of the lensing effect between the f( R) gravity and general relativity does appear at the third order when √{f''(0)/f'(0)} is larger than the distance d_0 to the gravitational source. However, the difference between these two kinds of theories will disappear in the axially symmetric spacetime region. Therefore only in very rare case the f( R) theories are distinguishable from general relativity by gravitational lensing effect in a third-order post-Newtonian approximation.
DEFF Research Database (Denmark)
Fromager, Emmanuel; Jensen, Hans Jørgen Aagaard
2011-01-01
-cluster theories, self-consistency effects are introduced in the density functional part, which for an exact solution requires iterations. They are generally assumed to be small but no detailed study has been performed so far. Here, the authors analyze self-consistency when using Møller-Plesset-type (MP......Range-separated density-functional theory combines wave function theory for the long-range part of the two-electron interaction with density-functional theory for the short-range part. When describing the long-range interaction with non-variational methods, such as perturbation or coupled......) perturbation theory for the long range interaction. The lowest-order self-consistency corrections to the wave function and the energy, that enter the perturbation expansions at the second and fourth order, respectively, are both expressed in terms of the one-electron reduced density matrix. The computational...
Analytical theory of effective interactions in binary colloidal systems of soft particles.
Majka, M; Góra, P F
2014-09-01
While density functional theory with integral equations techniques are very efficient tools in the numerical analysis of complex fluids, analytical insight into the phenomenon of effective interactions is still limited. In this paper, we propose a theory of binary systems that results in a relatively simple analytical expression combining arbitrary microscopic potentials into effective interaction. The derivation is based on translating a many-particle Hamiltonian including particle-depletant and depletant-depletant interactions into the occupation field language, which turns the partition function into multiple Gaussian integrals, regardless of what microscopic potentials are chosen. As a result, we calculate the effective Hamiltonian and discuss when our formula is a dominant contribution to the effective interactions. Our theory allows us to analytically reproduce several important characteristics of systems under scrutiny. In particular, we analyze the following: the effective attraction as a demixing factor in the binary systems of Gaussian particles, the screening of charged spheres by ions, which proves equivalent to Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, effective interactions in the binary mixtures of Yukawa particles, and the system of particles consisting of both a repulsive core and an attractive/repulsive Yukawa interaction tail. For this last case, we reproduce the "attraction-through-repulsion" and "repulsion-through-attraction" effects previously observed in simulations.
Theory and measurement of the electron cloud effect
Harkay, K C
1999-01-01
Photoelectrons produced through the interaction of synchrotron radiation and the vacuum chamber walls can be accelerated by a charged particle beam, acquiring sufficient energy to produce secondary electrons (SEs) in collisions with the walls. If the secondary-electron yield (SEY) coefficient of the wall material is greater than one, a runaway condition can develop. In addition to the SEY, the degree of amplification depends on the beam intensity and temporal distribution. As the electron cloud builds up along a train of stored bunches, a transverse perturbation of the head bunch can be communicated to trailing bunches in a wakefield-like interaction with the cloud. The electron cloud effect is especially of concern for the high-intensity PEP-II (SLAC) and KEK B-factories and at the Large Hadron Collider (LHC) at CERN. An initiative was undertaken at the Advanced Photon Source (APS) storage ring to characterize the electron cloud in order to provide realistic limits on critical input parameters in the models ...
Cluster multipole theory for anomalous Hall effect in antiferromagnets
Suzuki, M.-T.; Koretsune, T.; Ochi, M.; Arita, R.
2017-03-01
We introduce a cluster extension of multipole moments to discuss the anomalous Hall effect (AHE) in both ferromagnetic (FM) and antiferromagnetic (AFM) states in a unified framework. We first derive general symmetry requirements for the AHE in the presence or absence of the spin-orbit coupling by considering the symmetry of the Berry curvature in k space. The cluster multipole (CMP) moments are then defined to quantify the macroscopic magnetization in noncollinear AFM states as a natural generalization of the magnetization in FM states. We identify the macroscopic CMP order which induces the AHE. The theoretical framework is applied to the noncollinear AFM states of Mn3Ir , for which an AHE was predicted in a first-principles calculation, and Mn3Z (Z =Sn ,Ge ), for which a large AHE was recently discovered experimentally. We further compare the AHE in Mn3Z and bcc Fe in terms of the CMP. We show that the AHE in Mn3Z is characterized by the magnetization of a cluster octupole moment in the same manner as that in bcc Fe characterized by the magnetization of the dipole moment.
Effective hospital leadership for quality: theory and practice.
Preston, A P; Saunders, I W; O'Sullivan, D; Garrigan, E; Rice, J
1995-01-01
Hospitals need excellent leadership to be efficient in the use of scarce stakeholder resources and to be effective in the competitive provision of services to multiple customers. This study was conducted with the cooperation of the executive team at a large government-funded hospital in Brisbane. It focused on understanding the conceptual models of leadership held by members of the executive and comparing this model with an externally derived model of leadership. Performance on the local model was estimated by cross-linking performance assessment on the external model. Members of the executive espoused, and were also rated by others in the hospital as practising, to a moderate degree, a transformational style of leadership. An overall evaluation of quality practice in the hospital revealed the use of data, the understanding of processes and the formation of supplier partnerships as the areas of hospital activity most limiting the ability to improve. The implications of the conceptual model and performance levels are discussed in relation to the introduction of quality management practice in the hospital, and in terms of management development. A complementary paper focusing on quality implementation as perceived at different staff levels in the hospital is in preparation.
Obstruction of black hole singularity by quantum field theory effects
Energy Technology Data Exchange (ETDEWEB)
Abedi, Jahed; Arfaei, Hessamaddin [Department of Physics, Sharif University of Technology,P.O. Box 11155-9161, Tehran, Irany (Iran, Islamic Republic of); School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2016-03-21
We consider the back reaction of the energy due to quantum fluctuation of the background fields considering the trace anomaly for Schwarzschild black hole. It is shown that it will result in modification of the horizon and also formation of an inner horizon. We show that the process of collapse of a thin shell stops before formation of the singularity at a radius slightly smaller than the inner horizon at the order of (c{sub A}(M/(M{sub p}))){sup 1/3}l{sub p}. After the collapse stops the reverse process takes place. Thus we demonstrate that without turning on quantum gravity and just through the effects the coupling of field to gravity as trace anomaly of quantum fluctuations the formation of the singularity through collapse is obstructed. An important consequence of our work is existence of an extremal solution with zero temperature and a mass which is lower bound for the Schwazschild solution. This solution is also the asymptotic final stable state after Hawking radiation.
Effective Field Theory Approaches To B Meson Decay
Williamson, A R
2005-01-01
In this thesis we look at a variety of B meson decays. These decays are important for measuring the CKM matrix elements and over-constraining the standard model. We consider two categories of decays: inclusive semi-leptonic and exclusive non-leptonic. Inclusive semi-leptonic B¯ → X uℓνℓ decays are the theoretically cleanest ways to extract the CKM matrix element | Vub|. A large B¯ → Xuℓν background reduces the available phase space, leaving the decay rate sensitive to the non-perturbative shape function of the B meson. We study the O(Λ QCD/mb) corrections to the hadronic invariant mass spectrum dΓ/dsH in B¯ → Xuℓν ℓ decays, and discuss the implications for the extraction of |Vub|. Using simple models for the subleading shape functions, the effects of subleading operators are estimated to be at the few percent level for experimentally relevant cuts. The subleading correction...
Baryonic forces and hyperons in nuclear matter from SU(3) chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Petschauer, Stefan Karl
2016-02-12
In this work the baryon-baryon interaction is studied at next-to-leading order in SU(3) chiral effective field theory and applied to hyperon-nucleon scattering. The properties of hyperons in isospin-symmetric as well as asymmetric nuclear matter are calculated within the Bruecker-Hartree-Fock formalism. Moreover, the leading three-baryon interaction is derived and its low-energy constants are estimated from decuplet intermediate states. We conclude, that chiral effective field theory is a well-suited tool to describe the baryonic forces.
Effective field theory and electroweak baryogenesis in the singlet-extended Standard Model
Energy Technology Data Exchange (ETDEWEB)
Damgaard, P.H. [Niels Bohr International Academy and Discovery Center, The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen Ø, DK-2100 (Denmark); Haarr, A. [Faculty of Science and Technology, University of Stavanger,Stavanger, N-4036 (Norway); O’Connell, D. [Higgs Centre for Theoretical Physics, School of Physics and Astronomy,The University of Edinburgh, Edinburgh, Scotland, EH9 3JZ (United Kingdom); Tranberg, A. [Faculty of Science and Technology, University of Stavanger,Stavanger, N-4036 (Norway)
2016-02-16
Electroweak baryogenesis is a simple and attractive candidate mechanism for generating the observed baryon asymmetry in the Universe. Its viability is sometimes investigated in terms of an effective field theory of the Standard Model involving higher dimension operators. We investigate the validity of such an effective field theory approach to the problem of identifying electroweak phase transitions strong enough for electroweak baryogenesis to be successful. We identify and discuss some pitfalls of this approach due to the modest hierarchy between mass scales of heavy degrees or freedom and the Higgs, and the possibility of dimensionful couplings violating the decoupling between light and heavy degrees of freedom.
DEFF Research Database (Denmark)
Johansen, Tine Rosenthal; Henriksen, Thomas Duus
2013-01-01
This paper illustrates two models for using learning games to teach across disciplines and classes. Two different learning games are used for bringing together students from different courses to facilitate cross-disciplinary classes on management and organisational learning.......This paper illustrates two models for using learning games to teach across disciplines and classes. Two different learning games are used for bringing together students from different courses to facilitate cross-disciplinary classes on management and organisational learning....
Burgess, C. P.; Hayman, Peter; Rummel, Markus; Williams, Matt; Zalavári, László
2017-07-01
We apply point-particle effective field theory (PPEFT) to compute the leading shifts due to finite-sized source effects in the Coulomb bound energy levels of a relativistic spinless charged particle. This is the analogue for spinless electrons of calculating the contribution of the charge-radius of the source to these levels, and our calculation disagrees with standard calculations in several ways. Most notably we find there are two effective interactions with the same dimension that contribute to leading order in the nuclear size, one of which captures the standard charge-radius contribution. The other effective operator is a contact interaction whose leading contribution to δE arises linearly (rather than quadratically) in the small length scale, ɛ, characterizing the finite-size effects, and is suppressed by ( Zα)5. We argue that standard calculations miss the contributions of this second operator because they err in their choice of boundary conditions at the source for the wave-function of the orbiting particle. PPEFT predicts how this boundary condition depends on the source's charge radius, as well as on the orbiting particle's mass. Its contribution turns out to be crucial if the charge radius satisfies ɛ ≲ ( Zα)2 a B , where a B is the Bohr radius, because then relativistic effects become important for the boundary condition. We show how the problem is equivalent to solving the Schrödinger equation with competing Coulomb, inverse-square and delta-function potentials, which we solve explicitly. A similar enhancement is not predicted for the hyperfine structure, due to its spin-dependence. We show how the charge-radius effectively runs due to classical renormalization effects, and why the resulting RG flow is central to predicting the size of the energy shifts (and is responsible for its being linear in the source size). We discuss how this flow is relevant to systems having much larger-than-geometric cross sections, such as those with large
On the Effective Action of Dressed Mean Fields for N=4 Super-Yang-Mills Theory
Cvetic, Gorazd; Kondrashuk, Igor; Schmidt, Ivan
2006-01-01
On the basis of the general considerations such as R-operation and Slavnov-Taylor identity we show that the effective action, being understood as Legendre transform of the logarithm of the path integral, possesses particular structure in N = 4 supersymmetric Yang-Mills theory for kernels of the effective action expressed in terms of the dressed effective fields. These dressed effective fields have been introduced in our previous papers as actual variables of the effective action. The concept of dressed effective fields naturally appears in the framework of solution to Slavnov-Taylor identity. The particularity of the structure is independence of these kernels on the ultraviolet regularization scale Λ. These kernels are functions of mutual spacetime distances and of the gauge coupling. The fact that β function in this theory vanishes is used significantly.
Effective Action of Dressed Mean Fields for {N}=4 Super-Yang Theory
Cvetič, Gorazd; Kondrashuk, Igor; Schmidt, Ivan
Based on general considerations such as R-operation and Slavnov-Taylor identity we show that the effective action, being understood as Legendre transform of the logarithm of the path integral, possesses particular structure in {N}=4 supersymmetric Yang-Mills theory for kernels of the effective action expressed in terms of the dressed effective fields. These dressed effective fields have been introduced in our previous papers as actual variables of the effective action. The concept of dressed effective fields naturally appears in the framework of solution to Slavnov-Taylor identity. The particularity of the structure is the independence of these kernels on the ultraviolet regularization scale Λ. These kernels are functions of mutual spacetime distances and of the gauge coupling. The fact that β function in this theory is zero is used significantly.
On the Effective Action of Dressed Mean Fields for N = 4 Super-Yang-Mills Theory
Directory of Open Access Journals (Sweden)
Gorazd Cvetic
2006-01-01
Full Text Available On the basis of the general considerations such as R-operation and Slavnov-Taylor identity we show that the effective action, being understood as Legendre transform of the logarithm of the path integral, possesses particular structure in N = 4 supersymmetric Yang-Mills theory for kernels of the effective action expressed in terms of the dressed effective fields. These dressed effective fields have been introduced in our previous papers as actual variables of the effective action. The concept of dressed effective fields naturally appears in the framework of solution to Slavnov-Taylor identity. The particularity of the structure is independence of these kernels on the ultraviolet regularization scale Λ. These kernels are functions of mutual spacetime distances and of the gauge coupling. The fact that β function in this theory vanishes is used significantly.
Reformulation of the Hermitean 1-matrix model as an effective field theory
Energy Technology Data Exchange (ETDEWEB)
Klitz, Alexander
2009-07-15
The formal Hermitean 1-matrix model is shown to be equivalent to an effective field theory. The correlation functions and the free energy of the matrix model correspond directly to the correlation functions and the free energy of the effective field theory. The loop equation of the field theory coupling constants is stated. Despite its length, this loop equation is simpler than the loop equations in the matrix model formalism itself since it does not contain operator inversions in any sense, but consists instead only of derivative operators and simple projection operators. Therefore the solution of the loop equation could be given for an arbitrary number of cuts up to the fifth order in the topological expansion explicitly. Two different methods of obtaining the contributions to the free energy of the higher orders are given, one depending on an operator H and one not depending on it. (orig.)
Analysis of the Effect of Water Activity on Ice Formation Using a New Theory of Nucleation
Barahona, Donifan
2013-01-01
In this work a new theory of nucleation is developed and used to investigate the effect of water activity on the formation of ice within super-cooled droplets. The new theory is based on a novel concept where the interface is assumed to be made of liquid molecules trapped by the solid matrix. Using this concept new expressions are developed for the critical ice germ size and the nucleation work, with explicit dependencies on temperature and water activity. However unlike previous approaches, the new theory does not depend on the interfacial tension between liquid and ice. Comparison against experimental results shows that the new theory is able to reproduce the observed effect of water activity on nucleation rate and freezing temperature. It allows for the first time a theoretical derivation of the constant shift in water activity between melting and nucleation. The new theory offers a consistent thermodynamic view of ice nucleation, simple enough to be applied in atmospheric models of cloud formation.
Directory of Open Access Journals (Sweden)
Vladimir Burtman
2015-07-01
Full Text Available One of the major tasks of the petroleum resource-efficient technologies (pREFFIT is the development and improvement of the methods of exploration for energy resources. This review paper summarizes the results of the research on induced polarization (IP effect in reservoir rocks conducted by the University of Utah Consortium for Electromagnetic Modeling and Inversion (CEMI and TechnoImaging. The electrical IP effect in hydrocarbon (HC bearing reservoir rocks having nonmetallic minerals is usually associated with membrane polarization, which is caused by a variation in the mobility of the ions throughout the rock structure. This mobility is related to the size and shape of the pores filled with electrolyte and the double electrical layers. We have studied the IP response of multiphase porous systems by conducting complex resistivity (CR frequency-domain IP measurements for two different groups of samples: sands and sandstones containing salt water in pores and those whose unsaturated pores were filled with synthetic oil. We have also studied selected carbonate reservoir formations, typical of some major HC deposits. The generalized effective-medium theory of induced polarization (GEMTIP was used to analyze the IP parameters of the measured responses. This paper presents a conceptual model of polarizing clusters to explain the observed IP phenomena. The results of this study show that the HC bearing sands and sandstone samples and carbonate rocks are characterized by a significant IP response. These experimental observations, compared with the theoretical modeling based on the GEMTIP approach, confirm earlier geophysical experiments with the application of the IP method for HC exploration.
Froehlich, Laura; Martiny, Sarah E; Deaux, Kay; Goetz, Thomas; Mok, Sog Yee
2016-09-01
This research explores implicit theory of intelligence (TOI) as a moderator of stereotype activation effects on test performance for members of negatively stereotyped and of favourably stereotyped groups. In Germany, Turkish-origin migrants are stereotyped as low in verbal ability. We predicted that on a test diagnostic of verbal intelligence, endorsement of an entity TOI predicts stereotype threat effects for Turkish-origin students and stereotype lift effects for German students. This effect could account for some of the performance gap between immigrants and host society members after stereotype activation. Study 1 (N = 107) established structural equivalence of implicit theories across the ethnic groups. In two experimental studies (Study 2: N = 182, Study 3: N = 190), we tested the moderating effect of TOI in a 2 (stereotype activation: diagnostic vs. non-diagnostic test) × 2 (ethnicity: German vs. Turkish migration background) experimental design. The results showed that when the test was described as diagnostic of verbal intelligence, higher entity theory endorsement predicted stereotype threat effects for Turkish-origin students (Study 2 and Study 3) and stereotype lift effects for German students (Study 3). The results are discussed in terms of practical implications for educational settings and theoretical implications for processes underlying stereotype activation effects. © 2016 The British Psychological Society.
Effect of Multiple Intelligence Theory Practice on Student Success by Bloom's Taxonomy
Uzunoz, Abdulkadir
2011-01-01
In this study, it is aimed to determine the effects of the "Multiple Intelligence Theory" on the retention and achievement of the students according to Bloom Taxonomy. This study is a research as an experimental model. Research in academic year of 2008/2009 in Foca Izmir Lesbos Reha Country High School 9 Class is conducted on students.…
Bemani Naeini, Ma'ssoumeh
2015-01-01
Gardner's Multiple Intelligences Theory (MIT), however having been embraced in the field of language acquisition, has apparently failed to play a role in research on learning styles as an alternative construct. This study aims at examining the potential effects of MI-based activities, as learning styles, on the listening proficiency of Iranian…
DEFF Research Database (Denmark)
Uskov, Alexander V.; Berg, Tommy Winther; Mørk, Jesper
2004-01-01
A theory for pulse amplification and saturation in quantum dot (QD) semiconductor optical amplifiers (SOAs) is developed. In particular, the maximum bit rate at which a data stream of pulses can be amplified without significant patterning effects is investigated. Simple expressions are derived...
Effects of Guided Writing Strategies on Students' Writing Attitudes Based on Media Richness Theory
Lan, Yu-Feng; Hung, Chun-Ling; Hsu, Hung-Ju
2011-01-01
The purpose of this paper is to develop different guided writing strategies based on media richness theory and further evaluate the effects of these writing strategies on younger students' writing attitudes in terms of motivation, enjoyment and anxiety. A total of 66 sixth-grade elementary students with an average age of twelve were invited to…
Zero-range effective field theory for resonant wino dark matter. Part I. Framework
Braaten, Eric; Johnson, Evan; Zhang, Hong
2017-11-01
The most dramatic "Sommerfeld enhancements" of neutral-wino-pair annihilation occur when the wino mass is near a critical value where there is a zero-energy S-wave resonance at the neutral-wino-pair threshold. Near such a critical mass, low-energy winos can be described by a zero-range effective field theory in which the winos interact nonperturbatively through a contact interaction. The effective field theory is controlled by a renormalization-group fixed point at which the neutral and charged winos are degenerate in mass and their scattering length is infinite. The parameters of the zero-range effective field theory can be determined by matching wino-wino scattering amplitudes calculated by solving the Schrödinger equation for winos interacting through a potential due to the exchange of weak gauge bosons. If the wino mass is larger than the critical value, the resonance is a wino-pair bound state. The power of the zero-range effective field theory is illustrated by calculating the rate for formation of the bound state in the collision of two neutral winos through the emission of two soft photons.
Low energy structure of the nucleon from chiral effective field theory
Directory of Open Access Journals (Sweden)
Alarcón Jose Manuel
2014-01-01
Full Text Available We present some updated results regarding the scalar and electromagnetic structure of the nucleon obtained by the relativistic formulation of chiral effective field theory with baryons. We compare them with previous determinations available in the literature, and show their relevance for searches of physics beyond the standard model in the low energy frontier.
