D-brane instantons and the effective field theory of flux compactifications
NASA Astrophysics Data System (ADS)
Uranga, Angel M.
2009-01-01
We provide a description of the effects of fluxes on euclidean D-brane instantons purely in terms of the 4d effective action. The effect corresponds to the dressing of the effective non-perturbative 4d effective vertex with 4d flux superpotential interactions, generated when the moduli fields made massive by the flux are integrated out. The description in terms of effective field theory allows a unified description of non-perturbative effects in all flux compactifications of a given underlying fluxless model, globally in the moduli space of the latter. It also allows us to describe explicitly the effects on D-brane instantons of fluxes with no microscopic description, like non-geometric fluxes. At the more formal level, the description has interesting connections with the bulk-boundary map of open-closed two-dimensional topological string theory, and with the Script N = 1 special geometry.
Unified theory of effective interaction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Takayanagi, Kazuo, E-mail: k-takaya@sophia.ac.jp
2016-09-15
We present a unified description of effective interaction theories in both algebraic and graphic representations. In our previous work, we have presented the Rayleigh–Schrödinger and Bloch perturbation theories in a unified fashion by introducing the main frame expansion of the effective interaction. In this work, we start also from the main frame expansion, and present various nonperturbative theories in a coherent manner, which include generalizations of the Brandow, Brillouin–Wigner, and Bloch–Horowitz theories on the formal side, and the extended Krenciglowa–Kuo and the extended Lee–Suzuki methods on the practical side. We thus establish a coherent and comprehensive description of both perturbativemore » and nonperturbative theories on the basis of the main frame expansion.« less
Sandars, John; Patel, Rakesh S; Goh, Poh Sun; Kokatailo, Patricia K; Lafferty, Natalie
2015-01-01
There is an increasing use of technology for teaching and learning in medical education but often the use of educational theory to inform the design is not made explicit. The educational theories, both normative and descriptive, used by medical educators determine how the technology is intended to facilitate learning and may explain why some interventions with technology may be less effective compared with others. The aim of this study is to highlight the importance of medical educators making explicit the educational theories that inform their design of interventions using technology. The use of illustrative examples of the main educational theories to demonstrate the importance of theories informing the design of interventions using technology. Highlights the use of educational theories for theory-based and realistic evaluations of the use of technology in medical education. An explicit description of the educational theories used to inform the design of an intervention with technology can provide potentially useful insights into why some interventions with technology are more effective than others. An explicit description is also an important aspect of the scholarship of using technology in medical education.
Good IR duals of bad quiver theories
NASA Astrophysics Data System (ADS)
Dey, Anindya; Koroteev, Peter
2018-05-01
The infrared dynamics of generic 3d N = 4 bad theories (as per the good-bad-ugly classification of Gaiotto and Witten) are poorly understood. Examples of such theories with a single unitary gauge group and fundamental flavors have been studied recently, and the low energy effective theory around some special point in the Coulomb branch was shown to have a description in terms of a good theory and a certain number of free hypermultiplets. A classification of possible infrared fixed points for bad theories by Bashkirov, based on unitarity constraints and superconformal symmetry, suggest a much richer set of possibilities for the IR behavior, although explicit examples were not known. In this note, we present a specific example of a bad quiver gauge theory which admits a good IR description on a sublocus of its Coulomb branch. The good description, in question, consists of two decoupled quiver gauge theories with no free hypermultiplets.
Probability Theory Plus Noise: Descriptive Estimation and Inferential Judgment.
Costello, Fintan; Watts, Paul
2018-01-01
We describe a computational model of two central aspects of people's probabilistic reasoning: descriptive probability estimation and inferential probability judgment. This model assumes that people's reasoning follows standard frequentist probability theory, but it is subject to random noise. This random noise has a regressive effect in descriptive probability estimation, moving probability estimates away from normative probabilities and toward the center of the probability scale. This random noise has an anti-regressive effect in inferential judgement, however. These regressive and anti-regressive effects explain various reliable and systematic biases seen in people's descriptive probability estimation and inferential probability judgment. This model predicts that these contrary effects will tend to cancel out in tasks that involve both descriptive estimation and inferential judgement, leading to unbiased responses in those tasks. We test this model by applying it to one such task, described by Gallistel et al. ). Participants' median responses in this task were unbiased, agreeing with normative probability theory over the full range of responses. Our model captures the pattern of unbiased responses in this task, while simultaneously explaining systematic biases away from normatively correct probabilities seen in other tasks. Copyright © 2018 Cognitive Science Society, Inc.
Aesthetic Description and Realism in Art Education.
ERIC Educational Resources Information Center
Brown, Neil C. M.
1989-01-01
Looks at the usefulness of a stable realism for questions related to the description and understanding of art works. Explores two theories which may resolve the antagonism between representational meanings and their assertion as true properties of the work: (1) Wiggin's concept of authentic effect; and (2) Petit's theory of rectification and…
Topological BF field theory description of topological insulators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cho, Gil Young; Moore, Joel E., E-mail: jemoore@berkeley.edu; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
2011-06-15
Research Highlights: > We show that a BF theory is the effective theory of 2D and 3D topological insulators. > The non-gauge-invariance of the bulk theory yields surface terms for a bosonized Dirac fermion. > The 'axion' term in electromagnetism is correctly obtained from gapped surfaces. > Generalizations to possible fractional phases are discussed in closing. - Abstract: Topological phases of matter are described universally by topological field theories in the same way that symmetry-breaking phases of matter are described by Landau-Ginzburg field theories. We propose that topological insulators in two and three dimensions are described by a version ofmore » abelian BF theory. For the two-dimensional topological insulator or quantum spin Hall state, this description is essentially equivalent to a pair of Chern-Simons theories, consistent with the realization of this phase as paired integer quantum Hall effect states. The BF description can be motivated from the local excitations produced when a {pi} flux is threaded through this state. For the three-dimensional topological insulator, the BF description is less obvious but quite versatile: it contains a gapless surface Dirac fermion when time-reversal-symmetry is preserved and yields 'axion electrodynamics', i.e., an electromagnetic E . B term, when time-reversal symmetry is broken and the surfaces are gapped. Just as changing the coefficients and charges of 2D Chern-Simons theory allows one to obtain fractional quantum Hall states starting from integer states, BF theory could also describe (at a macroscopic level) fractional 3D topological insulators with fractional statistics of point-like and line-like objects.« less
Saeri, Alexander K; Ogilvie, Claudette; La Macchia, Stephen T; Smith, Joanne R; Louis, Winnifred R
2014-01-01
The present research adopts an extended theory of the planned behavior model that included descriptive norms, risk, and trust to investigate online privacy protection in Facebook users. Facebook users (N = 119) completed a questionnaire assessing their attitude, subjective injunctive norm, subjective descriptive norm, perceived behavioral control, implicit perceived risk, trust of other Facebook users, and intentions toward protecting their privacy online. Behavior was measured indirectly 2 weeks after the study. The data show partial support for the theory of planned behavior and strong support for the independence of subjective injunctive and descriptive norms. Risk also uniquely predicted intentions over and above the theory of planned behavior, but there were no unique effects of trust on intentions, nor of risk or trust on behavior. Implications are discussed.
London equation for monodromy inflation
NASA Astrophysics Data System (ADS)
Kaloper, Nemanja; Lawrence, Albion
2017-03-01
We focus on the massive gauge theory formulation of axion monodromy inflation. We argue that a gauge symmetry hidden in these models is the key mechanism protecting inflation from dangerous field theory and quantum gravity corrections. The effective theory of large-field inflation is dual to a massive U (1 ) 4-form gauge theory, which is similar to a massive gauge theory description of superconductivity. The gauge theory explicitly realizes the old Julia-Toulouse proposal for a low-energy description of a gauge theory in a defect condensate. While we work mostly with the example of quadratic axion potential induced by flux monodromy, we discuss how other types of potentials can arise from the inclusion of gauge-invariant corrections to the theory.
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
L'vov, Victor A.; Taras Shevchenko National University, Kyiv 01601; Kosogor, Anna, E-mail: annakosogor@gmail.com
2016-01-07
A simple thermodynamic theory is proposed for the quantitative description of giant magnetocaloric effect observed in metamagnetic shape memory alloys. Both the conventional magnetocaloric effect at the Curie temperature and the inverse magnetocaloric effect at the transition from the ferromagnetic austenite to a weakly magnetic martensite are considered. These effects are evaluated from the Landau-type free energy expression involving exchange interactions in a system of a two magnetic sublattices. The findings of the thermodynamic theory agree with first-principles calculations and experimental results from Ni-Mn-In-Co and Ni-Mn-Sn alloys, respectively.
Theories on Educational Effectiveness and Ineffectiveness
ERIC Educational Resources Information Center
Scheerens, Jaap
2015-01-01
Following Snow's (1973) description of an "inductive" process of theory formation, this article addresses the organization of the knowledge base on school effectiveness. A multilevel presentation stimulated the conceptualization of educational effectiveness as an integration of system-level, school-level, and classroom-level…
Toward an instructionally oriented theory of example-based learning.
Renkl, Alexander
2014-01-01
Learning from examples is a very effective means of initial cognitive skill acquisition. There is an enormous body of research on the specifics of this learning method. This article presents an instructionally oriented theory of example-based learning that integrates theoretical assumptions and findings from three research areas: learning from worked examples, observational learning, and analogical reasoning. This theory has descriptive and prescriptive elements. The descriptive subtheory deals with (a) the relevance and effectiveness of examples, (b) phases of skill acquisition, and (c) learning processes. The prescriptive subtheory proposes instructional principles that make full exploitation of the potential of example-based learning possible. Copyright © 2013 Cognitive Science Society, Inc.
Magnetic order at a single-crystal surface in the diffuse-scattering theory
NASA Astrophysics Data System (ADS)
Zasada, I.
2003-06-01
A theoretical description of incoherent spin-dependent multiple scattering of electrons at a magnetically disordered single-crystal surface is reported. A formalism in which the spin operators specify the magnetic state of a surface atom is used for the description of magnetic order at the surface. The theory is based upon the concepts used in multiple scattering spin-dependent diffuse LEED theory (DSPLEED) theory. In the present considerations, this theory is extended to the case of magnetic materials by using the time-independent Dirac equation with an effective magnetic field. Thus, an expression for incoherent spin-dependent intensity for magnetic material is obtained. It depends on the Fourier transform on the surface lattice of the spin-pair correlation function and, as a consequence, on the magnetic properties of the surface. The equations for the description of magnetization and various correlation functions in the frame of effective field theory are derived and the results of the numerical calculations are presented for the particular case of Ni(1 0 0) surface. The spin-orbit induced and exchange asymmetries are calculated. It is found that the magnetic DSPLEED is sensitive to the properties of the surface characterized by the spin-pair correlation functions. Thus, it is demonstrated that the magnetic DSPLEED can be an effective method in the investigation of critical behaviour of magnetic surfaces.
Optimal free descriptions of many-body theories
NASA Astrophysics Data System (ADS)
Turner, Christopher J.; Meichanetzidis, Konstantinos; Papić, Zlatko; Pachos, Jiannis K.
2017-04-01
Interacting bosons or fermions give rise to some of the most fascinating phases of matter, including high-temperature superconductivity, the fractional quantum Hall effect, quantum spin liquids and Mott insulators. Although these systems are promising for technological applications, they also present conceptual challenges, as they require approaches beyond mean-field and perturbation theory. Here we develop a general framework for identifying the free theory that is closest to a given interacting model in terms of their ground-state correlations. Moreover, we quantify the distance between them using the entanglement spectrum. When this interaction distance is small, the optimal free theory provides an effective description of the low-energy physics of the interacting model. Our construction of the optimal free model is non-perturbative in nature; thus, it offers a theoretical framework for investigating strongly correlated systems.
Large-N kinetic theory for highly occupied systems
NASA Astrophysics Data System (ADS)
Walz, R.; Boguslavski, K.; Berges, J.
2018-06-01
We consider an effective kinetic description for quantum many-body systems, which is not based on a weak-coupling or diluteness expansion. Instead, it employs an expansion in the number of field components N of the underlying scalar quantum field theory. Extending previous studies, we demonstrate that the large-N kinetic theory at next-to-leading order is able to describe important aspects of highly occupied systems, which are beyond standard perturbative kinetic approaches. We analyze the underlying quasiparticle dynamics by computing the effective scattering matrix elements analytically and solve numerically the large-N kinetic equation for a highly occupied system far from equilibrium. This allows us to compute the universal scaling form of the distribution function at an infrared nonthermal fixed point within a kinetic description, and we compare to existing lattice field theory simulation results.
Emergent geometric description for a topological phase transition in the Kitaev superconductor model
NASA Astrophysics Data System (ADS)
Kim, Ki-Seok; Park, Miok; Cho, Jaeyoon; Park, Chanyong
2017-10-01
Resorting to Wilsonian renormalization group (RG) transformations, we propose an emergent geometric description for a topological phase transition in the Kitaev superconductor model. An effective field theory consists of an emergent bulk action with an extra dimension, an ultraviolet (UV) boundary condition for an initial value of a coupling function, and an infrared (IR) effective action with a fully renormalized coupling function. The bulk action describes the evolution of the coupling function along the direction of the extra dimension, where the extra dimension is identified with an RG scale and the resulting equation of motion is nothing but a β function. In particular, the IR effective field theory turns out to be consistent with a Callan-Symanzik equation which takes into account both the bulk and IR boundary contributions. This derived Callan-Symanzik equation gives rise to a metric structure. Based on this emergent metric tensor, we uncover the equivalence of the entanglement entropy between the emergent geometric description and the quantum field theory in the vicinity of the quantum critical point.
A holographic model for black hole complementarity
Lowe, David A.; Thorlacius, Larus
2016-12-07
Here, we explore a version of black hole complementarity, where an approximate semiclassical effective field theory for interior infalling degrees of freedom emerges holo-graphically from an exact evolution of exterior degrees of freedom. The infalling degrees of freedom have a complementary description in terms of outgoing Hawking radiation and must eventually decohere with respect to the exterior Hamiltonian, leading to a breakdown of the semiclassical description for an infaller. Trace distance is used to quantify the difference between the complementary time evolutions, and to define a decoherence time. We propose a dictionary where the evolution with respect to the bulkmore » effective Hamiltonian corresponds to mean field evolution in the holographic theory. In a particular model for the holographic theory, which exhibits fast scrambling, the decoherence time coincides with the scrambling time. The results support the hypothesis that decoherence of the infalling holographic state and disruptive bulk effects near the curvature singularity are comple-mentary descriptions of the same physics, which is an important step toward resolving the black hole information paradox.« less
Ultrastrong coupling in supersymmetric gauge theories
DOE Office of Scientific and Technical Information (OSTI.GOV)
Buchel, Alex
1999-10-04
We study 'ultrastrong' coupling points in scale-invariant N=2 gauge theories. These are theories where, naively, the coupling becomes infinite, and is not related by S-duality to a weak coupling point. These theories have been somewhat of a mystery, since in the M-theory description they correspond to points where parallel M 5-branes coincide. Using the low-energy effective field theory arguments we relate these theories to other known N=2 CFT.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dijkgraaf, Robbert; Gopakumar, Rajesh; Ooguri, Hirosi
We argue that the holographic description of four-dimensional Bogomol'nyi-Prasad-Sommerfield black holes naturally includes multicenter solutions. This suggests that the holographic dual to the gauge theory is not a single AdS{sub 2}xS{sup 2} but a coherent ensemble of them. We verify this in a particular class of examples, where the two-dimensional Yang-Mills theory gives a holographic description of the black holes obtained by branes wrapping Calabi-Yau cycles. Using the free fermionic formulation, we show that O(e{sup -N}) nonperturbative effects entangle the two Fermi surfaces. In an Euclidean description, the wave function of the multicenter black holes gets mapped to the Hartle-Hawkingmore » wave function of baby universes. This provides a concrete realization, within string theory, of effects that can be interpreted as the creation of baby universes. We find that, at least in the case we study, the baby universes do not lead to a loss of quantum coherence, in accord with general arguments.« less
Effects of tunnelling and asymmetry for system-bath models of electron transfer
NASA Astrophysics Data System (ADS)
Mattiat, Johann; Richardson, Jeremy O.
2018-03-01
We apply the newly derived nonadiabatic golden-rule instanton theory to asymmetric models describing electron-transfer in solution. The models go beyond the usual spin-boson description and have anharmonic free-energy surfaces with different values for the reactant and product reorganization energies. The instanton method gives an excellent description of the behaviour of the rate constant with respect to asymmetry for the whole range studied. We derive a general formula for an asymmetric version of the Marcus theory based on the classical limit of the instanton and find that this gives significant corrections to the standard Marcus theory. A scheme is given to compute this rate based only on equilibrium simulations. We also compare the rate constants obtained by the instanton method with its classical limit to study the effect of tunnelling and other quantum nuclear effects. These quantum effects can increase the rate constant by orders of magnitude.
Infrared computations of defect Schur indices
Córdova, Clay; Gaiotto, Davide; Shao, Shu-Heng
2016-11-18
We conjecture a formula for the Schur index of four-dimensional N = 2 theories in the presence of boundary conditions and/or line defects, in terms of the low-energy effective Seiberg-Witten description of the system together with massive BPS excitations. We test our proposal in a variety of examples for SU(2) gauge theories, either conformal or asymptotically free. We use the conjecture to compute these defect-enriched Schur indices for theories which lack a Lagrangian description, such as Argyres-Douglas theories. We demonstrate in various examples that line defect indices can be expressed as sums of characters of the associated two-dimensional chiral algebramore » and that for Argyres-Douglas theories the line defect OPE reduces in the index to the Verlinde algebra.« less
Infrared computations of defect Schur indices
DOE Office of Scientific and Technical Information (OSTI.GOV)
Córdova, Clay; Gaiotto, Davide; Shao, Shu-Heng
We conjecture a formula for the Schur index of four-dimensional N = 2 theories in the presence of boundary conditions and/or line defects, in terms of the low-energy effective Seiberg-Witten description of the system together with massive BPS excitations. We test our proposal in a variety of examples for SU(2) gauge theories, either conformal or asymptotically free. We use the conjecture to compute these defect-enriched Schur indices for theories which lack a Lagrangian description, such as Argyres-Douglas theories. We demonstrate in various examples that line defect indices can be expressed as sums of characters of the associated two-dimensional chiral algebramore » and that for Argyres-Douglas theories the line defect OPE reduces in the index to the Verlinde algebra.« less
The boundaries of instance-based learning theory for explaining decisions from experience.
Gonzalez, Cleotilde
2013-01-01
Most demonstrations of how people make decisions in risky situations rely on decisions from description, where outcomes and their probabilities are explicitly stated. But recently, more attention has been given to decisions from experience where people discover these outcomes and probabilities through exploration. More importantly, risky behavior depends on how decisions are made (from description or experience), and although prospect theory explains decisions from description, a comprehensive model of decisions from experience is yet to be found. Instance-based learning theory (IBLT) explains how decisions are made from experience through interactions with dynamic environments (Gonzalez et al., 2003). The theory has shown robust explanations of behavior across multiple tasks and contexts, but it is becoming unclear what the theory is able to explain and what it does not. The goal of this chapter is to start addressing this problem. I will introduce IBLT and a recent cognitive model based on this theory: the IBL model of repeated binary choice; then I will discuss the phenomena that the IBL model explains and those that the model does not. The argument is for the theory's robustness but also for clarity in terms of concrete effects that the theory can or cannot account for. Copyright © 2013 Elsevier B.V. All rights reserved.
Social influence in child care centers: a test of the theory of normative social behavior.
Lapinski, Maria Knight; Anderson, Jenn; Shugart, Alicia; Todd, Ewen
2014-01-01
Child care centers are a unique context for studying communication about the social and personal expectations about health behaviors. The theory of normative social behavior (TNSB; Rimal & Real, 2005 ) provides a framework for testing the role of social and psychological influences on handwashing behaviors among child care workers. A cross-sectional survey of child care workers in 21 centers indicates that outcome expectations and group identity increase the strength of the relationship between descriptive norms and handwashing behavior. Injunctive norms also moderate the effect of descriptive norms on handwashing behavior such that when strong injunctive norms are reported, descriptive norms are positively related to handwashing, but when weak injunctive norms are reported, descriptive norms are negatively related to handwashing. The findings suggest that communication interventions in child care centers can focus on strengthening injunctive norms in order to increase handwashing behaviors in child care centers. The findings also suggest that the theory of normative social behavior can be useful in organizational contexts.
A quantum-classical theory with nonlinear and stochastic dynamics
NASA Astrophysics Data System (ADS)
Burić, N.; Popović, D. B.; Radonjić, M.; Prvanović, S.
2014-12-01
The method of constrained dynamical systems on the quantum-classical phase space is utilized to develop a theory of quantum-classical hybrid systems. Effects of the classical degrees of freedom on the quantum part are modeled using an appropriate constraint, and the interaction also includes the effects of neglected degrees of freedom. Dynamical law of the theory is given in terms of nonlinear stochastic differential equations with Hamiltonian and gradient terms. The theory provides a successful dynamical description of the collapse during quantum measurement.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Valkenburg, Wessel; Hu, Bin, E-mail: valkenburg@lorentz.leidenuniv.nl, E-mail: hu@lorentz.leidenuniv.nl
2015-09-01
We present a description for setting initial particle displacements and field values for simulations of arbitrary metric theories of gravity, for perfect and imperfect fluids with arbitrary characteristics. We extend the Zel'dovich Approximation to nontrivial theories of gravity, and show how scale dependence implies curved particle paths, even in the entirely linear regime of perturbations. For a viable choice of Effective Field Theory of Modified Gravity, initial conditions set at high redshifts are affected at the level of up to 5% at Mpc scales, which exemplifies the importance of going beyond Λ-Cold Dark Matter initial conditions for modifications of gravitymore » outside of the quasi-static approximation. In addition, we show initial conditions for a simulation where a scalar modification of gravity is modelled in a Lagrangian particle-like description. Our description paves the way for simulations and mock galaxy catalogs under theories of gravity beyond the standard model, crucial for progress towards precision tests of gravity and cosmology.« less
Fundamental Neutron Physics: Theory and Analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gudkov, Vladimir
The goal of the proposal was to study the possibility of searching for manifestations of new physics beyond the Standard model in fundamental neutron physics experiments. This involves detailed theoretical analyses of parity- and time reversal invariance-violating processes in neutron-induced reactions, properties of neutron β-decay, and the precise description of properties of neutron interactions with nuclei. To describe neutron-nuclear interactions, we use both the effective field theory approach and the theory of nuclear reaction with phenomenological nucleon potentials for the systematic description of parity- and time reversal-violating effects in the consistent way. A major emphasis of our research during themore » funding period has been the study of parity violation (PV) and time reversal invariance violation (TRIV) in few-body systems. We studied PV effects in non-elastic processes in three-nucleon system using both ”DDH-like” and effective field theory (EFT) approaches. The wave functions were obtained by solving three-body Faddeev equations in configuration space for a number of realistic strong potentials. The observed model dependence for the DDH approach indicates intrinsic difficulty in the description of nuclear PV effects, and it could be the reason for the observed discrepancies in the nuclear PV data analysis. It shows that the DDH approach could be a reasonable approach for analysis of PV effects only if exactly the same strong and weak potentials are used in calculating all PV observables in all nuclei. However, the existing calculations of nuclear PV effects were performed using different potentials; therefore, strictly speaking, one cannot compare the existing results of these calculations among themselves.« less
Light-front field theory in the description of hadrons
NASA Astrophysics Data System (ADS)
Ji, Chueng-Ryong
2017-03-01
We discuss the use of light-front field theory in the descriptions of hadrons. In particular, we clarify the confusion in the prevailing notion of the equivalence between the infinite momentum frame and the light-front dynamics and the advantage of the light-front dynamics in hadron physics. As an application, we present our recent work on the flavor asymmetry in the proton sea and identify the presence of the delta-function contributions associated with end-point singularities arising from the chiral effective theory calculation. The results pave the way for phenomenological applications of pion cloud models that are manifestly consistent with the chiral symmetry properties of QCD.