Describing one- and two-neutron halos in effective field theory
Indian Academy of Sciences (India)
2014-11-01
Nov 1, 2014 ... c Indian Academy of Sciences. Vol. 83, No. 5. — journal of. November 2014 physics pp. 661–671. Describing one- and two-neutron halos in effective field theory. DANIEL R PHILLIPS. Department of Physics and Astronomy and Institute of Nuclear and Particle Physics,. Ohio University, Athens, OH 45701, ...
Leading Effective Educational Technology in K-12 School Districts: A Grounded Theory
Hill, Lara Gillian C.
2011-01-01
A systematic grounded theory qualitative study was conducted investigating the process of effectively leading educational technology in New Jersey public K-12 school districts. Data were collected from educational technology district leaders (whether formal or non-formal administrators) and central administrators through a semi-structured online…
Limitations of effective medium theory in multilayer graphite/hBN heterostructures
DEFF Research Database (Denmark)
Petersen, René; Pedersen, Thomas Garm; Gjerding, Morten Niklas
2016-01-01
We apply effective medium theory (EMT) to metamaterials consisting of a varying number of consecutive sheets of graphene and hexagonal boron nitride, and compare this with a full calculation of the permittivity and the reflection based on the tight binding method and the transfer matrix method...
The premotor theory of attention as an account for the Simon effect
van der Lubbe, Robert Henricus Johannes; Abrahamse, E.L.; de Kleine, Elian
2012-01-01
The Simon effect refers to the phenomenon that responses are faster when the irrelevant location of a stimulus corresponds with the response location than when these locations do not correspond. In the current paper we examined the viability of an updated version of the premotor theory of attention
Sensevy, Gérard
2014-01-01
This paper presents an exploratory study of two consecutive reading sessions conducted in primary school by two different teachers. Our purpose is twofold. From a theoretical viewpoint, we propose a tentative set of conditions of teaching effectiveness by relying on the Joint Action Theory in Didactics. From a methodological viewpoint, drawing on…
Dijkstra, Arie; Rothman, Alexander; Pietersma, Suzanne
2011-01-01
According to Regulatory Focus theory (RFT), outcomes in persuasive messages can be framed in four different ways, as gains, non-gains, losses or non-losses. In study 1, the persuasiveness of all four frames was compared and the presence/absence effect that was expected on the basis of the
Ash, Ivan K.
2009-01-01
Hindsight bias has been shown to be a pervasive and potentially harmful decision-making bias. A review of 4 competing cognitive reconstruction theories of hindsight bias revealed conflicting predictions about the role and effect of expectation or surprise in retrospective judgment formation. Two experiments tested these predictions examining the…
Effective mass theory of a two-dimensional quantum dot in the ...
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 3. Effective mass theory of a two-dimensional quantum dot in the presence of magnetic field. Himanshu ... The standard kinetic energy operator of quantum mechanics for this position-dependent mass is non-Hermitian and needs to be modified. This is ...
The Limits of Multiple Resource Theory in Display Formatting: Effects of Task Integration
1984-04-01
The Limits of Multiple Resource Theory in Display Fonnattlng: Effects of task integration Christopher 0. Wickens, University of Illinois; David ...In R. Sugarman (Ed.) Proceedings 25th Annual Meeting Human Factors Society. Santa Monica: Human Factors, 1981. 444 :^% 2&£&i . vv^vk-.viv.^v •:.:>::>>\\^L^>^>: S:->::VV>X-^:
Zero-Range Effective Field Theory for Resonant Wino Dark Matter
Johnson, Evan; Braaten, Eric; Zhang, Hong
2017-01-01
The most dramatic ``Sommerfeld enhancements'' of neutral-wino-pair annihilation occur when the wino mass is tuned to near critical values where there is a zero-energy S-wave resonance at the neutral-wino-pair threshold. If the wino mass is larger than the critical value, the resonance is a wino-pair bound state. If the wino mass is near a critical value, low-energy winos can be described by a zero-range effective field theory in which the winos interact nonperturbatively through a contact interaction. The parameters of the zero-range effective field theory can be determined by matching wino scattering amplitudes calculated by solving the Schrödinger equation for a nonrelativistic effective field theory in which the winos interact nonperturbatively through a potential due to the exchange of weak gauge bosons. The power of the zero-range effective field theory is illustrated by calculating the rate for formation of the bound state in the collision of two neutral winos through the emission of two soft photons. Supported in part by DOE grant DE-FG02-05ER15715.
Stern, Luli; Barnea, Nitza; Shauli, Sofia
2008-01-01
The objective of this study was to evaluate the effect of a dynamic software simulation on the understanding of the kinetic molecular theory by 7th graders. Students in the control group (n = 62) studied a curricular unit that addressed the differences in arrangement and motion of molecules in the three phases of matter. The experimental group (n…
Describing one-and two-neutron halos in effective field theory
Indian Academy of Sciences (India)
2014-11-01
Nov 1, 2014 ... Click here to view fulltext PDF ... In this paper, the recent work our group has undertaken on effective field theory (EFT) analyses of experimental data pertaining to one- and two-neutron halo nuclei is discussed. The cases of 19C and 8Li (one-neutron halos) and 22C (two-neutron halo) are considered.
Microprestress-Solidification Theory for Concrete Creep. I: Aging and Drying Effects
DEFF Research Database (Denmark)
Bazant, Z.P.; Hauggaard-Nielsen, Anders Boe; Baweja, S.
1997-01-01
A new physical theory and constitutive model for the effects of long-term aging and drying on concrete creep are proposed. The previously proposed solidification theory, in which the aging is explained and modeled by the volume growth (into the pores of hardened portland cement paste) of a nonaging......-term creep, deviatoric as well as volumetric, is assumed to originate from viscous shear slips between the opposite walls of the micropores in which the bonds or bridges that cross the micropores (and transmit the microprestress) break and reform. The long-term aging exhibited by the flow term in the creep...
Renormalization Group Equations of d=6 Operators in the Standard Model Effective Field Theory
CERN. Geneva
2015-01-01
The one-loop renormalization group equations for the Standard Model (SM) Effective Field Theory (EFT) including dimension-six operators are calculated. The complete 2499 × 2499 one-loop anomalous dimension matrix of the d=6 Lagrangian is obtained, as well as the contribution of d=6 operators to the running of the parameters of the renormalizable SM Lagrangian. The presence of higher-dimension operators has implications for the flavor problem of the SM. An approximate holomorphy of the one-loop anomalous dimension matrix is found, even though the SM EFT is not a supersymmetric theory.
Kapoyannis, A. S.; Kalkanis, G.
2017-03-01
We develop a simulation to facilitate the teaching of the photoelectric effect in an introductory course on quantum mechanics at undergraduate level. Through a Visual Basic program we describe the interaction of light with electrons in a metal conductor in the phenomenon according to the classical theory. The description includes both the microscopic interaction, as well as the predictions of the theory for the experimental results, arising from the microscopic scale. The predictions of the classical model are in stark contrast with the experimental results of a real photoelectric device.
Nuclear Quantum Effects in Water and Aqueous Systems: Experiment, Theory, and Current Challenges.
Ceriotti, Michele; Fang, Wei; Kusalik, Peter G; McKenzie, Ross H; Michaelides, Angelos; Morales, Miguel A; Markland, Thomas E
2016-07-13
Nuclear quantum effects influence the structure and dynamics of hydrogen-bonded systems, such as water, which impacts their observed properties with widely varying magnitudes. This review highlights the recent significant developments in the experiment, theory, and simulation of nuclear quantum effects in water. Novel experimental techniques, such as deep inelastic neutron scattering, now provide a detailed view of the role of nuclear quantum effects in water's properties. These have been combined with theoretical developments such as the introduction of the principle of competing quantum effects that allows the subtle interplay of water's quantum effects and their manifestation in experimental observables to be explained. We discuss how this principle has recently been used to explain the apparent dichotomy in water's isotope effects, which can range from very large to almost nonexistent depending on the property and conditions. We then review the latest major developments in simulation algorithms and theory that have enabled the efficient inclusion of nuclear quantum effects in molecular simulations, permitting their combination with on-the-fly evaluation of the potential energy surface using electronic structure theory. Finally, we identify current challenges and future opportunities in this area of research.
Chen, Ruirui; Senbayram, Mehmet; Blagodatsky, Sergey; Myachina, Olga; Dittert, Klaus; Lin, Xiangui; Blagodatskaya, Evgenia; Kuzyakov, Yakov
2014-07-01
The increasing input of anthropogenically derived nitrogen (N) to ecosystems raises a crucial question: how does available N modify the decomposer community and thus affects the mineralization of soil organic matter (SOM). Moreover, N input modifies the priming effect (PE), that is, the effect of fresh organics on the microbial decomposition of SOM. We studied the interactive effects of C and N on SOM mineralization (by natural (13) C labelling adding C4 -sucrose or C4 -maize straw to C3 -soil) in relation to microbial growth kinetics and to the activities of five hydrolytic enzymes. This encompasses the groups of parameters governing two mechanisms of priming effects - microbial N mining and stoichiometric decomposition theories. In sole C treatments, positive PE was accompanied by a decrease in specific microbial growth rates, confirming a greater contribution of K-strategists to the decomposition of native SOM. Sucrose addition with N significantly accelerated mineralization of native SOM, whereas mineral N added with plant residues accelerated decomposition of plant residues. This supports the microbial mining theory in terms of N limitation. Sucrose addition with N was accompanied by accelerated microbial growth, increased activities of β-glucosidase and cellobiohydrolase, and decreased activities of xylanase and leucine amino peptidase. This indicated an increased contribution of r-strategists to the PE and to decomposition of cellulose but the decreased hemicellulolytic and proteolytic activities. Thus, the acceleration of the C cycle was primed by exogenous organic C and was controlled by N. This confirms the stoichiometric decomposition theory. Both K- and r-strategists were beneficial for priming effects, with an increasing contribution of K-selected species under N limitation. Thus, the priming phenomenon described in 'microbial N mining' theory can be ascribed to K-strategists. In contrast, 'stoichiometric decomposition' theory, that is, accelerated OM
Orbital effect of the magnetic field in dynamical mean-field theory
Acheche, S.; Arsenault, L.-F.; Tremblay, A.-M. S.
2017-12-01
The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms calls for systematic studies of orbital effects of the magnetic field on the self-energy of interacting systems. Here we demonstrate theoretically that orbital effects of magnetic fields can be treated within single-site dynamical mean-field theory with a translationally invariant quantum impurity problem. As an example, we study the one-band Hubbard model on the square lattice using iterated perturbation theory as an impurity solver. We recover the expected quantum oscillations in the scattering rate, and we show that the magnetic fields allow the interaction-induced effective mass to be measured through the single-particle density of states accessible in tunneling experiments. The orbital effect of magnetic fields on scattering becomes particularly important in the Hofstadter butterfly regime.
DEFF Research Database (Denmark)
Wubs, Martijn; Yan, Wei; Amooghorban, Ehsan
2013-01-01
A well-known challenge for fabricating metamaterials is to make unit cells significantly smaller than the operating wavelength of light, so one can be sure that effective-medium theories apply. But do they apply? Here we show that nonlocal response in the metal constituents of the metamaterial...... leads to modified effective parameters for strongly subwavelength unit cells. For infinite hyperbolic metamaterials, nonlocal response gives a very large finite upper bound to the optical density of states that otherwise would diverge. Moreover, for finite hyperbolic metamaterials we show that nonlocal...... response affects their operation as superlenses, and interestingly that sometimes nonlocal theory predicts the better imaging. Finally, we discuss how to describe metamaterials effectively in quantum optics. Media with loss or gain have associated quantum noise, and the question is whether the effective...
Kanazawa, Takuya; Wettig, Tilo
2014-10-01
We generalize QCD at asymptotically large isospin chemical potential to an arbitrary even number of flavors. We also allow for small quark chemical potentials, which stress the coincident Fermi surfaces of the paired quarks and lead to a sign problem in Monte Carlo simulations. We derive the corresponding low-energy effective theory in both p- and ɛ-expansion and quantify the severity of the sign problem. We construct the random matrix theory describing our physical situation and show that it can be mapped to a known random matrix theory at low baryon density so that new insights can be gained without additional calculations. In particular, we explain the Silver Blaze phenomenon at high isospin density. We also introduce stressed singular values of the Dirac operator and relate them to the pionic condensate. Finally we comment on extensions of our work to two-color QCD.
The Effectiveness of Choice Theory in Quality of Life and Resilience of Drug Users
Directory of Open Access Journals (Sweden)
somaye najafi
2015-06-01
Full Text Available Objective: This study was an attempt to evaluate the effectiveness of the application of choice theory in quality of life and resilience of male drug users of Tehran. Method: An experimental research design with pretest-posttest and control group was employed for this study wherein 40 drug users were randomly selected from a governmental center. The experimental group was exposed to twelve 90-minute intervention sessions of choice theory. Then, both groups were tested. The follow-up was performed two months later. Quality of life questionnaire and Connor-Davidson resilience scale were used for data collection purposes. Results: The results of this study showed that the application of choice theory had an impact on quality of life and resilience. This finding was actively present in the follow-up, as well. Conclusion: This Method can be used to treat addicts.
Directory of Open Access Journals (Sweden)
aghdas karimi
2014-08-01
Full Text Available Introduction: according to the ethology theory mother infant separation immediately after birth can interfere with the infants innate behaviors for the initiation of breastfeeding. The aim of this study was to the effect of an interventional program based on the Theory of Ethology on infant breast feeding competence Materials and Methods: 114 primiparous, Iranian, healthy, full term mothers between 18-35 years with normal vaginal delivery who intended to breastfeed their babies. They were put in direct skin to skin contact with their infants immediately after birth for two hours. Then, rates of infant breastfeeding competence were compared with a control group receiving routine hospital cares. Results: Rates of infant breastfeeding competence were higher in the skin to skin contact group compared to routine care group (p=0.0001. Conclusion: mother- infant early skin to skin contact promotes infants natural feeding behaviors leading to higher rates of infant breastfeeding competence. These findings confirm the Theory of Ethology.
Directory of Open Access Journals (Sweden)
aghdas karimi
2014-12-01
Full Text Available Introduction: according to the ethology theory mother infant separation immediately after birth can interfere with the infants innate behaviors for the initiation of breastfeeding. The aim of this study was to the effect of an interventional program based on the Theory of Ethology on infant breast feeding competence Materials and Methods: 114 primiparous, Iranian, healthy, full term mothers between 18-35 years with normal vaginal delivery who intended to breastfeed their babies. They were put in direct skin to skin contact with their infants immediately after birth for two hours. Then, rates of infant breastfeeding competence were compared with a control group receiving routine hospital cares. Results: Rates of infant breastfeeding competence were higher in the skin to skin contact group compared to routine care group (p=0.0001. Conclusion: mother- infant early skin to skin contact promotes infants natural feeding behaviors leading to higher rates of infant breastfeeding competence. These findings confirm the Theory of Ethology.
Amemiya, Tomo; Taki, Masato; Kanazawa, Toru; Arai, Shigehisa
2014-03-01
The asymmetric invisibility cloak is a special cloak with unidirectional transparency; that is, a person in the cloak should not be seen from the outside but should be able to see the outside. Existing theories of designing invisibility cloaks cannot be used for asymmetric cloaking because they are based on the transformation optics that uses Riemannian metric tensor independent of direction. To overcome this problem, we propose introducing directionality into invisibility cloaking. Our theory is based on ``the theory of effective magnetic field for photons'' proposed by Stanford University.[2] To realize asymmetric cloaking, we have extended the Stanford's theory to add the concept of ``effective electric field for photons.'' The effective electric and the magnetic field can be generated using a photonc resonator lattice, which is a kind of metamaterial. The Hamiltonian for photons in these fields has a similar form to that of the Hamiltonian for a charged particle in an electromagnetic field. An incident photon therefore experiences a ``Lorentz-like'' and a ``Coulomb-like'' force and shows asymmetric movement depending of its travelling direction.We show the procedure of designing actual invisibility cloaks using the photonc resonator lattice and confirm their operation with the aid of computer simulation. This work was supported in part by the MEXT; JSPS KAKENHI Grant Numbers #24246061, #24656046, #25420321, #25420322.
Low frequency sound scattering from spherical assemblages of bubbles using effective medium theory.
Hahn, Thomas R
2007-12-01
The determination of the acoustic field scattered by an underwater assembly of gas bubbles or similar resonant monopole scatterers is of considerable theoretical and practical interest. This problem is addressed from a theoretical point of view within the framework of the effective medium theory for the case of spherically shaped assemblages. Although being valid more generally, the effective medium theory is an ideal instrument to study multiple scattering effects such as low frequency collective resonances, acoustically coupled breathing modes of the entire assembly. Explicit expressions for the scattering amplitude and cross sections are derived, as well as closed form expressions for the resonance frequency and spectral shape of the fundamental collective mode utilizing analytical S-matrix methods. This approach allows, in principle, a simultaneous inversion for the assembly radius and void fraction directly from the scattering cross sections. To demonstrate the validity of the approach, the theory is applied to the example of idealized, spherically shaped schools of swim bladder bearing fish. The analytic results of the theory are compared to numerical first-principle benchmark computations and excellent agreement is found, even for densely packed schools and frequencies across the bladder resonance.
Framing Effects are Robust to Linguistic Disambiguation: A Critical Test of Contemporary Theory
Chick, Christina F.; Reyna, Valerie F.; Corbin, Jonathan C.
2015-01-01
Theoretical accounts of risky choice framing effects assume that decision makers interpret framing options as extensionally equivalent, such that if 600 lives are at stake, saving 200 implies that 400 die. However, many scholars have argued that framing effects are caused, instead, by filling in pragmatically implied information. This linguistic ambiguity hypothesis is grounded in neo-Gricean pragmatics, information leakage, and schema theory. In two experiments, we conducted a critical test ...
Bayless, Sarah; Harvey, Alistair, J.
2016-01-01
The effect of alcohol intoxication on central and peripheral attention was examined as a test of Alcohol Myopia Theory (AMT). Previous research has supported AMT in the context of visual attention, but few studies have examined the effects of alcohol intoxication on central and peripheral attention. The study followed a 2 (alcohol treatment) × 2 (array size) × 2 (task type) mixed design. Forty-one participants (placebo or intoxicated) viewed an array of four or six colored circles, while simu...
Effective Gravitational Wave Stress-energy Tensor in Alternative Theories of Gravity
Stein, Leo C; Hughes, Scott A
2010-01-01
The inspiral of binary systems in vacuum is controlled by the rate of change of the system's energy, angular momentum and Carter constant. In alternative theories, such a change is induced by the effective stress-energy carried away by gravitational radiation and any other propagating degrees of freedom. We employ perturbation theory and the short-wavelength approximation to compute this stress-energy tensor in a wide class of alternative theories. We find that this tensor is generally a modification of that first computed by Isaacson, where the corrections can dominate over the general relativistic term. In a wide class of theories, however, these corrections identically vanish at asymptotically flat, future, null infinity, reducing the stress-energy tensor to Isaacson's. We exemplify this phenomenon by first considering dynamical Chern-Simons modified gravity, which corrects the action via a scalar field and the contraction of the Riemann tensor and its dual. We then consider a wide class of theories with d...
Linking Adverse Childhood Effects and Attachment: A Theory of Etiology for Sexual Offending.
Grady, Melissa D; Levenson, Jill S; Bolder, Tess
2016-01-25
Sexual violence continues to be a significant public health problem affecting significant portions of the population. Unfortunately, an agreed upon theory of etiology remains elusive leading to challenges in developing effective prevention and treatment interventions. Recently, there is a growing body of literature examining the role of adverse childhood experiences (ACEs) in the development of sexually violent behavior. This research has begun to explore the rates of various types of child maltreatments and family dysfunction in individuals who have been convicted of a sexual crime. These empirical inquiries have been primarily descriptive in nature and have not yet provided a cohesive theoretical model as to why the presence of ACEs might contribute to sexually abusive behavior. This article suggests that attachment theory offers an explanatory link between early adversity and sexually abusive behavior in adulthood. We first summarize important attachment theory concepts, then integrate them with research in the area of developmental psychopathology and ACEs, and finally propose a model by which attachment can be used as an explanatory theory for subsequent sexualized coping and sexually abusive behaviors. Finally, this article explores the implications for practice, policy, and research using this explanatory theory as a framework for understanding sexual violence. © The Author(s) 2016.
Molecular Theory and the Effects of Solute Attractive Forces on Hydrophobic Interactions.
Chaudhari, Mangesh I; Rempe, Susan B; Asthagiri, D; Tan, L; Pratt, L R
2016-03-03
The role of solute attractive forces on hydrophobic interactions is studied by coordinated development of theory and simulation results for Ar atoms in water. We present a concise derivation of the local molecular field (LMF) theory for the effects of solute attractive forces on hydrophobic interactions, a derivation that clarifies the close relation of LMF theory to the EXP approximation applied to this problem long ago. The simulation results show that change from purely repulsive atomic solute interactions to include realistic attractive interactions diminishes the strength of hydrophobic bonds. For the Ar-Ar rdfs considered pointwise, the numerical results for the effects of solute attractive forces on hydrophobic interactions are opposite in sign and larger in magnitude than predicted by LMF theory. That comparison is discussed from the point of view of quasichemical theory, and it is suggested that the first reason for this difference is the incomplete evaluation within LMF theory of the hydration energy of the Ar pair. With a recent suggestion for the system-size extrapolation of the required correlation function integrals, the Ar-Ar rdfs permit evaluation of osmotic second virial coefficients B2. Those B2's also show that incorporation of attractive interactions leads to more positive (repulsive) values. With attractive interactions in play, B2 can change from positive to negative values with increasing temperatures. This is consistent with the puzzling suggestions of decades ago that B2 ≈ 0 for intermediate cases of temperature or solute size. In all cases here, B2 becomes more attractive with increasing temperature.
DEFF Research Database (Denmark)
Thomsen, Jon Juel
2003-01-01
, as was done in a few related studies¿¿unless the system has very low modal density or heavy damping; thus first-order consideration to resonance effects is included. Using the specific example with experimental support to put confidence on the proposed theory, expressions for predicting the stiffening effect...... for a more general class of continuous systems in differential operator form are also provided.......One effect of strong mechanical high-frequency excitation may be to apparently "stiffen" a structure, a well-described phenomenon for discrete systems. The present study provides theoretical and experimental results on this effect for continuous elastic structures. A laboratory experiment is set up...
Neutralizing substitutes for leadership theory: leadership effects and common-source bias.
Dionne, Shelley D; Yammarino, Francis J; Atwater, Leanne E; James, Lawrence R
2002-06-01
The purpose of this research was to examine alternative models of substitutes for leadership theory given the general lack of empirical support for the moderating effects postulated by the theory. On this basis, the research posited that the effects of substitutes also could be conceptualized as mediated relations. The research examined moderated and mediated relations for several sets of leader behaviors and substitutes that have been examined in the literature. The research design sampled 49 organizations, with 940 subordinates rating 156 leaders. Results, although generally not supportive of the moderator or mediator hypotheses, essentially demonstrated that leadership matters. The findings also suggest that prior significant effects in substitutes literature may be merely a statistical artifact, resulting from common-source bias.
World-volume effective action of exotic five-brane in M-theory
Energy Technology Data Exchange (ETDEWEB)
Kimura, Tetsuji [Research and Education Center for Natural Sciences, Keio University, Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521 (Japan); Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan); Sasaki, Shin [Department of Physics, Kitasato University,Sagamihara 252-0373 (Japan); Yata, Masaya [Department of Physics, National University of Singapore,2, Science Drive 3, Singapore 117542 (Singapore)
2016-02-25
We study the world-volume effective action of an exotic five-brane, known as the M-theory 5{sup 3}-brane (M5{sup 3}-brane) in eleven dimensions. The supermultiplet of the world-volume theory is the N=(2,0) tensor multiplet in six dimensions. The world-volume action contains three Killing vectors k̂{sub Î}{sup M} (Î=1,2,3) associated with the U(1){sup 3} isometry. We find the effective T-duality rule for the eleven-dimensional backgrounds that transforms the M5-brane effective action to that of the M5{sup 3}-brane. We also show that our action provides the source term for the M5{sup 3}-brane geometry in eleven-dimensional supergravity.
Elastic α-{sup 12}C scattering at low energies in cluster effective field theory
Energy Technology Data Exchange (ETDEWEB)
Ando, Shung-Ichi [Sunmoon University, School of Mechanical and ICT Convergence Engineering, Asan, Chungnam (Korea, Republic of)
2016-05-15
The elastic α-{sup 12}C scattering at low energies is studied employing an effective field theory in which the α and {sup 12}C states are treated as elementary-like fields. We discuss scales of the theory in the stellar energy region where the {sup 12}C(α, γ){sup 16}O process occurs, and then obtain an expression of the elastic scattering amplitudes in terms of effective-range parameters. Using experimental data of the phase shifts for l=0,1, 2 channels at low energies, for which the resonance regions are avoided, we fix values of the parameters and find that the phase shifts at the low energies are well reproduced by using three effective-range parameters for each channel. Furthermore, we discuss problems and uncertainties of the present approach when the amplitudes are extrapolated to the stellar energy region. (orig.)
DAMA confronts null searches in the effective theory of dark matter-nucleon interactions
Energy Technology Data Exchange (ETDEWEB)
Catena, Riccardo [Department of Physics, Chalmers University of Technology,Kemigården 1, Gothenburg (Sweden); Ibarra, Alejandro; Wild, Sebastian [Physik-Department T30d, Technische Universität München,James-Franck-Straße, 85748 Garching (Germany)
2016-05-17
We examine the dark matter interpretation of the modulation signal reported by the DAMA experiment from the perspective of effective field theories displaying Galilean invariance. We consider the most general effective coupling leading to the elastic scattering of a dark matter particle with spin 0 or 1/2 off a nucleon, and we analyze the compatibility of the DAMA signal with the null results from other direct detection experiments, as well as with the non-observation of a high energy neutrino flux in the direction of the Sun from dark matter annihilation. To this end, we develop a novel semi-analytical approach for comparing experimental results in the high-dimensional parameter space of the non-relativistic effective theory. Assuming the standard halo model, we find a strong tension between the dark matter interpretation of the DAMA modulation signal and the null result experiments. We also list possible ways-out of this conclusion.
Directory of Open Access Journals (Sweden)
Farah Qamar
2016-06-01
Full Text Available Since Socrates’ time, reasoning is considered valuable for the justification of speaker’s belief along with Thomas Aquinas’ testing of his thinking to answer his own thinking. Critical thinking has been part of discussion among the educators for its significance and application for last many decades. Many educators have conducted researches on the assessment of critical thinking within a domain or across the domain in order to test students’ critical thinking skills and its effect on their learning. Similarly, critical thinking is highly valuable for the study of literature as it explicitly asked for learners’ beliefs, perceptions, and judgments in order to remove the ambiguity of thought. Perfection of thought can be achieved with the use of critical thinking skills while training of mind needs interaction between literary text and the reader as literature has the capacity to achieve mental traits specified to critical thinking. Accordingly, this report presents a relationship between critical thinking skills and English literature study along with reader response theory techniques considering that without the use of critical thinking skills and reader response theory, study of literature is haphazard hence for the application of reader response theory, literary text is inevitable. In essence, I aim to highlight the effectiveness of critical thinking skills for the study of literature while emphasizing the significance of reader response theory which is also inevitable for the study of literature and for the use of critical thinking skills.
A quantum theory account of order effects and conjunction fallacies in political judgments.
Yearsley, James M; Trueblood, Jennifer S
2017-09-06
Are our everyday judgments about the world around us normative? Decades of research in the judgment and decision-making literature suggest the answer is no. If people's judgments do not follow normative rules, then what rules if any do they follow? Quantum probability theory is a promising new approach to modeling human behavior that is at odds with normative, classical rules. One key advantage of using quantum theory is that it explains multiple types of judgment errors using the same basic machinery, unifying what have previously been thought of as disparate phenomena. In this article, we test predictions from quantum theory related to the co-occurrence of two classic judgment phenomena, order effects and conjunction fallacies, using judgments about real-world events (related to the U.S. presidential primaries). We also show that our data obeys two a priori and parameter free constraints derived from quantum theory. Further, we examine two factors that moderate the effects, cognitive thinking style (as measured by the Cognitive Reflection Test) and political ideology.
Effective theory for heavy quark QCD at finite temperature and density with stochastic quantization
Energy Technology Data Exchange (ETDEWEB)
Neuman, Mathias
2015-07-01
In this thesis we presented the derivation as well as the numerical and analytical treatment of an effective theory for lattice Quantum Chromodynamics (LQCD). We derived the effective theory directly from LQCD, which allows us to systematically introduce further improvements. The derivation was performed by means of an expansion around the limit of infinite quark masses and infinite gauge coupling. Using this theory we were able to derive results in the region of large densities. This region is, due to the sign problem, inaccessible to standard LQCD approaches. Although LQCD simulations at large densities have been performed recently by applying stochastic quantization, those are still limited to lattice with low numbers of timeslices and therefor can not reach the low temperature region. Furthermore, they can not be crosschecked with Monte-Carlo simulations. Since the equivalence between stochastic quantization and Monte-Carlo is unproven for the case of finite density systems, new approaches to access the cold dense region of the QCD phase diagram are desirable. The effective theory presented in this thesis provides such an approach. We introduced continuum QCD in chapter 2. In chapter 3 we presented how LQCD, i.e. QCD in a discretized space-time, can be formulated and used as a tool to explore the non-perturbative regions of the QCD phase diagram. Special emphasis was placed on simulations at finite baryon densities and the numerical problems that arise in this region. These problems are caused by the complexification of the action and are known as the sign problem. We gave a detailed presentation of the derivation of our effective theory in chapter 4. For this we performed expansions around the limit of strong coupling and static quarks, κ=β=0, introducing corrections order by order in the expansion parameters κ and β. Truncating the theory at different orders allowed us to determine the parameter region where the convergence to full LQCD is good. The gauge
Greville-Harris, Maddy; Bostock, Jennifer; Din, Amy; Graham, Cynthia A; Lewith, George; Liossi, Christina; O'Riordan, Tim; White, Peter; Yardley, Lucy; Bishop, Felicity L
2016-06-10
According to established ethical principles and guidelines, patients in clinical trials should be fully informed about the interventions they might receive. However, information about placebo-controlled clinical trials typically focuses on the new intervention being tested and provides limited and at times misleading information about placebos. We aimed to create an informative, scientifically accurate, and engaging website that could be used to improve understanding of placebo effects among patients who might be considering taking part in a placebo-controlled clinical trial. Our approach drew on evidence-, theory-, and person-based intervention development. We used existing evidence and theory about placebo effects to develop content that was scientifically accurate. We used existing evidence and theory of health behavior to ensure our content would be communicated persuasively, to an audience who might currently be ignorant or misinformed about placebo effects. A qualitative 'think aloud' study was conducted in which 10 participants viewed prototypes of the website and spoke their thoughts out loud in the presence of a researcher. The website provides information about 10 key topics and uses text, evidence summaries, quizzes, audio clips of patients' stories, and a short film to convey key messages. Comments from participants in the think aloud study highlighted occasional misunderstandings and off-putting/confusing features. These were addressed by modifying elements of content, style, and navigation to improve participants' experiences of using the website. We have developed an evidence-based website that incorporates theory-based techniques to inform members of the public about placebos and placebo effects. Qualitative research ensured our website was engaging and convincing for our target audience who might not perceive a need to learn about placebo effects. Before using the website in clinical trials, it is necessary to test its effects on key outcomes
The ``Folk Theorem'' on effective field theory: How does it fare in nuclear physics?
Rho, Mannque
2017-10-01
This is a brief history of what I consider as very important, some of which truly seminal, contributions made by young Korean nuclear theorists, mostly graduate students working on PhD thesis in 1990s and early 2000s, to nuclear effective field theory, nowadays heralded as the first-principle approach to nuclear physics. The theoretical framework employed is an effective field theory anchored on a single scale-invariant hidden local symmetric Lagrangian constructed in the spirit of Weinberg's "Folk Theorem" on effective field theory. The problems addressed are the high-precision calculations on the thermal np capture, the solar pp fusion process, the solar hep process — John Bahcall's challenge to nuclear theorists — and the quenching of g A in giant Gamow-Teller resonances and the whopping enhancement of first-forbidden beta transitions relevant in astrophysical processes. Extending adventurously the strategy to a wild uncharted domain in which a systematic implementation of the "theorem" is far from obvious, the same effective Lagrangian is applied to the structure of compact stars. A surprising, unexpected, result on the properties of massive stars, totally different from what has been obtained up to day in the literature, is predicted, such as the precocious onset of conformal sound velocity together with a hint for the possible emergence in dense matter of hidden symmetries such as scale symmetry and hidden local symmetry.
Saffari, Shahab; Hashemian, Mohammad; Toghraie, Davood
2017-09-01
Based on nonlocal Timoshenko beam theory, dynamic stability of functionally graded (FG) nanobeam under axial and thermal loading was investigated. Surface stress effects were implemented according to Gurtin-Murdoch continuum theory. Using power law distribution for FGM and von Karman geometric nonlinearity, governing equations were derived based on Hamilton's principle. The developed nonlocal models have the capability of interpreting small scale effects. Pasternak elastic medium was employed to represent the interaction of the FG nanobeam and the surrounding elastic medium. A parametric study was conducted to focus influences of the static load factor, temperature change, gradient index, nonlocal parameter, slenderness ratio, surface effect and springs constants of the elastic medium on the dynamic instability region (DIR) of the FG beam with simply-supported boundary conditions. It was found that differences between DIRs predicted by local and nonlocal beam theories are significant for beams with lower aspect ratio. Moreover, it was observed that in contrast to high temperature environments, at low temperatures, increasing the temperature change moves the origin of the DIR to higher excitation frequency zone and leads to further stability. Considering surface stress effects shifts the DIR of FG beam to higher frequency zone, also increasing the gradient index enhances the frequency of DIR.
Anatomy of One-Loop Effective Action in Noncommutative Scalar Field Theories
Kiem, Youngjai; Sato, Haru-Tada; Yee, Jung-Tay; Kiem, Youngjai; Rey, Soo-Jong; Sato, Haru-Tada; Yee, Jung-Tay
2002-01-01
One-loop effective action of noncommutative scalar field theory with cubic self-interaction is studied. Utilizing worldline formulation, both planar and nonplanar part of the effective action are computed explicitly. We find complete agreement of the result with Seiberg-Witten limit of string worldsheet computation and standard Feynman diagrammatics. We prove that, at low-energy and large noncommutativity limit, nonplanar part of the effective action is simplified enormously and is resummable into a quadratic action of scalar open Wilson line operators.
Quantum optical effective-medium theory for loss-compensated metamaterials
DEFF Research Database (Denmark)
Amooghorban, Ehsan; Mortensen, N. Asger; Wubs, Martijn
2013-01-01
effective parameters are insufficient to describe the propagation of quantum states of light. Furthermore, we propose a quantum optical effective-medium theory instead and show that it correctly predicts the properties of the light emerging from loss-compensated metamaterials. © 2013 American Physical...... strategy to compensate for the inevitable losses in metallic components of metamaterials is to add optical gain material. Here we study the quantum optics of such loss-compensated metamaterials at frequencies for which effective parameters can be unambiguously determined. We demonstrate that the usual...
Analytical theory and possible detection of the ac quantum spin Hall effect.
Deng, W Y; Ren, Y J; Lin, Z X; Shen, R; Sheng, L; Sheng, D N; Xing, D Y
2017-07-11
We develop an analytical theory of the low-frequency ac quantum spin Hall (QSH) effect based upon the scattering matrix formalism. It is shown that the ac QSH effect can be interpreted as a bulk quantum pumping effect. When the electron spin is conserved, the integer-quantized ac spin Hall conductivity can be linked to the winding numbers of the reflection matrices in the electrodes, which also equal to the bulk spin Chern numbers of the QSH material. Furthermore, a possible experimental scheme by using ferromagnetic metals as electrodes is proposed to detect the topological ac spin current by electrical means.
The Nc dependencies of baryon masses: Analysis with Lattice QCD and Effective Theory
Energy Technology Data Exchange (ETDEWEB)
Calle Cordon, Alvaro C. [JLAB; DeGrand, Thomas A. [University of Colorado; Goity, Jose L. [JLAB
2014-07-01
Baryon masses at varying values of Nc and light quark masses are studied with Lattice QCD and the results are analyzed in a low energy effective theory based on a combined framework of the 1/Nc and Heavy Baryon Chiral Perturbation Theory expansions. Lattice QCD results for Nc=3, 5 and 7 obtained in quenched calculations, as well as results for unquenched calculations for Nc=3, are used for the analysis. The results are consistent with a previous analysis of Nc=3 LQCD results, and in addition permit the determination of sub-leading in 1/Nc effects in the spin-flavor singlet component of the baryon masses as well as in the hyperfine splittings.
Energy Technology Data Exchange (ETDEWEB)
Degrande, Celine [CERN, Theory Division, Geneva 23 (Switzerland); Fuks, Benjamin [Sorbonne Universites, UPMC Univ. Paris 06, Paris (France); CNRS, Paris (France); Mawatari, Kentarou [Universite Grenoble-Alpes, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Vrije Universiteit Brussel, Theoretische Natuurkunde and IIHE/ELEM, International Solvay Institutes, Brussels (Belgium); Mimasu, Ken [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); Universite catholique de Louvain, Centre for Cosmology, Particle Physics and Phenomenology (CP3), Louvain-la-Neuve (Belgium); Sanz, Veronica [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)
2017-04-15
We study the impact of dimension-six operators of the standard model effective field theory relevant for vector-boson fusion and associated Higgs boson production at the LHC. We present predictions at the next-to-leading order accuracy in QCD that include matching to parton showers and that rely on fully automated simulations. We show the importance of the subsequent reduction of the theoretical uncertainties in improving the possible discrimination between effective field theory and standard model results, and we demonstrate that the range of the Wilson coefficient values allowed by a global fit to LEP and LHC Run I data can be further constrained by LHC Run II future results. (orig.)
Degrande, Celine; Mawatari, Kentarou; Mimasu, Ken; Sanz, Veronica
2017-04-25
We study the impact of dimension-six operators of the standard model effective field theory relevant for vector-boson fusion and associated Higgs boson production at the LHC. We present predictions at the next-to-leading order accuracy in QCD that include matching to parton showers and that rely on fully automated simulations. We show the importance of the subsequent reduction of the theoretical uncertainties in improving the possible discrimination between effective field theory and standard model results, and we demonstrate that the range of the Wilson coefficient values allowed by a global fit to LEP and LHC Run I data can be further constrained by LHC Run II future results.
Liu, Xu; Greenhalgh, Stewart; Zhou, Bing; Heinson, Graham
2016-12-01
A method using modified attenuation factor function is suggested to determine the parameters of the generalized Zener model approximating the attenuation factor function. This method is applied to constitute the poroviscoelastic model based on the effective Biot theory which considers the attenuative solid frame of reservoir. In the poroviscoelastic model, frequency-dependent bulk modulus and shear modulus of solid frame are represented by generalized Zener models. As an application, the borehole logging dispersion equations from Biot theory are extended to include effects from the intrinsic body attenuation in formation media in full-frequency range. The velocity dispersions of borehole guided waves are calculated to investigate the influence from attenuative bore fluid, attenuative solid frame of the formation and impermeable bore wall.
Higgs production at NLO in the Standard Model Effective Field theory
Deutschmann, Nicolas
2017-07-01
The Effective Field Theory approach is a fruitful way of constraining new physics in a model independent way. As the Higgs sector is one of the most popular candidate for deviations from the Standard Model, it is particularly important that the constraints extracted from the experimental data on the Higgs boson be as meaningful as possible, which entails making accurate and precise theoretical predictions. In this proceeding, I discuss a two loop calculation performed to improve the existing Leading Order result for the Higgs gluon-fusion cross section in the Standard Model Effective Field Theory. We present the modern multi-loop calculation techniques employed to obtain this result and highlight the unusual divergence structure of the amplitude.
Addressing the Proton Radius Puzzle Using QED-NRQED Effective Field Theory
Dye, Steven
2017-09-01
The proton radius puzzle, i.e. the large discrepancy in the extraction of the proton charge radius between regular and muonic hydrogen, challenges our understanding of the structure of the proton. It can also be an indication of a new force that couples to muons, but not to electrons. An effective field theory analysis using Non Relativistic Quantum Electrodynamics (NRQED) indicates that the muonic hydrogen result can be interpreted as a large, compared to some model estimates, muon-proton spin-independent contact interaction. The muonic hydrogen result can be tested by a muon-proton scattering experiment, MUSE, that is planned at the Paul Scherrer Institute in Switzerland. The typical momenta of the muons in this experiment are of the order of the muon mass. In this energy regime the muons are relativistic but the protons are still non-relativistic. The interaction between the muons and protons can be described by a hybrid QED-NRQED effective field theory.
Effects of action planning and coping planning within the theory of planned behaviour
DEFF Research Database (Denmark)
Pakpour, Amir H.; Zedi, Isa mohammadi; Chatzisarantis, Nikos
2011-01-01
Objective: Patients on dialysis have low physical activity levels. The aim of the study was to examine the validity of action planning and coping planning within the theory of planned behaviour framework, for predicting physical activity behaviour of patients on hemodialysis. Methods: One hundred...... and forty four patients who were undergoing emodialysis were selected from dialysis centers. The mean age of the patients was 56.61 (SD= 11.38) years. The patients completed a questionnaire including variables from the theory of planned behaviour, action planning and coping planning. Physical activity...... was prospectively assessed at 4-weeks with the validated International Physical Activity Questionnaire self-report measure. A hierarchical regression analysis was performed to examine the effects of action planning and coping planning on physical activity behaviour. Results: There was a main effect for coping...