Trautmann, Stefan T; van de Kuilen, Gijs
2012-01-01
Attitudes toward risks are central to organizational decisions. These attitudes are commonly modeled by prospect theory. Construal level theory has been proposed as an alternative theory of risky choice, accounting for psychological distance deriving from temporal, spatial and social aspects of risk that are typical of agency situations. Unnoticed in the literature, the two theories make contradicting predictions. The current study investigates which theory provides a better description of risky decisions in the presence of temporal, spatial, and social factors. We find that the psychophysical effects modeled by prospect theory dominate the psychological distance effects of construal level theory. Copyright © 2011 Elsevier B.V. All rights reserved.
Joint density-functional theory and its application to systems in solution
NASA Astrophysics Data System (ADS)
Petrosyan, Sahak A.
The physics of solvation, the interaction of water with solutes, plays a central role in chemistry and biochemistry, and it is essential for the very existence of life. Despite the central importance of water and the advent of the quantum theory early in the twentieth century, the link between the fundamental laws of physics and the observable properties of water remain poorly understood to this day. The central goal of this thesis is to develop a new formalism and framework to make the study of systems (solutes or surfaces) in contact with liquid water as practical and accurate as standard electronic structure calculations without the need for explicit averaging over large ensembles of configurations of water molecules. The thesis introduces a new form of density functional theory for the ab initio description of electronic systems in contact with a molecular liquid environment. This theory rigorously joins an electron density-functional for the electrons of a solute with a classical density-functional theory for the liquid into a single variational principle for the free energy of the combined system. Using the new form of density-functional theory for the ab initio description of electronic systems in contact with a molecular liquid environment, the thesis then presents the first detailed study of the impact of a solvent on the surface chemistry of Cr2O3, the passivating layer of stainless steel alloys. In comparison to a vacuum, we predict that the presence of water has little impact on the adsorption of chloride ions to the oxygen-terminated surface but has a dramatic effect on the binding of hydrogen to that surface. A key ingredient of a successful joint density functional theory is a good approximate functional for describing the solvent. We explore how the simplest examples of the best known class of approximate forms for the classical density functional fail when applied directly to water. The thesis then presents a computationally efficient density-functional theory for water which overcomes this difficulty and gives reasonable agreement with molecular dynamics simulation data for the solvation of hard spheres in water and sufficient agreement with experimental data for hydration of inert gas atoms to justify its use in a joint theory with standard approximate density functionals used in electronic structure calculations. The last study in the thesis combines the previous ideas and presenting an approximate model density functional which includes a description of cavitation effects through a classical density-functional theory; a description of dielectric effects through a non-local polarizability, and a description of the coupling of the solvent to the electrons of the solute through a pseudopotential. Without any empirical fitting of parameters to solvation data, this theory predicts solvation energies at least as well as state-of-the-art quantum-chemical cavity approaches, which do employ such fitting. Although this agreement without adjustable parameters is very encouraging and shows the promise of the joint density-functional approach, the functionals which we develop here are models and do not yet include all of the microscopic physics. The thesis concludes with a description of the directions future work should take to address this weakness.
Effective description of domain wall strings
NASA Astrophysics Data System (ADS)
Rodrigues, Davi R.; Abanov, Ar.; Sinova, J.; Everschor-Sitte, K.
2018-04-01
The analysis of domain wall dynamics is often simplified to one-dimensional physics. For domain walls in thin films, more realistic approaches require the description as two-dimensional objects. This includes the study of vortices and curvatures along the domain walls as well as the influence of boundary effects. Here we provide a theory in terms of soft modes that allows us to analytically study the physics of extended domain walls and their stability. By considering irregularly shaped skyrmions as closed domain walls, we analyze their plasticity and compare their dynamics with those of circular skyrmions. Our theory directly provides an analytical description of the excitation modes of magnetic skyrmions, previously accessible only through sophisticated micromagnetic numerical calculations and spectral analysis. These analytical expressions provide the scaling behavior of the different physics on parameters that experiments can test.
Kurkela, Aleksi; Vuorinen, Aleksi
2016-07-22
We generalize the state-of-the-art perturbative equation of state of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to O(g^{5}) in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated via a dimensionally reduced effective theory, while the soft nonzero modes are resummed using the hard thermal loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium.
Rimal, Rajiv N
2008-01-01
Informed by the theory of normative social behavior, this article sought to determine the underlying mediating and moderating factors in the relationship between descriptive norms and behavioral intentions. Furthermore, the theory was extended by asking whether and what role behavioral identity played in normative influences. Simulating the central message of norms-based interventions to reduce college students' alcohol consumption, in this field experiment, descriptive norms were manipulated by informing half of the students (n = 665) that their peers consumed less alcohol than they might believe. Others (n = 672) were not provided any norms information. students' injunctive norms, outcome expectations, group identity, behavioral identity, and behavioral intention surrounding alcohol consumption were then measured. Exposure to the low-norms information resulted in a significant drop in estimates of the prevalence of consumption. Injunctive norms and outcome expectations partially mediated and also moderated the relationship between descriptive norms and behavioral intentions. Group identity and behavioral identity also moderated the relationship between descriptive norms and behavioral intentions, but the effect size was relatively small for group identity. Implications for health campaigns are also discussed.
Evaluating the impact of grade crossing safety factors through signal detection theory
DOT National Transportation Integrated Search
2012-10-22
The purpose of this effort was to apply signal detection theory to descriptively model the impact : of five grade crossing safety factors to understand their effect on driver decision making. The : safety factors consisted of: improving commercial mo...
Chiral electroweak currents in nuclei
Riska, D. O.; Schiavilla, R.
2017-01-10
Here, the development of the chiral dynamics based description of nuclear electroweak currents is reviewed. Gerald E. (Gerry) Brown’s role in basing theoretical nuclear physics on chiral Lagrangians is emphasized. Illustrative examples of the successful description of electroweak observables of light nuclei obtained from chiral effective field theory are presented.
On the theoretical description of weakly charged surfaces.
Wang, Rui; Wang, Zhen-Gang
2015-03-14
It is widely accepted that the Poisson-Boltzmann (PB) theory provides a valid description for charged surfaces in the so-called weak coupling limit. Here, we show that the image charge repulsion creates a depletion boundary layer that cannot be captured by a regular perturbation approach. The correct weak-coupling theory must include the self-energy of the ion due to the image charge interaction. The image force qualitatively alters the double layer structure and properties, and gives rise to many non-PB effects, such as nonmonotonic dependence of the surface energy on concentration and charge inversion. In the presence of dielectric discontinuity, there is no limiting condition for which the PB theory is valid.
Nonlocal description of sound propagation through an array of Helmholtz resonators
NASA Astrophysics Data System (ADS)
Nemati, Navid; Kumar, Anshuman; Lafarge, Denis; Fang, Nicholas X.
2015-12-01
A generalized macroscopic nonlocal theory of sound propagation in rigid-framed porous media saturated with a viscothermal fluid has been recently proposed, which takes into account both temporal and spatial dispersion. Here, we consider applying this theory, which enables the description of resonance effects, to the case of sound propagation through an array of Helmholtz resonators whose unusual metamaterial properties, such as negative bulk moduli, have been experimentally demonstrated. Three different calculations are performed, validating the results of the nonlocal theory, related to the frequency-dependent Bloch wavenumber and bulk modulus of the first normal mode, for 1D propagation in 2D or 3D periodic structures. xml:lang="fr"
Process of Coping with Radiation Therapy.
ERIC Educational Resources Information Center
Johnson, Jean E.; And Others
1989-01-01
Evaluated ability of self-regulation and emotional-drive theories to explain effects of informational intervention entailing objective descriptions of experience on outcomes of coping with radiation therapy among 84 men with prostate cancer. Consistent with self-regulation theory, similarity between expectations and experience and degree of…
NASA Astrophysics Data System (ADS)
Heslar, John; Telnov, Dmitry; Chu, Shih-I.
2012-06-01
We present a self-interaction-free (SIC) time-dependent density-functional theory (TDDFT) for the treatment of double ionization processes of many-electron systems. The method is based on the Krieger-Li-Iafrate (KLI) treatment of the optimized effective potential (OEP) theory and the incorporation of an explicit self-interaction correction (SIC) term. In the framework of the time-dependent density functional theory, we have performed 3D calculations of double ionization of He and Be atoms by strong near-infrared laser fields. We make use of the exchange-correlation potential with the integer discontinuity which improves the description of the double ionization process. We found that proper description of the double ionization requires the TDDFT exchange-correlation potential with the discontinuity with respect to the variation of the spin particle numbers (SPN) only. The results for the intensity-dependent probabilities of single and double ionization are presented and reproduce the famous ``knee'' structure.
Leading-order classical Lagrangians for the nonminimal standard-model extension
NASA Astrophysics Data System (ADS)
Reis, J. A. A. S.; Schreck, M.
2018-03-01
In this paper, we derive the general leading-order classical Lagrangian covering all fermion operators of the nonminimal standard-model extension (SME). Such a Lagrangian is considered to be the point-particle analog of the effective field theory description of Lorentz violation that is provided by the SME. At leading order in Lorentz violation, the Lagrangian obtained satisfies the set of five nonlinear equations that govern the map from the field theory to the classical description. This result can be of use for phenomenological studies of classical bodies in gravitational fields.
Chiral effective theory of dark matter direct detection
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bishara, Fady; Brod, Joachim; Grinstein, Benjamin
2017-02-01
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.more » Our results consistently keep the leading contributions in chiral counting for each of the initial Wilson coefficients.« less
On the emergence of classical gravity
NASA Astrophysics Data System (ADS)
Larjo, Klaus
In this thesis I will discuss how certain black holes arise as an effective, thermodynamical description from non-singular microstates in string theory. This provides a possible solution to the information paradox, and strengthens the case for treating black holes as thermodynamical objects. I will characterize the data defining a microstate of a black hole in several settings, and demonstrate that most of the data is unmeasurable for a classical observer. I will further show that the data that is measurable is universal for nearly all microstates, making it impossible for a classical observer to distinguish between microstates, thus giving rise to an effective statistical description for the black hole. In the first half of the thesis I will work with two specific systems: the half-BPS sector of [Special characters omitted.] = 4 super Yang-Mills the and the conformal field theory corresponding to the D1/D5 system; in both cases the high degree of symmetry present provides great control over potentially intractable computations. For these systems, I will further specify the conditions a quantum mechanical microstate must satisfy in order to have a classical description in terms of a unique metric, and define a 'metric operator' whose eigenstates correspond to classical geometries. In the second half of the thesis I will consider a much broader setting, general [Special characters omitted.] = I superconformal quiver gauge the= ories and their dual gravity theories, and demonstrate that a similar effective description arises also in this setting.
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.
Sharma [ital et] [ital al]. reply:
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sharma, M.M.; Lalazissis, G.A.; Hillebrandt, W.
1994-09-26
We believe that the different density and isospin dependence [5] of the spin[minus]orbit term is responsible for differences in shell effects found in the RMF theory as compared to the Skyrme approach. The importance of the spin[minus]orbit contribution in the RMF theory has been underlined in the successful description [6] of anomalous isotope shifts in Pb nuclei in the RMF theory as against the Skyrme theory which is unable to do so. (AIP)
"Lagrangian" for a Non-Lagrangian Field Theory with N=2 Supersymmetry.
Gadde, Abhijit; Razamat, Shlomo S; Willett, Brian
2015-10-23
We suggest that at least some of the strongly coupled N=2 quantum field theories in 4D can have a nonconformal N=1 Lagrangian description flowing to them at low energies. In particular, we construct such a description for the N=2 rank one superconformal field theory with E(6) flavor symmetry, for which a Lagrangian description was previously unavailable. We utilize this description to compute several supersymmetric partition functions.
List, Nanna Holmgaard; Kauczor, Joanna; Saue, Trond; Jensen, Hans Jørgen Aagaard; Norman, Patrick
2015-06-28
We present a formulation of molecular response theory for the description of a quantum mechanical molecular system in the presence of a weak, monochromatic, linearly polarized electromagnetic field without introducing truncated multipolar expansions. The presentation focuses on a description of linear absorption by adopting the energy-loss approach in combination with the complex polarization propagator formulation of response theory. Going beyond the electric-dipole approximation is essential whenever studying electric-dipole-forbidden transitions, and in general, non-dipolar effects become increasingly important when addressing spectroscopies involving higher-energy photons. These two aspects are examined by our study of the near K-edge X-ray absorption fine structure of the alkaline earth metals (Mg, Ca, Sr, Ba, and Ra) as well as the trans-polyenes. In following the series of alkaline earth metals, the sizes of non-dipolar effects are probed with respect to increasing photon energies and a detailed assessment of results is made in terms of studying the pertinent transition electron densities and in particular their spatial extension in comparison with the photon wavelength. Along the series of trans-polyenes, the sizes of non-dipolar effects are probed for X-ray spectroscopies on organic molecules with respect to the spatial extension of the chromophore.
Notes on Barkas-Andersen effect
NASA Astrophysics Data System (ADS)
Sigmund, Peter; Schinner, Andreas
2014-10-01
Stimulated by recent statements in the literature on electronic stopping of heavy ions in matter, we try to clarify some central theoretical aspects of the Barkas-Andersen effect, about which there does not seem to be unanimous agreement in the community. We address the role of inner versus outer target shells, of projectile screening by bound electrons, the interference between Lindhard's description and perturbation theory, as well as the equivalence between a single-electron versus Fermi-gas description of the effect.
Deformed Calogero-Sutherland model and fractional quantum Hall effect
NASA Astrophysics Data System (ADS)
Atai, Farrokh; Langmann, Edwin
2017-01-01
The deformed Calogero-Sutherland (CS) model is a quantum integrable system with arbitrary numbers of two types of particles and reducing to the standard CS model in special cases. We show that a known collective field description of the CS model, which is based on conformal field theory (CFT), is actually a collective field description of the deformed CS model. This provides a natural application of the deformed CS model in Wen's effective field theory of the fractional quantum Hall effect (FQHE), with the two kinds of particles corresponding to electrons and quasi-hole excitations. In particular, we use known mathematical results about super-Jack polynomials to obtain simple explicit formulas for the orthonormal CFT basis proposed by van Elburg and Schoutens in the context of the FQHE.
ERIC Educational Resources Information Center
Park, Hee Sun; Smith, Sandi W.
2007-01-01
The effects of the attitudinal, normative, and perceived behavioral control (PBC) components of the theory of planned behavior and personal- and societal-level descriptive and injunctive norms were investigated with regard to their impact on the intent to enroll on a state organ-donor registry and the intent to engage in family discussion about…
Holographic renormalization group and cosmology in theories with quasilocalized gravity
NASA Astrophysics Data System (ADS)
Csáki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John
2001-03-01
We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.
Holographic renormalization group and cosmology in theories with quasilocalized gravity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.
2001-03-15
We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowskimore » space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.« less
Health values and prospect theory.
Treadwell, J R; Lenert, L A
1999-01-01
Health values are important components of medical decisions. Experimental data suggest that people value health in complex and dynamic ways. Prospect theory is a descriptive theory of choice that may accurately characterize how people assign values to health states. The authors first provide background on prospect theory and how it can be applied to health values. Next, they review the relevant health research and find mixed support for prospect theory. Last, they discuss implications of prospect theory for cost-effectiveness analysis. The application of prospect theory to health deserves further research because it may help clarify the link between health and values.
What correlation effects are covered by density functional theory?
NASA Astrophysics Data System (ADS)
He, Yuan; Grafenstein, Jurgen; Kraka, Elfi; Cremer, Dieter
The electron density distribution rho(r) generated by a DFT calculation was systematically studied by comparison with a series of reference densities obtained by wavefunction theory (WFT) methods that cover typical electron correlation effects. As a sensitive indicator for correlation effects the dipole moment of the CO molecule was used. The analysis reveals that typical LDA and GGA exchange functionals already simulate effects that are actually reminiscent of pair and three-electron correlation effects covered by MP2, MP4, and CCSD(T) in WFT. Correlation functionals contract the density towards the bond and the valence region thus taking negative charge out of the van der Waals region. It is shown that these improvements are relevant for the description of van der Waals interactions. Similar to certain correlated single-determinant WFT methods, BLYP and other GGA functionals underestimate ionic terms needed for a correct description of polar bonds. This is compensated for in hybrid functionals by mixing in HF exchange. The balanced mixing of local and non-local exchange and correlation effects leads to the correct description of polar bonds as in the B3LYP description of the CO molecule. The density obtained with B3LYP is closer to CCSD and CCSD(T) than to MP2 or MP4, which indicates that the B3LYP hybrid functional mimics those pair and three-electron correlation effects, which in WFT are only covered by coupled cluster methods.
Theories of hydrophobic effects and the description of free volume in complex liquids
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pratt, L.R.; Garde, S.; Hummer, G.
1998-12-31
Recent progress on molecular theories of hydration of nonpolar solutes in liquid aqueous solution has lead to new ways to thinking about the old issue of free volume in liquids. This article surveys the principal new results with particular attention to the context of general issues of packing in liquids.
Effective field theory for triaxially deformed nuclei
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Heslar, John; Telnov, Dmitry A.; Chu, Shih-I.
2013-05-01
We present a self-interaction-free time-dependent density-functional theory (TDDFT) for the treatment of double-ionization processes of many-electron systems. The method is based on the extension of the Krieger-Li-Iafrate (KLI) treatment of the optimized effective potential (OEP) theory and the incorporation of an explicit self-interaction correction (SIC) term. In the framework of the time-dependent density functional theory, we have performed three-dimensional (3D) calculations of double ionization of He and Be atoms by intense near-infrared laser fields. We make use of the exchange-correlation potential with the integer discontinuity which improves the description of the double-ionization process. We found that a proper description of the double ionization requires the TDDFT exchange-correlation potential with the discontinuity with respect to the variation of the total particle number (TPN). The results for the intensity-dependent rates of double ionization of He and Be atoms are presented.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kampf, Karol; Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holesovickach 2, 18000 Prague; Novotny, Jiri
2010-06-01
We study in detail various aspects of the renormalization of the spin-1 resonance propagator in the effective field theory framework. First, we briefly review the formalisms for the description of spin-1 resonances in the path integral formulation with the stress on the issue of propagating degrees of freedom. Then we calculate the one-loop 1{sup --} meson self-energy within the resonance chiral theory in the chiral limit using different methods for the description of spin-1 particles, namely, the Proca field, antisymmetric tensor field, and the first-order formalisms. We discuss in detail technical aspects of the renormalization procedure which are inherent tomore » the power-counting nonrenormalizable theory and give a formal prescription for the organization of both the counterterms and one-particle irreducible graphs. We also construct the corresponding propagators and investigate their properties. We show that the additional poles corresponding to the additional one-particle states are generated by loop corrections, some of which are negative norm ghosts or tachyons. We count the number of such additional poles and briefly discuss their physical meaning.« less
A review of carrier thermoelectric-transport theory in organic semiconductors.
Lu, Nianduan; Li, Ling; Liu, Ming
2016-07-20
Carrier thermoelectric-transport theory has recently become of growing interest and numerous thermoelectric-transport models have been proposed for organic semiconductors, due to pressing current issues involving energy production and the environment. The purpose of this review is to provide a theoretical description of the thermoelectric Seebeck effect in organic semiconductors. Special attention is devoted to the carrier concentration, temperature, polaron effect and dipole effect dependence of the Seebeck effect and its relationship to hopping transport theory. Furthermore, various theoretical methods are used to discuss carrier thermoelectric transport. Finally, an outlook of the remaining challenges ahead for future theoretical research is provided.
Therapeutic Theory and Social Context: A Social Constructionist Perspective.
ERIC Educational Resources Information Center
Lynch, Gordon
1997-01-01
Explores the foundation of therapeutic theory from the perspective of social constructionism. Proposes a theoretical description of the interaction between an individual and the social context in the formation of therapeutic theory. Then explores this description in relation to the early life and subsequent therapeutic theory of Carl Rogers. (RJM)
Effective field theory models for nonviolent information transfer from black holes
NASA Astrophysics Data System (ADS)
Giddings, Steven B.; Shi, Yinbo
2014-06-01
Transfer of quantum information from the interior of a black hole to its atmosphere is described, in models based on effective field theory. This description illustrates that such transfer need not be violent to the semiclassical geometry or to infalling observers, and in particular can avoid producing a singular horizon or "firewall". One can specifically quantify the rate of information transfer and show that a rate necessary to unitarize black hole evaporation produces a relatively mild modification to the stress tensor near the horizon. In an exterior description of the transfer, the new interactions responsible for it are approximated by "effective sources" acting on fields in the black hole atmosphere. If the necessary interactions couple to general modes in the black hole atmosphere, one also finds a straightforward mechanism for information transfer rates to increase when a black hole is mined, avoiding paradoxical behavior. Correspondence limits are discussed, in the presence of such new interactions, for both small black holes and large ones; the near-horizon description of the latter is approximately that of Rindler space.
Safety belt promotion: theory and practice.