Bound-state field-theory approach to proton-structure effects in muonic hydrogen
Mohr, Peter J.; Griffith, J.; Sapirstein, J.
2013-05-01
A bound-state field-theory approach to muonic hydrogen is set up using a variant of the Furry representation in which the lowest-order Hamiltonian describes a muon in the presence of a point Coulomb field, but the origin of the binding field is taken to be three charged quarks in the proton, which are modeled as Dirac particles that move freely within a spherical well. Bound-state field-theory techniques are used to evaluate one- and two-photon effects. Particular attention is paid to two-photon-exchange diagrams, which include the effect of proton polarizability. In addition, the modification of the electromagnetic self energy of the proton by the electric field of the muon is examined. Finally, the model is used to carry out a calculation of the static electric polarizability of the proton.
New Constraints on Dark Matter Effective Theories from Standard Model Loops
Crivellin, Andreas; Procura, Massimiliano
2014-01-01
We consider an effective field theory for a gauge singlet Dirac dark matter (DM) particle interacting with the Standard Model (SM) fields via effective operators suppressed by the scale $\\Lambda \\gtrsim 1$ TeV. We perform a systematic analysis of the leading loop contributions to spin-independent (SI) DM--nucleon scattering using renormalization group evolution between $\\Lambda$ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity-suppressed and spin-dependent can actually contribute to SI scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are comparable to LHC bounds, and will significantly improve in the near future. Interestingly, the loop contribution we find is maximally isospin violating even if the underlying theory is isospin conserving.
New constraints on dark matter effective theories from standard model loops.
Crivellin, Andreas; D'Eramo, Francesco; Procura, Massimiliano
2014-05-16
We consider an effective field theory for a gauge singlet Dirac dark matter particle interacting with the standard model fields via effective operators suppressed by the scale Λ ≳ 1 TeV. We perform a systematic analysis of the leading loop contributions to spin-independent Dirac dark matter-nucleon scattering using renormalization group evolution between Λ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity suppressed and spin dependent can actually contribute to spin-independent scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are already significantly stronger than LHC bounds, and will improve in the near future. Interestingly, the loop contribution we find is isospin violating even if the underlying theory is isospin conserving.
Jing, Ting Jing; Tarmizi, Rohani Ahmad; Bakar, Kamariah Abu; Aralas, Dalia
2017-01-01
This study investigates the effect of utilizing Variation Theory Based Strategy on students' algebraic achievement and motivation in learning algebra. The study used quasi-experimental non-equivalent control group research design and involved 56 Form Two (Secondary Two) students in two classes (28 in experimental group, 28 in control group) in Malaysia The first class of students went through algebra class taught with Variation Theory Based Strategy (VTBS) while the second class of students experienced conventional teaching strategy. The instruments used for the study were a 24-item Algebra Test and 36-item Instructional Materials Motivation Survey. Result from analysis of Covariance indicated that experimental group students achieved significantly better test scores than control group. Result of Multivariate Analysis of Variance also shows evidences of significant effect of VTBS on experimental students' overall motivation in all the five subscales; attention, relevance, confidence, and satisfaction. These results suggested the utilization of VTBS would improve students' learning in algebra.
Excluded-volume effects for a hadron gas in Yang-Mills theory
Alba, Paolo; Nada, Alessandro; Panero, Marco; Stöcker, Horst
2016-01-01
When the multiplicities of particles produced in heavy-ion collisions are fitted to the hadron-resonance-gas model, excluded-volume effects play a significant role. In this work, we study the impact of such effects onto the equation of state of pure Yang-Mills theory at low temperatures, comparing the predictions of the statistical model with lattice results. In particular, we present a detailed analysis of the SU(2) and SU(3) Yang-Mills theories: we find that, for both of them, the best fits to the equilibrium thermodynamic quantities are obtained when one assumes that the volume of different glueball states is inversely proportional to their mass. The implications of these findings for QCD are discussed.
Appealing to fear: A meta-analysis of fear appeal effectiveness and theories.
Tannenbaum, Melanie B; Hepler, Justin; Zimmerman, Rick S; Saul, Lindsey; Jacobs, Samantha; Wilson, Kristina; Albarracín, Dolores
2015-11-01
Fear appeals are a polarizing issue, with proponents confident in their efficacy and opponents confident that they backfire. We present the results of a comprehensive meta-analysis investigating fear appeals' effectiveness for influencing attitudes, intentions, and behaviors. We tested predictions from a large number of theories, the majority of which have never been tested meta-analytically until now. Studies were included if they contained a treatment group exposed to a fear appeal, a valid comparison group, a manipulation of depicted fear, a measure of attitudes, intentions, or behaviors concerning the targeted risk or recommended solution, and adequate statistics to calculate effect sizes. The meta-analysis included 127 articles (9% unpublished) yielding 248 independent samples (NTotal = 27,372) collected from diverse populations. Results showed a positive effect of fear appeals on attitudes, intentions, and behaviors, with the average effect on a composite index being random-effects d = 0.29. Moderation analyses based on prominent fear appeal theories showed that the effectiveness of fear appeals increased when the message included efficacy statements, depicted high susceptibility and severity, recommended one-time only (vs. repeated) behaviors, and targeted audiences that included a larger percentage of female message recipients. Overall, we conclude that (a) fear appeals are effective at positively influencing attitude, intentions, and behaviors; (b) there are very few circumstances under which they are not effective; and (c) there are no identified circumstances under which they backfire and lead to undesirable outcomes. (c) 2015 APA, all rights reserved).
Appealing to fear: A Meta-Analysis of Fear Appeal Effectiveness and Theories
Tannenbaum, Melanie B.; Hepler, Justin; Zimmerman, Rick S.; Saul, Lindsey; Jacobs, Samantha; Wilson, Kristina; Albarracin, Dolores
2018-01-01
Fear appeals are a polarizing issue, with proponents confident in their efficacy and opponents confident that they backfire. We present the results of a comprehensive meta-analysis investigating fear appeals’ effectiveness for influencing attitudes, intentions, and behaviors. We tested predictions from a large number of theories, the majority of which have never been tested meta-analytically until now. Studies were included if they contained a treatment group exposed to a fear appeal, a valid comparison group, a manipulation of depicted fear, a measure of attitudes, intentions, or behaviors concerning the targeted risk or recommended solution, and adequate statistics to calculate effect sizes. The meta-analysis included 127 papers (9% unpublished) yielding 248 independent samples (NTotal = 27,372) collected from diverse populations. Results showed a positive effect of fear appeals on attitudes, intentions, and behaviors, with the average effect on a composite index being random-effects d¯ = 0.29. Moderation analyses based on prominent fear appeal theories showed that the effectiveness of fear appeals increased when the message included efficacy statements, depicted high susceptibility and severity, recommended one-time only (vs. repeated) behaviors, and targeted audiences that included a larger percentage of female message recipients. Overall, we conclude that (a) fear appeals are effective at positively influencing attitude, intentions, and behaviors, (b) there are very few circumstances under which they are not effective, and (c) there are no identified circumstances under which they backfire and lead to undesirable outcomes. PMID:26501228
Rourke, Liam; Leong, Jessica; Chatterly, Patricia
2018-02-16
Phenomenon: An evidence-informed era of medical education encourages the generation and use of comparative-effectiveness reviews, yet the reviews often conclude, curiously, that all instructional approaches are equally effective. We used a conditions-based learning theory to structure a review of the comparative-effectiveness literature on electrocardiogram instruction. We searched MEDLINE, EMBASE (Ovid), ERIC (Ovid), PsycINFO (Ovid), and CINAHL (EBSCO) from inception to June 2016. We selected prospective studies that examined the effect of instructional interventions on participants' knowledge and skill with electrocardiogram interpretation. Two reviewers extracted information on the quality of the studies, the effect of instruction on the acquisition of knowledge and skill, and instructional quality. Instructional quality is an index of the extent to which instruction incorporates 4 practices of Gagne's conditions-based learning theory: presenting information, eliciting performance, providing feedback, and assessing learning. Twenty-five studies (3,286 participants) evaluating 47 instructional interventions were synthesized. The methodological quality of most studies was moderate. Instructional quality varied: All interventions presented information and assessed learning, but fewer than half elicited performances or provided feedback. Instructional interventions that incorporated all 4 components improved trainees' abilities considerably more than those that incorporated 3 or fewer; respectively, standardized mean difference (SMD) = 2.80, 95% confidence interval (CI) [2.05, 3.55], versus SMD = 1.44, 95% CI [1.18, 1.69]. Studies that compared "innovative" to "traditional" types of instruction did not yield a significant pooled effect: SMD = 0.18, 95% CI [-0.09, 0.45]. Insights: The use of a conditions-based learning theory to organize the comparative-effectiveness literature reveals differences in the instructional impact of different instructional approaches. It
Situated learning theory: adding rate and complexity effects via Kauffman's NK model.
Yuan, Yu; McKelvey, Bill
2004-01-01
For many firms, producing information, knowledge, and enhancing learning capability have become the primary basis of competitive advantage. A review of organizational learning theory identifies two approaches: (1) those that treat symbolic information processing as fundamental to learning, and (2) those that view the situated nature of cognition as fundamental. After noting that the former is inadequate because it focuses primarily on behavioral and cognitive aspects of individual learning, this paper argues the importance of studying learning as interactions among people in the context of their environment. It contributes to organizational learning in three ways. First, it argues that situated learning theory is to be preferred over traditional behavioral and cognitive learning theories, because it treats organizations as complex adaptive systems rather than mere information processors. Second, it adds rate and nonlinear learning effects. Third, following model-centered epistemology, it uses an agent-based computational model, in particular a "humanized" version of Kauffman's NK model, to study the situated nature of learning. Using simulation results, we test eight hypotheses extending situated learning theory in new directions. The paper ends with a discussion of possible extensions of the current study to better address key issues in situated learning.
Raab, Marius Hans; Auer, Nikolas; Ortlieb, Stefan A; Carbon, Claus-Christian
2013-01-01
Reptile prime ministers and flying Nazi saucers-extreme and sometimes off-wall conclusion are typical ingredients of conspiracy theories. While individual differences are a common research topic concerning conspiracy theories, the role of extreme statements in the process of acquiring and passing on conspiratorial stories has not been regarded in an experimental design so far. We identified six morphological components of conspiracy theories empirically. On the basis of these content categories a set of narrative elements for a 9/11 story was compiled. These elements varied systematically in terms of conspiratorial allegation, i.e., they contained official statements concerning the events of 9/11, statements alleging to a conspiracy limited in time and space as well as extreme statements indicating an all-encompassing cover-up. Using the method of narrative construction, 30 people were given a set of cards with these statements and asked to construct the course of events of 9/11 they deem most plausible. When extreme statements were present in the set, the resulting stories were more conspiratorial; the number of official statements included in the narrative dropped significantly, whereas the self-assessment of the story's plausibility did not differ between conditions. This indicates that blatant statements in a pool of information foster the synthesis of conspiracy theories on an individual level. By relating these findings to one of Germany's most successful (and controversial) non-fiction books, we refer to the real-world dangers of this effect.
A Study On The Effect Of Multiple Intelligences Theory Upon The Success Level Of Genders
Oral, Imran
2007-04-01
In this study, the effects of Multiple Intelligences theory upon the success level of genders were investigated at three high schools in Konya. In conclusion, a significant difference has not been found between groups for multiple intelligences and groups for pre-tests. In general, the female student groups were more successful than the male student groups regarding post-test. However, this result did not cause a significant difference between the groups.
D.W. Vahey; J.Y. Zhu; C.J. Houtman
2006-01-01
The measurement of effective residual ink concentration (ERIC) in recycled papers depends on their opacity. For opacity less than 97.0%, the method is based on application of the Kubelka-Munk theory to diffuse reflection from papers measured once with a black backing and again with a thick backing of the same papers. At opacities above 97.0%, the two reflection values...
Ma’ssoumeh Bemani Naeini
2015-01-01
Gardner’s Multiple Intelligences Theory (MIT), however having been embraced in the field of language acquisition, has apparently failed to play a role in research on learning styles as an alternative construct. This study aims at examining the potential effects of MI-based activities, as learning styls, on the listening proficiency of Iranian TEFL university students. Based on two assumptions derived from MIT, one of the experimental groups (EG1; N=30) worked on activities across intelligen...
Effectiveness of design: training university teachers through integration of theory and practice
DEFF Research Database (Denmark)
Rump, Camilla Østerberg; Christiansen, Frederik V; Evans, Robert Harry
sustainable improvement in student learning outcomes, such courses must be designed in a way which results in a conceptual change in the participant teachers’ conception of teaching, from a teacher focused to a student focused conception. It has been shown, that on the average, teacher training...... to elements resulting in successful integration of theory and practice, and to some success in initiating educational development. Discussions of how to assess long term effects are anticipated....
EFTfitter: a tool for interpreting measurements in the context of effective field theories
Energy Technology Data Exchange (ETDEWEB)
Castro, Nuno [Universidade do Minho, Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Departamento de Fisica, Braga (Portugal); Universidade do Porto, Departamento de Fisica e Astronomia, Faculdade de Ciencias, Porto (Portugal); Erdmann, Johannes; Grunwald, Cornelius; Kroeninger, Kevin [TU Dortmund, Lehrstuhl fuer Experimentelle Physik IV, Dortmund (Germany); Rosien, Nils-Arne [Universitaet Goettingen, II. Physikalisches Institut, Goettingen (Germany)
2016-08-15
Over the past years, the interpretation of measurements in the context of effective field theories has attracted much attention in the field of particle physics. We present a tool for interpreting sets of measurements in such models using a Bayesian ansatz by calculating the posterior probabilities of the corresponding free parameters numerically. An example is given, in which top-quark measurements are used to constrain anomalous couplings at the Wtb-vertex. (orig.)
Theory of the magnon-mediated tunnel magneto-Seebeck effect
Flebus, Benedetta; Bauer, Gerrit E. W.; Duine, Rembert A.; Tserkovnyak, Yaroslav
2017-09-01
The tunnel magneto-Seebeck effect is the dependence of the thermopower of magnetic tunnel junctions on the magnetic configuration. It is conventionally interpreted in terms of a thermoelectric generalization of the tunnel magnetoresistance. Here, we investigate the heat-driven electron transport in these junctions associated with electron-magnon scattering, using stochastic Landau-Lifshitz phenomenology and quantum kinetic theory. Our findings challenge the widely accepted single-electron picture of the tunneling thermopower in magnetic junctions.
Mazziotta, Agostino; Mummendey, Amélie; Stephen C Wright
2011-01-01
Abstract This contribution examines the role of vicarious contact (observing in-group members having successful cross-group contact) as a tool to improve intergroup relations. Expanding previous research on indirect intergroup contact, vicarious contact (1) integrates and applies concepts of social-cognitive theory (Bandura, 1986) to the field of intergroup contact research; (2) broadens the study of indirect contact effects to the observation of successful cross-group interactions...
The orbifolder. A tool to study the low energy effective theory of heterotic orbifolds
Energy Technology Data Exchange (ETDEWEB)
Nilles, H.P. [Bonn Univ. (Germany). Bethe Center for Theoretical Physics and Physikalisches Institut; Ramos-Sanchez, S. [Universidad Nacional Autonoma de Mexico (UNAM), Mexico City (Mexico). Dept. of Theoretical Physics; Vaudrevange, P.K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Technische Univ. Muenchen, Garching (Germany). Physik-Department; Arnold-Sommerfeld-Center for Theoretical Physics, Muenchen (Germany); Wingerter, A. [CNRS/IN2P3, INPG, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie
2011-10-15
The orbifolder is a program developed in C{sup ++} that computes and analyzes the low-energy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models (e.g. MSSM-like models) and to analyze their vacuum-configurations. (orig.)
Feynman rules for the Standard Model Effective Field Theory in R ξ -gauges
Dedes, A.; Materkowska, W.; Paraskevas, M.; Rosiek, J.; Suxho, K.
2017-06-01
We assume that New Physics effects are parametrized within the Standard Model Effective Field Theory (SMEFT) written in a complete basis of gauge invariant operators up to dimension 6, commonly referred to as "Warsaw basis". We discuss all steps necessary to obtain a consistent transition to the spontaneously broken theory and several other important aspects, including the BRST-invariance of the SMEFT action for linear R ξ -gauges. The final theory is expressed in a basis characterized by SM-like propagators for all physical and unphysical fields. The effect of the non-renormalizable operators appears explicitly in triple or higher multiplicity vertices. In this mass basis we derive the complete set of Feynman rules, without resorting to any simplifying assumptions such as baryon-, lepton-number or CP conservation. As it turns out, for most SMEFT vertices the expressions are reasonably short, with a noticeable exception of those involving 4, 5 and 6 gluons. We have also supplemented our set of Feynman rules, given in an appendix here, with a publicly available Mathematica code working with the FeynRules package and producing output which can be integrated with other symbolic algebra or numerical codes for automatic SMEFT amplitude calculations.
IS ASSIMILATION THEORY DEAD? THE EFFECT OF ASSIMILATION ON ADOLESCENT WELL-BEING.
Greenman, Emily; Xie, Yu
2008-03-01
The relationship between assimilation and the well-being of immigrant children has been the focus of debate in the recent sociological literature. Much of this work has questioned whether classical theories of immigrant adaptation, which assumed assimilation to be an integral part of the process of upward mobility for immigrants, are still applicable to today's immigrant children. This study reevaluates the applicability of classical assimilation theory with a comprehensive empirical assessment of the relationship between assimilation and the well-being of Hispanic and Asian immigrant adolescents. Using Add Health data, we examine the effect of different aspects of assimilation on educational achievement, psychological well-being, and at-risk behaviors. We find that the effect of assimilation varies greatly depending on the ethnic group and outcome under consideration, but that it is generally related to both greater academic achievement and more at-risk behavior. We conclude that assimilation theory is still relevant, but suggest an interpretation that emphasizes a process of decreasing differences between groups rather than either detrimental or beneficial effects of assimilation.
Elements of QED-NRQED effective field theory: NLO scattering at leading power
Dye, Steven P.; Gonderinger, Matthew; Paz, Gil
2016-07-01
The proton radius puzzle, i.e. the large discrepancy in the extraction of the proton charge radius between regular and muonic hydrogen, challenges our understanding of the structure of the proton. It can also be an indication of a new force that couples to muons, but not to electrons. An effective field theory analysis using nonrelativistic quantum electrodynamics (NRQED) indicates that the muonic hydrogen result can be interpreted as a large, compared to some model estimates, muon-proton spin-independent contact interaction. The muonic hydrogen result can be tested by a muon-proton scattering experiment, MUSE, that is planned at the Paul Scherrer Institute in Switzerland. The typical momenta of the muons in this experiment are of the order of the muon mass. In this energy regime the muons are relativistic but the protons are still nonrelativistic. The interaction between the muons and protons can be described by a hybrid QED-NRQED effective field theory. We present some elements of this effective field theory. In particular we consider O (Z α ) scattering up to power m2/M2 , where m (M ) is the muon (proton) mass and Z =1 for a proton, and O (Z2α2) scattering at leading power. We show how the former reproduces Rosenbluth scattering up to power m2/M2 and the latter the relativistic scattering off a static potential. Proton structure corrections at O (Z2α2) will be considered in a subsequent paper.
Effective Principles In Designing E-Course In Light Of Learning Theories
Directory of Open Access Journals (Sweden)
Muhammad K. AFIFI
2014-01-01
Full Text Available The researchers conducted an exploratory study to determine the design quality of some E-courses delivered via the web to a number of colleagues at the university. Results revealed a number of shortcomings in the design of these courses, mostly due to the absence of effective principles in the design of these E-courses, especially principles of pedagogy in relation to learning theories. So, this study seeks to identify effective principles in the design of courses for internet-based learning in the light of current learning theories, by answering the following question: What are the most effective principles when designing E-learning courses in the light of current learning theories? After an extensive review and analysis of the literature and previous studies relating to quality standards for the instructional design of E-courses delivered via the web, in particular, and quality standards for E-learning, in general, the results of this study revealed a number of principles for course design in E-learning. These are: identifying learning and performance outcomes; identifying methods and strategies of learning; designing learning activities; providing feedback and motivating the learner and determining the context and impact of learning. In the light of the findings of this study, with reference to the literature, we present a set of recommendations and pedagogical implications for professionals working in course design in E-learning at University of Dammam.