Nelson, G D; Moffit, P B
1988-02-01
The purpose of this paper is to provide practitioners a rationale and description of selected theoretically based approaches to safety belt promotion. Theory failure is a threat to the integrity and effectiveness of safety belt promotion. The absence of theory driven programs designed to promote safety belt use is a concern of this paper. Six theoretical models from the social and behavioral sciences are reviewed with suggestions for application to promoting safety belt use and include Theory of Reasoned Action, the Health Belief Model, Fear Arousal, Operant Learning, Social Learning Theory, and Diffusion of Innovations. Guidelines for the selection and utilization of theory are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
List, Nanna Holmgaard, E-mail: nhl@sdu.dk; Jensen, Hans Jørgen Aagaard; Kauczor, Joanna
2015-06-28
We present a formulation of molecular response theory for the description of a quantum mechanical molecular system in the presence of a weak, monochromatic, linearly polarized electromagnetic field without introducing truncated multipolar expansions. The presentation focuses on a description of linear absorption by adopting the energy-loss approach in combination with the complex polarization propagator formulation of response theory. Going beyond the electric-dipole approximation is essential whenever studying electric-dipole-forbidden transitions, and in general, non-dipolar effects become increasingly important when addressing spectroscopies involving higher-energy photons. These two aspects are examined by our study of the near K-edge X-ray absorption fine structure ofmore » the alkaline earth metals (Mg, Ca, Sr, Ba, and Ra) as well as the trans-polyenes. In following the series of alkaline earth metals, the sizes of non-dipolar effects are probed with respect to increasing photon energies and a detailed assessment of results is made in terms of studying the pertinent transition electron densities and in particular their spatial extension in comparison with the photon wavelength. Along the series of trans-polyenes, the sizes of non-dipolar effects are probed for X-ray spectroscopies on organic molecules with respect to the spatial extension of the chromophore.« less
Chai, Jeng-Da
2017-01-28
We propose hybrid schemes incorporating exact exchange into thermally assisted-occupation-density functional theory (TAO-DFT) [J.-D. Chai, J. Chem. Phys. 136, 154104 (2012)] for an improved description of nonlocal exchange effects. With a few simple modifications, global and range-separated hybrid functionals in Kohn-Sham density functional theory (KS-DFT) can be combined seamlessly with TAO-DFT. In comparison with global hybrid functionals in KS-DFT, the resulting global hybrid functionals in TAO-DFT yield promising performance for systems with strong static correlation effects (e.g., the dissociation of H 2 and N 2 , twisted ethylene, and electronic properties of linear acenes), while maintaining similar performance for systems without strong static correlation effects. Besides, a reasonably accurate description of noncovalent interactions can be efficiently achieved through the inclusion of dispersion corrections in hybrid TAO-DFT. Relative to semilocal density functionals in TAO-DFT, global hybrid functionals in TAO-DFT are generally superior in performance for a wide range of applications, such as thermochemistry, kinetics, reaction energies, and optimized geometries.
Yang, Bo
2018-06-01
Based on the theory of normative social behavior (Rimal & Real, 2005), this study examined the effects of descriptive norms, close versus distal peer injunctive norms, and interdependent self-construal on college students' intentions to consume alcohol. Results of a cross-sectional study conducted among U.S. college students (N = 581) found that descriptive norms, close, and distal peer injunctive norms had independent effects on college students' intentions to consume alcohol. Furthermore, close peer injunctive norms moderated the effects of descriptive norms on college students' intentions to consume alcohol and the interaction showed different patterns among students with a strong and weak interdependent self-construal. High levels of close peer injunctive norms weakened the relationship between descriptive norms and intentions to consume alcohol among students with a strong interdependent self-construal but strengthened the relationship between descriptive norms and intentions to consume alcohol among students with a weak interdependent self-construal. Implications of the findings for norms-based research and college drinking interventions are discussed.
ERIC Educational Resources Information Center
Winter, Paul A.
1998-01-01
Describes a study that applied marketing and advertising theory to recruit community-college business faculty. The reactions of male and female target applicants to recruitment advertisements and job descriptions were assessed, with differences found between the two groups. Discusses results, and implications for practice, theory and research. (36…
Student Success Skills: An Evidence-Based Cognitive and Social Change Theory for Student Achievement
ERIC Educational Resources Information Center
Lemberger, Matthew E.; Brigman, Greg; Webb, Linda; Moore, Molly M.
2012-01-01
An overview of the Student Success Skills program is offered, including descriptions of the curricular structure, extant research support related to SSS effectiveness for academic achievement and improved school behaviors, and a theory of change for student development. Recent research has demonstrated the value of the SSS program as it connects…
The relationship between symbolic interactionism and interpretive description.
Oliver, Carolyn
2012-03-01
In this article I explore the relationship between symbolic interactionist theory and interpretive description methodology. The two are highly compatible, making symbolic interactionism an excellent theoretical framework for interpretive description studies. The pragmatism underlying interpretive description supports locating the methodology within this cross-disciplinary theory to make it more attractive to nonnursing researchers and expand its potential to address practice problems across the applied disciplines. The theory and method are so compatible that symbolic interactionism appears to be part of interpretive description's epistemological foundations. Interpretive description's theoretical roots have, to date, been identified only very generally in interpretivism and the philosophy of nursing. A more detailed examination of its symbolic interactionist heritage furthers the contextualization or forestructuring of the methodology to meet one of its own requirements for credibility.
Towards weakly constrained double field theory
NASA Astrophysics Data System (ADS)
Lee, Kanghoon
2016-08-01
We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon) transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.
Emergent dimensions and branes from large-N confinement
NASA Astrophysics Data System (ADS)
Cherman, Aleksey; Poppitz, Erich
2016-12-01
N =1 S U (N ) super-Yang-Mills theory on R3×S1 is believed to have a smooth dependence on the circle size L . Making L small leads to calculable nonperturbative color confinement, mass gap, and string tensions. For finite N , the small-L low-energy dynamics is described by a three-dimensional effective theory. The large-N limit, however, reveals surprises: the infrared dual description is in terms of a theory with an emergent fourth dimension, curiously reminiscent of T-duality in string theory. Here, however, the emergent dimension is a lattice, with momenta related to the S1-winding of the gauge field holonomy, which takes values in ZN. Furthermore, the low-energy description is given by a nontrivial gapless theory, with a space-like z =2 Lifshitz scale invariance and operators that pick up anomalous dimensions as L is increased. Supersymmetry-breaking deformations leave the long-distance theory scale-invariant, but change the Lifshitz scaling exponent to z =1 , and lead to an emergent Lorentz symmetry at small L . Adding a small number of fundamental fermion fields leads to matter localized on three-dimensional branes in the emergent four-dimensional theory.
On electro-hydrodynamic effects over liquids under influence of corona discharge
NASA Astrophysics Data System (ADS)
Bychkov, V. L.; Abakumov, V. I.; Bikmukhametova, A. R.; Chernikov, V. A.; Safronenkov, D. A.
2018-03-01
Electrohydrodynamic effects over liquids under high voltage electrode are considered in experiments with corona discharge. Simple theory is applied for description of a funnel appearance over a liquid is presented. New types of electrohydrodynamic instabilities are revealed.
Low-energy dynamics of gravitation
NASA Astrophysics Data System (ADS)
Torma, Tibor
The present status of theories of quantum gravity are reviewed from the low energy point of view. String theory relates classical black-hole type solutions of Einstein- like equations (e.g. axidilaton gravity) to the string vacuum. Several such solutions are proposed and their properties are investigated, including their behavior under supersymmetry transformations. A general feature of all possible quantum theories of gravitation is that they lead to a field theory description at low (as compared to the Planck mass) energies. The theoretical consistency, uniqueness and consequences of such an effective theory are investigated. I show that a power counting theorem allows for the momentum expansion that defines the effective theory even in the presence of large masses. I also show that graviton-graviton scattering is free of potential infrared and collinear divergencies that plague perturbative discussions of Yang-Mills theories.
Zhao, Huanhuan; Zhang, Heyun; Xu, Yan
2017-01-31
The present study attempts to examine the effect of perceived descriptive norms on corrupt intention (e.g., bribe-taking intention) and then further explore the psychological mechanism underlying this effect. Based on social cognitive theory, we established a mediation model in which moral disengagement partially mediated the link between perceived descriptive norms and corrupt intention. In Study 1, participants (N = 690) completed a series of questionnaires, and the results demonstrated that, while perceived descriptive norms were positively associated with corrupt intention, it was partially mediated by moral disengagement. In Study 2, we conducted a priming experiment (N = 161) to test the causal relationship and psychological mechanism between perceived descriptive norms and corrupt intention. The results revealed that perceived descriptive norms triggered the propensity of individuals to morally disengage, which in turn, partially increased their corrupt intention. This study not only extends previous research by providing evidence that moral disengagement may be one of the reasons why perceived descriptive norms facilitate corrupt intention, but also suggests that reshaping normative beliefs and preventing the moral disengagement of individuals may be the effective ways to curb corrupt behaviours. © 2017 International Union of Psychological Science.
Effective field theories for superconducting systems with multiple Fermi surfaces
DOE Office of Scientific and Technical Information (OSTI.GOV)
Braga, P.R., E-mail: pedro.rangel.braga@gmail.com; Granado, D.R., E-mail: diegorochagrana@uerj.br; Department of Physics and Astronomy, Ghent University, Krijgslaan 281-S9, 9000 Gent
2016-11-15
In this work we investigate the description of superconducting systems with multiple Fermi surfaces. For the case of one Fermi surface we re-obtain the result that the superconductor is more precisely described as a topological state of matter. Studying the case of more than one Fermi surface, we obtain the effective theory describing a time reversal symmetric topological superconductor. These results are obtained by employing a general procedure to construct effective low energy actions describing states of electromagnetic systems interacting with charges and defects. The procedure consists in taking into account the proliferation or dilution of these charges and defectsmore » and its consequences for the low energy description of the electromagnetic response of the system. We find that the main ingredient entering the low energy characterization of the system with more than one Fermi surface is a non-conservation of the canonical supercurrent triggered by particular vortex configurations.« less
Effective field theory for deformed atomic nuclei
Papenbrock, Thomas F.; Weidenmüller, H. A.
2016-04-13
In this paper, we present an effective field theory (EFT) for a model-independent description of deformed atomic nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections are computed, the EFT accounts for finer details such as the variation of the moment of inertia with the band head and the small magnitudes of interband E2 transitions. Finally, for rotational bands with a finite spin of the band head, the EFT is equivalent to the theory of a charged particle on the sphere subject to a magnetic monopole field.
NASA Astrophysics Data System (ADS)
Zabavnikova, T. A.; Kadashevich, Yu. I.; Pomytkin, S. P.
2018-05-01
A geometric non-linear endochronic theory of inelasticity in tensor parametric form is considered. In the framework of this theory, the creep strains are modelled. The effect of various schemes of applying stresses and changing of material properties on the development of creep strains is studied. The constitutive equations of the model are represented by non-linear systems of ordinary differential equations which are solved in MATLAB environment by implicit difference method. Presented results demonstrate a good qualitative agreement of theoretical data and experimental observations including the description of the tertiary creep and pre-fracture of materials.
Higher order string effects and the properties of the Pomeron
Kharzeev, Dmitri; Shuryak, Edward; Zahed, Ismail
2018-01-18
In this paper, we revisit the description of the Pomeron within the effective string theory of QCD. Using a string duality relation, we show how the static potential maps onto the high-energy scattering amplitude that exhibits the Pomeron behavior. Besides the Pomeron intercept and slope, new additional terms stemming from the higher order string corrections are shown to affect both the growth of the nucleon’s size at high energies and its profile in impact parameter space. The stringy description also allows for an odderon that only disappears in critical dimension. Lastlyl, some of the Pomeron’s features that emerge within themore » effective string description can be studied at the future EIC collider.« less
Quark Mass Functions and Pion Structure in the Covariant Spectator Theory
Biernat, Elmar P.; Gross, Franz; Pena, Teresa; ...
2018-05-24
The Covariant Spectator Theory is applied to the description of quarks and the pion. The dressed quark mass function is calculated dynamically in Minkowski space and used in the calculation of the pion electromagnetic form factor. The effects of the mass function on the pion form factor and the different quark-pole contributions to the triangle diagram then are analyzed.
Quark Mass Functions and Pion Structure in the Covariant Spectator Theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Biernat, Elmar P.; Gross, Franz; Pena, Teresa
The Covariant Spectator Theory is applied to the description of quarks and the pion. The dressed quark mass function is calculated dynamically in Minkowski space and used in the calculation of the pion electromagnetic form factor. The effects of the mass function on the pion form factor and the different quark-pole contributions to the triangle diagram then are analyzed.
Phenomenological model for transient deformation based on state variables
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jackson, M S; Cho, C W; Alexopoulos, P
The state variable theory of Hart, while providing a unified description of plasticity-dominated deformation, exhibits deficiencies when it is applied to transient deformation phenomena at stresses below yield. It appears that the description of stored anelastic strain is oversimplified. Consideration of a simple physical picture based on continuum dislocation pileups suggests that the neglect of weak barriers to dislocation motion is the source of these inadequacies. An appropriately modified description incorporating such barriers then allows the construction of a macroscopic model including transient effects. Although the flow relations for the microplastic element required in the new theory are not known,more » tentative assignments may be made for such functions. The model then exhibits qualitatively correct behavior when tensile, loading-unloading, reverse loading, and load relaxation tests are simulated. Experimental procedures are described for determining the unknown parameters and functions in the new model.« less
Pair production processes and flavor in gauge-invariant perturbation theory
NASA Astrophysics Data System (ADS)
Egger, Larissa; Maas, Axel; Sondenheimer, René
2017-12-01
Gauge-invariant perturbation theory is an extension of ordinary perturbation theory which describes strictly gauge-invariant states in theories with a Brout-Englert-Higgs effect. Such gauge-invariant states are composite operators which have necessarily only global quantum numbers. As a consequence, flavor is exchanged for custodial quantum numbers in the Standard Model, recreating the fermion spectrum in the process. Here, we study the implications of such a description, possibly also for the generation structure of the Standard Model. In particular, this implies that scattering processes are essentially bound-state-bound-state interactions, and require a suitable description. We analyze the implications for the pair-production process e+e-→f¯f at a linear collider to leading order. We show how ordinary perturbation theory is recovered as the leading contribution. Using a PDF-type language, we also assess the impact of sub-leading contributions. To lowest order, we find that the result is mainly influenced by how large the contribution of the Higgs at large x is. This gives an interesting, possibly experimentally testable, scenario for the formal field theory underlying the electroweak sector of the Standard Model.
Inequivalent coherent state representations in group field theory
NASA Astrophysics Data System (ADS)
Kegeles, Alexander; Oriti, Daniele; Tomlin, Casey
2018-06-01
In this paper we propose an algebraic formulation of group field theory and consider non-Fock representations based on coherent states. We show that we can construct representations with an infinite number of degrees of freedom on compact manifolds. We also show that these representations break translation symmetry. Since such representations can be regarded as quantum gravitational systems with an infinite number of fundamental pre-geometric building blocks, they may be more suitable for the description of effective geometrical phases of the theory.
NASA Astrophysics Data System (ADS)
Riseborough, P. S.; Lawrence, J. M.
2016-08-01
We review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effect and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger’s theorem, the Friedel sum rule, the Schrieffer-Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Noziéres exhaustion principle, Doniach’s diagram, the Anderson lattice model, the Slave-Boson method, etc.
Tachyon driven quantum cosmology in string theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Garcia-Compean, H.; Garcia-Jimenez, G.; Obregon, O.
2005-03-15
Recently an effective action of the SDp-brane decaying process in string theory has been proposed. This effective description involves the Tachyon driven matter coupled to bosonic ten-dimensional Type II supergravity. Here the Hamiltonian formulation of this system is given. Exact solutions for the corresponding quantum theory by solving the Wheeler-deWitt equation in the late-time limit of the rolling tachyon are found. The energy spectrum and the probability densities for several values of p are shown and their possible interpretation is discussed. In the process the effects of electromagnetic fields are also incorporated and it is shown that in this casemore » the interpretation of tachyon regarded as 'matter clock' is modified.« less
[Media coverage of suicide: From the epidemiological observations to prevention avenues].
Notredame, Charles-Édouard; Pauwels, Nathalie; Walter, Michel; Danel, Thierry; Vaiva, Guillaume
2015-12-01
Media coverage of suicide can result in increased morbi-mortality suicidal rates, due to an imitation process in those who are particularly vulnerable. This phenomenon is known as "Werther effect". Werther effect's magnitude depends on several qualitative and quantitative characteristics of the media coverage, in a dose-effect relationship. An extensive (in terms of audience and history repetition) and salient coverage (glorification of suicide, description of the suicidal method, etc.) increases the risk of contagion. Celebrities' suicide is particularly at risk of Werther effect. Media may also have a preventive role with respect to suicide. Indeed, according to "Papageno effect", journalists could, under certain conditions, help preventing suicide when reporting suicide stories. Two main theories in the field of social psychology have been proposed to account for Werther and Papageno effects: social learning theory and differential identification. Identification of Werther and Papageno effects uncovers new responsibilities and potentialities for the journalists in terms of public health. Their description provides a basis for promising targeted prevention actions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
What Is Grammar and Why Teach It?
ERIC Educational Resources Information Center
Greenbaum, Sidney
The word "grammar" can be used in many ways: a general theory of language description; a theory for describing one language; a description of a particular language, either in the form of a book (an "English grammar") or the contents of that book; an ideal as opposed to actual description of a language; the properties and processes of a language…
Normative and descriptive accounts of the influence of power and contingency on causal judgement.
Perales, José C; Shanks, David R
2003-08-01
The power PC theory (Cheng, 1997) is a normative account of causal inference, which predicts that causal judgements are based on the power p of a potential cause, where p is the cause-effect contingency normalized by the base rate of the effect. In three experiments we demonstrate that both cause-effect contingency and effect base-rate independently affect estimates in causal learning tasks. In Experiment 1, causal strength judgements were directly related to power p in a task in which the effect base-rate was manipulated across two positive and two negative contingency conditions. In Experiments 2 and 3 contingency manipulations affected causal estimates in several situations in which power p was held constant, contrary to the power PC theory's predictions. This latter effect cannot be explained by participants' conflation of reliability and causal strength, as Experiment 3 demonstrated independence of causal judgements and confidence. From a descriptive point of view, the data are compatible with Pearce's (1987) model, as well as with several other judgement rules, but not with the Rescorla-Wagner (Rescorla & Wagner, 1972) or power PC models.
Quantum equivalence of f (R) gravity and scalar-tensor theories in the Jordan and Einstein frames
NASA Astrophysics Data System (ADS)
Ohta, Nobuyoshi
2018-03-01
The f(R) gravity and scalar-tensor theory are known to be equivalent at the classical level. We study if this equivalence is valid at the quantum level. There are two descriptions of the scalar-tensor theory in the Jordan and Einstein frames. It is shown that these three formulations of the theories give the same determinant or effective action on shell, and thus they are equivalent at the quantum one-loop level on shell in arbitrary dimensions. We also compute the one-loop divergence in f(R) gravity on an Einstein space.
Modeling Adversaries in Counterterrorism Decisions Using Prospect Theory.
Merrick, Jason R W; Leclerc, Philip
2016-04-01
Counterterrorism decisions have been an intense area of research in recent years. Both decision analysis and game theory have been used to model such decisions, and more recently approaches have been developed that combine the techniques of the two disciplines. However, each of these approaches assumes that the attacker is maximizing its utility. Experimental research shows that human beings do not make decisions by maximizing expected utility without aid, but instead deviate in specific ways such as loss aversion or likelihood insensitivity. In this article, we modify existing methods for counterterrorism decisions. We keep expected utility as the defender's paradigm to seek for the rational decision, but we use prospect theory to solve for the attacker's decision to descriptively model the attacker's loss aversion and likelihood insensitivity. We study the effects of this approach in a critical decision, whether to screen containers entering the United States for radioactive materials. We find that the defender's optimal decision is sensitive to the attacker's levels of loss aversion and likelihood insensitivity, meaning that understanding such descriptive decision effects is important in making such decisions. © 2014 Society for Risk Analysis.
Behavioural studies of strategic thinking in games.
Camerer, Colin F.
2003-05-01
Game theory is a mathematical language for describing strategic interactions, in which each player's choice affects the payoff of other players (where players can be genes, people, companies, nation-states, etc.). The impact of game theory in psychology has been limited by the lack of cognitive mechanisms underlying game-theoretic predictions. 'Behavioural game theory' is a recent approach linking game theory to cognitive science by adding cognitive details about 'social utility functions', theories of limits on iterated thinking, and statistical theories of how players learn and influence others. New directions include the effects of game descriptions on choice ('framing'), strategic heuristics, and mental representation. These ideas will help root game theory more deeply in cognitive science and extend the scope of both enterprises.
ERIC Educational Resources Information Center
Campbell, Bernadette; Mark, Melvin M.
2015-01-01
Evaluation theories can be tested in various ways. One approach, the experimental analogue study, is described and illustrated in this article. The approach is presented as a method worthy to use in the pursuit of what Alkin and others have called descriptive evaluation theory. Drawing on analogue studies conducted by the first author, we…
ERIC Educational Resources Information Center
Yanchar, Stephen C.; Faulconer, James E.
2011-01-01
This article presents the concept of facilitative theorizing as an alternative to prescriptive and descriptive theory in educational technology. The authors contend that these traditional forms of theory do not offer sufficient assistance to practitioners as they go about everyday design work. Facilitative theorizing, as an alternative, is…
Hacking the quantum revolution: 1925-1975
NASA Astrophysics Data System (ADS)
Schweber, Silvan S.
2015-01-01
I argue that the quantum revolution should be seen as an Ian Hacking type of scientific revolution: a profound, longue durée, multidisciplinary process of transforming our understanding of physical nature, with deep-rooted social components from the start. The "revolution" exhibits a characteristic style of reasoning - the hierarchization of physical nature - and developed and uses a specific language - quantum field theory (QFT). It is by virtue of that language that the quantum theory has achieved some of its deepest insights into the description of the dynamics of the physical world. However, the meaning of what a quantum field theory is and what it describes has deeply altered, and one now speaks of "effective" quantum field theories. Interpreting all present day quantum field theories as but "effective" field theories sheds additional light on Phillip Anderson's assertion that "More is different". This important element is addressed in the last part of the paper.
The predictive validity of prospect theory versus expected utility in health utility measurement.
Abellan-Perpiñan, Jose Maria; Bleichrodt, Han; Pinto-Prades, Jose Luis
2009-12-01
Most health care evaluations today still assume expected utility even though the descriptive deficiencies of expected utility are well known. Prospect theory is the dominant descriptive alternative for expected utility. This paper tests whether prospect theory leads to better health evaluations than expected utility. The approach is purely descriptive: we explore how simple measurements together with prospect theory and expected utility predict choices and rankings between more complex stimuli. For decisions involving risk prospect theory is significantly more consistent with rankings and choices than expected utility. This conclusion no longer holds when we use prospect theory utilities and expected utilities to predict intertemporal decisions. The latter finding cautions against the common assumption in health economics that health state utilities are transferable across decision contexts. Our results suggest that the standard gamble and algorithms based on, should not be used to value health.