The matter power spectrum in redshift space using effective field theory
Fonseca de la Bella, Lucía; Regan, Donough; Seery, David; Hotchkiss, Shaun
2017-11-01
The use of Eulerian 'standard perturbation theory' to describe mass assembly in the early universe has traditionally been limited to modes with k lesssim 0.1 h/Mpc at z=0. At larger k the SPT power spectrum deviates from measurements made using N-body simulations. Recently, there has been progress in extending the reach of perturbation theory to larger k using ideas borrowed from effective field theory. We revisit the computation of the redshift-space matter power spectrum within this framework, including for the first time the full one-loop time dependence. We use a resummation scheme proposed by Vlah et al. to account for damping of baryonic acoustic oscillations due to large-scale random motions and show that this has a significant effect on the multipole power spectra. We renormalize by comparison to a suite of custom N-body simulations matching the MultiDark MDR1 cosmology. At z=0 and for scales k lesssim 0.4 h/Mpc we find that the EFT furnishes a description of the real-space power spectrum up to ~ 2%, for the l = 0 mode up to ~ 5%, and for the l = 2, 4 modes up to ~ 25%. We argue that, in the MDR1 cosmology, positivity of the l=0 mode gives a firm upper limit of k ≈ 0.74 h/Mpc for the validity of the one-loop EFT prediction in redshift space using only the lowest-order counterterm. We show that replacing the one-loop growth factors by their Einstein-de Sitter counterparts is a good approximation for the l=0 mode, but can induce deviations as large as 2% for the l=2, 4 modes. An accompanying software bundle, distributed under open source licenses, includes Mathematica notebooks describing the calculation, together with parallel pipelines capable of computing both the necessary one-loop SPT integrals and the effective field theory counterterms.
Effective field theory of an anomalous Hall metal from interband quantum fluctuations
Chua, Victor; Assawasunthonnet, Wathid; Fradkin, Eduardo
2017-07-01
We construct an effective field theory, a two-dimensional two-component metallic system described by a model with two Fermi surfaces ("pockets"). This model describes a translationally invariant metallic system with two types of fermions, each with its own Fermi surface, with forward scattering interactions. This model, in addition to the O (2 ) rotational invariance, has a U (1 )×U (1 ) symmetry of separate charge conservation for each Fermi surface. For sufficiently attractive interactions in the d -wave (quadrupolar) channel, this model has an interesting phase diagram that includes a spontaneously generated anomalous Hall metal phase. We derive the Landau-Ginzburg effective action of quadrupolar order parameter fields which enjoys an O (2 )×U (1 ) global symmetry associated to spatial isotropy and the internal U (1 ) relative phase symmetries, respectively. We show that the order parameter theory is dynamically local with a dynamical scaling of z =2 and perform a one-loop renormalization group analysis of the Landau-Ginzburg theory. The electronic liquid crystal phases that result from spontaneous symmetry breaking are studied and we show the presence of Landau damped Nambu-Goldstone modes at low momenta that is a signature of non-Fermi-liquid behavior. Electromagnetic linear response is also analyzed in both the normal and symmetry broken phases from the point of view of the order parameter theory. The nature of the coupling of electromagnetism to the order parameter fields in the normal phase is non-minimal and decidedly contains a precursor to the anomalous Hall response in the form of a order-parameter-dependent Chern-Simons term in the effective action.
Lattice simulation of a center symmetric three dimensional effective theory for SU(2) Yang-Mills
Energy Technology Data Exchange (ETDEWEB)
Smith, Dominik
2010-11-17
We present lattice simulations of a center symmetric dimensionally reduced effective field theory for SU(2) Yang Mills which employ thermal Wilson lines and three-dimensional magnetic fields as fundamental degrees of freedom. The action is composed of a gauge invariant kinetic term, spatial gauge fields and a potential for theWilson line which includes a ''fuzzy'' bag term to generate non-perturbative fluctuations between Z(2) degenerate ground states. The model is studied in the limit where the gauge fields are set to zero as well as the full model with gauge fields. We confirm that, at moderately weak coupling, the ''fuzzy'' bag term leads to eigenvalue repulsion in a finite region above the deconfining phase transition which shrinks in the extreme weak-coupling limit. A non-trivial Z(N) symmetric vacuum arises in the confined phase. The effective potential for the Polyakov loop in the theory with gauge fields is extracted from the simulations including all modes of the loop as well as for cooled configurations where the hard modes have been averaged out. The former is found to exhibit a non-analytic contribution while the latter can be described by a mean-field like ansatz with quadratic and quartic terms, plus a Vandermonde potential which depends upon the location within the phase diagram. Other results include the exact location of the phase boundary in the plane spanned by the coupling parameters, correlation lengths of several operators in the magnetic and electric sectors and the spatial string tension. We also present results from simulations of the full 4D Yang-Mills theory and attempt to make a qualitative comparison to the 3D effective theory. (orig.)
Ahmavaara, Anni; Houston, Diane M
2007-09-01
Dweck has emphasized the role of pupils' implicit theories about intellectual ability in explaining variations in their engagement, persistence and achievement. She has also highlighted the role of confidence in one's intelligence as a factor influencing educational attainment. The aim of this paper is to develop a model of achievement aspiration in adolescence and to compare young people who are educated at a selective grammar school with those who attend a non-selective 'secondary modern' school. The sample consisted of 856 English secondary school pupils in years 7 and 10 from two selective and two non-selective secondary schools. Questionnaires were completed in schools. The findings are consistent with the model, showing that achievement aspiration is predicted directly by gender, school type and type of intelligence theory. Importantly, school type also affects aspirations indirectly, with effects being mediated by confidence in one's own intelligence and perceived academic performance. Intelligence theory also affects aspirations indirectly with effects being mediated by perceived academic performance, confidence and self-esteem. Additionally, intelligence theory has a stronger effect on aspirations in the selective schools than in the non-selective schools. The findings provide substantial support for Dweck's self-theory, showing that implicit theories are related to aspirations. However, the way in which theory of intelligence relates to age and gender suggests there may be important cross-cultural or contextual differences not addressed by Dweck's theory. Further research should also investigate the causal paths between aspirations, implicit theories of intelligence and the impact of school selection.
Effective medium theory for a system of C{sub 60} molecules
Energy Technology Data Exchange (ETDEWEB)
Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of)
2016-06-15
An effective medium theory is developed to study the effective permittivity of a system of C{sub 60} molecules. We use a two-dimensional, spherical, two-fluid hydrodynamic model to describe the linear response of the π and σ electrons over the each C{sub 60} molecule. A general expression for the electromagnetic wave attenuation coefficient of the system is then deduced, and its functional dependence on the filling factor is presented. Furthermore, the dispersion characteristics of electromagnetic oscillations of the system are studied.
Chiral Effective Theory Methods and their Application to the Structure of Hadrons from Lattice QCD
Shanahan, P E
2016-01-01
For many years chiral effective theory (ChEFT) has enabled and supported lattice QCD calculations of hadron observables by allowing systematic effects from unphysical lattice parameters to be controlled. In the modern era of precision lattice simulations approaching the physical point, ChEFT techniques remain valuable tools. In this review we discuss the modern uses of ChEFT applied to lattice studies of hadron structure in the context of recent determinations of important and topical quantities. We consider muon g-2, strangeness in the nucleon, the proton radius, nucleon polarizabilities, and sigma terms relevant to the prediction of dark-matter-hadron interaction cross-sections, among others.
A short guide to topological terms in the effective theories of condensed matter.
Tanaka, Akihiro; Takayoshi, Shintaro
2015-02-01
This article is meant as a gentle introduction to the topological terms that often play a decisive role in effective theories describing topological quantum effects in condensed matter systems. We first take up several prominent examples, mainly from the area of quantum magnetism and superfluids/superconductors. We then briefly discuss how these ideas are now finding incarnations in the studies of symmetry-protected topological phases, which are in a sense a generalization of the concept of topological insulators to a wider range of materials, including magnets and cold atoms.
Setting limits on Effective Field Theories: the case of Dark Matter
Pobbe, Federico; Wulzer, Andrea; Zanetti, Marco
2017-08-01
The usage of Effective Field Theories (EFT) for LHC new physics searches is receiving increasing attention. It is thus important to clarify all the aspects related with the applicability of the EFT formalism in the LHC environment, where the large available energy can produce reactions that overcome the maximal range of validity, i.e. the cutoff, of the theory. We show that this does not forbid to set rigorous limits on the EFT parameter space through a modified version of the ordinary binned likelihood hypothesis test, which we design and validate. Our limit-setting strategy can be carried on in its full-fledged form by the LHC experimental collaborations, or performed externally to the collaborations, through the Simplified Likelihood approach, by relying on certain approximations. We apply it to the recent CMS mono-jet analysis and derive limits on a Dark Matter (DM) EFT model. DM is selected as a case study because the limited reach on the DM production EFT Wilson coefficient and the structure of the theory suggests that the cutoff might be dangerously low, well within the LHC reach. However our strategy can also be applied, if needed, to EFT's parametrising the indirect effects of heavy new physics in the Electroweak and Higgs sectors.
Effective field theory for the quantum electrodynamics of a graphene wire
Faccioli, P.; Lipparini, E.
2009-07-01
We study the low-energy quantum electrodynamics of electrons and holes in a thin graphene wire. We develop an effective field theory (EFT) based on an expansion in p/pT , where pT is the typical momentum of electrons and holes in the transverse direction, while p are the momenta in the longitudinal direction. We show that, to the lowest order in (p/pT) , our EFT theory is formally equivalent to the exactly solvable Schwinger model. By exploiting such an analogy, we find that the ground state of the quantum wire contains a condensate of electron-hole pairs. The excitation spectrum is saturated by electron-hole collective bound states, and we calculate the dispersion law of such modes. We also compute the dc conductivity per unit length at zero chemical potential and find gs(e2)/(h) , where gs=4 is the degeneracy factor.
The effective U(1)-Higgs theory at strong coupling on optical lattices?
Bazavov, Alexei; Tsai, Shan-Wen; Meurice, Yannick
2014-01-01
We discuss the U(1)-Higgs model in two dimensions in the strongly coupled regime. If we neglect the plaquette interactions, we generate an effective theory where link variables are integrated out, producing 4-field operators. Plaquette interactions can be restored order by order as in recent calculations with staggered fermions. In the case of a SU(2) gauge theory with fermions, this strong coupling expansion can be related to the strong coupling expansion of Fermi-Hubbard models possibly implementable on optical lattice. We would like to provide a similar construction relating the U(1)-Higgs model to some Bose-Hubbard model. As a first step in this direction, we discuss a recent proposal to implement the O(2) model on optical lattices using a 87Rb and 41K Bose-Bose mixture of cold atoms.
Nonequilibrium Green's function theory for nonadiabatic effects in quantum electron transport.
Kershaw, Vincent F; Kosov, Daniel S
2017-12-14
We develop nonequilibrium Green's function-based transport theory, which includes effects of nonadiabatic nuclear motion in the calculation of the electric current in molecular junctions. Our approach is based on the separation of slow and fast time scales in the equations of motion for Green's functions by means of the Wigner representation. Time derivatives with respect to central time serve as a small parameter in the perturbative expansion enabling the computation of nonadiabatic corrections to molecular Green's functions. Consequently, we produce a series of analytic expressions for non-adiabatic electronic Green's functions (up to the second order in the central time derivatives), which depend not solely on the instantaneous molecular geometry but likewise on nuclear velocities and accelerations. An extended formula for electric current is derived which accounts for the non-adiabatic corrections. This theory is concisely illustrated by the calculations on a model molecular junction.
String states, loops and effective actions in noncommutative field theory and matrix models
Directory of Open Access Journals (Sweden)
Harold C. Steinacker
2016-09-01
Full Text Available Refining previous work by Iso, Kawai and Kitazawa, we discuss bi-local string states as a tool for loop computations in noncommutative field theory and matrix models. Defined in terms of coherent states, they exhibit the stringy features of noncommutative field theory. This leads to a closed form for the 1-loop effective action in position space, capturing the long-range non-local UV/IR mixing for scalar fields. The formalism applies to generic fuzzy spaces. The non-locality is tamed in the maximally supersymmetric IKKT or IIB model, where it gives rise to supergravity. The linearized supergravity interactions are obtained directly in position space at one loop using string states on generic noncommutative branes.
String states, loops and effective actions in noncommutative field theory and matrix models
Energy Technology Data Exchange (ETDEWEB)
Steinacker, Harold C., E-mail: harold.steinacker@univie.ac.at
2016-09-15
Refining previous work by Iso, Kawai and Kitazawa, we discuss bi-local string states as a tool for loop computations in noncommutative field theory and matrix models. Defined in terms of coherent states, they exhibit the stringy features of noncommutative field theory. This leads to a closed form for the 1-loop effective action in position space, capturing the long-range non-local UV/IR mixing for scalar fields. The formalism applies to generic fuzzy spaces. The non-locality is tamed in the maximally supersymmetric IKKT or IIB model, where it gives rise to supergravity. The linearized supergravity interactions are obtained directly in position space at one loop using string states on generic noncommutative branes.
Trierweiller, Andréa Cristina; Peixe, Blênio César Severo; Tezza, Rafael; Pereira, Vera Lúcia Duarte do Valle; Pacheco, Waldemar; Bornia, Antonio Cezar; de Andrade, Dalton Francisco
2012-01-01
The aim of this paper is to measure the effectiveness of the organizations Information and Communication Technology (ICT) from the point of view of the manager, using Item Response Theory (IRT). There is a need to verify the effectiveness of these organizations which are normally associated to complex, dynamic, and competitive environments. In academic literature, there is disagreement surrounding the concept of organizational effectiveness and its measurement. A construct was elaborated based on dimensions of effectiveness towards the construction of the items of the questionnaire which submitted to specialists for evaluation. It demonstrated itself to be viable in measuring organizational effectiveness of ICT companies under the point of view of a manager through using Two-Parameter Logistic Model (2PLM) of the IRT. This modeling permits us to evaluate the quality and property of each item placed within a single scale: items and respondents, which is not possible when using other similar tools.
Directory of Open Access Journals (Sweden)
Meng-Hui Wang
2015-01-01
Full Text Available The detection of islanding effect is a highly important topic for photovoltaic (PV power system. The islanding effect occurs when the distributed power source is disconnected from the main supply while the power is still supplied in partial load area, which may injure the set maintenance personnel or damage the equipment. Combining chaotic synchronization and extension theory, this research is to propose a novel detection method to distinguish the occurrence of islanding effect based on nonautonomous Chua’s circuit. To demonstrate the effectiveness of the proposed method, this paper applies PSIM to simulate the PV power system. The experimental results show that the accuracy of the proposed method achieves 98% on islanding effect.
W-pair production near threshold in unstable particle effective theory
Energy Technology Data Exchange (ETDEWEB)
Falgari, Pietro
2008-11-07
In this thesis we present a dedicated study of the four-fermion production process e{sup +}e{sup -}{yields}{mu}{sup -} anti {nu}{sub {mu}}u anti dX near the W-pair production threshold, in view of its importance for a precise determination of the W-boson mass at the ILC. The calculation is performed in the framework of unstable-particle effective theory, which allows for a gauge-invariant inclusion of instability effects, and for a systematic approximation of the full cross section with an expansion in the coupling constants, the ratio {gamma}{sub W}/M{sub W}, and the non-relativistic velocity v of the W boson. The effective-theory result, computed to next-to-leading order in the expansion parameters {gamma}{sub W}/M{sub W}{proportional_to}{alpha}{sub ew}{proportional_to}v{sup 2}, is compared to the full numerical next-to-leading order calculation of the four-fermion production cross section, and agreement to better than 0.5% is found in the region of validity of the effective theory. Furthermore, we estimate the contributions of missing higher-order corrections to the four-fermion process, and how they translate into an error on the W-boson mass determination. We find that the dominant theoretical uncertainty on MW is currently due to an incomplete treatment of initial-state radiation, while the remaining combined uncertainty of the two NLO calculations translates into {delta}M{sub W}{approx} 5 MeV. The latter error is removed by an explicit computation of the dominant missing terms, which originate from the expansion in v of next-to-next-to-leading order Standard Model diagrams. The effect of resummation of logarithmically-enhanced terms is also investigated, but found to be negligible. (orig.)
The effectiveness of group selection theory on the quality of drug addicted life
Directory of Open Access Journals (Sweden)
M Sodani
2017-01-01
Full Text Available Backgrounds and aim: Increase in addiction in the community and the plight of its people demand for improving the problems of addicts, indicate a need for individuals to interventions and training expertise. The aim of this study was to investigate the effectiveness of group selection theory on the quality of drug addicted life. . Methods: This study is an quasi-experimental design with pretest-posttest and follow up with the control group. The study population included: all addicted people who referred to ahvaz addiction treatment center in 2015. 50 addicts were selected by using of available sampling and randomly divided into two experimental group (number=25 and control group (number=25. The participants were completed the quality of life inventory in three stages (pre-test, post-test and follow-up after 60 days. The experimental group was received group training of the concepts of selection theory of 10 sessions of 90 minutes per week.Statistical data were analyzed using of covariance(ANCOVA analysis. Results: Group training theory led to a significant difference among pretest, posttest, and follow-up of quality of addicted people life (p <0.001. In this case, the post-test and follow-up, after controlling of pre-test score, the experimental group compared to the control group higher quality of life was reported. Conclusion: Group training of selected theory about the role of choosing a behavior, five senses the importance of self control, the role of effective behavior, the way of need fulfilment, responsibility, self worth, Quality world, seven destructive behavior, seven caring behavior, faiure identification and success identification can result in increasing the quality of life for addicted people.
Hogg, Michael A; Martin, Robin; Epitropaki, Olga; Mankad, Aditi; Svensson, Alicia; Weeden, Karen
2005-07-01
Two studies compared leader-member exchange (LMX) theory and the social identity theory of leadership. Study 1 surveyed 439 employees of organizations in Wales, measuring work group salience, leader-member relations, and perceived leadership effectiveness. Study 2 surveyed 128 members of organizations in India, measuring identification not salience and also individualism/collectivism. Both studies provided good support for social identity predictions. Depersonalized leader-member relations were associated with greater leadership effectiveness among high-than low-salient groups (Study 1) and among high than low identifiers (Study 2). Personalized leadership effectiveness was less affected by salience (Study 1) and unaffected by identification (Study 2). Low-salience groups preferred personalized leadership more than did high-salience groups (Study 1). Low identifiers showed no preference but high identifiers preferred depersonalized leadership (Study 2). In Study 2, collectivists did not prefer depersonalized as opposed to personalized leadership, whereas individualists did, probably because collectivists focus more on the relational self.
Moon, Byongook; Morash, Merry
2017-01-01
The present study of 659 Korean adolescents tests General Strain Theory's (GST) utility in explaining gender differences in delinquency causation. It models the effects of key strains, negative emotions, and a composite measure of several conditioning factors separately for boys and girls and for delinquency. Consistent with the theory, males and…
Directory of Open Access Journals (Sweden)
Reeves Scott
2006-02-01
Full Text Available Abstract The Improved Clinical Effectiveness through Behavioural Research Group (ICEBeRG authors assert that a key weakness in implementation research is the unknown applicability of a given intervention outside its original site and problem, and suggest that use of explicit theory offers an effective solution. This assertion is problematic for three primary reasons. First, the presence of an underlying theory does not necessarily ease the task of judging the applicability of a piece of empirical evidence. Second, it is not clear how to translate theory reliably into intervention design, which undoubtedly involves the diluting effect of "common sense." Thirdly, there are many theories, formal and informal, and it is not clear why any one should be given primacy. To determine whether explicitly theory-based interventions are, on average, more effective than those based on implicit theories, pragmatic trials are needed. Until empirical evidence is available showing the superiority of theory-based interventions, the use of theory should not be used as a basis for assessing the value of implementation studies by research funders, ethics committees, editors or policy decision makers.
Nuclear structure effects on heavy-ion reactions with microscopic theory
Directory of Open Access Journals (Sweden)
Vo-Phuoc K.
2016-01-01
Full Text Available The self-consistent mean-field Hartree–Fock (HF theory, both static and time-dependent (TDHF versions, is used to study static and dynamic properties of fusion reactions between even 40–54Ca isotopes and 116Sn. The bare nucleus-nucleus potential, calculated with the frozen HF approach, is affected by the groundstate density of the nuclei. However, once dynamical effects are included, as in TDHF, the static effects on the barrier are essentially washed out. Dynamic properties of the nuclei, including low-lying vibrational modes, are calculated with TDHF and selectively used in coupled-channels calculations to identify which modes have the most effect on the TDHF fusion threshold. Vibrations cannot fully explain the difference between the static HF and TDHF fusion barriers trend so other dynamical effects such as transfer are considered.
On the covariant formalism of the effective field theory of gravity and leading order corrections
DEFF Research Database (Denmark)
Codello, Alessandro; Jain, Rajeev Kumar
2016-01-01
We construct the covariant effective field theory of gravity as an expansion in inverse powers of the Planck mass, identifying the leading and next-to-leading quantum corrections. We determine the form of the effective action for the cases of pure gravity with cosmological constant as well...... as gravity coupled to matter. By means of heat kernel methods we renormalize and compute the leading quantum corrections to quadratic order in a curvature expansion. The final effective action in our covariant formalism is generally non-local and can be readily used to understand the phenomenology...... on different spacetimes. In particular, we point out that on curved backgrounds the observable leading quantum gravitational effects are less suppressed than on Minkowski spacetime....