Applying Psychological Theories to Promote Long-Term Maintenance of Health Behaviors
Joseph, Rodney P.; Daniel, Casey L.; Thind, Herpreet; Benitez, Tanya J.; Pekmezi, Dori
2014-01-01
Behavioral health theory provides a framework for researchers to design, implement, and evaluate the effects of health promotion programs. However, limited research has examined theories used in interventions to promote long-term maintenance of health behaviors. The purpose of this review was to evaluate the available literature and identify prominent behavioral health theories used in intervention research to promote maintenance of health behaviors. We reviewed theories used in intervention research assessing long-term maintenance (≥ 6 months post-intervention) of physical activity, weight loss, and smoking cessation. Five prominent behavioral theories were referenced by the 34 studies included in the review: Self-Determination Theory, Theory of Planned Behavior, Social Cognitive Theory, Transtheoretical Model, and Social Ecological Model. Descriptions and examples of applications of these theories are provided. Implications for future research are discussed. PMID:28217036
ERIC Educational Resources Information Center
Peat, D.; And Others
1989-01-01
Describes an instructional model, Strategies Program for Effective Learning/Thinking (SPELT), that was developed to translate cognitive psychological theory and research into a practical instructional program. The extent to which SPELT conforms to current instructional design principles is examined, and macro versus micro instructional sequencing…
Unified cosmic history in modified gravity: From F(R) theory to Lorentz non-invariant models
NASA Astrophysics Data System (ADS)
Nojiri, Shin'Ichi; Odintsov, Sergei D.
2011-08-01
The classical generalization of general relativity is considered as the gravitational alternative for a unified description of the early-time inflation with late-time cosmic acceleration. The structure and cosmological properties of a number of modified theories, including traditional F(R) and Hořava-Lifshitz F(R) gravity, scalar-tensor theory, string-inspired and Gauss-Bonnet theory, non-local gravity, non-minimally coupled models, and power-counting renormalizable covariant gravity are discussed. Different representations of and relations between such theories are investigated. It is shown that some versions of the above theories may be consistent with local tests and may provide a qualitatively reasonable unified description of inflation with the dark energy epoch. The cosmological reconstruction of different modified gravities is provided in great detail. It is demonstrated that eventually any given universe evolution may be reconstructed for the theories under consideration, and the explicit reconstruction is applied to an accelerating spatially flat Friedmann-Robertson-Walker (FRW) universe. Special attention is paid to Lagrange multiplier constrained and conventional F(R) gravities, for latter F(R) theory, the effective ΛCDM era and phantom divide crossing acceleration are obtained. The occurrences of the Big Rip and other finite-time future singularities in modified gravity are reviewed along with their solutions via the addition of higher-derivative gravitational invariants.
Nguyen, Manh Cuong; Yao, Yongxin; Wang, Cai-Zhuang; ...
2018-05-16
The dependence of the magnetocrystalline anisotropy energy (MAE) in MCo 5 (M = Y, La, Ce, Gd) and CoPt on the Coulomb correlations and strength of spin orbit (SO) interaction within the GGA + U scheme is investigated. A range of parameters suitable for the satisfactory description of key magnetic properties is determined. We show that for a large variation of SO interaction the MAE in these materials can be well described by the traditional second order perturbation theory. We also show that in these materials the MAE can be both proportional and negatively proportional to the orbital moment anisotropymore » (OMA) of Co atoms. Dependence of relativistic effects on Coulomb correlations, applicability of the second order perturbation theory for the description of MAE, and effective screening of the SO interaction in these systems are discussed using a generalized virial theorem. Finally, such determined sets of parameters of Coulomb correlations can be used in much needed large scale atomistic simulations.« less
NASA Astrophysics Data System (ADS)
Nguyen, Manh Cuong; Yao, Yongxin; Wang, Cai-Zhuang; Ho, Kai-Ming; Antropov, Vladimir P.
2018-05-01
The dependence of the magnetocrystalline anisotropy energy (MAE) in MCo5 (M = Y, La, Ce, Gd) and CoPt on the Coulomb correlations and strength of spin orbit (SO) interaction within the GGA + U scheme is investigated. A range of parameters suitable for the satisfactory description of key magnetic properties is determined. We show that for a large variation of SO interaction the MAE in these materials can be well described by the traditional second order perturbation theory. We also show that in these materials the MAE can be both proportional and negatively proportional to the orbital moment anisotropy (OMA) of Co atoms. Dependence of relativistic effects on Coulomb correlations, applicability of the second order perturbation theory for the description of MAE, and effective screening of the SO interaction in these systems are discussed using a generalized virial theorem. Such determined sets of parameters of Coulomb correlations can be used in much needed large scale atomistic simulations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, Manh Cuong; Yao, Yongxin; Wang, Cai-Zhuang
The dependence of the magnetocrystalline anisotropy energy (MAE) in MCo 5 (M = Y, La, Ce, Gd) and CoPt on the Coulomb correlations and strength of spin orbit (SO) interaction within the GGA + U scheme is investigated. A range of parameters suitable for the satisfactory description of key magnetic properties is determined. We show that for a large variation of SO interaction the MAE in these materials can be well described by the traditional second order perturbation theory. We also show that in these materials the MAE can be both proportional and negatively proportional to the orbital moment anisotropymore » (OMA) of Co atoms. Dependence of relativistic effects on Coulomb correlations, applicability of the second order perturbation theory for the description of MAE, and effective screening of the SO interaction in these systems are discussed using a generalized virial theorem. Finally, such determined sets of parameters of Coulomb correlations can be used in much needed large scale atomistic simulations.« less
Q-balls of quasi-particles in a (2, 0)-theory model of the fractional quantum Hall effect
NASA Astrophysics Data System (ADS)
Ganor, Ori J.; Hong, Yoon Pyo; Moore, Nathan; Sun, Hao-Yu; Tan, Hai Siong; Torres-Chicon, Nesty R.
2015-09-01
A toy model of the fractional quantum Hall effect appears as part of the low-energy description of the Coulomb branch of the A 1 (2 , 0)-theory formulated on ({S}^1× {{R}}^2)/{{Z}}_k , where the generator of {{Z}}_k acts as a combination of translation on S 1 and rotation by 2 π/k on {{R}}^2 . At low energy the configuration is described in terms of a 4+1D Super-Yang-Mills theory on a cone ({{R}}^2/{{Z}}_k) with additional 2+1D degrees of freedom at the tip of the cone that include fractionally charged particles. These fractionally charged "quasi-particles" are BPS strings of the (2 , 0)-theory wrapped on short cycles. We analyze the large k limit, where a smooth cigar-geometry provides an alternative description. In this framework a W-boson can be modeled as a bound state of k quasi-particles. The W-boson becomes a Q-ball, and it can be described as a soliton solution of Bogomolnyi monopole equations on a certain auxiliary curved space. We show that axisymmetric solutions of these equations correspond to singular maps from AdS 3 to AdS 2, and we present some numerical results and an asymptotic expansion.
Scaling theory of magnetoresistance and carrier localization in Ga1-xMnxAs.
Moca, C P; Sheu, B L; Samarth, N; Schiffer, P; Janko, B; Zarand, G
2009-04-03
We compare experimental resistivity data on Ga1-xMnxAs films with theoretical calculations using a scaling theory for strongly disordered ferromagnets. The characteristic features of the temperature dependent resistivity can be quantitatively understood through this approach as originating from the close vicinity of the metal-insulator transition. However, accounting for thermal fluctuations is crucial for a quantitative description of the magnetic field induced changes in resistance. While the noninteracting scaling theory is in reasonable agreement with the data, we find clear evidence for interaction effects at low temperatures.
Mabry, Amanda; Turner, Monique Mitchell
2016-01-01
The high prevalence of sexual assault on college campuses has led to the implementation of health communication programs to prevent sexual assault. A few novel programs focus on primary prevention by targeting social norms related to gender and masculinity among men through bystander intervention. Guided by the theory of normative social behavior, this study sought to examine the relative effect of campaigns communicating positive versus negative injunctive norms and the interaction between exposure to such campaign messages and perceived descriptive norms and relevant cognitive moderators (e.g., outcome expectations, injunctive norms, group identity, ego involvement) among men. A 2 (high/low descriptive norms) × 2 (high/low moderator) × 3 (public service announcement) independent groups quasi-experimental design (N = 332) was used. Results indicated that messages communicating positive injunctive norms were most effective among men who were least likely to engage in bystander intervention. Furthermore, descriptive norms played a significant role in behavioral intentions, such that those with stronger norms were more likely to report intentions to engage in bystander behaviors in the future. Similarly, the moderators of aspiration, injunctive norms, social approval, and ego involvement had a significant positive effect on behavioral intentions. These findings have important implications for future message design strategy and audience segmentation.
Framing effects and risk-sensitive decision making.
Mishra, Sandeep; Gregson, Margaux; Lalumière, Martin L
2012-02-01
Prospect theory suggests that people are risk-averse when facing gains, but risk-prone when facing losses, a pattern known as the framing effect. Although framing effects have been widely demonstrated, few studies have investigated framing effects under conditions of need. Risk-sensitivity theory predicts that decision makers should prefer high-risk options in situations of high need, when lower risk options are unlikely to meet those needs. In two experiments, we examined (1) whether framing effects occurred in behavioural tasks involving risky decision making from description and decision making from experience, (2) whether participants' risky decision making conformed to the predictions of risk-sensitivity theory, and (3) whether decision framing interacted with conditions of need to influence decision making under risk. The results suggest that under all circumstances, risky decision making conformed to the predictions of risk-sensitivity theory. Framing effects were at least partially demonstrable under all experimental conditions. Finally, negative frames interacted with situations of high need to produce particularly elevated levels of risky choice. Together, the results suggest that risk-sensitivity theory can augment prospect theory to explain choice under conditions of need. ©2011 The British Psychological Society.
Effective description of higher-order scalar-tensor theories
DOE Office of Scientific and Technical Information (OSTI.GOV)
Langlois, David; Mancarella, Michele; Vernizzi, Filippo
Most existing theories of dark energy and/or modified gravity, involving a scalar degree of freedom, can be conveniently described within the framework of the Effective Theory of Dark Energy, based on the unitary gauge where the scalar field is uniform. We extend this effective approach by allowing the Lagrangian in unitary gauge to depend on the time derivative of the lapse function. Although this dependence generically signals the presence of an extra scalar degree of freedom, theories that contain only one propagating scalar degree of freedom, in addition to the usual tensor modes, can be constructed by requiring the initialmore » Lagrangian to be degenerate. Starting from a general quadratic action, we derive the dispersion relations for the linear perturbations around Minkowski and a cosmological background. Our analysis directly applies to the recently introduced Degenerate Higher-Order Scalar-Tensor (DHOST) theories. For these theories, we find that one cannot recover a Poisson-like equation in the static linear regime except for the subclass that includes the Horndeski and so-called 'beyond Horndeski' theories. We also discuss Lorentz-breaking models inspired by Horava gravity.« less
Polarization and Compressibility of Oblique Kinetic Alfven Waves
NASA Technical Reports Server (NTRS)
Hunana, Peter; Goldstein, M. L.; Passot, T.; Sulem, P. L.; Laveder, D.; Zank, G. P.
2012-01-01
Even though solar wind, as a collisionless plasma, is properly described by the kineticMaxwell-Vlasov description, it can be argued that much of our understanding of solar wind observational data comes from an interpretation and numerical modeling which is based on a fluid description of magnetohydrodynamics. In recent years, there has been a significant interest in better understanding the importance of kinetic effects, i.e. the differences between the kinetic and usual fluid descriptions. Here we concentrate on physical properties of oblique kinetic Alfvn waves (KAWs), which are often recognized as one of the key ingredients in the solar wind turbulence cascade. We use three different fluid models with various degrees of complexity and calculate polarization and magnetic compressibility of oblique KAWs (propagation angle q = 88), which we compare to solutions derived from linear kinetic theory. We explore a wide range of possible proton plasma b = [0.1,10.0] and a wide range of length scales krL = [0.001,10.0]. It is shown that the classical isotropic two-fluid model is very compressible in comparison with kinetic theory and that the largest discrepancy occurs at scales larger than the proton gyroscale. We also show that the two-fluid model contains a large error in the polarization of electric field, even at scales krL 1. Furthermore, to understand these discrepancies between the two-fluid model and the kinetic theory, we employ two versions of the Landau fluid model that incorporate linear low-frequency kinetic effects such as Landau damping and finite Larmor radius (FLR) corrections into the fluid description. It is shown that Landau damping significantly reduces the magnetic compressibility and that FLR corrections (i.e. nongyrotropic contributions) are required to correctly capture the polarization.We also show that, in addition to Landau damping, FLR corrections are necessary to accurately describe the damping rate of KAWs. We conclude that kinetic effects are important even at scales which are significantly larger than the proton gyroscale krL 1.
Wake curvature and trailing edge interaction effects in viscous flow over airfoils
NASA Technical Reports Server (NTRS)
Melnik, R. E.
1979-01-01
A theory developed for analyzing viscous flows over airfoils at high Reynolds numbers is described. The theory includes a complete treatment of viscous interaction effects induced by the curved wake behind the airfoil and accounts for normal pressure gradients across the boundary layer in the trailing edge region. A brief description of a computer code that was developed to solve the extended viscous interaction equations is given. Comparisons of the theoretical results with wind tunnel data for two rear loaded airfoils at supercritical conditions are presented.
NASA Astrophysics Data System (ADS)
de Blas, J.; Criado, J. C.; Pérez-Victoria, M.; Santiago, J.
2018-03-01
We compute all the tree-level contributions to the Wilson coefficients of the dimension-six Standard-Model effective theory in ultraviolet completions with general scalar, spinor and vector field content and arbitrary interactions. No assumption about the renormalizability of the high-energy theory is made. This provides a complete ultraviolet/infrared dictionary at the classical level, which can be used to study the low-energy implications of any model of interest, and also to look for explicit completions consistent with low-energy data.
NASA Technical Reports Server (NTRS)
Mcruer, D. T.; Clement, W. F.; Allen, R. W.
1981-01-01
Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.
Is Bare Band Description of Carrier Transport Appropriate in Pentacene?
NASA Astrophysics Data System (ADS)
Andersen, John D.; Giuggioli, Luca; Kenkre, V. M.
2002-03-01
Experiments on injected charges in pentacene single crystals reveal mobilities typical of inorganic semiconductors and temperature dependence (for T<430K) suggesting bandlike behavior.(J. H. Schon, C. Kloc, and B. Batlogg, Phys. Rev. Lett. 86, 3843 (2001)) Polaronic bands, particularly their narrowing with increasing temperature, were invoked(V. M. Kenkre, John D. Andersen, D.H. Dunlap, and C.B. Duke, Phys. Rev. Lett. 62, 1165 (1989)) in the related naphthalene problem.(L. B. Schein, C. B. Duke, and A.R. McGhie, Phys. Rev. Lett. 40, 197 (1978); L. B. Schein, W. Warta, and N. Karl, Chem. Phys. Lett. 100, 34 (1983)) Because the low temperature mobility values in pentacene suggest moderately large bandwidths, we address two questions. Does a bare wide (effectively infinite) band description work for pentacene for T<400K? And, is a bare finite band description compatible with those data? These questions are answered by modifications of a theory originally constructed for inorganic materials and a newly developed mobility theory.
Extending the Theory of Normative Social Behavior to Predict Hand-Washing among Koreans.
Chung, Minwoong; Lapinski, Maria Knight
2018-04-10
The current study tests the predictions of the theory of normative social behavior (TNSB) in a hand-washing context in a Korean sample and extends the theory to examine the role of perceived publicness, a variable believed to activate face concerns, as a moderator of the norm-behavior relationship. The findings show substantial main effects for all of the study variables on behavior. In addition, the descriptive norm-behavior relationship is moderated by perceived publicness and outcome expectations, but the nature of the interactions is not consistent with that evidenced in previous literature on US samples. Implications for normative theory and communication campaigns are discussed.
Analytical description of the transverse Anderson localization of light
NASA Astrophysics Data System (ADS)
Schirmacher, Walter; Leonetti, Marco; Ruocco, Giancarlo
2017-04-01
We develop an analytical theory for describing the transverse localization properties of light beams in optical fibers with lateral disorder. This theory, which starts from the widely used paraxial approximation for the Helmholtz equation of the electric field, is a combination of an effective-medium theory for transverse disorder with the self-consistent localization theory of Vollhardt and Wölfle. We obtain explicit expressions for the dependence of the transverse localization length on the direction along the fiber. These results are in agreement with simulational data published recently by Karbasi et al. In particular we explain the focussing mechanism leading to the establishment of narrow transparent channels along the sample.
Mean-Field Description of Ionic Size Effects with Non-Uniform Ionic Sizes: A Numerical Approach
Zhou, Shenggao; Wang, Zhongming; Li, Bo
2013-01-01
Ionic size effects are significant in many biological systems. Mean-field descriptions of such effects can be efficient but also challenging. When ionic sizes are different, explicit formulas in such descriptions are not available for the dependence of the ionic concentrations on the electrostatic potential, i.e., there is no explicit, Boltzmann type distributions. This work begins with a variational formulation of the continuum electrostatics of an ionic solution with such non-uniform ionic sizes as well as multiple ionic valences. An augmented Lagrange multiplier method is then developed and implemented to numerically solve the underlying constrained optimization problem. The method is shown to be accurate and efficient, and is applied to ionic systems with non-uniform ionic sizes such as the sodium chloride solution. Extensive numerical tests demonstrate that the mean-field model and numerical method capture qualitatively some significant ionic size effects, particularly those for multivalent ionic solutions, such as the stratification of multivalent counterions near a charged surface. The ionic valence-to-volume ratio is found to be the key physical parameter in the stratification of concentrations. All these are not well described by the classical Poisson–Boltzmann theory, or the generalized Poisson–Boltzmann theory that treats uniform ionic sizes. Finally, various issues such as the close packing, limitation of the continuum model, and generalization of this work to molecular solvation are discussed. PMID:21929014
NASA Technical Reports Server (NTRS)
Silva, Walter A.
1993-01-01
The presentation begins with a brief description of the motivation and approach that has been taken for this research. This will be followed by a description of the Volterra Theory of Nonlinear Systems and the CAP-TSD code which is an aeroelastic, transonic CFD (Computational Fluid Dynamics) code. The application of the Volterra theory to a CFD model and, more specifically, to a CAP-TSD model of a rectangular wing with a NACA 0012 airfoil section will be presented.
Time-domain theory of gyrotron traveling wave amplifiers operating at grazing incidence
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ginzburg, N. S., E-mail: ginzburg@appl.sci-nnov.ru; Nizhny Novgorod State University, Gagarin Ave., 23, 603950 Nizhny Novgorod; Sergeev, A. S.
Time-domain theory of the gyrotron traveling wave tube (gyro-TWT) operating at grazing incidence has been developed. The theory is based on a description of wave propagation by a parabolic equation. The results of the simulations are compared with experimental results of the observation of subnanosecond pulse amplification in a gyro-TWT consisting of three gain sections separated by severs. The theory developed can also be used successfully for a description of amplification of monochromatic signals.
Relativistic effects on the bonding and properties of the hydrides of platinum
NASA Technical Reports Server (NTRS)
Dyall, Kenneth G.
1993-01-01
The ground state of PtH2 and several low-lying states of PtH(+) and PtH have been studied at the all-electron self-consistent-field level of theory to examine the importance of relativistic effects. The results of calculations based on Dirac-Hartree-Fock theory, nonrelativistic theory, and the spin-free no-pair relativistic approximation of Hess are compared to separate the effects of the spin-free terms and the spin-orbit terms of the Hamiltonian on the relativistic corrections to the molecular properties. Comparison is also made between first-order perturbation theory including the one-electron spin-free terms and the method of Hess to determine the size of effects beyond first order. It is found that the spin-orbit interaction significantly affects the properties and energetics of these molecules because of the participation of the Pt 5d orbitals in the bonding, and that effects beyond first order in perturbation theory are large. Any treatment of Pt compounds will have to include both the spin-free and spin-orbit interactions for an accurate description.
Horizons of description: Black holes and complementarity
NASA Astrophysics Data System (ADS)
Bokulich, Peter Joshua Martin
Niels Bohr famously argued that a consistent understanding of quantum mechanics requires a new epistemic framework, which he named complementarity . This position asserts that even in the context of quantum theory, classical concepts must be used to understand and communicate measurement results. The apparent conflict between certain classical descriptions is avoided by recognizing that their application now crucially depends on the measurement context. Recently it has been argued that a new form of complementarity can provide a solution to the so-called information loss paradox. Stephen Hawking argues that the evolution of black holes cannot be described by standard unitary quantum evolution, because such evolution always preserves information, while the evaporation of a black hole will imply that any information that fell into it is irrevocably lost---hence a "paradox." Some researchers in quantum gravity have argued that this paradox can be resolved if one interprets certain seemingly incompatible descriptions of events around black holes as instead being complementary. In this dissertation I assess the extent to which this black hole complementarity can be undergirded by Bohr's account of the limitations of classical concepts. I begin by offering an interpretation of Bohr's complementarity and the role that it plays in his philosophy of quantum theory. After clarifying the nature of classical concepts, I offer an account of the limitations these concepts face, and argue that Bohr's appeal to disturbance is best understood as referring to these conceptual limits. Following preparatory chapters on issues in quantum field theory and black hole mechanics, I offer an analysis of the information loss paradox and various responses to it. I consider the three most prominent accounts of black hole complementarity and argue that they fail to offer sufficient justification for the proposed incompatibility between descriptions. The lesson that emerges from this dissertation is that we have as much to learn from the limitations facing our scientific descriptions as we do from the successes they enjoy. Because all of our scientific theories offer at best limited, effective accounts of the world, an important part of our interpretive efforts will be assessing the borders of these domains of description.
ERIC Educational Resources Information Center
Kelcey, Benjamin; Dong, Nianbo; Spybrook, Jessaca; Cox, Kyle
2017-01-01
Designs that facilitate inferences concerning both the total and indirect effects of a treatment potentially offer a more holistic description of interventions because they can complement "what works" questions with the comprehensive study of the causal connections implied by substantive theories. Mapping the sensitivity of designs to…
Crane, David; Brown, Jamie; Kaner, Eileen; Beyer, Fiona; Muirhead, Colin; Hickman, Matthew; Redmore, James; de Vocht, Frank; Beard, Emma; Michie, Susan
2018-01-01
Background Applying theory to the design and evaluation of interventions is likely to increase effectiveness and improve the evidence base from which future interventions are developed, though few interventions report this. Objective The aim of this paper was to assess how digital interventions to reduce hazardous and harmful alcohol consumption report the use of theory in their development and evaluation, and whether reporting of theory use is associated with intervention effectiveness. Methods Randomized controlled trials were extracted from a Cochrane review on digital interventions for reducing hazardous and harmful alcohol consumption. Reporting of theory use within these digital interventions was investigated using the theory coding scheme (TCS). Reported theory use was analyzed by frequency counts and descriptive statistics. Associations were analyzed with meta-regression models. Results Of 41 trials involving 42 comparisons, half did not mention theory (50% [21/42]), and only 38% (16/42) used theory to select or develop the intervention techniques. Significant heterogeneity existed between studies in the effect of interventions on alcohol reduction (I2=77.6%, P<.001). No significant associations were detected between reporting of theory use and intervention effectiveness in unadjusted models, though the meta-regression was underpowered to detect modest associations. Conclusions Digital interventions offer a unique opportunity to refine and develop new dynamic, temporally sensitive theories, yet none of the studies reported refining or developing theory. Clearer selection, application, and reporting of theory use is needed to accurately assess how useful theory is in this field and to advance the field of behavior change theories. PMID:29490895
Interferometry theory for the block 2 processor
NASA Technical Reports Server (NTRS)
Thomas, J. B.