Modeling and optimizing the performance of plasmonic solar cells using effective medium theory
Energy Technology Data Exchange (ETDEWEB)
Piralaee, M. [Research Institute of Applied Physics and Astronomy, University of Tabriz, Tabriz, 51665-163 (Iran, Islamic Republic of); Photonics Group, Aras International Campus, University of Tabriz, Tabriz (Iran, Islamic Republic of); Asgari, A., E-mail: asgari@tabrizu.ac.ir [Research Institute of Applied Physics and Astronomy, University of Tabriz, Tabriz, 51665-163 (Iran, Islamic Republic of); School of Electrical, Electronic and Computer Engineering, University of Western Australia, Crawley, WA 6009 (Australia); Siahpoush, V. [Research Institute of Applied Physics and Astronomy, University of Tabriz, Tabriz, 51665-163 (Iran, Islamic Republic of)
2017-02-05
In this paper, the effects of random Ag nanoparticle used within the active layer of Si based thin film solar cell are investigated. To avoid the complexity of taking into account all random nanoparticles, an effective dielectric function for random Ag nanoparticles and Si nanocomposites is used that is the Maxwell–Garnet theory along with Percus–Yevick correction term. Considering the energy reservation law and using the effective dielectric function, the absorbance of the active layer, therefore, the solar cell's maximum short current density is obtained. Also, the maximum external quantum efficiency of the solar cell is obtained using the optimum values for the radius and filling fraction of Ag nanoparticles. - Highlights: • A random plasmonic thin film solar cells is studied theoretically. • Silver nanoparticles are randomly distributed through the active layer of solar cell. • The Maxwell–Garnett effective medium theory is used to describe the optical properties. • We have found an optimum situation in which maximum short circuit current density is obtained. • The maximum EQE are found for Ag particles of 7.5 nm radius and filling fraction of 0.05.
Parameter-free effective field theory calculation for the solar proton-fusion and hep processes
Energy Technology Data Exchange (ETDEWEB)
T.S. Park; L.E. Marcucci; R. Schiavilla; M. Viviani; A. Kievsky; S. Rosati; K. Kubodera; D.P. Min; M. Rho
2002-08-01
Spurred by the recent complete determination of the weak currents in two-nucleon systems up to {Omicron}(Q{sup 3}) in heavy-baryon chiral perturbation theory, we carry out a parameter-free calculation of the threshold S-factors for the solar pp (proton-fusion) and hep processes in an effective field theory that combines the merits of the standard nuclear physics method and systematic chiral expansion. The power of the EFT adopted here is that one can correlate in a unified formalism the weak-current matrix elements of two-, three- and four-nucleon systems. Using the tritium {beta}-decay rate as an input to fix the only unknown parameter in the theory, we can evaluate the threshold S factors with drastically improved precision; the results are S{sub pp}(0) = 3.94 x (1 {+-} 0.004) x 10{sup -25} MeV-b and S{sub hep}(0) = (8.6 {+-} 1.3) x 10{sup -20} keV-b. The dependence of the calculated S-factors on the momentum cutoff parameter {Lambda} has been examined for a physically reasonable range of {Lambda}. This dependence is found to be extremely small for the pp process, and to be within acceptable levels for the hep process, substantiating the consistency of our calculational scheme.
Priors on the effective dark energy equation of state in scalar-tensor theories
Raveri, Marco; Bull, Philip; Silvestri, Alessandra; Pogosian, Levon
2017-10-01
Constraining the dark energy (DE) equation of state, wDE, is one of the primary science goals of ongoing and future cosmological surveys. In practice, with imperfect data and incomplete redshift coverage, this requires making assumptions about the evolution of wDE with redshift z . These assumptions can be manifested in a choice of a specific parametric form, which can potentially bias the outcome, or else one can reconstruct wDE(z ) nonparametrically, by specifying a prior covariance matrix that correlates values of wDE at different redshifts. In this work, we derive the theoretical prior covariance for the effective DE equation of state predicted by general scalar-tensor theories with second order equations of motion (Horndeski theories). This is achieved by generating a large ensemble of possible scalar-tensor theories using a Monte Carlo methodology, including the application of physical viability conditions. We also separately consider the special subcase of the minimally coupled scalar field, or quintessence. The prior shows a preference for tracking behaviors in the most general case. Given the covariance matrix, theoretical priors on parameters of any specific parametrization of wDE(z ) can also be readily derived by projection.
Sotiropoulou, Rafaella-Eleni P.; Nenes, Athanasios; Adams, Peter J.; Seinfeld, John H.
2007-01-01
In situ observations of aerosol and cloud condensation nuclei (CCN) and the GISS GCM Model II' with an online aerosol simulation and explicit aerosol-cloud interactions are used to quantify the uncertainty in radiative forcing and autoconversion rate from application of Kohler theory. Simulations suggest that application of Koehler theory introduces a 10-20% uncertainty in global average indirect forcing and 2-11% uncertainty in autoconversion. Regionally, the uncertainty in indirect forcing ranges between 10-20%, and 5-50% for autoconversion. These results are insensitive to the range of updraft velocity and water vapor uptake coefficient considered. This study suggests that Koehler theory (as implemented in climate models) is not a significant source of uncertainty for aerosol indirect forcing but can be substantial for assessments of aerosol effects on the hydrological cycle in climatically sensitive regions of the globe. This implies that improvements in the representation of GCM subgrid processes and aerosol size distribution will mostly benefit indirect forcing assessments. Predictions of autoconversion, by nature, will be subject to considerable uncertainty; its reduction may require explicit representation of size-resolved aerosol composition and mixing state.
Directory of Open Access Journals (Sweden)
Zeinab Jalambadani
2015-10-01
Full Text Available Background and Aim: Dysmenorrhea is one of the most common problems in females. “Theory of Planned Behavior” is one of the important theories that explains the main process of adopting health behaviors. The present study assessed applying “ the Theory of Planned Behavior in relaxation training regarding the severity and duration of painful dysmenorrhea in Mashhad girl students. Materials and Methods: In this Semi-experimental study, 160 first year intermediate students of Mashhad city who suffered from dysmenorrhea were assessed.They had been randomly selected from 5 girl high- schools in the 6th educational district. They were divided into equal groups “case” and “control”. Intervention was made in four sessions. The requisite data was gathered by means of a researcher designed questionnaire before and 3 months after the education of the students. Finally, the obtained data was fed into SPSS software (v:16 using statistical tests including Wilcoxon, Mann-Whitney, Independent T-test, Paired T and X2. Results: After educational intervention, mean level of knowledge, attitude, perceived behavioral control, and willed performance of relaxation techniques significantly increased in the case group (P<0.05. These changes were not significant in the control group. Besides, no statistically significant difference in subjective norms was observed between the two groups after intervention. Meditation education group was increased significantly (P<0.05. Conclusion: Education of relaxation base on the Theory of Planned Behavior is effective in reduced pain intensity and its duration.
Hořava Gravity in the Effective Field Theory formalism: From cosmology to observational constraints
Frusciante, Noemi; Raveri, Marco; Vernieri, Daniele; Hu, Bin; Silvestri, Alessandra
2016-09-01
We consider Hořava gravity within the framework of the effective field theory (EFT) of dark energy and modified gravity. We work out a complete mapping of the theory into the EFT language for an action including all the operators which are relevant for linear perturbations with up to sixth order spatial derivatives. We then employ an updated version of the EFTCAMB/EFTCosmoMC package to study the cosmology of the low-energy limit of Hořava gravity and place constraints on its parameters using several cosmological data sets. In particular we use cosmic microwave background (CMB) temperature-temperature and lensing power spectra by Planck 2013, WMAP low- ℓ polarization spectra, WiggleZ galaxy power spectrum, local Hubble measurements, Supernovae data from SNLS, SDSS and HST and the baryon acoustic oscillations measurements from BOSS, SDSS and 6dFGS. We get improved upper bounds, with respect to those from Big Bang Nucleosynthesis, on the deviation of the cosmological gravitational constant from the local Newtonian one. At the level of the background phenomenology, we find a relevant rescaling of the Hubble rate at all epoch, which has a strong impact on the cosmological observables; at the level of perturbations, we discuss in details all the relevant effects on the observables and find that in general the quasi-static approximation is not safe to describe the evolution of perturbations. Overall we find that the effects of the modifications induced by the low-energy Hořava gravity action are quite dramatic and current data place tight bounds on the theory parameters.
Effect of music therapy on oncologic staff bystanders: a substantive grounded theory.
O'Callaghan, Clare; Magill, Lucanne
2009-06-01
Oncologic work can be satisfying but also stressful, as staff support patients and families through harsh treatment effects, uncertain illness trajectories, and occasional death. Although formal support programs are available, no research on the effects of staff witnessing patients' supportive therapies exists. This research examines staff responses to witnessing patient-focused music therapy (MT) programs in two comprehensive cancer centers. In Study 1, staff were invited to anonymously complete an open-ended questionnaire asking about the relevance of a music therapy program for patients and visitors (what it does; whether it helps). In Study 2, staff were theoretically sampled and interviewed regarding the personal effects of witnessing patient-centered music therapy. Data from each study were comparatively analyzed according to grounded theory procedures. Positive and negative cases were evident and data saturation arguably achieved. In Study 1, 38 staff unexpectedly described personally helpful emotional, cognitive, and team effects and consequent improved patient care. In Study 2, 62 staff described 197 multiple personal benefits and elicited patient care improvements. Respondents were mostly nursing (57) and medical (13) staff. Only three intrusive effects were reported: audibility, initial suspicion, and relaxation causing slowing of work pace. A substantive grounded theory emerged applicable to the two cancer centers: Staff witnessing MT can experience personally helpful emotions, moods, self-awarenesses, and teamwork and thus perceive improved patient care. Intrusive effects are uncommon. Music therapy's benefits for staff are attributed to the presence of live music, the human presence of the music therapist, and the observed positive effects in patients and families. Patient-centered oncologic music therapy in two cancer centers is an incidental supportive care modality for staff, which can reduce their stress and improve work environments and perceived
Comparing the Effectiveness of SPSS and EduG Using Different Designs for Generalizability Theory
Teker, Gulsen Tasdelen; Guler, Nese; Uyanik, Gulden Kaya
2015-01-01
Generalizability theory (G theory) provides a broad conceptual framework for social sciences such as psychology and education, and a comprehensive construct for numerous measurement events by using analysis of variance, a strong statistical method. G theory, as an extension of both classical test theory and analysis of variance, is a model which…
Simulated behaviour of field-assisted ionisation in the theory of Synthetic Poole Frenkel effect
Pillonnet, A.; Ongaro, R.
1991-01-01
A simulation is made of the behaviour of dc-current versus electric field when use is made of a new approach of Poole and Poole-Frenkel (PF) theories, we designated as Synthetic Poole Frenkel (SPF) effect (Ongaro and Pillonnet, in IEE Proc. PtA 138, 127-37). Quantitative illustration shows that our SPF approach succeeds fairly well in joining in a unique formulation the early Poole and PF approaches, which appear then as limiting cases. However, it is stressed that difficulties can be expecte...
Transport formulas for multi-component plasmas within the effective potential theory framework
Kagan, Grigory
2016-01-01
The recently proposed effective potential theory [Phys. Rev. Lett. 110, 235001 (2013)] allows evaluating transport in coupled plasmas with the well-developed formalisms for systems with binary collisions. To facilitate practical implementation of this concept in fluid models of multi-component plasmas, compact expressions for the transport coefficients in terms the generalized Coulomb logarithms are summarized from existing prescriptions. For weakly coupled plasmas, characterized by Debye-shielded Coulomb interaction potential, expressions become fully analytical. In coupled plasmas the generalized Coulomb logarithms need to be evaluated numerically. Routines implementing the described formalisms are included as supplemental material.
$\\bar d - \\bar u$ asymmetry in the proton in chiral effective theory
Energy Technology Data Exchange (ETDEWEB)
Salamu, Yusupujiang [Institute of High Energy Physics, CAS, Beijing (China); Ji, Chueng -Ryong [North Carolina State Univ., Raleigh, NC (United States); Melnitchouk, W. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wang, P. [Institute of High Energy Physics, Beijing (China); Theoretical Physics Center for Science Facilities, CAS, Beijing (China)
2015-03-25
We compute the $\\bar d - \\bar u$ asymmetry in the proton in chiral effective theory, including both nucleon and Δ degrees of freedom, within both relativistic and heavy baryon frameworks. In addition to the distribution at $x>0$, we estimate the correction to the integrated asymmetry arising from zero momentum contributions from pion rainbow and bubble diagrams at $x=0$, which have not been accounted for in previous analyses. In conclusion, we find that the empirical $x$ dependence of $\\bar d - \\bar u$ as well as the integrated asymmetry can be well reproduced in terms of a transverse momentum cutoff parameter.
Effective field theories for heavy Majorana neutrinos in a thermal bath
Energy Technology Data Exchange (ETDEWEB)
Biondini, Simone
2016-05-06
In the leptogenesis framework Majorana neutrinos are at the origin of the baryon asymmetry in the universe. We develop an effective field theory for non-relativistic Majorana fermions and we apply it to the case of a heavy Majorana neutrino decaying in a hot plasma of Standard Model particles, whose temperature is much smaller than the mass of the Majorana neutrino but still much larger than the electroweak scale. Moreover we compute systematically thermal corrections to the CP asymmetries in the Majorana neutrino decays.
Analytic theory of curvature effects for wave problems with general boundary conditions
DEFF Research Database (Denmark)
Willatzen, Morten; Gravesen, Jens; Voon, L. C. Lew Yan
2010-01-01
A formalism based on a combination of differential geometry and perturbation theory is used to obtain analytic expressions for confined eigenmode changes due to general curvature effects. In cases of circular-shaped and helix-shaped structures, where alternative analytic solutions can be found......, the perturbative solution is shown to yield the same result. The present technique allows the generalization of earlier results to arbitrary boundary conditions. The power of the method is illustrated using examples based on Maxwell’s and Schrödinger’s equations for applications in photonics and nanoelectronics....
Effective theory and breakdown of conformal symmetry in a long-range quantum chain
Lepori, L.; Vodola, D.; Pupillo, G.; Gori, G.; Trombettoni, A.
2016-11-01
We deal with the problem of studying the symmetries and the effective theories of long-range models around their critical points. A prominent issue is to determine whether they possess (or not) conformal symmetry (CS) at criticality and how the presence of CS depends on the range of the interactions. To have a model, both simple to treat and interesting, where to investigate these questions, we focus on the Kitaev chain with long-range pairings decaying with distance as power-law with exponent α. This is a quadratic solvable model, yet displaying non-trivial quantum phase transitions. Two critical lines are found, occurring respectively at a positive and a negative chemical potential. Focusing first on the critical line at positive chemical potential, by means of a renormalization group approach we derive its effective theory close to criticality. Our main result is that the effective action is the sum of two terms: a Dirac action SD, found in the short-range Ising universality class, and an "anomalous" CS breaking term SAN. While SD originates from low-energy excitations in the spectrum, SAN originates from the higher energy modes where singularities develop, due to the long-range nature of the model. At criticality SAN flows to zero for α > 2, while for α theory, we compared the two-fermion static correlation functions and the von Neumann entropy obtained from them with the ones calculated on the lattice, finding agreement. These results explain two observed features characteristic of long-range models, the hybrid decay of static correlation functions within gapped phases and the area-law violation for the von Neumann entropy. The proposed scenario is expected to hold in other long-range models displaying quasiparticle excitations in ballistic regime. From the effective theory one can also see that new phases emerge for α 2). Close to this line, where the minimum of the spectrum coincides with the momentum where singularities develop, the critical exponents
Energy Technology Data Exchange (ETDEWEB)
Epelbaum, E. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); Gasparyan, A.M. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); SSC RF ITEP, Moscow (Russian Federation); Gegelia, J. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); Tbilisi State University, Tbilisi (Georgia); Schindler, M.R. [University of South Carolina, Department of Physics and Astronomy, Columbia (United States)
2014-03-15
We calculate the deuteron electromagnetic form factors in a modified version of Weinberg's chiral effective field theory approach to the two-nucleon system. We derive renormalizable integral equations for the deuteron without partial wave decomposition. Deuteron form factors are extracted by applying the Lehmann-Symanzik-Zimmermann reduction formalism to the three-point correlation function of deuteron interpolating fields and the electromagnetic current operator. Numerical results of a leading-order calculation with removed cutoff regularization agree well with experimental data. (orig.)
Santos, Jander P.; Sá Barreto, F. C.
2017-10-01
Thermodynamic and magnetic properties of a trilayer nanostructure of hexagonal lattices described by the spin-1/2 Ising model are investigated by the use of the effective-field theory (EFT) with correlations. The results for the magnetization, the free energy, the internal energy, the entropy, the specific heat and the critical frontiers were obtained. The critical temperature and the compensation temperature are investigated with a negative interlayer coupling, in order to clarify the distinction between the ferromagnetic and ferrimagnetic behaviors. From the thermal variations of the total magnetization, the six compensation types can be found, i.e., L-, Q-, R-, S-, P-, and N-types.
Constraints on neutron star radii based on chiral effective field theory interactions.
Hebeler, K; Lattimer, J M; Pethick, C J; Schwenk, A
2010-10-15
We show that microscopic calculations based on chiral effective field theory interactions constrain the properties of neutron-rich matter below nuclear densities to a much higher degree than is reflected in commonly used equations of state. Combined with observed neutron star masses, our results lead to a radius R=9.7-13.9 km for a 1.4M⊙ star, where the theoretical range is due, in about equal amounts, to uncertainties in many-body forces and to the extrapolation to high densities.
Constraining top quark effective theory in the LHC Run II era
Energy Technology Data Exchange (ETDEWEB)
Buckley, Andy; Englert, Christoph; Ferrando, James; Miller, David J.; Moore, Liam; Russell, Michael; White, Chris D. [School of Physics and Astronomy, Scottish Universities Physics Alliance, University of Glasgow,Glasgow G12 8QQ, Scotland (United Kingdom); Collaboration: The TopFitter collaboration
2016-04-04
We perform an up-to-date global fit of top quark effective theory to experimental data from the Tevatron, and from LHC Runs I and II. Experimental data includes total cross-sections up to 13 TeV, as well as differential distributions, for both single top and pair production. We also include the top quark width, charge asymmetries, and polarisation information from top decay products. We present bounds on the coefficients of dimension six operators, and examine the interplay between inclusive and differential measurements, and Tevatron/LHC data. All results are currently in good agreement with the Standard Model.
Tkachenko, Sergey V
2008-01-01
The evaluation of the electromagnetic field coupling to transmission lines is an important problem in electromagnetic compatibility. The unabated increase in the operating frequency of electronic products and the emergence of sources of disturbances with higher frequency content (such as High Power Microwave and Ultra-Wide Band systems) have led to a breakdown of the TL approximation's basic assumptions for a number of applications. In the last decade or so, the generalization of the TL theory to take into account high frequency effects has emerged as an important topic of study in electromagn
A semi-empirical effective medium theory for metals and alloys
DEFF Research Database (Denmark)
Jacobsen, Karsten wedel; Stoltze, Per; Nørskov, Jens kehlet
1996-01-01
A detailed derivation of the simplest form of the effective medium theory for bonding in metallic systems is presented, and parameters for the fee metals Ni, Pd, Pt, Cu, Ag and Au are given. The derivation of parameters is discussed in detail to show how new parameterizations can be made....... The method and the parameterization is tested for a number of surface and bulk problems. In particular we present calculations of the energetics of metal atoms deposited on metal surfaces. The calculated energies include heats of adsorption, energies of overlayers, both pseudomorphic and relaxed, as well...
National Research Council Canada - National Science Library
Heydari, Abbas; Dashtgard, Ali; Moghadam, Zahra Emami
2014-01-01
.... Thus, the present study was conducted with an aim to examine the effect of Bandura's social cognitive theory implementation on addiction quitting of clients referred to Imam Reza Hospital addiction quitting clinic...
National Research Council Canada - National Science Library
Farrell, Philip S
2007-01-01
This paper explores operations that involve effects-based thinking (EBT) using Control Theory techniques in order to highlight the concept's fundamental characteristics in a simple and straightforward manner...
Effective field theory approach to open heavy flavor production in heavy-ion collisions
Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan
2017-03-01
We develop a version of Soft Collinear Effective Theory (SCET) which includes finite quark masses, as well as Glauber gluons that describe the interaction of collinear partons with QCD matter. In the framework of this new effective field theory, labeled SCETM,G, we derive the massive splitting functions in the vacuum and the QCD medium for the processes Q → Qg, Q → gQ and g\\to Q\\overline{Q} . The numerical effects due to finite quark masses are sizable and our results are consistent with the traditional approach to parton energy loss in the soft gluon emission limit. In addition, we present a new framework for including the medium-induced full splitting functions consistent with next-to-leading order calculations in QCD for inclusive hadron production. Finally, we show numerical results for the suppression of D- and B-mesons in heavy ion collisions at √{s_{NN}}=5.02 TeV and 2.76 TeV and compare to available data from the LHC.
Jones, Brian Kirby
The purpose of this grounded theory study was to develop a model explaining the role of differentiated instruction (DI) in effective middle school science teaching. The study examined the best teaching practices and differentiated elements from eight general education middle school science teachers, all scoring at the highest level of a teaching effectiveness measure on their evaluations, through a collection of observational, interview, survey, and teaching artifact data. The data were analyzed through the methodology of a systematic grounded theory qualitative approach using open, axial, and selective coding to develop a model describing how and to what degree effective middle school science teachers differentiated their best teaching practices. The model that emerged from the data shows instruction as a four-phase process and highlights the major elements of best practices and DI represented at each phase. The model also depicts how teachers narrowed the scope of their differentiating strategies as instruction progressed. The participants incorporated DI into their pedagogies, though in different degrees at each phase, and primarily by using variety to present concepts with multiple types of instruction followed by a series of sense-making activities related to several learning modalities. Teachers scaffolded students carefully, using informal and formal assessment data to inform future instructional decisions and especially their plans to reteach or extend on a concept. The model is intended to provide insight into the value of DI for middle school science teaching.
String-theoretic breakdown of effective field theory near black hole horizons
Dodelson, Matthew; Silverstein, Eva
2017-09-01
We investigate the validity of the equivalence principle near horizons in string theory, analyzing the breakdown of effective field theory caused by longitudinal string spreading effects. An experiment is set up where a detector is thrown into a black hole a long time after an early infalling string. Light cone gauge calculations, taken at face value, indicate a detectable level of root-mean-square longitudinal spreading of the initial string as measured by the late infaller. This results from the large relative boost between the string and detector in the near-horizon region, which develops automatically despite their modest initial energies outside the black hole and the weak curvature in the geometry. We subject this scenario to basic consistency checks, using these to obtain a relatively conservative criterion for its detectability. In a companion paper, we exhibit longitudinal nonlocality in well-defined gauge-invariant S-matrix calculations, obtaining results consistent with the predicted spreading albeit not in a direct analog of the black hole process. We discuss applications of this effect to the firewall paradox, and estimate the time and distance scales it predicts for new physics near black hole and cosmological horizons.
The effect of recreational clam harvesting on eelgrass (Zostera marina) was experimentally tested by raking or digging for clams in experimental 1-m2 plots located in a Yaquina Bay (Newport, OR) eelgrass meadow. After three monthly treatments, eelgrass measures of biomass, prima...
Brorsen, Kurt R; Yang, Yang; Hammes-Schiffer, Sharon
2017-08-03
Nuclear quantum effects such as zero point energy play a critical role in computational chemistry and often are included as energetic corrections following geometry optimizations. The nuclear-electronic orbital (NEO) multicomponent density functional theory (DFT) method treats select nuclei, typically protons, quantum mechanically on the same level as the electrons. Electron-proton correlation is highly significant, and inadequate treatments lead to highly overlocalized nuclear densities. A recently developed electron-proton correlation functional, epc17, has been shown to provide accurate nuclear densities for molecular systems. Herein, the NEO-DFT/epc17 method is used to compute the proton affinities for a set of molecules and to examine the role of nuclear quantum effects on the equilibrium geometry of FHF-. The agreement of the computed results with experimental and benchmark values demonstrates the promise of this approach for including nuclear quantum effects in calculations of proton affinities, pKa's, optimized geometries, and reaction paths.
Dialectical thinking and health behaviors: the effects of theory of planned behavior.
Jiang, Feng; Lu, Su; Hou, Yubo; Yue, Xiaodong
2013-01-01
The primary purpose of this study was to investigate whether the theory of planned behavior (TPB) mediated the relationship between dialectical thinking and health behaviors. A sample of 285 undergraduates was tested with a dialectical thinking styles scale, health promoting lifestyle profiles, and TPB questionnaires. Structural equation modeling was used for data analysis. Results indicated that all the three dimensions of thinking styles (belief in the connection, acceptance of change, and acceptance of contradiction) exerted significant effects on TPB constructs. Specifically, the connection and the change dimensions had positive effects on health behaviors mediated by TPB, whereas the contradiction dimension had a negative effect. Model 2 showed a satisfactory fit, demonstrating the influential pathways between dialectical thinking and health behaviors. Implications in issues of health promotion and future research are discussed.
Eggers, Sander M; Taylor, Myra; Sathiparsad, Reshma; Bos, Arjan ER; de Vries, Hein
2015-01-01
Despite its popularity, few studies have assessed the temporal stability and cross-lagged effects of the Theory of Planned Behavior factors: Attitude, subjective norms and self-efficacy. For this study, 298 adolescent learners from KwaZulu-Natal, South Africa, filled out a Theory of Planned Behavior questionnaire on teenage pregnancy at baseline and after 6 months. Structural equation modeling showed that there were considerable cross-lagged effects between attitude and subjective norms. Temp...
1999-11-08
In these lectures I will build up the concept of field theory using the language of Feynman diagrams. As a starting point, field theory in zero spacetime dimensions is used as a vehicle to develop all the necessary techniques: path integral, Feynman diagrams, Schwinger-Dyson equations, asymptotic series, effective action, renormalization etc. The theory is then extended to more dimensions, with emphasis on the combinatorial aspects of the diagrams rather than their particular mathematical structure. The concept of unitarity is used to, finally, arrive at the various Feynman rules in an actual, four-dimensional theory. The concept of gauge-invariance is developed, and the structure of a non-abelian gauge theory is discussed, again on the level of Feynman diagrams and Feynman rules.
Point-particle effective field theory I: classical renormalization and the inverse-square potential
Burgess, C. P.; Hayman, Peter; Williams, M.; Zalavári, László
2017-04-01
Singular potentials (the inverse-square potential, for example) arise in many situations and their quantum treatment leads to well-known ambiguities in choosing boundary conditions for the wave-function at the position of the potential's singularity. These ambiguities are usually resolved by developing a self-adjoint extension of the original prob-lem; a non-unique procedure that leaves undetermined which extension should apply in specific physical systems. We take the guesswork out of this picture by using techniques of effective field theory to derive the required boundary conditions at the origin in terms of the effective point-particle action describing the physics of the source. In this picture ambiguities in boundary conditions boil down to the allowed choices for the source action, but casting them in terms of an action provides a physical criterion for their determination. The resulting extension is self-adjoint if the source action is real (and involves no new degrees of freedom), and not otherwise (as can also happen for reasonable systems). We show how this effective-field picture provides a simple framework for understanding well-known renormalization effects that arise in these systems, including how renormalization-group techniques can resum non-perturbative interactions that often arise, particularly for non-relativistic applications. In particular we argue why the low-energy effective theory tends to produce a universal RG flow of this type and describe how this can lead to the phenomenon of reaction catalysis, in which physical quantities (like scattering cross sections) can sometimes be surprisingly large compared to the underlying scales of the source in question. We comment in passing on the possible relevance of these observations to the phenomenon of the catalysis of baryon-number violation by scattering from magnetic monopoles.
Mandula, Jeffrey E.; Ogilvie, Michael C.
1998-02-01
In the lattice formulation of heavy quark effective theory, the value of the ``classical velocity'' v, as defined through the separation of the four-momentum of a heavy quark into a part proportional to the heavy quark mass and a residual part that remains finite in the heavy quark limit (P=Mv+p), is different from its value as it appears in the bare heavy quark propagator [S-1(p)=v.p]. The origin of the difference, which is effectively a lattice-induced renormalization, is the reduction of Lorentz [or O(4)] invariance to (hyper)cubic invariance. The renormalization is finite and depends specifically on the form of the discretization of the reduced heavy quark Dirac equation. For the forward time, centered space discretization, we compute this renormalization nonperturbatively, using an ensemble of lattices at β=6.1 provided by the Fermilab ACP-MAPS Collaboration. The calculation makes crucial use of a variationally optimized smeared operator for creating composite heavy-light mesons. It has the property that its propagator achieves an asymptotic plateau in just a few Euclidean time steps. For comparison, we also compute the shift perturbatively, to one loop in lattice perturbation theory. The nonperturbative calculation of the leading multiplicative shift in the classical velocity is considerably different from the one-loop estimate and indicates that for the above parameters v--> is reduced by about 10-13 %.
Biello, Joseph A.; Samson, René
2015-03-01
The subject of this paper is competitive effects between multiple reaction sinks. A theory based on off-center monopoles is developed for the steady-state diffusion equation and for the convection-diffusion equation with a constant flow field. The dipolar approximation for the diffusion equation with two equal reaction centres is compared with the exact solution. The former turns out to be remarkably accurate, even for two touching spheres. Numerical evidence is presented to show that the same holds for larger clusters (with more than two spheres). The theory is extended to the convection-diffusion equation with a constant flow field. As one increases the convective velocity, the competitive effects between the reactive centres gradually become less significant. This is demonstrated for a number of cluster configurations. At high flow velocities, the current methodology breaks down. Fixing this problem will be the subject of future research. The current method is useful as an easy-to-use tool for the calibration of other more complicated models in mass and/or heat transfer.
Frustrated magnetism and caloric effects in Mn-based antiperovskite nitrides: Ab initio theory
Zemen, J.; Mendive-Tapia, E.; Gercsi, Z.; Banerjee, R.; Staunton, J. B.; Sandeman, K. G.
2017-05-01
We model changes of magnetic ordering in Mn-based antiperovskite nitrides driven by biaxial lattice strain at zero and at finite temperature. We employ a noncollinear spin-polarized density functional theory to compare the response of the geometrically frustrated exchange interactions to a tetragonal symmetry breaking (the so called piezomagnetic effect) across a range of Mn3AN (A = Rh, Pd, Ag, Co, Ni, Zn, Ga, In, Sn) at zero temperature. Building on the robustness of the effect we focus on Mn3GaN and extend our study to finite temperature using the disordered local moment (DLM) first-principles electronic structure theory to model the interplay between the ordering of Mn magnetic moments and itinerant electron states. We discover a rich temperature-strain magnetic phase diagram with two previously unreported phases stabilized by strains larger than 0.75% and with transition temperatures strongly dependent on strain. We propose an elastocaloric cooling cycle crossing two of the available phase transitions to achieve simultaneously a large isothermal entropy change (due to the first-order transition) and a large adiabatic temperature change (due to the second-order transition).
Parameters of heavy quark effective theory from N{sub f}=2 lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Blossier, Benoit [CNRS, Orsay (France). LPT; Paris-11 Univ., 91 - Orsay (France); Della Morte, Michele [Mainz Univ. (Germany). Inst. fuer Kernphysik; Fritzsch, Patrick [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Garron, Nicolas [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Heitger, Jochen [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Simma, Hubert; Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Tantalo, Nazario [Rome-3 Univ. (Italy). Dipt. di Fisica; INFN, Sezione di Roma (Italy)
2012-07-15
We report on a non-perturbative determination of the parameters of the lattice Heavy Quark Effective Theory (HQET) Lagrangian and of the time component of the heavy-light axial-vector current with N{sub f} = 2 flavors of massless dynamical quarks. The effective theory is considered at the 1/m{sub h} order, and the heavy mass m{sub h} covers a range from slightly above the charm to beyond the beauty region. These HQET parameters are needed to compute, for example, the b-quark mass, the heavy-light spectrum and decay constants in the static approximation and to order 1/m{sub h} in HQET. The determination of the parameters is done non-perturbatively. The computation reported in this paper uses the plaquette gauge action and two different static actions for the heavy quark described by HQET. For the light-quark action we choose non-perturbatively O(a)-improved Wilson fermions.
Ju, Y. Sungtaek
2017-10-01
Thermodynamics of the electric double layer has received renewed interest for its potential applications in low-grade waste heat harvesting and reversible heating/cooling in supercapacitors. We apply a size-modified mean field theory to analytically capture the influence on the pseudo-Seebeck coefficient S = ∂φ0/∂T)σ of different factors, including the electrode potential φ0, asymmetry in ion sizes, and ion concentration, under a fixed electrode surface charge σ. The pseudo-Seebeck coefficient is predicted to scale as φ0/T at low electrode potentials, but it reaches limiting values when the electrode potential exceeds crossover values due to the steric effect. The qualitative behavior changes substantially, however, when the temperature dependence of the permittivity is taken into account. The pseudo-Seebeck coefficient S is then predicted to scale linearly with φ0 even at high electrode potentials, significantly over-predicting the experimental values. This suggests a strong influence of phenomena not captured in the mean field theory, such as deviation of local effective permittivity from the bulk value, thermally facilitated adsorption or desorption of ions on electrode surfaces, and weakening of ionic associations with temperature.
Effect of education based on theory of planned behavior in healthy cooking
Directory of Open Access Journals (Sweden)
Rabea Agh Atabay
2017-09-01
Full Text Available Healthy eating habits can reduce the risk of several chronic diseases and decrease overall mortality in women by 11%. Regarding the crucial role of women in feeding the family, we investigated the effect of education in healthy cooking behavior of rural women by applying the Theory of Planned Behavior (TPB. A sample of native women in rural areas of Chabahar (n=152, who aged 12-75 years old, were selected by multistage sampling. Pre and post intervention measures of TPB variables, knowledge, and behavior were conducted via questionnaire. The educational intervention was performed with the help of high school girl students for the intervention group. There were positive significant changes in healthy cooking behavior intention, knowledge, subjective norms, perceived behavioral control, and behavior in the intervention group, while none of these changes were significant in the control group. The results suggest that educational intervention based on the theory of planned behavior can be effective in healthy cooking behavior of rural women of Chabahar.
A precise determination of αs from LEP thrust data using effective field theory
Becher, Thomas; Schwartz, Matthew D.
2008-07-01
Starting from a factorization theorem in Soft-Collinear Effective Theory, the thrust distribution in e+e- collisions is calculated including resummation of the next-to-next-to-next-to leading logarithms. This is a significant improvement over previous calculations which were only valid to next-to-leading logarithmic order. The fixed-order expansion of the resummed result approaches the exact fixed-order distribution towards the kinematic endpoint. This close agreement provides a verification of both the effective field theory expression and recently completed next-to-next-to-leading fixed-order event shapes. The resummed distribution is then matched to fixed order, resulting in a distribution valid over a large range of thrust. A fit to ALEPH and OPAL data from LEP 1 and LEP 2 produces αs(mZ) = 0.1172±0.0010±0.0008±0.0012±0.0012, where the uncertainties are respectively statistical, systematic, hadronic, and perturbative. This is one of the world's most precise extractions of αs to date.
Directory of Open Access Journals (Sweden)
Ma’ssoumeh Bemani Naeini
2015-08-01
Full Text Available Gardner’s Multiple Intelligences Theory (MIT, however having been embraced in the field of language acquisition, has apparently failed to play a role in research on learning styles as an alternative construct. This study aims at examining the potential effects of MI-based activities, as learning styls, on the listening proficiency of Iranian TEFL university students. Based on two assumptions derived from MIT, one of the experimental groups (EG1; N=30 worked on activities across intelligences while the other experimental group (EG2; N=30 focused on the activities related to their most developed intelligence. McKenzie’s (1999 MI Inventory was used to identify the subjects’ preferred intelligences. There was a significant difference between listening scores on TOEFL before and after the intervention of MI-based activities as well as between the two experimental groups, indicating EG1 outperforming EG2. So, as the findings reveal, integration of MIT can significantly contribute to the enhancement of EFL learners’ listening comprehension and the effect is even more significant if teachers practice an integration of all intelligences rather than the most developed ones, only. Keywords: Multiple Intelligences Theory, learning styles, listening proficiency, Iranian EFL context
Effect of theory of mind and peer victimization on the schizotypy–aggression relationship
Lam, Bess Y H; Raine, Adrian; Lee, Tatia M C
2016-01-01
Prior longitudinal studies have established the relationship between schizophrenia and violence. However, previous studies on aggression and schizotypal personality are scarce. The present study examines whether peer victimization mediates the relationship between schizotypy and reactive-proactive aggression, and whether theory of mind (ToM) moderates this mediation. Schizotypy, peer victimization, reactive-proactive aggression, and ToM were assessed in 237 undergraduates. Peer victimization mediated the relationship between schizotypy and reactive aggression. ToM moderated this mediation effect; although peer victimization partially explains the schizotypy–aggression relationship, higher ToM skills weakened the detrimental effect of schizotypy on peer victimization which in turn reduces reactive aggression. In contrast, the moderated mediation was not significant for the proactive aggression model. Findings help delineate the underlying mechanism of the relationship between schizotypy and aggression. It is suggested that aggression could be reduced by enhancing ToM skills, thereby reducing peer victimization and the resultant schizotypy. PMID:27336052
Modal theory of slow light enhanced third-order nonlinear effects in photonic crystal waveguides.
Chen, Tao; Sun, Junqiang; Li, Linsen
2012-08-27
In this paper, we derive the couple-mode equations for third-order nonlinear effects in photonic crystal waveguides by employing the modal theory. These nonlinear interactions include self-phase modulation, cross-phase modulation and degenerate four-wave mixing. The equations similar to that in nonlinear fiber optics could be expanded and applied for third-order nonlinear processes in other periodic waveguides. Based on the equations, we systematically analyze the group-velocity dispersion, optical propagation loss, effective interaction area, slow light enhanced factor and phase mismatch for a slow light engineered silicon photonic crystal waveguide. Considering the two-photon and free-carrier absorptions, the wavelength conversion efficiencies in two low-dispersion regions are numerically simulated by utilizing finite difference method. Finally, we investigate the influence of slow light enhanced multiple four-wave-mixing process on the conversion efficiency.
Beyond the dark matter effective field theory and a simplified model approach at colliders
Directory of Open Access Journals (Sweden)
Seungwon Baek
2016-05-01
Full Text Available Direct detection of and LHC search for the singlet fermion dark matter (SFDM model with Higgs portal interaction are considered in a renormalizable model where the full Standard Model (SM gauge symmetry is imposed by introducing a singlet scalar messenger. In this model, direct detection is described by an effective operator mqq¯qχ¯χ as usual, but the full amplitude for monojet + E̸T involves two intermediate scalar propagators, which cannot be seen within the effective field theory (EFT or in the simplified model without the full SM gauge symmetry. We derive the collider bounds from the ATLAS monojet + E̸T as well as the CMS tt¯+E̸T data, finding out that the bounds and the interpretation of the results are completely different from those obtained within the EFT or simplified models. It is pointed out that it is important to respect unitarity, renormalizability and local gauge invariance of the SM.
Ghost-Free Massive $f(R)$ Theories Modelled as Effective Einstein Spaces and Cosmic Acceleration
Vacaru, Sergiu I
2014-01-01
We study how massive ghost-free gravity $f(R)$-modified theories, MGFTs, can be encoded into generic off-diagonal Einstein spaces. Using "auxiliary" connections completely defined by the metric fields and adapted to nonholonomic frames with associated to nonlinear connection structure, we decouple and integrate in certain general forms the field equations in MGFT. Imposing additional nonholonomic constraints, we can generate Levi--Civita, LC, configurations and mimic MGFT effects via off-diagonal interactions of effective Einstein and/or Einstein-Cartan gravity with nonholonomically induced torsion. The cosmological evolution of ghost-free off--diagonal Einstein spaces is investigated. Certain compatibility of MGFT cosmology to small off-diagonal deformations of $\\Lambda $CDM models is established. %
Stein, M.
1985-01-01
Nonlinear strain displacement relations for three-dimensional elasticity are determined in orthogonal curvilinear coordinates. To develop a two-dimensional theory, the displacements are expressed by trigonometric series representation through-the-thickness. The nonlinear strain-displacement relations are expanded into series which contain all first and second degree terms. In the series for the displacements only the first few terms are retained. Insertion of the expansions into the three-dimensional virtual work expression leads to nonlinear equations of equilibrium for laminated and thick plates and shells that include the effects of transverse shearing. Equations of equilibrium and buckling equations are derived for flat plates and cylindrical shells. The shell equations reduce to conventional transverse shearing shell equations when the effects of the trigonometric terms are omitted and to classical shell equations when the trigonometric terms are omitted and the shell is assumed to be thin.
Directory of Open Access Journals (Sweden)
Lena Wimmer
2016-07-01
Full Text Available The present paper reports a pilot study which tested cognitive effects of mindfulness practice in a theory-driven approach. Thirty-four fifth graders received either a mindfulness training which was based on the mindfulness-based stress reduction approach (experimental group, a concentration training (active control group or no treatment (passive control group. Based on the operational definition of mindfulness by Bishop et al. (2004, effects on sustained attention, cognitive flexibility, cognitive inhibition and data-driven as opposed to schema-based information processing were predicted. These abilities were assessed in a pre-post design by means of a vigilance test, a reversible figures test, the Wisconsin Card Sorting Test, a Stroop test, a visual search task, and a recognition task of prototypical faces. Results suggest that the mindfulness training specifically improved cognitive inhibition and data-driven information processing.