1987-01-01
Presented is the interferometry theory for the Block 2 processor, including a high-level functional description and a discussion of data structure. The analysis covers the major processing steps: cross-correlation, fringe counter-rotation, transformation to the frequency domain, phase calibration, bandwidth synthesis, and extraction of the observables of amplitude, phase, phase rate, and delay. Also included are analyses for fractional bitshift correction, station clock error, ionosphere correction, and effective frequencies for the observables.
Effective field theories for topological insulators by functional bosonization
NASA Astrophysics Data System (ADS)
Chan, AtMa; Hughes, Taylor L.; Ryu, Shinsei; Fradkin, Eduardo
2013-02-01
Effective field theories that describe the dynamics of a conserved U(1) current in terms of “hydrodynamic” degrees of freedom of topological phases in condensed matter are discussed in general dimension D=d+1 using the functional bosonization technique. For noninteracting topological insulators (superconductors) with a conserved U(1) charge and characterized by an integer topological invariant [more specifically, they are topological insulators in the complex symmetry classes (class A and AIII), and in the “primary series” of topological insulators, in the eight real symmetry classes], we derive the BF-type topological field theories supplemented with the Chern-Simons (when D is odd) or the θ (when D is even) terms. For topological insulators characterized by a Z2 topological invariant (the first and second descendants of the primary series), their topological field theories are obtained by dimensional reduction. Building on this effective field theory description for noninteracting topological phases, we also discuss, following the spirit of the parton construction of the fractional quantum Hall effect by Block and Wen, the putative “fractional” topological insulators and their possible effective field theories, and use them to determine the physical properties of these nontrivial quantum phases.
4D superfield reduction of 5D orbifold SUGRA and heterotic M-theory
NASA Astrophysics Data System (ADS)
Paccetti Correia, Filipe; Schmidt, Michael G.; Tavartkiladze, Zurab
2006-09-01
We present a detailed study of the reduction to 4D of 5D supergravity compactified on the S/Z orbifold. For this purpose we develop and employ a recently proposed N=1 conformal superfield description of the 5D supergravity couplings to Abelian vector and hypermultiplets. In particular, we obtain a unique relation of the "radion" to chiral superfields as in global 5D SUSY and we can embed the universal hypermultiplet into this formalism. In our approach, it is transparent how the superconformal structure of the effective 4D actions is inherited from the one of the original 5D supergravity. We consider both ungauged and gauged 5D supergravities. This includes compactifications in unwarped geometries, generalizations of the supersymmetric Randall-Sundrum (RS) model as well as 5D heterotic M-theory. In the unwarped case, after obtaining the effective Kähler potentials and superpotentials, we demonstrate that the tree-level 4D potentials have flat and/or tachyonic directions. One-loop corrections to the Kähler potential and gaugino condensation are presented as suitable tools for moduli stabilization to be discussed in subsequent work. Turning to the RS-like models, we obtain a master formula for the Kähler potential for an arbitrary number of vector and hyper moduli, which we evaluate exactly for special cases. Finally, we formulate the superfield description of 5D heterotic M-theory and obtain its effective 4D description for the universal ( h=1) case, in the presence of an arbitrary number of bulk 5-branes. We present, as a check of our expressions, time-dependent solutions of 4D heterotic M-theory, which uplift to 5D solutions generalizing the ones recently found in [W. Chen, Z.-W. Chong, G.W. Gibbons, H. Lü, C.N. Pope, Hořava-Witten stability: Eppur si muove, Nucl. Phys. B 732 (2006) 118, hep-th/0502077].
Unambiguous formalism for higher order Lagrangian field theories
NASA Astrophysics Data System (ADS)
Campos, Cédric M.; de León, Manuel; Martín de Diego, David; Vankerschaver, Joris
2009-11-01
The aim of this paper is to propose an unambiguous intrinsic formalism for higher order field theories which avoids the arbitrariness in the generalization of the conventional description of field theories, and implies the existence of different Cartan forms and Legendre transformations. We propose a differential-geometric setting for the dynamics of a higher order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both the Lagrangian and the Hamiltonian description, since the field equations are formulated using the Lagrangian on a higher order jet bundle and the canonical multisymplectic form on its affine dual. As both of these objects are uniquely defined, the Skinner-Rusk approach has the advantage that it does not suffer from the arbitrariness in conventional descriptions. The result is that we obtain a unique and global intrinsic version of the Euler-Lagrange equations for higher order field theories. Several examples illustrate our construction.
Empirical data and moral theory. A plea for integrated empirical ethics.
Molewijk, Bert; Stiggelbout, Anne M; Otten, Wilma; Dupuis, Heleen M; Kievit, Job
2004-01-01
Ethicists differ considerably in their reasons for using empirical data. This paper presents a brief overview of four traditional approaches to the use of empirical data: "the prescriptive applied ethicists," "the theorists," "the critical applied ethicists," and "the particularists." The main aim of this paper is to introduce a fifth approach of more recent date (i.e. "integrated empirical ethics") and to offer some methodological directives for research in integrated empirical ethics. All five approaches are presented in a table for heuristic purposes. The table consists of eight columns: "view on distinction descriptive-prescriptive sciences," "location of moral authority," "central goal(s)," "types of normativity," "use of empirical data," "method," "interaction empirical data and moral theory," and "cooperation with descriptive sciences." Ethicists can use the table in order to identify their own approach. Reflection on these issues prior to starting research in empirical ethics should lead to harmonization of the different scientific disciplines and effective planning of the final research design. Integrated empirical ethics (IEE) refers to studies in which ethicists and descriptive scientists cooperate together continuously and intensively. Both disciplines try to integrate moral theory and empirical data in order to reach a normative conclusion with respect to a specific social practice. IEE is not wholly prescriptive or wholly descriptive since IEE assumes an interdepence between facts and values and between the empirical and the normative. The paper ends with three suggestions for consideration on some of the future challenges of integrated empirical ethics.
ERIC Educational Resources Information Center
Evans, Nicole Stayton
2013-01-01
The measurement of student perceptions of learning effectiveness is often used as a tool at universities to enhance the quality of course offerings. The recent growth in online course offerings creates new challenges in evaluating learning effectiveness. This study used three principles of adult learning theory, foundation, self-concept, and…
Refringence, field theory and normal modes
NASA Astrophysics Data System (ADS)
Barceló, Carlos; Liberati, Stefano; Visser, Matt
2002-06-01
In a previous paper [Barceló C et al 2001 Class. Quantum Grav. 18 3595-610 (Preprint gr-qc/0104001)] we have shown that the occurrence of curved spacetime 'effective Lorentzian geometries' is a generic result of linearizing an arbitrary classical field theory around some nontrivial background configuration. This observation explains the ubiquitous nature of the 'analogue models' for general relativity that have recently been developed based on condensed matter physics. In the simple (single scalar field) situation analysed in our previous paper, there is a single unique effective metric; more complicated situations can lead to bi-metric and multi-metric theories. In the present paper we will investigate the conditions required to keep the situation under control and compatible with experiment - either by enforcing a unique effective metric (as would be required to be strictly compatible with the Einstein equivalence principle), or at the worst by arranging things so that there are multiple metrics that are all 'close' to each other (in order to be compatible with the Eötvös experiment). The algebraically most general situation leads to a physical model whose mathematical description requires an extension of the usual notion of Finsler geometry to a Lorentzian-signature pseudo-Finsler geometry; while this is possibly of some interest in its own right, this particular case does not seem to be immediately relevant for either particle physics or gravitation. The key result is that wide classes of theories lend themselves to an effective metric description. This observation provides further evidence that the notion of 'analogue gravity' is rather generic.
Quantum optics. Gravity meets quantum physics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Adams, Bernhard W.
2015-02-27
Albert Einstein’s general theory of relativity is a classical formulation but a quantum mechanical description of gravitational forces is needed, not only to investigate the coupling of classical and quantum systems but simply to give a more complete description of our physical surroundings. In this issue of Nature Photonics, Wen-Te Liao and Sven Ahrens reveal a link between quantum and gravitational physics. They propose that in the quantum-optical effect of superradiance, the world line of electromagnetic radiation is changed by the presence of a gravitational field.
Statistical effects in large N supersymmetric gauge theories
NASA Astrophysics Data System (ADS)
Czech, Bartlomiej Stanislaw
This thesis discusses statistical simplifications arising in supersymmetric gauge theories in the limit of large rank. Applications involve the physics of black holes and the problem of predicting the low energy effective theory from a landscape of string vacua. The first part of this work uses the AdS/CFT correspondence to explain properties of black holes. We establish that in the large charge sector of toric quiver gauge theories there exists a typical state whose structure is closely mimicked by almost all other states. Then, working in the settings of the half-BPS sector of N = 4 super-Yang-Mills theory, we show that in the dual gravity theory semiclassical observations cannot distinguish a pair of geometries corresponding to two generic heavy states. Finally, we argue on general grounds that these conclusions are exponentially enhanced in quantum cosmological settings. The results establish that one may consistently account for the entropy of a black hole with heavy states in the dual field theory and suggest that the usual properties of black holes arise as artifacts of imposing a semiclassical description on a quantum system. In the second half we develop new tools to determine the infrared behavior of quiver gauge theories in a certain class. We apply the dynamical results to a toy model of the landscape of effective field theories defined at some high energy scale, and derive firm statistical predictions for the low energy effective theory.
Ito, Tiffany A.; Henry, Erika A.; Cordova, Kismet A.; Bryan, Angela D.
2015-01-01
Opinions about marijuana use within the US are becoming increasingly favorable, making it important to understand how psychosocial influences impact individuals’ use within this context. Here we use the Theory of Planned Behavior (TPB) to examine the influence of initial attitudes, norms, and efficacy to resist use on initial intentions, and then the effect of initial intentions on actual marijuana use measured one year later using data drawn from a community with relatively high use. We expanded the traditional TPB model by investigating two types of normative influence (descriptive and injunctive) and two types of intentions (use intentions and proximity intentions), reasoning that exposure to high use in the population may produce high descriptive norms and proximity intentions overall, but not necessarily increase actual use. By contrast, we expected greater variability in injunctive norms and use intentions and that only use intentions would predict actual use. Consistent with hypotheses, intentions to use marijuana were predicted by injunctive norms (and attitudes) and in turn predicted marijuana use one year later. By contrast, descriptive norms were relatively high among all participants and did not predict intentions. Moreover, proximity intentions were not predictive of actual use. We also found that increasing intentions to use over a one year period predicted greater use. Given the greater efficacy of theory-based as compared to non-theory-based interventions, these findings provide critical information for the design of successful interventions to decrease marijuana-associated harms. PMID:26168227
Renormalization group evolution of the universal theories EFT
Wells, James D.; Zhang, Zhengkang
2016-06-21
The conventional oblique parameters analyses of precision electroweak data can be consistently cast in the modern framework of the Standard Model effective field theory (SMEFT) when restrictions are imposed on the SMEFT parameter space so that it describes universal theories. However, the usefulness of such analyses is challenged by the fact that universal theories at the scale of new physics, where they are matched onto the SMEFT, can flow to nonuniversal theories with renormalization group (RG) evolution down to the electroweak scale, where precision observables are measured. The departure from universal theories at the electroweak scale is not arbitrary, butmore » dictated by the universal parameters at the matching scale. But to define oblique parameters, and more generally universal parameters at the electroweak scale that directly map onto observables, additional prescriptions are needed for the treatment of RG-induced nonuniversal effects. Finally, we perform a RG analysis of the SMEFT description of universal theories, and discuss the impact of RG on simplified, universal-theories-motivated approaches to fitting precision electroweak and Higgs data.« less
Renormalization group evolution of the universal theories EFT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wells, James D.; Zhang, Zhengkang
The conventional oblique parameters analyses of precision electroweak data can be consistently cast in the modern framework of the Standard Model effective field theory (SMEFT) when restrictions are imposed on the SMEFT parameter space so that it describes universal theories. However, the usefulness of such analyses is challenged by the fact that universal theories at the scale of new physics, where they are matched onto the SMEFT, can flow to nonuniversal theories with renormalization group (RG) evolution down to the electroweak scale, where precision observables are measured. The departure from universal theories at the electroweak scale is not arbitrary, butmore » dictated by the universal parameters at the matching scale. But to define oblique parameters, and more generally universal parameters at the electroweak scale that directly map onto observables, additional prescriptions are needed for the treatment of RG-induced nonuniversal effects. Finally, we perform a RG analysis of the SMEFT description of universal theories, and discuss the impact of RG on simplified, universal-theories-motivated approaches to fitting precision electroweak and Higgs data.« less
Negative energy, superluminosity, and holography
NASA Astrophysics Data System (ADS)
Polchinski, Joseph; Susskind, Leonard; Toumbas, Nicolaos
1999-10-01
The holographic connection between large N super Yang-Mills (SYM) theory and gravity in anti-de Sitter (AdS) space requires unfamiliar behavior of the SYM theory in the limit that the curvature of the AdS geometry becomes small. The paradoxical behavior includes superluminal oscillations and negative energy density. These effects typically occur in the SYM description of events which take place far from the boundary of AdS when the signal from the event arrives at the boundary. The paradoxes can be resolved by assuming a very rich collection of hidden degrees of freedom of the SYM theory which store information but give rise to no local energy density. These degrees of freedom, called precursors, are needed to make possible sudden apparently acausal energy momentum flows. Such behavior would be impossible in classical field theory as a consequence of the positivity of the energy density. However we show that these effects are not only allowed in quantum field theory but that we can model them in free quantum field theory.
A meta-analysis of the relations between three types of peer norms and adolescent sexual behavior
van de Bongardt, Daphne; Reitz, Ellen; Sandfort, Theo; Deković, Maja
2018-01-01
The aim of the present meta-analysis was to investigate the associations between three types of peer norms–descriptive norms (peer sexual behaviors), injunctive norms (peer sexual attitudes), and peer pressure to have sex–and two adolescent sexual behavior outcomes (sexual activity and sexual risk behavior). Adolescent sexual activity was more strongly associated with descriptive norms (ESrfixed = .40) than with injunctive norms (ESrfixed = .22) or peer pressure (ESrfixed = .10). Compared with the sexual activity outcome, the effect size for descriptive norms (peer sexual risk behavior) for sexual risk behavior was smaller (ESrfixed = .11). Age, gender, peer type, and socio-cultural context significantly moderated these associations. Additional analyses of longitudinal studies suggested that selection effects were stronger than socialization effects. These findings offer empirical support for the conceptual distinction between three types of peer norms and hold important implications for theory, research, and intervention strategies. PMID:25217363
Regulating Emotional Responses to Climate Change – A Construal Level Perspective
Ejelöv, Emma; Hansla, André; Bergquist, Magnus; Nilsson, Andreas
2018-01-01
This experimental study (N = 139) examines the role of emotions in climate change risk communication. Drawing on Construal Level Theory, we tested how abstract vs. concrete descriptions of climate threat affect basic and self-conscious emotions and three emotion regulation strategies: changing oneself, repairing the situation and distancing oneself. In a 2 × 2 between subjects factorial design, climate change consequences were described as concrete/abstract and depicted as spatially proximate/distant. Results showed that, as hypothesized, increased self-conscious emotions mediate overall positive effects of abstract description on self-change and repair attempts. Unexpectedly and independent of any emotional process, a concrete description of a spatially distant consequence is shown to directly increase self-change and repair attempts, while it has no such effects when the consequence is spatially proximate. “Concretizing the remote” might refer to a potentially effective strategy for overcoming spatial distance barriers and motivating mitigating behavior. PMID:29780340
Regulating Emotional Responses to Climate Change - A Construal Level Perspective.
Ejelöv, Emma; Hansla, André; Bergquist, Magnus; Nilsson, Andreas
2018-01-01
This experimental study ( N = 139) examines the role of emotions in climate change risk communication. Drawing on Construal Level Theory, we tested how abstract vs. concrete descriptions of climate threat affect basic and self-conscious emotions and three emotion regulation strategies: changing oneself, repairing the situation and distancing oneself. In a 2 × 2 between subjects factorial design, climate change consequences were described as concrete/abstract and depicted as spatially proximate/distant. Results showed that, as hypothesized, increased self-conscious emotions mediate overall positive effects of abstract description on self-change and repair attempts. Unexpectedly and independent of any emotional process, a concrete description of a spatially distant consequence is shown to directly increase self-change and repair attempts, while it has no such effects when the consequence is spatially proximate. "Concretizing the remote" might refer to a potentially effective strategy for overcoming spatial distance barriers and motivating mitigating behavior.
Development of the Lunar and Solar Perturbations in the Motion of an Artificial Satellite
NASA Technical Reports Server (NTRS)
Musen, P.; Bailie, A.; Upton, E.
1961-01-01
Problems relating to the influence of lunar and solar perturbations on the motion of artificial satellites are analyzed by an extension of Cayley's development of the perturbative function in the lunar theory. In addition, the results are modified for incorporation into the Hansen-type theory used by the NASA Space Computing Center. The theory is applied to the orbits of the Vanguard I and Explorer VI satellites, and the results of detailed computations for these satellites are given together with a physical description of the perturbations in terms of resonance effects.
A description of the mechanical behavior of composite solid propellants based on molecular theory
NASA Technical Reports Server (NTRS)
Landel, R. F.
1976-01-01
Both the investigation and the representation of the stress-strain response (including rupture) of gum and filled elastomers can be based on a simple functional statement. Internally consistent experiments are used to sort out the effects of time, temperature, strain and crosslink density on gum rubbers. All effects are readily correlated and shown to be essentially independent of the elastomer when considered in terms of non-dimensionalized stress, strain and time. A semiquantitative molecular theory is developed to explain this result. The introduction of fillers modifies the response, but, guided by the framework thus provided, their effects can be readily accounted for.
Hemispheric Dissociation and Dyslexia in a Computational Model of Reading
ERIC Educational Resources Information Center
Monaghan, Padraic; Shillcock, Richard
2008-01-01
There are several causal explanations for dyslexia, drawing on distinctions between dyslexics and control groups at genetic, biological, or cognitive levels of description. However, few theories explicitly bridge these different levels of description. In this paper, we review a long-standing theory that some dyslexics' reading impairments are due…
Tretyakov, Nikita; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen; Dünweg, Burkhard; Daoulas, Kostas Ch
2016-10-07
Classical density functional theory is applied to investigate the validity of a phenomenological force-balance description of the stability of the Cassie state of liquids on substrates with nanoscale corrugation. A bulk free-energy functional of third order in local density is combined with a square-gradient term, describing the liquid-vapor interface. The bulk free energy is parameterized to reproduce the liquid density and the compressibility of water. The square-gradient term is adjusted to model the width of the water-vapor interface. The substrate is modeled by an external potential, based upon the Lennard-Jones interactions. The three-dimensional calculation focuses on substrates patterned with nanostripes and square-shaped nanopillars. Using both the force-balance relation and density-functional theory, we locate the Cassie-to-Wenzel transition as a function of the corrugation parameters. We demonstrate that the force-balance relation gives a qualitatively reasonable description of the transition even on the nanoscale. The force balance utilizes an effective contact angle between the fluid and the vertical wall of the corrugation to parameterize the impalement pressure. This effective angle is found to have values smaller than the Young contact angle. This observation corresponds to an impalement pressure that is smaller than the value predicted by macroscopic theory. Therefore, this effective angle embodies effects specific to nanoscopically corrugated surfaces, including the finite range of the liquid-solid potential (which has both repulsive and attractive parts), line tension, and the finite interface thickness. Consistently with this picture, both patterns (stripes and pillars) yield the same effective contact angles for large periods of corrugation.
Stationary and non-stationary nonlinear optical spectroscopy on surface polaritons
NASA Technical Reports Server (NTRS)
Ponath, H. E.
1984-01-01
A phenomenological theory is given for non-stationary electromagnetic surface waves propagating along the boundary plane between two homogeneous isotropic media. The description of nonlinear optical effects using shortened wave equations is demonstrated for spontaneous and simulated Raman scattering processes on surface polaritons.
History and Quasi-History in Physics Education - Part 2.
ERIC Educational Resources Information Center
Whitaker, M. A. B.
1979-01-01
Examines how quasi-history, by eliminating the social dimension, distorts its description of major scientific advances in one of two distinct ways; either almost trivial or almost mystical. Uses two examples, Einstein's theory of the photoelectric effect and Planck's discovery of his law. (GA)
Garnett, Claire; Crane, David; Brown, Jamie; Kaner, Eileen; Beyer, Fiona; Muirhead, Colin; Hickman, Matthew; Redmore, James; de Vocht, Frank; Beard, Emma; Michie, Susan
2018-02-28
Applying theory to the design and evaluation of interventions is likely to increase effectiveness and improve the evidence base from which future interventions are developed, though few interventions report this. The aim of this paper was to assess how digital interventions to reduce hazardous and harmful alcohol consumption report the use of theory in their development and evaluation, and whether reporting of theory use is associated with intervention effectiveness. Randomized controlled trials were extracted from a Cochrane review on digital interventions for reducing hazardous and harmful alcohol consumption. Reporting of theory use within these digital interventions was investigated using the theory coding scheme (TCS). Reported theory use was analyzed by frequency counts and descriptive statistics. Associations were analyzed with meta-regression models. Of 41 trials involving 42 comparisons, half did not mention theory (50% [21/42]), and only 38% (16/42) used theory to select or develop the intervention techniques. Significant heterogeneity existed between studies in the effect of interventions on alcohol reduction (I 2 =77.6%, P<.001). No significant associations were detected between reporting of theory use and intervention effectiveness in unadjusted models, though the meta-regression was underpowered to detect modest associations. Digital interventions offer a unique opportunity to refine and develop new dynamic, temporally sensitive theories, yet none of the studies reported refining or developing theory. Clearer selection, application, and reporting of theory use is needed to accurately assess how useful theory is in this field and to advance the field of behavior change theories. ©Claire Garnett, David Crane, Jamie Brown, Eileen Kaner, Fiona Beyer, Colin Muirhead, Matthew Hickman, James Redmore, Frank de Vocht, Emma Beard, Susan Michie. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 28.02.2018.
Ziegler, Tom; Krykunov, Mykhaylo
2010-08-21
It is well known that time-dependent density functional theory (TD-DFT) based on standard gradient corrected functionals affords both a quantitative and qualitative incorrect picture of charge transfer transitions between two spatially separated regions. It is shown here that the well known failure can be traced back to the use of linear response theory. Further, it is demonstrated that the inclusion of higher order terms readily affords a qualitatively correct picture even for simple functionals based on the local density approximation. The inclusion of these terms is done within the framework of a newly developed variational approach to excitation energies called constrained variational density functional theory (CV-DFT). To second order [CV(2)-DFT] this theory is identical to adiabatic TD-DFT within the Tamm-Dancoff approximation. With inclusion of fourth order corrections [CV(4)-DFT] it affords a qualitative correct description of charge transfer transitions. It is finally demonstrated that the relaxation of the ground state Kohn-Sham orbitals to first order in response to the change in density on excitation together with CV(4)-DFT affords charge transfer excitations in good agreement with experiment. The new relaxed theory is termed R-CV(4)-DFT. The relaxed scheme represents an effective way in which to introduce double replacements into the description of single electron excitations, something that would otherwise require a frequency dependent kernel.
Strangeness S =-1 hyperon-nucleon scattering in covariant chiral effective field theory
NASA Astrophysics Data System (ADS)
Li, Kai-Wen; Ren, Xiu-Lei; Geng, Li-Sheng; Long, Bingwei
2016-07-01
Motivated by the successes of covariant baryon chiral perturbation theory in one-baryon systems and in heavy-light systems, we study relevance of relativistic effects in hyperon-nucleon interactions with strangeness S =-1 . In this exploratory work, we follow the covariant framework developed by Epelbaum and Gegelia to calculate the Y N scattering amplitude at leading order. By fitting the five low-energy constants to the experimental data, we find that the cutoff dependence is mitigated, compared with the heavy-baryon approach. Nevertheless, the description of the experimental data remains quantitatively similar at leading order.
Redistribution of resonance radiation. II - The effect of magnetic fields.
NASA Technical Reports Server (NTRS)
Omont, A.; Cooper, J.; Smith, E. W.
1973-01-01
Previously obtained results for scattering of radiation in the presence of collisions are restated in a density matrix formalism which employs an irreducible-tensor description of the radiation field. This formalism is particularly useful for problems associated with radiative transfer theory. The redistribution is then extended to include the effect of a weak magnetic field. By averaging over a finite bandwidth which is on the order of the Doppler width, simplified expressions of physical significance for the scattering in the Doppler core and the Lorentz wings are obtained. Expressions are also obtained for the corresponding source function of radiative transfer theory.
A superstring field theory for supergravity
NASA Astrophysics Data System (ADS)
Reid-Edwards, R. A.; Riccombeni, D. A.
2017-09-01
A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.
Can a Linear Sigma Model Describe Walking Gauge Theories at Low Energies?
NASA Astrophysics Data System (ADS)
Gasbarro, Andrew
2018-03-01
In recent years, many investigations of confining Yang Mills gauge theories near the edge of the conformal window have been carried out using lattice techniques. These studies have revealed that the spectrum of hadrons in nearly conformal ("walking") gauge theories differs significantly from the QCD spectrum. In particular, a light singlet scalar appears in the spectrum which is nearly degenerate with the PNGBs at the lightest currently accessible quark masses. This state is a viable candidate for a composite Higgs boson. Presently, an acceptable effective field theory (EFT) description of the light states in walking theories has not been established. Such an EFT would be useful for performing chiral extrapolations of lattice data and for serving as a bridge between lattice calculations and phenomenology. It has been shown that the chiral Lagrangian fails to describe the IR dynamics of a theory near the edge of the conformal window. Here we assess a linear sigma model as an alternate EFT description by performing explicit chiral fits to lattice data. In a combined fit to the Goldstone (pion) mass and decay constant, a tree level linear sigma model has a Χ2/d.o.f. = 0.5 compared to Χ2/d.o.f. = 29.6 from fitting nextto-leading order chiral perturbation theory. When the 0++ (σ) mass is included in the fit, Χ2/d.o.f. = 4.9. We remark on future directions for providing better fits to the σ mass.
A phenomenological description of space-time noise in quantum gravity.
Amelino-Camelia, G
2001-04-26
Space-time 'foam' is a geometric picture of the smallest size scales in the Universe, which is characterized mainly by the presence of quantum uncertainties in the measurement of distances. All quantum-gravity theories should predict some kind of foam, but the description of the properties of this foam varies according to the theory, thereby providing a possible means of distinguishing between such theories. I previously showed that foam-induced distance fluctuations would introduce a new source of noise to the measurements of gravity-wave interferometers, but the theories are insufficiently developed to permit detailed predictions that would be of use to experimentalists. Here I propose a phenomenological approach that directly describes space-time foam, and which leads naturally to a picture of distance fluctuations that is independent of the details of the interferometer. The only unknown in the model is the length scale that sets the overall magnitude of the effect, but recent data already rule out the possibility that this length scale could be identified with the 'string length' (10-34 m < Ls < 10-33 m). Length scales even smaller than the 'Planck length' (LP approximately 10-35 m) will soon be probed experimentally.
System Design Description for the TMAD Code
DOE Office of Scientific and Technical Information (OSTI.GOV)
Finfrock, S.H.
This document serves as the System Design Description (SDD) for the TMAD Code System, which includes the TMAD code and the LIBMAKR code. The SDD provides a detailed description of the theory behind the code, and the implementation of that theory. It is essential for anyone who is attempting to review or modify the code or who otherwise needs to understand the internal workings of the code. In addition, this document includes, in Appendix A, the System Requirements Specification for the TMAD System.
Lee, Hyo
2011-08-01
There are few studies investigating psychosocial mechanisms in Korean Americans' exercise behavior. The present study tested the usefulness of the theory of planned behavior in predicting Korean American's exercise behavior and whether the descriptive norm (i.e., perceptions of what others do) improved the predictive validity of the theory of planned behavior. Using a retrospective design and self-report measures, web-survey responses from 198 Korean-American adults were analyzed using hierarchical regression analyses. The theory of planned behavior constructs accounted for 31% of exercise behavior and 43% of exercise intention. Intention and perceived behavioral control were significant predictors of exercise behavior. Although the descriptive norm did not augment the theory of planned behavior, all original constructs--attitude, injunctive norm (a narrow definition of subjective norm), and perceived behavioral control--statistically significantly predicted leisure-time physical activity intention. Future studies should consider random sampling, prospective design, and objective measures of physical activity.
Lopes; Oden
1999-06-01
In recent years, descriptive models of risky choice have incorporated features that reflect the importance of particular outcome values in choice. Cumulative prospect theory (CPT) does this by inserting a reference point in the utility function. SP/A (security-potential/aspiration) theory uses aspiration level as a second criterion in the choice process. Experiment 1 compares the ability of the CPT and SP/A models to account for the same within-subjects data set and finds in favor of SP/A. Experiment 2 replicates the main finding of Experiment 1 in a between-subjects design. The final discussion brackets the SP/A result by showing the impact on fit of both decreasing and increasing the number of free parameters. We also suggest how the SP/A approach might be useful in modeling investment decision making in a descriptively more valid way and conclude with comments on the relation between descriptive and normative theories of risky choice. Copyright 1999 Academic Press.
Recent results and persisting problems in modeling flow induced coalescence
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fortelný, I., E-mail: fortelny@imc.cas.cz, E-mail: juza@imc.cas.cz; Jza, J., E-mail: fortelny@imc.cas.cz, E-mail: juza@imc.cas.cz
2014-05-15
The contribution summarizes recent results of description of the flow induced coalescence in immiscible polymer blends and addresses problems that call for which solving. The theory of coalescence based on the switch between equations for matrix drainage between spherical or deformed droplets provides a good agreement with more complicated modeling and available experimental data for probability, P{sub c}, that the collision of droplets will be followed by their fusion. A new equation for description of the matrix drainage between deformed droplets, applicable to the whole range of viscosity ratios, p, of the droplets and matrixes, is proposed. The theory facilitatesmore » to consider the effect of the matrix elasticity on coalescence. P{sub c} decreases with the matrix relaxation time but this decrease is not pronounced for relaxation times typical of most commercial polymers. Modeling of the flow induced coalescence in concentrated systems is needed for prediction of the dependence of coalescence rate on volume fraction of droplets. The effect of the droplet anisometry on P{sub c} should be studied for better understanding the coalescence in flow field with high and moderate deformation rates. A reliable description of coalescence in mixing and processing devices requires proper modeling of complex flow fields.« less
A fluid description of plasma double-layers
NASA Technical Reports Server (NTRS)
Levine, J. S.; Crawford, F. W.
1979-01-01
The space-charge double-layer that forms between two plasmas with different densities and thermal energies was investigated using three progressively realistic models which are treated by fluid theory, and take into account four species of particles: electrons and ions reflected by the double-layer, and electrons and ions transmitted through it. The two plasmas are assumed to be cold, and the self-consistent potential, electric field and space-charge distributions within the double-layer are determined. The effects of thermal velocities are taken into account for the reflected particles, and the modifications to the cold plasma solutions are established. Further modifications due to thermal velocities of the transmitted particles are examined. The applicability of a one dimensional fluid description, rather than plasma kinetic theory, is discussed. Theoretical predictions are compared with double layer potentials and lengths deduced from laboratory and space plasma experiments.
Lorentz- and CPT-symmetry studies in subatomic physics
NASA Astrophysics Data System (ADS)
Lehnert, Ralf
2016-12-01
Subatomic systems provide an exquisite test bench for spacetime symmetries. This work motivates such measurements, reviews the effective field theory test framework for the description of Lorentz and CPT violation, and employs this framework to study the phenomenology of spacetime-symmetry breaking in various subatomic systems.
ERIC Educational Resources Information Center
Sovik, Nils
1980-01-01
A description is given of an experiment investigating the applicability of a cybernetic theory in teaching children psychomotor skills. Results showed a learning effect in copying for younger subjects, in tracing for older subjects, and in tracking for all subjects. (GK)
Anero, Jesús G; Español, Pep; Tarazona, Pedro
2013-07-21
We present a generalization of Density Functional Theory (DFT) to non-equilibrium non-isothermal situations. By using the original approach set forth by Gibbs in his consideration of Macroscopic Thermodynamics (MT), we consider a Functional Thermo-Dynamics (FTD) description based on the density field and the energy density field. A crucial ingredient of the theory is an entropy functional, which is a concave functional. Therefore, there is a one to one connection between the density and energy fields with the conjugate thermodynamic fields. The connection between the three levels of description (MT, DFT, FTD) is clarified through a bridge theorem that relates the entropy of different levels of description and that constitutes a generalization of Mermin's theorem to arbitrary levels of description whose relevant variables are connected linearly. Although the FTD level of description does not provide any new information about averages and correlations at equilibrium, it is a crucial ingredient for the dynamics in non-equilibrium states. We obtain with the technique of projection operators the set of dynamic equations that describe the evolution of the density and energy density fields from an initial non-equilibrium state towards equilibrium. These equations generalize time dependent density functional theory to non-isothermal situations. We also present an explicit model for the entropy functional for hard spheres.
Non-Abelian Bosonization and Fractional Quantum Hall Transitions
NASA Astrophysics Data System (ADS)
Hui, Aaron; Mulligan, Michael; Kim, Eun-Ah
A fully satisfying theoretical description for the quantum phase transition between fractional quantum Hall plateaus remains an outstanding problem. Experiments indicate scaling exponents that are not readily obtained in conventional theories. Using insights from duality, we describe a class of quantum critical effective theories that produce qualitatively realistic scaling exponents for the transition. We discuss the implications of our results for the physically-relevant interactions controlling this broad class of quantum critical behavior. Supported by National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1650441.
Hartogsohn, Ido
2016-12-01
Placebo response theory and set and setting theory are two fields which examine how non-biological factors shape the response to therapy. Both consider factors such as expectancy, preparation and beliefs to be crucial for understanding the extra-pharmacological processes which shape the response to drugs. Yet there are also fundamental differences between the two theories. Set and setting concerns itself with response to psychoactive drugs only; placebo theory relates to all therapeutic interventions. Placebo theory is aimed at medical professionals; set and setting theory is aimed at professionals and drug users alike. Placebo theory is primarily descriptive, describing how placebo acts; set and setting theory is primarily prescriptive, educating therapists and users on how to control and optimize the effects of drugs. This paper examines how placebo theory and set and setting theory can complement and benefit each other, broadening our understanding of how non-biological factors shape response to drugs and other treatment interventions. © The Author(s) 2016.
NASA Astrophysics Data System (ADS)
Fiorini, Rodolfo A.; Dacquino, Gianfranco
2005-03-01
GEOGINE (GEOmetrical enGINE), a state-of-the-art OMG (Ontological Model Generator) based on n-D Tensor Invariants for n-Dimensional shape/texture optimal synthetic representation, description and learning, was presented in previous conferences elsewhere recently. Improved computational algorithms based on the computational invariant theory of finite groups in Euclidean space and a demo application is presented. Progressive model automatic generation is discussed. GEOGINE can be used as an efficient computational kernel for fast reliable application development and delivery in advanced biomedical engineering, biometric, intelligent computing, target recognition, content image retrieval, data mining technological areas mainly. Ontology can be regarded as a logical theory accounting for the intended meaning of a formal dictionary, i.e., its ontological commitment to a particular conceptualization of the world object. According to this approach, "n-D Tensor Calculus" can be considered a "Formal Language" to reliably compute optimized "n-Dimensional Tensor Invariants" as specific object "invariant parameter and attribute words" for automated n-Dimensional shape/texture optimal synthetic object description by incremental model generation. The class of those "invariant parameter and attribute words" can be thought as a specific "Formal Vocabulary" learned from a "Generalized Formal Dictionary" of the "Computational Tensor Invariants" language. Even object chromatic attributes can be effectively and reliably computed from object geometric parameters into robust colour shape invariant characteristics. As a matter of fact, any highly sophisticated application needing effective, robust object geometric/colour invariant attribute capture and parameterization features, for reliable automated object learning and discrimination can deeply benefit from GEOGINE progressive automated model generation computational kernel performance. Main operational advantages over previous, similar approaches are: 1) Progressive Automated Invariant Model Generation, 2) Invariant Minimal Complete Description Set for computational efficiency, 3) Arbitrary Model Precision for robust object description and identification.
ERIC Educational Resources Information Center
Temkin, Sanford
This dissertation begins with a description of some methods employed in making public-sector resource-allocation decisions, with conclusions on the appropriateness of each method for evaluating the ongoing programs of a school system. The second section has been rewritten and published as "A Comprehensive Theory of Cost-Effectiveness" (EA 002…
NASA Astrophysics Data System (ADS)
Aboona, Bassam; Holt, Jeremy
2017-09-01
Chiral effective field theory provides a modern framework for understanding the structure and dynamics of nuclear many-body systems. Recent works have had much success in applying the theory to describe the ground- and excited-state properties of light and medium-mass atomic nuclei when combined with ab initio numerical techniques. Our aim is to extend the application of chiral effective field theory to describe the nuclear equation of state required for supercomputer simulations of core-collapse supernovae. Given the large range of densities, temperatures, and proton fractions probed during stellar core collapse, microscopic calculations of the equation of state require large computational resources on the order of one million CPU hours. We investigate the use of graphics processing units (GPUs) to significantly reduce the computational cost of these calculations, which will enable a more accurate and precise description of this important input to numerical astrophysical simulations. Cyclotron Institute at Texas A&M, NSF Grant: PHY 1659847, DOE Grant: DE-FG02-93ER40773.
Theory of gas hydrates: effect of the approximation of rigid water lattice.
Pimpalgaonkar, Hrushikesh; Veesam, Shivanand K; Punnathanam, Sudeep N
2011-08-25
One of the assumptions of the van der Waals and Platteeuw theory for gas hydrates is that the host water lattice is rigid and not distorted by the presence of guest molecules. In this work, we study the effect of this approximation on the triple-point lines of the gas hydrates. We calculate the triple-point lines of methane and ethane hydrates via Monte Carlo molecular simulations and compare the simulation results with the predictions of van der Waals and Platteeuw theory. Our study shows that even if the exact intermolecular potential between the guest molecules and water is known, the dissociation temperatures predicted by the theory are significantly higher. This has serious implications to the modeling of gas hydrate thermodynamics, and in spite of the several impressive efforts made toward obtaining an accurate description of intermolecular interactions in gas hydrates, the theory will suffer from the problem of robustness if the issue of movement of water molecules is not adequately addressed. © 2011 American Chemical Society
2013-01-01
Objective Several physical activity interventions have been effective in improving the health outcomes of breast cancer survivors. However, few interventions have provided detailed descriptions regarding how such interventions work. To develop evidence-based practice in this field, detailed descriptions of intervention development and delivery is needed. This paper aims to (1) describe the theory-and evidence-based development of the Move More for Life program, a physical activity program for breast cancer survivors; and (2) serve as an exemplar for theory-based applied research. Method The program-planning model outlined by Kreuter and colleagues was used to develop the computer-tailored intervention. Results The tailoring guide developed by Kreuter and colleagues served as a useful program planning tool in terms of integrating theory and evidence-based best practice into intervention strategies. Overall, participants rated the intervention positively, with the majority reporting that the tailored materials caught their attention, were personally relevant to them, and were useful for helping them to change their behaviour. However, there was considerable room for improvement. Conclusion The Move More for Life program is an example of a theory-based, low-cost and potentially sustainable strategy to physical activity promotion and may stand as an exemplar for Social Cognitive Theory-based applied research. By providing a detailed description of the development of the Move More for Life program, a critical evaluation of the working mechanisms of the intervention is possible, and will guide researchers in the replication or adaption and re-application of the specified techniques. This has potential implications for researchers examining physical activity promotion among cancer survivors and for researchers exploring distance-based physical activity promotion techniques among other populations. Trial registrations Australian New Zealand Clinical Trials Registry (ANZCTR) identifier: ACTRN12611001061921. PMID:24192320
Behavior of Man in Health and Illness, Nursing 103A.
ERIC Educational Resources Information Center
Bakke, Sandra I.
A description is provided of a course, "Behavior of Man in Health and Illness," designed to introduce first-year undergraduate nursing students to the theories and concepts related to the health-illness continuum, the stress of illness, and coping theory. The description begins with an overview of course content, followed by information on the…
Emotional Intelligence: Theory and Description--A Competency Model for Interpersonal Effectiveness
ERIC Educational Resources Information Center
Kunnanatt, James Thomas
2008-01-01
Purpose: Despite the crucial role that emotional intelligence (EI) could play in improving individuals' performance and career prospects in organizations, employees, executives and career professionals across the world are still in search of practical frameworks for understanding the concept. This is because EI research outputs from academics…
Effects of the coupling of quasiparticle and collective vibrations on the properties of 120Sn
NASA Astrophysics Data System (ADS)
Vigezzi, Enrico
2018-03-01
Assuming quasiparticles and collective vibrations as fundamental modes of excitation and taking into account their interplay within the framework of Nuclear Field Theory, it is possible to give an accurate and comprehensive description of the low-energy spectrum of the superfluid nucleus 120Sn.
Dynamic Articulation of Vowels.
ERIC Educational Resources Information Center
Morgan, Willie B.
1979-01-01
A series of exercises and a theory of vowel descriptions can help minimize speakers' problems of excessive tension, awareness of tongue height, and tongue retraction. Eight exercises to provide Forward Facial Stretch neutralize tensions in the face and vocal resonator and their effect on the voice. Three experiments in which sounds are repeated…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hedegård, Erik Donovan, E-mail: erik.hedegard@phys.chem.ethz.ch; Knecht, Stefan; Reiher, Markus, E-mail: markus.reiher@phys.chem.ethz.ch
2015-06-14
We present a new hybrid multiconfigurational method based on the concept of range-separation that combines the density matrix renormalization group approach with density functional theory. This new method is designed for the simultaneous description of dynamical and static electron-correlation effects in multiconfigurational electronic structure problems.
Teacher Role Breadth and its Relationship to Student-Reported Teacher Support
ERIC Educational Resources Information Center
Phillippo, Kate L.; Stone, Susan
2013-01-01
This study capitalizes on a unique, nested data set comprised of students ("n" = 531) and teachers ("n" = 45) in three high schools that explicitly incorporated student support roles into teachers' job descriptions. Drawing from research on student-teacher relationships, teacher effects on student outcomes, and role theory,…
Time-domain self-consistent theory of frequency-locking regimes in gyrotrons with low-Q resonators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ginzburg, N. S., E-mail: ginzburg@appl.sci-nnov.ru; Nizhny Novgorod State University, 603950, gagarin av., 23, Nizhny Novgorod; Sergeev, A. S.
2015-03-15
A time-domain theory of frequency-locking gyrotron oscillators with low-Q resonators has been developed. The presented theory is based on the description of wave propagation by a parabolic equation taking into account the external signal by modification of boundary conditions. We show that the developed model can be effectively used for simulations of both single- and multi-mode operation regimes in gyrotrons driven by an external signal. For the case of low-Q resonators typical for powerful gyrotrons, the external signal can influence the axial field profile inside the interaction space significantly and, correspondingly, the value of the electron orbital efficiency.
Descriptions of carbon isotopes within the energy density functional theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ismail, Atef; Cheong, Lee Yen; Yahya, Noorhana
2014-10-24
Within the energy density functional (EDF) theory, the structure properties of Carbon isotopes are systematically studied. The shell model calculations are done for both even-A and odd-A nuclei, to study the structure of rich-neutron Carbon isotopes. The EDF theory indicates the single-neutron halo structures in {sup 15}C, {sup 17}C and {sup 19}C, and the two-neutron halo structures in {sup 16}C and {sup 22}C nuclei. It is also found that close to the neutron drip-line, there exist amazing increase in the neutron radii and decrease on the binding energies BE, which are tightly related with the blocking effect and correspondingly themore » blocking effect plays a significant role in the shell model configurations.« less
Learning Theory Foundations of Simulation-Based Mastery Learning.
McGaghie, William C; Harris, Ilene B
2018-06-01
Simulation-based mastery learning (SBML), like all education interventions, has learning theory foundations. Recognition and comprehension of SBML learning theory foundations are essential for thoughtful education program development, research, and scholarship. We begin with a description of SBML followed by a section on the importance of learning theory foundations to shape and direct SBML education and research. We then discuss three principal learning theory conceptual frameworks that are associated with SBML-behavioral, constructivist, social cognitive-and their contributions to SBML thought and practice. We then discuss how the three learning theory frameworks converge in the course of planning, conducting, and evaluating SBML education programs in the health professions. Convergence of these learning theory frameworks is illustrated by a description of an SBML education and research program in advanced cardiac life support. We conclude with a brief coda.
Spiky strings and single trace operators in gauge theories
NASA Astrophysics Data System (ADS)
Kruczenski, Martin
2005-08-01
We consider single trace operators of the form Script Ol1...ln = Tr D+l1F...D+lnF which are common to all gauge theories. We argue that, when all li are equal and large, they have a dual description as strings with cusps, or spikes, one for each field F. In the case of Script N = 4 SYM, we compute the energy as a function of angular momentum by finding the corresponding solutions in AdS5 and compare with a 1-loop calculation of the anomalous dimension. As in the case of two spikes (twist two operators), there is agreement in the functional form but not in the coupling constant dependence. After that, we analyze the system in more detail and find an effective classical mechanics describing the motion of the spikes. In the appropriate limit, it is the same (up to the coupling constant dependence) as the coherent state description of linear combinations of the operators Script Ol1...ln such that all li are equal on average. This agreement provides a map between the operators in the boundary and the position of the spikes in the bulk. We further suggest that moving the spikes in other directions should describe operators with derivatives other than D+ indicating that these ideas are quite generic and should help in unraveling the string description of the large-N limit of gauge theories.