Geiger, Vince; Anderson, Judy; Hurrell, Derek
2017-02-01
The characteristics that typify an effective teacher of mathematics and the environments that support effective teaching practices have been a long-term focus of educational research. In this article we report on an aspect of a larger study that investigated `best practice' in mathematics teaching and learning across all Australian states and territories. A case study from one Australian state was developed from data collected via classroom observations and semi-structured interviews with school leaders and teachers and analysed using Valsiner's zone theory. A finding of the study is that `successful' practice is strongly tied to school context and the cultural practices that have been developed by school leaders and teachers to optimise student learning opportunities. We illustrate such an alignment of school culture and practice through a vignette based on a case of one `successful' school.
A THEORY OF CONSUMER’S PERCEIVED RISK UNDER THE HALO EFFECT
Directory of Open Access Journals (Sweden)
Dorian-Laurenţiu FLOREA
2015-06-01
Full Text Available Despite being largely tackled by a manifold of sciences, perceived risk is still a rather unclear concept concerning its formation and update. In today’s economy, where poor purchase decisions are so easy to make, consumers have developed mental shields residing in actions based on perceived risk. This paper develops and tests a theory of perceived risk formation under the halo effect, based on correlation analysis in two forms: rankings individuals on their contribution to the correlations increase and partial correlations. Both internal and external halo effects were found, emerging from the perceived risk component – functional risk, financial risk, social risk, physical risk, psychological risk and time risk –, brand attitude, product category attitude, consumer’s regret, others’ regret expressed through word-of-mouth, recency, and awareness of awareness. The intricate halo that was revealed needs further attention from the scientific community in order to better delimit halo sources and, eventually, to explain its variability.
Sadideen, Hazim; Kneebone, Roger
2012-09-01
Teaching practical skills is a core component of undergraduate and postgraduate surgical education. It is crucial to optimize our current learning and teaching models, particularly in a climate of decreased clinical exposure. This review explores the role of educational theory in promoting effective learning in practical skills teaching. Peer-reviewed publications, books, and online resources from national bodies (eg, the UK General Medical Council) were reviewed. This review highlights several aspects of surgical education, modeling them on current educational theory. These include the following: (1) acquisition and retention of motor skills (Miller's triangle; Fitts' and Posner's theory), (2) development of expertise after repeated practice and regular reinforcement (Ericsson's theory), (3) importance of the availability of expert assistance (Vygotsky's theory), (4) learning within communities of practice (Lave and Wenger's theory), (5) importance of feedback in learning practical skills (Boud, Schon, and Endes' theories), and (6) affective component of learning. It is hoped that new approaches to practical skills teaching are designed in light of our understanding of educational theory. Copyright © 2012 Elsevier Inc. All rights reserved.
Bas, Gökhan
2016-01-01
The main purpose of this study is to determine the effect of multiple intelligences theory (MIT)-based education on students' academic achievement. In this research, the meta-analytic method was adopted to determine this effect, and studies related to this subject carried out in Turkey were compiled. The effect sizes of the studies included in the…
DEFF Research Database (Denmark)
Bjerg, Ole; Presskorn-Thygesen, Thomas
2017-01-01
The paper is a contribution to current debates about conspiracy theories within philosophy and cultural studies. Wittgenstein’s understanding of language is invoked to analyse the epistemological effects of designating particular questions and explanations as a ‘conspiracy theory’. It is demonstr......The paper is a contribution to current debates about conspiracy theories within philosophy and cultural studies. Wittgenstein’s understanding of language is invoked to analyse the epistemological effects of designating particular questions and explanations as a ‘conspiracy theory......’. It is demonstrated how such a designation relegates these questions and explanations beyond the realm of meaningful discourse. In addition, Agamben’s concept of sovereignty is applied to explore the political effects of using the concept of conspiracy theory. The exceptional epistemological status assigned...... to alleged conspiracy theories within our prevalent paradigms of knowledge and truth is compared to the exceptional legal status assigned to individuals accused of terrorism under the War on Terror. The paper concludes by discussing the relation between conspiracy theory and ‘the paranoid style...
Surface effects on mean inner potentials studied using density functional theory
Energy Technology Data Exchange (ETDEWEB)
Pennington, Robert S., E-mail: robert.pennington@uni-ulm.de [Institute for Experimental Physics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm (Germany); Boothroyd, Chris B.; Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre and Peter Grüneberg Institute, Forschungzentrum Jülich, 52425 Jülich (Germany)
2015-12-15
Quantitative materials characterization using electron holography frequently requires knowledge of the mean inner potential, but reported experimental mean inner potential measurements can vary widely. Using density functional theory, we have simulated the mean inner potential for materials with a range of different surface conditions and geometries. We use both “thin-film” and “nanowire” specimen geometries. We consider clean bulk-terminated surfaces with different facets and surface reconstructions using atom positions from both structural optimization and experimental data and we also consider surfaces both with and without adsorbates. We find that the mean inner potential is surface-dependent, with the strongest dependency on surface adsorbates. We discuss the outlook and perspective for future mean inner potential measurements. - Highlights: • Density functional theory (DFT) is used to simulate mean inner potentials (MIP). • Applications for MIP electron holography measurements are considered. • MIPs are found to be surface-dependent, for thin-film and nanowire geometries. • The DFT simulation precision is extensively tested for multiple materials. • Surface adsorbates can create a strong positive or negative effect.
Generalized slow roll in the unified effective field theory of inflation
Motohashi, Hayato; Hu, Wayne
2017-07-01
We provide a compact and unified treatment of power spectrum observables for the effective field theory (EFT) of inflation with the complete set of operators that lead to second-order equations of motion in metric perturbations in both space and time derivatives, including Horndeski and Gleyzes-Langlois-Piazza-Vernizzi theories. We relate the EFT operators in ADM form to the four additional free functions of time in the scalar and tensor equations. Using the generalized slow-roll formalism, we show that each power spectrum can be described by an integral over a single source that is a function of its respective sound horizon. With this correspondence, existing model independent constraints on the source function can be simply reinterpreted in the more general inflationary context. By expanding these sources around an optimized freeze-out epoch, we also provide characterizations of these spectra in terms of five slow-roll hierarchies whose leading-order forms are compact and accurate as long as EFT coefficients vary only on time scales greater than an e -fold. We also clarify the relationship between the unitary gauge observables employed in the EFT and the comoving gauge observables of the postinflationary universe.
Wong, Ting Yat; Yuen, Kenneth S L; Li, Wang On
2014-01-01
The Internet provides an easily accessible way to meet certain needs. Over-reliance on it leads to problematic use, which studies show can be predicted by psychological distress. Self-determination theory proposes that we all have the basic need for autonomy, competency, and relatedness. This has been shown to explain the motivations behind problematic Internet use. This study hypothesizes that individuals who are psychologically disturbed because their basic needs are not being met are more vulnerable to becoming reliant on the Internet when they seek such needs satisfaction from online activities, and tests a model in which basic needs predict problematic Internet use, fully mediated by psychological distress. Problematic Internet use, psychological distress, and basic needs satisfaction were psychometrically measured in a sample of 229 Hong Kong University students and structural equation modeling was used to test the hypothesized model. All indices showed the model has a good fit. Further, statistical testing supported a mediation effect for psychological distress between needs satisfaction and problematic Internet use. The results extend our understanding of the development and prevention of problematic Internet use based on the framework of self-determination theory. Psychological distress could be used as an early predictor, while preventing and treating problematic Internet use should emphasize the fulfillment of unmet needs.
The orbifolder: A tool to study the low-energy effective theory of heterotic orbifolds
Nilles, H. P.; Ramos-Sánchez, S.; Vaudrevange, P. K. S.; Wingerter, A.
2012-06-01
The orbifolder is a program developed in C++ that computes and analyzes the low-energy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models (e.g. MSSM-like models) and to analyze their vacuum configurations. Program summaryProgram title: orbifolder Catalogue identifier: AELR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 145 572 No. of bytes in distributed program, including test data, etc.: 930 517 Distribution format: tar.gz Programming language:C++ Computer: Personal computer Operating system: Tested on Linux (Fedora 15, Ubuntu 11, SuSE 11) Word size: 32 bits or 64 bits Classification: 11.1 External routines: Boost (http://www.boost.org/), GSL (http://www.gnu.org/software/gsl/) Nature of problem: Calculating the low-energy spectrum of heterotic orbifold compactifications. Solution method: Quadratic equations on a lattice; representation theory; polynomial algebra. Running time: Less than a second per model.
Atomic theory of viscoelastic response and memory effects in metallic glasses
Cui, Bingyu; Yang, Jie; Qiao, Jichao; Jiang, Minqiang; Dai, Lanhong; Wang, Yun-Jiang; Zaccone, Alessio
2017-09-01
An atomic-scale theory of the viscoelastic response of metallic glasses is derived from first principles, using a Zwanzig-Caldeira-Leggett system-bath Hamiltonian as a starting point within the framework of nonaffine linear response to mechanical deformation. This approach provides a generalized Langevin equation (GLE) as the average equation of motion for an atom or ion in the material, from which non-Markovian nonaffine viscoelastic moduli are extracted. These can be evaluated using the vibrational density of states (DOS) as input, where the boson peak plays a prominent role in the mechanics. To compare with experimental data for binary ZrCu alloys, a numerical DOS was obtained from simulations of this system, which also take electronic degrees of freedom into account via the embedded-atom method for the interatomic potential. It is shown that the viscoelastic α -relaxation, including the α -wing asymmetry in the loss modulus, can be very well described by the theory if the memory kernel (the non-Markovian friction) in the GLE is taken to be a stretched-exponential decaying function of time. This finding directly implies strong memory effects in the atomic-scale dynamics and suggests that the α -relaxation time is related to the characteristic time scale over which atoms retain memory of their previous collision history. This memory time grows dramatically below the glass transition.
TASI Lectures on Holographic Space-Time, SUSY, and Gravitational Effective Field Theory
Banks, Tom
2012-11-01
I argue that the conventional field theoretic notion of vacuum state is not valid in quantum gravity. The arguments use gravitational effective field theory, as well as results from string theory, particularly the AdS/CFT correspondence. Different solutions of the same low energy gravitational field equations correspond to different quantum systems, rather than different states in the same system. I then introduce holographic space-time a quasi-local quantum mechanical construction based on the holographic principle. I argue that models of quantum gravity in asymptotically flat space-time will be exactly super-Poincare invariant, because the natural variables of holographic space-time for such a system, are the degrees of freedom of massless superparticles. The formalism leads to a non-singular quantum Big Bang cosmology, in which the asymptotic future is required to be a de Sitter space, with cosmological constant (c.c.) determined by cosmological initial conditions. It is also approximately SUSic in the future, with the gravitino mass KΛ1/4.
The Effective Field Theory of Large Scale Structures at Two Loops
Carrasco, John Joseph M.; Green, Daniel; Senatore, Leonardo
2014-01-01
Large scale structure surveys promise to be the next leading probe of cosmological information. It is therefore crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbation theory for the weakly non-linear regime of dark matter, where correlation functions are computed in an expansion of the wavenumber k of a mode over the wavenumber associated with the non-linear scale k_nl. Since most of the information is contained at high wavenumbers, it is necessary to compute higher order corrections to correlation functions. After the one-loop correction to the matter power spectrum, we estimate that the next leading one is the two-loop contribution, which we compute here. At this order in k/k_nl, there is only one counterterm in the EFTofLSS that must be included, though this term contributes both at tree-level and in several one-loop diagrams. We also discuss correlation functions involving the velocity and momentum fields...
Theory of plasmonic effects in nonlinear optics: the case of graphene
Rostami, Habib; Katsnelson, Mikhail I.; Polini, Marco; Mikhail I. Katsnelson Collaboration; Habib Rostami; Marco Polini Collaboration
The nonlinear optical properties of two-dimensional electronic systems are beginning to attract considerable interest both in the theoretical and experimental sectors. Recent experiments on the nonlinear optical properties of graphene reveal considerably strong third harmonic generation and four-wave mixing of this single-atomic-layer electronic system. We develop a large-N theory of electron-electron interaction corrections to multi-legged Feynman diagrams describing second- and third-order nonlinear response functions. Our theory is completely general and is useful to understand all second- and third-order nonlinear effects, including harmonic generation, wave mixing, and photon drag. We apply our theoretical framework to the case of graphene, by carrying out microscopic calculations of the second- and third-order nonlinear response functions of an interacting two-dimensional gas of massless Dirac fermions. We compare our results with recent measurements, where all-optical launching of graphene plasmons has been achieved. This work was supported by Fondazione Istituto Italiano di Tecnologia, the European Union's Horizon 2020 research and innovation programme under Grant agreement No. 696656 GrapheneCore, and the ERC Advanced Grant 338957 FEMTO/NANO (M.I.K.).
Physics Colloquium: Theory of the spin wave Seebeck effect in magnetic insulators
Université de Genève
2011-01-01
Geneva University Physics Department 24, quai Ernest-Ansermet CH-1211 Geneva 4 Lundi 28 février 2011 17h00 - École de Physique, Auditoire Stückelberg Theory of the spin wave Seebeck effect in magnetic insulators Prof. Gerrit Bauer Delft University of Technology The subfield of spin caloritronics addresses the coupling of heat, charge and spin currents in nanostructures. In the center of interest is here the spin Seebeck effect, which was discovered in an iron-nickel alloy. Uchida et al. recently observed the effect also in an electrically insulating Yttrium Iron Garnett (YIG) thin magnetic film. To our knowledge this is the first observation of a Seebeck effect generated by an insulator, implying that the physics is fundamentally different from the conventional Seebeck effect in metals. We explain the experiments by the pumping of a spin current into the detecting contacts by the thermally excited magnetization dynamics. In this talk I will give a brief overview over the state o...
[Biological effect and tumor risk of diagnostic x-rays. The "war of the theories"].
Selzer, E; Hebar, A
2012-10-01
Since the introduction of ionizing radiation as a treatment and diagnostic tool in humans, scientists have been trying to estimate its side effects and potential health risks. There is now ample evidence for the principal existence of a direct relationship between higher doses and the risks of side effects. Most of the uncertainties lie in the field of low-dose effects especially with respect to the risk of cancer induction. Low-dose effects are usually of relevance in diagnostic medicine while high-dose radiation effects are typically observed after radiotherapeutic treatment for cancer or after nuclear accidents. The current state of the "war of theories" may be summarized as follows: one group of scientists and health regulatory officials favors the hypothesis that there is no threshold dose, i.e. the linear-no-threshold hypothesis (LNT) of radiation which can be regarded as safe. On the contrary, the critics of this hypothesis suggest that the risks of doses below 50 mSv are not measurable or even of clinical relevance and are not adequately described by a linear dose-response relationship. The aim of this article is to summarize the major unresolved issues in this field. Arguments are presented why the validity of the LNT model in the low-dose range should be regarded as at least inconsistent and is thus questionable.
Determination of Thermal Conductivity of Silicate Matrix for Applications in Effective Media Theory
Fiala, Lukáš; Jerman, Miloš; Reiterman, Pavel; Černý, Robert
2018-02-01
Silicate materials have an irreplaceable role in the construction industry. They are mainly represented by cement-based- or lime-based materials, such as concrete, cement mortar, or lime plaster, and consist of three phases: the solid matrix and air and water present in the pores. Therefore, their effective thermal conductivity depends on thermal conductivities of the involved phases. Due to the time-consuming experimental determination of the effective thermal conductivity, its calculation by means of homogenization techniques presents a reasonable alternative. In the homogenization theory, both volumetric content and particular property of each phase need to be identified. For porous materials the most problematic part is to accurately identify thermal conductivity of the solid matrix. Due to the complex composition of silicate materials, the thermal conductivity of the matrix can be determined only approximately, based on the knowledge of thermal conductivities of its major compounds. In this paper, the thermal conductivity of silicate matrix is determined using the measurement of a sufficiently large set of experimental data. Cement pastes with different open porosities are prepared, dried, and their effective thermal conductivity is determined using a transient heat-pulse method. The thermal conductivity of the matrix is calculated by means of extrapolation of the effective thermal conductivity versus porosity functions to zero porosity. Its practical applicability is demonstrated by calculating the effective thermal conductivity of a three-phase silicate material and comparing it with experimental data.
On the effective theory of type II string compactifications on nilmanifolds and coset spaces
Energy Technology Data Exchange (ETDEWEB)
Caviezel, Claudio
2009-07-30
In this thesis we analyzed a large number of type IIA strict SU(3)-structure compactifications with fluxes and O6/D6-sources, as well as type IIB static SU(2)-structure compactifications with fluxes and O5/O7-sources. Restricting to structures and fluxes that are constant in the basis of left-invariant one-forms, these models are tractable enough to allow for an explicit derivation of the four-dimensional low-energy effective theory. The six-dimensional compact manifolds we studied in this thesis are nilmanifolds based on nilpotent Lie-algebras, and, on the other hand, coset spaces based on semisimple and U(1)-groups, which admit a left-invariant strict SU(3)- or static SU(2)-structure. In particular, from the set of 34 distinct nilmanifolds we identified two nilmanifolds, the torus and the Iwasawa manifold, that allow for an AdS{sub 4}, N = 1 type IIA strict SU(3)-structure solution and one nilmanifold allowing for an AdS{sub 4}, N = 1 type IIB static SU(2)-structure solution. From the set of all the possible six-dimensional coset spaces, we identified seven coset spaces suitable for strict SU(3)-structure compactifications, four of which also allow for a static SU(2)-structure compactification. For all these models, we calculated the four-dimensional low-energy effective theory using N = 1 supergravity techniques. In order to write down the most general four-dimensional effective action, we also studied how to classify the different disconnected ''bubbles'' in moduli space. (orig.)
Bulk magnon spin current theory for the longitudinal spin Seebeck effect
Energy Technology Data Exchange (ETDEWEB)
Rezende, S.M., E-mail: rezende@df.ufpe.br [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco (Brazil); Rodríguez-Suárez, R.L. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco (Brazil); Facultad de Física, Pontificia Universidad Católica de Chile, Casilla, 306 Santiago (Chile); Cunha, R.O.; López Ortiz, J.C.; Azevedo, A. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco (Brazil)
2016-02-15
The longitudinal spin Seebeck effect (LSSE) consists in the generation of a spin current parallel to a temperature gradient applied across the thickness of a bilayer made of a ferromagnetic insulator (FMI), such as yttrium iron garnet (YIG), and a metallic layer (ML) with strong spin orbit coupling, such as platinum. The LSSE is usually detected by a DC voltage generated along the ML due to the conversion of the spin current into a charge current perpendicular to the static magnetic field by means of the inverse spin Hall effect. Here we present a model for the LSSE that relies on the bulk magnon spin current created by the temperature gradient across the thickness of the FMI. We show that the spin current pumped into the metallic layer by the magnon accumulation in the FMI provides continuity of the spin current at the FMI/ML interface and is essential for the existence of the LSSE. The results of the theory are in good agreement with experimental LSSE data in YIG/Pt bilayers on the variation of the DC voltage with the sample temperature, with the FMI layer thickness and with the intensity of high magnetic fields. - Highlights: • We present a theory for the longitudinal spin Seebeck effect based on bulk magnons. • The model explains quantitatively the measured voltage in YIG/Pt created by the LSSE. • The model explains quantitatively the temperature dependence of LSSE measured in YIG/Pt. • The model agrees qualitatively with the measured dependence of LSSE with YIG thickness. • The model agrees qualitatively with the measured dependence of LSSE on magnetic field.
The Effectiveness of Separating Theory and Practicum as a Conduit to Learning Physiology
Schuijers, Johannes A.; McDonald, Stuart J.; Julien, Brianna L.; Lexis, Louise A.; Thomas, Colleen J.; Chan, Siew; Samiric, T.
2013-01-01
Many conventional science courses contain subjects embedded with laboratory-based activities. However, research on the benefits of positioning the practicals within the theory subject or developing them distinctly from the theory is largely absent. This report compared results in a physiology theory subject among three different cohorts of…
The Effect(s) of Teen Pregnancy: Reconciling Theory, Methods, and Findings.
Diaz, Christina J; Fiel, Jeremy E
2016-02-01
Although teenage mothers have lower educational attainment and earnings than women who delay fertility, causal interpretations of this relationship remain controversial. Scholars argue that there are reasons to predict negative, trivial, or even positive effects, and different methodological approaches provide some support for each perspective. We reconcile this ongoing debate by drawing on two heuristics: (1) each methodological strategy emphasizes different women in estimation procedures, and (2) the effects of teenage fertility likely vary in the population. Analyses of the Child and Young Adult Cohorts of the National Longitudinal Survey of Youth (N = 3,661) confirm that teen pregnancy has negative effects on most women's attainment and earnings. More striking, however, is that effects on college completion and early earnings vary considerably and are most pronounced among those least likely to experience an early pregnancy. Further analyses suggest that teen pregnancy is particularly harmful for those with the brightest socioeconomic prospects and who are least prepared for the transition to motherhood.