Spontaneous parity violation and SUSY strong gauge theory
NASA Astrophysics Data System (ADS)
Haba, Naoyuki; Ohki, Hiroshi
2012-07-01
We suggest simple models of spontaneous parity violation in supersymmetric strong gauge theory. We focus on left-right symmetric model and investigate vacuum with spontaneous parity violation. Non-perturbative effects are calculable in supersymmetric gauge theory, and we suggest new models. Our models show confinement, so that we try to understand them by using a dual description of the theory. The left-right symmetry breaking and electroweak symmetry breaking are simultaneously occurred with the suitable energy scale hierarchy. This structure has several advantages compared to the MSSM. The scale of the Higgs mass (left-right breaking scale) and that of VEVs are different, so the SUSY little hierarchy problems are absent. The second model also induces spontaneous supersymmetry breaking [1].
Systemic Thinking in Career Development Theory: Contributions of the Systems Theory Framework
ERIC Educational Resources Information Center
McMahon, Mary; Patton, Wendy
2018-01-01
This article considers systemic thinking in relation to the Systems Theory Framework (STF) and to career theory. An overview of systems theory and its applications is followed by a discussion of career theory to provide a context for the subsequent description of STF. The contributions of STF to career theory and to theory integration are…
On the reach of perturbative descriptions for dark matter displacement fields
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baldauf, Tobias; Zaldarriaga, Matias; Schaan, Emmanuel, E-mail: baldauf@ias.edu, E-mail: eschaan@astro.princeton.edu, E-mail: matiasz@ias.edu
We study Lagrangian Perturbation Theory (LPT) and its regularization in the Effective Field Theory (EFT) approach. We evaluate the LPT displacement with the same phases as a corresponding N-body simulation, which allows us to compare perturbation theory to the non-linear simulation with significantly reduced cosmic variance, and provides a more stringent test than simply comparing power spectra. We reliably detect a non-vanishing leading order EFT coefficient and a stochastic displacement term, uncorrelated with the LPT terms. This stochastic term is expected in the EFT framework, and, to the best of our understanding, is not an artifact of numerical errors ormore » transients in our simulations. This term constitutes a limit to the accuracy of perturbative descriptions of the displacement field and its phases, corresponding to a 1% error on the non-linear power spectrum at k = 0.2 h{sup −1}Mpc at z = 0. Predicting the displacement power spectrum to higher accuracy or larger wavenumbers thus requires a model for the stochastic displacement.« less
Power counting and Wilsonian renormalization in nuclear effective field theory
NASA Astrophysics Data System (ADS)
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.
The Classical Theory of Light Colors: a Paradigm for Description of Particle Interactions
NASA Astrophysics Data System (ADS)
Mazilu, Nicolae; Agop, Maricel; Gatu, Irina; Iacob, Dan Dezideriu; Butuc, Irina; Ghizdovat, Vlad
2016-06-01
The color is an interaction property: of the interaction of light with matter. Classically speaking it is therefore akin to the forces. But while forces engendered the mechanical view of the world, the colors generated the optical view. One of the modern concepts of interaction between the fundamental particles of matter - the quantum chromodynamics - aims to fill the gap between mechanics and optics, in a specific description of strong interactions. We show here that this modern description of the particle interactions has ties with both the classical and quantum theories of light, regardless of the connection between forces and colors. In a word, the light is a universal model in the description of matter. The description involves classical Yang-Mills fields related to color.
Toward Predictive Theories of Nuclear Reactions Across the Isotopic Chart: Web Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Escher, J. E.; Blackmon, J.; Elster, C.
Recent years have seen exciting new developments and progress in nuclear structure theory, reaction theory, and experimental techniques, that allow us to move towards a description of exotic systems and environments, setting the stage for new discoveries. The purpose of the 5-week program was to bring together physicists from the low-energy nuclear structure and reaction communities to identify avenues for achieving reliable and predictive descriptions of reactions involving nuclei across the isotopic chart. The 4-day embedded workshop focused on connecting theory developments to experimental advances and data needs for astrophysics and other applications. Nuclear theory must address phenomena from laboratorymore » experiments to stellar environments, from stable nuclei to weakly-bound and exotic isotopes. Expanding the reach of theory to these regimes requires a comprehensive understanding of the reaction mechanisms involved as well as detailed knowledge of nuclear structure. A recurring theme throughout the program was the desire to produce reliable predictions rooted in either ab initio or microscopic approaches. At the same time it was recognized that some applications involving heavy nuclei away from stability, e.g. those involving fi ssion fragments, may need to rely on simple parameterizations of incomplete data for the foreseeable future. The goal here, however, is to subsequently improve and refine the descriptions, moving to phenomenological, then microscopic approaches. There was overarching consensus that future work should also focus on reliable estimates of errors in theoretical descriptions.« less
Simplified models vs. effective field theory approaches in dark matter searches
NASA Astrophysics Data System (ADS)
De Simone, Andrea; Jacques, Thomas
2016-07-01
In this review we discuss and compare the usage of simplified models and Effective Field Theory (EFT) approaches in dark matter searches. We provide a state of the art description on the subject of EFTs and simplified models, especially in the context of collider searches for dark matter, but also with implications for direct and indirect detection searches, with the aim of constituting a common language for future comparisons between different strategies. The material is presented in a form that is as self-contained as possible, so that it may serve as an introductory review for the newcomer as well as a reference guide for the practitioner.
Kinetic theory of coupled oscillators.
Hildebrand, Eric J; Buice, Michael A; Chow, Carson C
2007-02-02
We present an approach for the description of fluctuations that are due to finite system size induced correlations in the Kuramoto model of coupled oscillators. We construct a hierarchy for the moments of the density of oscillators that is analogous to the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy in the kinetic theory of plasmas and gases. To calculate the lowest order system size effect, we truncate this hierarchy at second order and solve the resulting closed equations for the two-oscillator correlation function around the incoherent state. We use this correlation function to compute the fluctuations of the order parameter, including the effect of transients, and compare this computation with numerical simulations.
Context retrieval and description benefits for recognition of unfamiliar faces.
Jones, Todd C; Robinson, Kealagh; Steel, Brenna C
2018-04-19
Describing unfamiliar faces during or immediately after their presentation in a study phase can produce better recognition memory performance compared with a view-only control condition. We treated descriptions as elaborative information that is part of the study context and investigated how context retrieval influences recognition memory. Following general dual-process theories, we hypothesized that recollection would be used to recall descriptions and that description recall would influence recognition decisions, including the level of recognition confidence. In four experiments description conditions produced higher hit rates and higher levels of recognition confidence than control conditions. Participants recalled descriptive content on some trials, and this context retrieval was linked to an increase in the recognition confidence level. Repeating study faces in description conditions increased recognition scores, recognition confidence level, and context retrieval. Estimates of recollection from Yonelinas' (1994) dual-process signal detection ROCs were, on average, very close to the measures of context recall. Description conditions also produced higher estimates of familiarity. Finally, we found evidence that participants engaged in description activity in some ostensibly view-only trials. An emphasis on the information participants use in making their recognition decisions can advance understanding on description effects when descriptions are part of the study trial context. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Relativistic viscoelastic fluid mechanics.
Fukuma, Masafumi; Sakatani, Yuho
2011-08-01
A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.
Relativistic viscoelastic fluid mechanics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fukuma, Masafumi; Sakatani, Yuho
2011-08-15
A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for themore » propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.« less
NASA Astrophysics Data System (ADS)
Kruk, D.; Earle, K. A.; Mielczarek, A.; Kubica, A.; Milewska, A.; Moscicki, J.
2011-12-01
A general theory of lineshapes in nuclear quadrupole resonance (NQR), based on the stochastic Liouville equation, is presented. The description is valid for arbitrary motional conditions (particularly beyond the valid range of perturbation approaches) and interaction strengths. It can be applied to the computation of NQR spectra for any spin quantum number and for any applied magnetic field. The treatment presented here is an adaptation of the "Swedish slow motion theory," [T. Nilsson and J. Kowalewski, J. Magn. Reson. 146, 345 (2000), 10.1006/jmre.2000.2125] originally formulated for paramagnetic systems, to NQR spectral analysis. The description is formulated for simple (Brownian) diffusion, free diffusion, and jump diffusion models. The two latter models account for molecular cooperativity effects in dense systems (such as liquids of high viscosity or molecular glasses). The sensitivity of NQR slow motion spectra to the mechanism of the motional processes modulating the nuclear quadrupole interaction is discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kavanagh, D.L.; Antchagno, M.J.; Egawa, E.K.
1960-12-31
Operating instructions are presented for DMM, a Remington Rand 1103A program using one-space-dimensional multigroup diffusion theory to calculate the reactivity or critical conditions and flux distribution of a multiregion reactor. Complete descriptions of the routines and problem input and output specifications are also included. (D.L.C.)
ERIC Educational Resources Information Center
Loise W., Chege; Wamocho, Franciscah I.; Orodho, John Aluko
2014-01-01
This study sought to find out the effects of Early Childhood Education on children with hearing impairment (HI). Vigotsky's theory of cognitive development guided the study. Descriptive survey method was used. Target population included children with HI between ages 3-6 years and their parents, teachers, head teachers all from special schools in…
Optical activity caused by torsion stresses: the case of NaBi(MoO4)2 crystals.
Vasylkiv, Yuriy; Kvasnyuk, Oleksiy; Shopa, Yaroslav; Vlokh, Rostyslav
2013-05-01
We have found that torsion mechanical stresses induce the optical rotation effect in centrosymmetric NaBi(MoO4)2 crystals. We have suggested a description of the effect on the basis of nonlocal linear elasticity theory. It has been shown that the induced optical gyration is proportional to the stress gradient appearing due to the torsion.
Integrability of the Ad{{S}_{5}}\\times {{S}^{5}} superstring and its deformations
NASA Astrophysics Data System (ADS)
van Tongeren, Stijn J.
2014-10-01
This article reviews the application of integrability to the spectral problem of strings on Ad{{S}5}× {{S}5} and its deformations. We begin with a pedagogical introduction to integrable field theories culminating in the description of their finite-volume spectra through the thermodynamic Bethe ansatz (TBA). Next, we apply these ideas to the Ad{{S}5}× {{S}5} string and in later sections discuss how to account for particular integrable deformations. Through the AdS/CFT correspondence this gives an exact description of anomalous scaling dimensions of single trace operators in planar N=4 supersymmetry Yang-Mills theory, its ‘orbifolds’, and β and γ-deformed supersymmetric Yang-Mills theory. We also touch upon some subtleties arising in these deformed theories. Furthermore, we consider complex excited states (bound states) in the su(2) sector and give their TBA description. Finally we discuss the TBA for a quantum deformation of the Ad{{S}5}× {{S}5} superstring S-matrix, with close relations to among others Pohlmeyer reduced string theory, and briefly indicate more recent developments in this area.
A Meta-Analysis of the Relations Between Three Types of Peer Norms and Adolescent Sexual Behavior.
van de Bongardt, Daphne; Reitz, Ellen; Sandfort, Theo; Deković, Maja
2015-08-01
The aim of the present meta-analysis was to investigate the associations between three types of peer norms-descriptive norms (peer sexual behaviors), injunctive norms (peer sexual attitudes), and peer pressure to have sex-and two adolescent sexual behavior outcomes (sexual activity and sexual risk behavior). Adolescent sexual activity was more strongly associated with descriptive norms (ESrfixed=.40) than with injunctive norms (ESrfixed=.22) or peer pressure (ESrfixed=.10). Compared with the sexual activity outcome, the effect size for descriptive norms (peer sexual risk behavior) for sexual risk behavior was smaller (ESrfixed=.11). Age, gender, peer type, and socio-cultural context significantly moderated these associations. Additional analyses of longitudinal studies suggested that selection effects were stronger than socialization effects. These findings offer empirical support for the conceptual distinction between three types of peer norms and hold important implications for theory, research, and intervention strategies. © 2014 by the Society for Personality and Social Psychology, Inc.
Nonsingular bouncing cosmology: Consistency of the effective description
NASA Astrophysics Data System (ADS)
Koehn, Michael; Lehners, Jean-Luc; Ovrut, Burt
2016-05-01
We explicitly confirm that spatially flat nonsingular bouncing cosmologies make sense as effective theories. The presence of a nonsingular bounce in a spatially flat universe implies a temporary violation of the null energy condition, which can be achieved through a phase of ghost condensation. We calculate the scale of strong coupling and demonstrate that the ghost-condensate bounce remains trustworthy throughout, and that all perturbation modes within the regime of validity of the effective description remain under control. For this purpose we require the perturbed action up to third order in perturbations, which we calculate in both flat and co-moving gauge—since these two gauges allow us to highlight different physical aspects. Our conclusion is that there exist healthy descriptions of nonsingular bouncing cosmologies providing a viable resolution of the big-bang singularities in cosmological models. Our results also suggest a variant of ekpyrotic cosmology, in which entropy perturbations are generated during the contracting phase, but are only converted into curvature perturbations after the bounce.
The slab geometry laser. I - Theory
NASA Technical Reports Server (NTRS)
Eggleston, J. M.; Kane, T. J.; Kuhn, K.; Byer, R. L.; Unternahrer, J.
1984-01-01
Slab geometry solid-state lasers offer significant performance improvements over conventional rod-geometry lasers. A detailed theoretical description of the thermal, stress, and beam-propagation characteristics of a slab laser is presented. The analysis includes consideration of the effects of the zig-zag optical path, which eliminates thermal and stress focusing and reduces residual birefringence.
Equivalence of Einstein and Jordan frames in quantized anisotropic cosmological models
NASA Astrophysics Data System (ADS)
Pandey, Sachin; Pal, Sridip; Banerjee, Narayan
2018-06-01
The present work shows that the mathematical equivalence of the Jordan frame and its conformally transformed version, the Einstein frame, so as far as Brans-Dicke theory is concerned, survives a quantization of cosmological models, arising as solutions to the Brans-Dicke theory. We work with the Wheeler-deWitt quantization scheme and take up quite a few anisotropic cosmological models as examples. We effectively show that the transformation from the Jordan to the Einstein frame is a canonical one and hence two frames furnish equivalent description of same physical scenario.
Expanding the Bethe/Gauge dictionary
NASA Astrophysics Data System (ADS)
Bullimore, Mathew; Kim, Hee-Cheol; Lukowski, Tomasz
2017-11-01
We expand the Bethe/Gauge dictionary between the XXX Heisenberg spin chain and 2d N = (2, 2) supersymmetric gauge theories to include aspects of the algebraic Bethe ansatz. We construct the wave functions of off-shell Bethe states as orbifold defects in the A-twisted supersymmetric gauge theory and study their correlation functions. We also present an alternative description of off-shell Bethe states as boundary conditions in an effective N = 4 supersymmetric quantum mechanics. Finally, we interpret spin chain R-matrices as correlation functions of Janus interfaces for mass parameters in the supersymmetric quantum mechanics.
Gravitational consequences of modern field theories
NASA Technical Reports Server (NTRS)
Horowitz, Gary T.
1989-01-01
Some gravitational consequences of certain extensions of Einstein's general theory of relativity are discussed. These theories are not alternative theories of gravity in the usual sense. It is assumed that general relativity is the appropriate description of all gravitational phenomena which were observed to date.
NASA Technical Reports Server (NTRS)
Callier, Frank M.; Desoer, Charles A.
1991-01-01
The aim of this book is to provide a systematic and rigorous access to the main topics of linear state-space system theory in both the continuous-time case and the discrete-time case; and the I/O description of linear systems. The main thrusts of the work are the analysis of system descriptions and derivations of their properties, LQ-optimal control, state feedback and state estimation, and MIMO unity-feedback systems.
Dynamical description of the fission process using the TD-BCS theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Scamps, Guillaume, E-mail: scamps@nucl.phys.tohoku.ac.jp; Simenel, Cédric; Lacroix, Denis
2015-10-15
The description of fission remains a challenge for nuclear microscopic theories. The time-dependent Hartree-Fock approach with BCS pairing is applied to study the last stage of the fission process. A good agreement is found for the one-body observables: the total kinetic energy and the average mass asymmetry. The non-physical dependence of two-body observables with the initial shape is discussed.
Constraints on tree-level higher order gravitational couplings in superstring theory.
Stieberger, Stephan
2011-03-18
We consider the scattering amplitudes of five and six gravitons at tree level in superstring theory. Their power series expansions in the Regge slope α' are analyzed through the order α'(8) showing some interesting constraints on higher order gravitational couplings in the effective superstring action such as the absence of R(5) terms. Furthermore, some transcendentality constraints on the coefficients of the nonvanishing couplings are observed: the absence of zeta values of even weight through the order α'(8) like the absence of ζ(2)ζ(3)R(6) terms. Our analysis is valid for any superstring background in any space-time dimension, which allows for a conformal field theory description.
Henri Wallon's Theory of Early Child Development: The Role of Emotions
Veer
1996-12-01
The present paper gives an account of part of the stage theory of early child development of the French theorist Henri Wallon (1879-1962). Unlike his contemporary Jean Piaget, Wallon concentrated his efforts upon a description of the child's emotional development and the role emotions play in establishing the bond between child and caregiver. The description of Wallon's stage theory is preceded by biographical information and a presentation of his methodological views. It is argued that Wallon's theory is unique in its focus, exerted influence upon theorists such as Lev Vygotsky, and is basically compatible with modern insights about the nature of child development and the growth of intersubjectivity.
Experimental validation of a quasi-steady theory for the flow through the glottis
NASA Astrophysics Data System (ADS)
Vilain, C. E.; Pelorson, X.; Fraysse, C.; Deverge, M.; Hirschberg, A.; Willems, J.
2004-09-01
In this paper a theoretical description of the flow through the glottis based on a quasi-steady boundary layer theory is presented. The Thwaites method is used to solve the von Kármán equations within the boundary layers. In practice this makes the theory much easier to use compared to Pohlhausen's polynomial approximations. This theoretical description is evaluated on the basis of systematic comparison with experimental data obtained under steady flow or unsteady (oscillating) flow without and with moving vocal folds. Results tend to show that the theory reasonably explains the measured data except when unsteady or viscous terms become predominant. This happens particularly during the collision of the vocal folds.
Testing rank-dependent utility theory for health outcomes.
Oliver, Adam
2003-10-01
Systematic violations of expected utility theory (EU) have been reported in the context of both money and health outcomes. Rank-dependent utility theory (RDU) is currently the most popular and influential alternative theory of choice under circumstances of risk. This paper reports a test of the descriptive performance of RDU compared to EU in the context of health. When one of the options is certain, violations of EU that can be explained by RDU are found. When both options are risky, no evidence that RDU is a descriptive improvement over EU is found, though this finding may be due to the low power of the tests. Copyright 2002 John Wiley & Sons, Ltd.
Josephson effects in a Bose–Einstein condensate of magnons
DOE Office of Scientific and Technical Information (OSTI.GOV)
Troncoso, Roberto E., E-mail: r.troncoso.c@gmail.com; Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago; Núñez, Álvaro S., E-mail: alnunez@dfi.uchile.cl
A phenomenological theory is developed, that accounts for the collective dynamics of a Bose–Einstein condensate of magnons. In terms of such description we discuss the nature of spontaneous macroscopic interference between magnon clouds, highlighting the close relation between such effects and the well known Josephson effects. Using those ideas, we present a detailed calculation of the Josephson oscillations between two magnon clouds, spatially separated in a magnonic Josephson junction. -- Highlights: •We presented a theory that accounts for the collective dynamics of a magnon-BEC. •We discuss the nature of macroscopic interference between magnon-BEC clouds. •We remarked the close relation betweenmore » the above phenomena and Josephson’s effect. •We remark the distinctive oscillations that characterize the Josephson oscillations.« less
Dynamical effects in x-ray absorption spectra of graphene and monolayered h -BN on Ni(111)
NASA Astrophysics Data System (ADS)
Rusz, J.; Preobrajenski, A. B.; Ng, May Ling; Vinogradov, N. A.; Mårtensson, N.; Wessely, O.; Sanyal, B.; Eriksson, O.
2010-02-01
We present first-principles calculations of x-ray absorption spectra of graphene and hexagonal BN monolayer on the Ni(111) substrate. Including dynamical core-hole screening effects according to the theory of Mahan-Nozières-de Dominics (MND) results in an overall good agreement with previously published experimental data and our new observations. This approach provides a unified first-principles description of the electronic structure and core excitations in the sp2 -bonded materials on metal surfaces and a better insight into the dynamics of screening effects. We demonstrate in particular that the observed spectral features of graphene and hexagonal BN can be well reproduced with the MND theory, and that they are determined by a delicate balance between initial and final-state effects.
The Effect of Descriptive Norms on Pregaming Frequency: Tests of Five Moderators.
Merrill, Jennifer E; Kenney, Shannon R; Carey, Kate B
2016-07-02
Pregaming is highly prevalent on college campuses and associated with heightened levels of intoxication and risk of alcohol consequences. However, research examining the correlates of pregaming behavior is limited. Descriptive norms (i.e., perceptions about the prevalence or frequency of a behavior) are reliable and comparatively strong predictors of general drinking behavior, with recent evidence indicating that they are also associated with pregaming. We tested the hypothesis that higher descriptive norms for pregaming frequency would be associated with personal pregaming frequency. We also tested whether this effect would be stronger in the context of several theory-based moderators: female gender, higher injunctive norms (i.e., perceptions of others' attitudes toward a particular behavior), a more positive attitude toward pregaming, a stronger sense of identification with the drinking habits of other students, and stronger social comparison tendencies. College student drinkers (N = 198, 63% female) participated in an online survey assessing frequency of pregaming, descriptive norms, and hypothesized moderators. A multiple regression model revealed that higher descriptive norms, a more positive attitude toward pregaming, and stronger peer identification were significantly associated with greater pregaming frequency among drinkers. However, no moderators of the association between descriptive norms and pregaming frequency were observed. Descriptive norms are robust predictors of pregaming behavior, for both genders and across levels of several potential moderators. Future research seeking to understand pregaming behavior should consider descriptive norms, as well as personal attitudes and identification with student peers, as targets of interventions designed to reduce pregaming.
Group field theories for all loop quantum gravity
NASA Astrophysics Data System (ADS)
Oriti, Daniele; Ryan, James P.; Thürigen, Johannes
2015-02-01
Group field theories represent a second quantized reformulation of the loop quantum gravity state space and a completion of the spin foam formalism. States of the canonical theory, in the traditional continuum setting, have support on graphs of arbitrary valence. On the other hand, group field theories have usually been defined in a simplicial context, thus dealing with a restricted set of graphs. In this paper, we generalize the combinatorics of group field theories to cover all the loop quantum gravity state space. As an explicit example, we describe the group field theory formulation of the KKL spin foam model, as well as a particular modified version. We show that the use of tensor model tools allows for the most effective construction. In order to clarify the mathematical basis of our construction and of the formalisms with which we deal, we also give an exhaustive description of the combinatorial structures entering spin foam models and group field theories, both at the level of the boundary states and of the quantum amplitudes.
Density functional theory for open-shell singlet biradicals
NASA Astrophysics Data System (ADS)
Gräfenstein, Jürgen; Kraka, Elfi; Cremer, Dieter
1998-05-01
The description of open-shell singlet (OSS) σ- π biradicals by density functional theory (DFT) requires at least a two-configurational (TC) or, in general, a MC-DFT approach, which bears many unsolved problems. These can be avoided by reformulating the TC description in the spirit of restricted open shell theory for singlets (ROSS) and developing an exchange-correlation functional for ROSS-DFT. ROSS-DFT turns out to lead to reliable descriptions of geometry and vibrational frequencies for OSS biradicals. The relative energies of the OSS states obtained at the ROSS-B3LYP/6-311G(d,p) level are often better than the corresponding ROSS-MP2 results. However, in those cases where spin polarization in a conjugated π systems plays a role, DFT predicts the triplet state related to the OSS state 2-4 kcal/mol too stable.
Quantum theory as plausible reasoning applied to data obtained by robust experiments.
De Raedt, H; Katsnelson, M I; Michielsen, K
2016-05-28
We review recent work that employs the framework of logical inference to establish a bridge between data gathered through experiments and their objective description in terms of human-made concepts. It is shown that logical inference applied to experiments for which the observed events are independent and for which the frequency distribution of these events is robust with respect to small changes of the conditions under which the experiments are carried out yields, without introducing any concept of quantum theory, the quantum theoretical description in terms of the Schrödinger or the Pauli equation, the Stern-Gerlach or Einstein-Podolsky-Rosen-Bohm experiments. The extraordinary descriptive power of quantum theory then follows from the fact that it is plausible reasoning, that is common sense, applied to reproducible and robust experimental data. © 2016 The Author(s).
NASA Astrophysics Data System (ADS)
Pavlos, George P.
2017-12-01
In this study, we present the highlights of complexity theory (Part I) and significant experimental verifications (Part II) and we try to give a synoptic description of complexity theory both at the microscopic and at the macroscopic level of the physical reality. Also, we propose that the self-organization observed macroscopically is a phenomenon that reveals the strong unifying character of the complex dynamics which includes thermodynamical and dynamical characteristics in all levels of the physical reality. From this point of view, macroscopical deterministic and stochastic processes are closely related to the microscopical chaos and self-organization. The scientific work of scientists such as Wilson, Nicolis, Prigogine, Hooft, Nottale, El Naschie, Castro, Tsallis, Chang and others is used for the development of a unified physical comprehension of complex dynamics from the microscopic to the macroscopic level. Finally, we provide a comprehensive description of the novel concepts included in the complexity theory from microscopic to macroscopic level. Some of the modern concepts that can be used for a unified description of complex systems and for the understanding of modern complexity theory, as it is manifested at the macroscopic and the microscopic level, are the fractal geometry and fractal space-time, scale invariance and scale relativity, phase transition and self-organization, path integral amplitudes, renormalization group theory, stochastic and chaotic quantization and E-infinite theory, etc.
Variation and Linguistic Theory.
ERIC Educational Resources Information Center
Bailey, Charles-James N.
This volume presents principles and models for describing language variation, and introduces a time-based, dynamic framework for linguistic description. The book first summarizes some of the problems of grammatical description encountered from Saussure through the present and then outlines possibilities for new descriptions of language which take…
Reclaiming Deviance as a Unique Course from Criminology: Revisited.
ERIC Educational Resources Information Center
Kunkel, Karl R.
1999-01-01
Advocates separating the curriculum of deviance from criminological theory. Offers descriptions of a deviance course (introductory material, theories and issues in rule-making, and understanding rule-breaking behavior) and a criminological theory course (introductory discussion, theory focusing on the individual and social context, and critical…
Yanai, Takeshi; Kurashige, Yuki; Neuscamman, Eric; Chan, Garnet Kin-Lic
2010-01-14
We describe the joint application of the density matrix renormalization group and canonical transformation theory to multireference quantum chemistry. The density matrix renormalization group provides the ability to describe static correlation in large active spaces, while the canonical transformation theory provides a high-order description of the dynamic correlation effects. We demonstrate the joint theory in two benchmark systems designed to test the dynamic and static correlation capabilities of the methods, namely, (i) total correlation energies in long polyenes and (ii) the isomerization curve of the [Cu(2)O(2)](2+) core. The largest complete active spaces and atomic orbital basis sets treated by the joint DMRG-CT theory in these systems correspond to a (24e,24o) active space and 268 atomic orbitals in the polyenes and a (28e,32o) active space and 278 atomic orbitals in [Cu(2)O(2)](2+).
Scalar-tensor extension of the ΛCDM model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Algoner, W.C.; Velten, H.E.S.; Zimdahl, W., E-mail: w.algoner@cosmo-ufes.org, E-mail: velten@pq.cnpq.br, E-mail: winfried.zimdahl@pq.cnpq.br
2016-11-01
We construct a cosmological scalar-tensor-theory model in which the Brans-Dicke type scalar Φ enters the effective (Jordan-frame) Hubble rate as a simple modification of the Hubble rate of the ΛCDM model. This allows us to quantify differences between the background dynamics of scalar-tensor theories and general relativity (GR) in a transparent and observationally testable manner in terms of one single parameter. Problems of the mapping of the scalar-field degrees of freedom on an effective fluid description in a GR context are discused. Data from supernovae, the differential age of old galaxies and baryon acoustic oscillations are shown to strongly limitmore » potential deviations from the standard model.« less
NASA Astrophysics Data System (ADS)
Cremer, Dieter
The electron correlation effects covered by density functional theory (DFT) can be assessed qualitatively by comparing DFT densities ρ(r) with suitable reference densities obtained with wavefunction theory (WFT) methods that cover typical electron correlation effects. The analysis of difference densities ρ(DFT)-ρ(WFT) reveals that LDA and GGA exchange (X) functionals mimic non-dynamic correlation effects in an unspecified way. It is shown that these long range correlation effects are caused by the self-interaction error (SIE) of standard X functionals. Self-interaction corrected (SIC) DFT exchange gives, similar to exact exchange, for the bonding region a delocalized exchange hole, and does not cover any correlation effects. Hence, the exchange SIE is responsible for the fact that DFT densities often resemble MP4 or MP2 densities. The correlation functional changes X-only DFT densities in a manner observed when higher order coupling effects between lower order N-electron correlation effects are included. Hybrid functionals lead to changes in the density similar to those caused by SICDFT, which simply reflects the fact that hybrid functionals have been developed to cover part of the SIE and its long range correlation effects in a balanced manner. In the case of spin-unrestricted DFT (UDFT), non-dynamic electron correlation effects enter the calculation both via the X functional and via the wavefunction, which may cause a double-counting of correlation effects. The use of UDFT in the form of permuted orbital and broken-symmetry DFT (PO-UDFT, BS-UDFT) can lead to reasonable descriptions of multireference systems provided certain conditions are fulfilled. More reliable, however, is a combination of DFT and WFT methods, which makes the routine description of multireference systems possible. The development of such methods implies a separation of dynamic and non-dynamic correlation effects. Strategies for accomplishing this goal are discussed in general and tested in practice for CAS (complete active space)-DFT.
Some Remarks on Knowledge and Probability Arising from Counterfactual Quantum Effects
NASA Astrophysics Data System (ADS)
Lupacchini, Rossella
Can the mere possibility of a physical phenomenon affect the outcome of an experiment? In fact quantum theory presents us actual physical effects arising from "counterfactuals", that is physical effects brought about by things that might have happened, although they did not happen. How can it be? After a short outline of the quantum-mechanical description of physical reality, the occurrence of such counterfactual effects in quantum theory is illustrated by means of a Mach-Zehnder interferometer. Then these paradoxical phenomena undermining the very notion of physical event and questioning about which knowledge of physical reality can ever be obtained will be analysed using a classical possible-worlds model of knowledge and probability. Finally, a surprising application of counterfactual quantum effects producing a new kind of computing with no classical analogue will be shown.
Introducing older people to the theory of gerotranscendence.
Wadensten, Barbro
2005-11-01
This paper reports a study whose aims were to introduce the theory of gerotranscendence to a group of older people; to give participants in the group an opportunity to discuss their ageing process; to study how participants described their ageing in relation to the theory; and to gather participants' opinions about discussing their ageing in a group. The theory of gerotranscendence states that human development is a process extending into old age. Guidelines had previously been derived for its practical use in the care of older people, aiming to promote their development towards gerotranscendence. A qualitative descriptive approach was taken, and older people were invited to participate in group sessions at a day centre. At the sessions, participants discussed their ageing, and a video presentation about the theory of gerotranscendence was shown at one of the sessions. They were encouraged to discuss the description of the ageing process presented in the video and to link this to their own experiences of growing old. The discussion in each session was tape-recorded and transcribed verbatim. Data were analysed and categorized using qualitative methods. The data were collected in 2002. All women had an experience of ageing that was in some way in line with the theory's description, and they more or less agreed that this description of ageing was in accordance with their own ageing. They considered that it was interesting and fruitful to discuss ageing in a group. They felt that introduction of the view of ageing offered by the theory of gerotranscendence was beneficial because it gave them a more positive view of ageing which also allowed them to be as they were. It is possible to arrange this type of group activity for older people, resulting in possibilities to use aspects of the theory of gerotranscendence as an intervention in gerontological nursing.
Nigbur, Dennis; Lyons, Evanthia; Uzzell, David
2010-06-01
In an effort to contribute to greater understanding of norms and identity in the theory of planned behaviour, an extended model was used to predict residential kerbside recycling, with self-identity, personal norms, neighbourhood identification, and injunctive and descriptive social norms as additional predictors. Data from a field study (N=527) using questionnaire measures of predictor variables and an observational measure of recycling behaviour supported the theory. Intentions predicted behaviour, while attitudes, perceived control, and the personal norm predicted intention to recycle. The interaction between neighbourhood identification and injunctive social norms in turn predicted personal norms. Self-identity and the descriptive social norm significantly added to the original theory in predicting intentions as well as behaviour directly. A replication survey on the self-reported recycling behaviours of a random residential sample (N=264) supported the model obtained previously. These findings offer a useful extension of the theory of planned behaviour and some practicable suggestions for pro-recycling interventions. It may be productive to appeal to self-identity by making people feel like recyclers, and to stimulate both injunctive and descriptive norms in the neighbourhood.
de Nooijer, Jascha; Onnink, Monique; van Assema, Patricia
2010-08-01
In the Netherlands, a supplementation of 10 microg vitamin D is recommended for children (aged 0-4 years), given that vitamin D contributes to the development of healthy bones and deficiency during childhood is a risk factor for osteoporosis at a later age. However, only 60 % of the Dutch children receive sufficient vitamin D supplementation a day. In order to develop interventions to improve supplementation intake, it is necessary to gain insight into the behaviour of parents in giving their children vitamin D supplementation and its association with variables of the Theory of Planned Behaviour, moral and descriptive norms and habits. A cross-sectional survey to assess present supplementation-related behaviour, knowledge, received information, intention, attitude, subjective norm, perceived behavioural control, moral norm, descriptive norm and habit. Data obtained from a representative Internet Panel by means of electronic questionnaires. Parents (n 270) of children aged 0-4 years. Half of the parents (48.9 %) gave their child sufficient vitamin D supplementation. Giving the supplement at a fixed time, a positive intention and habit were significantly associated with actual behaviour. The higher age of the child, first-born status, a fixed time for taking vitamin supplementation, descriptive norm and moral obligation were significantly associated with intention. These results indicate that because many parents do not give their children adequate vitamin D supplementation, the promotion of supplementation during the first years of life is a necessity. Effective yet simple strategies should be developed, focused on improving moral obligation, descriptive norms and habit formation.
Janiszewski, Stefan; Karch, Andreas
2013-02-22
We argue that generic nonrelativistic quantum field theories with a holographic description are dual to Hořava gravity. We construct explicit examples of this duality embedded in string theory by starting with relativistic dual pairs and taking a nonrelativistic scaling limit.
New Paradoxes of Risky Decision Making
ERIC Educational Resources Information Center
Birnbaum, Michael H.
2008-01-01
During the last 25 years, prospect theory and its successor, cumulative prospect theory, replaced expected utility as the dominant descriptive theories of risky decision making. Although these models account for the original Allais paradoxes, 11 new paradoxes show where prospect theories lead to self-contradiction or systematic false predictions.…
Paradigms and Plastic Facts in the History of Valence.
ERIC Educational Resources Information Center
Zavaleta, David
1988-01-01
Traces the development of bonding theory and notes the influence of preconceived theory upon this development. Considers ideas of alchemy, Newton, Dalton, Lewis, and quantum mechanics. Suggests a move away from conservative descriptive approaches of bonding theory. (ML)
String Theory: Big Problem for Small Size
ERIC Educational Resources Information Center
Sahoo, S.
2009-01-01
String theory is the most promising candidate theory for a unified description of all the fundamental forces that exist in nature. It provides a mathematical framework that combines quantum theory with Einstein's general theory of relativity. The typical size of a string is of the order of 10[superscript -33] cm, called the Planck length. But due…
Antipov, Sergey V; Bhattacharyya, Swarnendu; El Hage, Krystel; Xu, Zhen-Hao; Meuwly, Markus; Rothlisberger, Ursula; Vaníček, Jiří
2017-11-01
Several strategies for simulating the ultrafast dynamics of molecules induced by interactions with electromagnetic fields are presented. After a brief overview of the theory of molecule-field interaction, we present several representative examples of quantum, semiclassical, and classical approaches to describe the ultrafast molecular dynamics, including the multiconfiguration time-dependent Hartree method, Bohmian dynamics, local control theory, semiclassical thawed Gaussian approximation, phase averaging, dephasing representation, molecular mechanics with proton transfer, and multipolar force fields. In addition to the general overview, some focus is given to the description of nuclear quantum effects and to the direct dynamics, in which the ab initio energies and forces acting on the nuclei are evaluated on the fly. Several practical applications, performed within the framework of the Swiss National Center of Competence in Research "Molecular Ultrafast Science and Technology," are presented: These include Bohmian dynamics description of the collision of H with H 2 , local control theory applied to the photoinduced ultrafast intramolecular proton transfer, semiclassical evaluation of vibrationally resolved electronic absorption, emission, photoelectron, and time-resolved stimulated emission spectra, infrared spectroscopy of H-bonding systems, and multipolar force fields applications in the condensed phase.
Dynamics of heterogeneous oscillator ensembles in terms of collective variables
NASA Astrophysics Data System (ADS)
Pikovsky, Arkady; Rosenblum, Michael
2011-04-01
We consider general heterogeneous ensembles of phase oscillators, sine coupled to arbitrary external fields. Starting with the infinitely large ensembles, we extend the Watanabe-Strogatz theory, valid for identical oscillators, to cover the case of an arbitrary parameter distribution. The obtained equations yield the description of the ensemble dynamics in terms of collective variables and constants of motion. As a particular case of the general setup we consider hierarchically organized ensembles, consisting of a finite number of subpopulations, whereas the number of elements in a subpopulation can be both finite or infinite. Next, we link the Watanabe-Strogatz and Ott-Antonsen theories and demonstrate that the latter one corresponds to a particular choice of constants of motion. The approach is applied to the standard Kuramoto-Sakaguchi model, to its extension for the case of nonlinear coupling, and to the description of two interacting subpopulations, exhibiting a chimera state. With these examples we illustrate that, although the asymptotic dynamics can be found within the framework of the Ott-Antonsen theory, the transients depend on the constants of motion. The most dramatic effect is the dependence of the basins of attraction of different synchronous regimes on the initial configuration of phases.
Antipov, Sergey V.; Bhattacharyya, Swarnendu; El Hage, Krystel; Xu, Zhen-Hao; Meuwly, Markus; Rothlisberger, Ursula; Vaníček, Jiří
2018-01-01
Several strategies for simulating the ultrafast dynamics of molecules induced by interactions with electromagnetic fields are presented. After a brief overview of the theory of molecule-field interaction, we present several representative examples of quantum, semiclassical, and classical approaches to describe the ultrafast molecular dynamics, including the multiconfiguration time-dependent Hartree method, Bohmian dynamics, local control theory, semiclassical thawed Gaussian approximation, phase averaging, dephasing representation, molecular mechanics with proton transfer, and multipolar force fields. In addition to the general overview, some focus is given to the description of nuclear quantum effects and to the direct dynamics, in which the ab initio energies and forces acting on the nuclei are evaluated on the fly. Several practical applications, performed within the framework of the Swiss National Center of Competence in Research “Molecular Ultrafast Science and Technology,” are presented: These include Bohmian dynamics description of the collision of H with H2, local control theory applied to the photoinduced ultrafast intramolecular proton transfer, semiclassical evaluation of vibrationally resolved electronic absorption, emission, photoelectron, and time-resolved stimulated emission spectra, infrared spectroscopy of H-bonding systems, and multipolar force fields applications in the condensed phase. PMID:29376107
Gyrotactic swimmer dispersion in pipe flow: testing the theory
NASA Astrophysics Data System (ADS)
Croze, Ottavio A.; Bearon, Rachel N.; Bees, Martin A.
2017-04-01
Suspensions of microswimmers are a rich source of fascinating new fluid mechanics. Recently we predicted the active pipe flow dispersion of gyrotactic microalgae, whose orientation is biased by gravity and flow shear. Analytical theory predicts that these active swimmers disperse in a markedly distinct manner from passive tracers (Taylor dispersion). Dispersing swimmers display nonzero drift and effective diffusivity that is non-monotonic with P$\\'e$clet number. Such predictions agree with numerical simulations, but hitherto have not been tested experimentally. Here, to facilitate comparison, we obtain new solutions of the axial dispersion theory accounting both for swimmer negative buoyancy and a local nonlinear response of swimmers to shear, provided by two alternative microscopic stochastic descriptions. We obtain new predictions for suspensions of the model swimming alga $\\it Dunaliella\\,salina$, whose motility and buoyant mass we parametrise using tracking video microscopy. We then present a new experimental method to measure gyrotactic dispersion using fluorescently stained $\\it D. salina$ and provide a preliminary comparison with predictions of a nonzero drift above the mean flow for each microscopic stochastic description. Finally, we propose further experiments for a full experimental characterisation of gyrotactic dispersion measures and discuss implications of our results for algal dispersion in industrial photobioreactors.
Generalized continuum modeling of scale-dependent crystalline plasticity
NASA Astrophysics Data System (ADS)
Mayeur, Jason R.
The use of metallic material systems (e.g. pure metals, alloys, metal matrix composites) in a wide range of engineering applications from medical devices to electronic components to automobiles continues to motivate the development of improved constitutive models to meet increased performance demands while minimizing cost. Emerging technologies often incorporate materials in which the dominant microstructural features have characteristic dimensions reaching into the submicron and nanometer regime. Metals comprised of such fine microstructures often exhibit unique and size-dependent mechanical response, and classical approaches to constitutive model development at engineering (continuum) scales, being local in nature, are inadequate for describing such behavior. Therefore, traditional modeling frameworks must be augmented and/or reformulated to account for such phenomena. Crystal plasticity constitutive models have proven quite capable of capturing first-order microstructural effects such as grain orientation (elastic/plastic anisotropy), grain morphology, phase distribution, etc. on the deformation behavior of both single and polycrystals, yet suffer from the same limitations as other local continuum theories with regard to capturing scale-dependent mechanical response. This research is focused on the development, numerical implementation, and application of a generalized (nonlocal) theory of single crystal plasticity capable of describing the scale-dependent mechanical response of both single and polycrystalline metals that arises as a result of heterogeneous deformation. This research developed a dislocation-based theory of micropolar single crystal plasticity. The majority of nonlocal crystal plasticity theories are predicated on the connection between gradients of slip and geometrically necessary dislocations. Due to the diversity of existing nonlocal crystal plasticity theories, a review, summary, and comparison of representative model classes is presented in Chapter 2 from a unified dislocation-based perspective. The discussion of the continuum crystal plasticity theories is prefaced by a brief review of discrete dislocation plasticity, which facilitates the comparison of certain model aspects and also serves as a reference for latter segments of the research which make connection to this constitutive description. Chapter 2 has utility not only as a literature review, but also as a synthesis and analysis of competing and alternative nonlocal crystal plasticity modeling strategies from a common viewpoint. The micropolar theory of single crystal plasticity is presented in Chapter 3. Two different types of flow criteria are considered - the so-called single and multicriterion theories, and several variations of the dislocation-based strength models appropriate for each theory are presented and discussed. The numerical implementation of the two-dimensional version of the constitutive theory is given in Chapter 4. A user element subroutine for the implicit commercial finite element code Abaqus/Standard is developed and validated through the solution of initial-boundary value problems with closed-form solutions. Convergent behavior of the subroutine is also demonstrated for an initial-boundary value problem exhibiting strain localization. In Chapter 5, the models are employed to solve several standard initial-boundary value problems for heterogeneously deforming single crystals including simple shearing of a semi-infinite constrained thin film, pure bending of thin films, and simple shearing of a metal matrix composite with elastic inclusions. The simulation results are compared to those obtained from the solution of equivalent boundary value problems using discrete dislocation dynamics and alternative generalized crystal plasticity theories. Comparison and calibration with respect to the former provides guidance in the specification of non-traditional material parameters that arise in the model formulation and demonstrates its effectiveness at capturing the heterogeneous deformation fields and size-dependent mechanical behavior predicted by a finer scale constitutive description. Finally, in Chapter 6, the models are applied to simulate the deformation behavior of small polycrystalline ensembles. Several grain boundary constitutive descriptions are explored and the response characteristics are analyzed with respect to experimental observations as well as results obtained from discrete dislocation dynamics and alternative nonlocal crystal plasticity theories. Particular attention is focused on how the various grain boundary descriptions serve to either locally concentrate or diffuse deformation heterogeneity as a function of grain size.
Construct Validation Theory Applied to the Study of Personality Dysfunction
Zapolski, Tamika C. B.; Guller, Leila; Smith, Gregory T.
2013-01-01
The authors review theory validation and construct validation principles as related to the study of personality dysfunction. Historically, personality disorders have been understood to be syndromes of heterogeneous symptoms. The authors argue that the syndrome approach to description results in diagnoses of unclear meaning and constrained validity. The alternative approach of describing personality dysfunction in terms of homogeneous dimensions of functioning avoids the problems of the syndromal approach and has been shown to provide more valid description and diagnosis. The authors further argue that description based on homogeneous dimensions of personality function/dysfunction is more useful, because it provides direct connections to validated treatments. PMID:22321263
A microscopic description of black hole evaporation via holography
Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan
2016-07-19
Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.
A microscopic description of black hole evaporation via holography
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan
Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.
Structural analysis and design of multivariable control systems: An algebraic approach
NASA Technical Reports Server (NTRS)
Tsay, Yih Tsong; Shieh, Leang-San; Barnett, Stephen
1988-01-01
The application of algebraic system theory to the design of controllers for multivariable (MV) systems is explored analytically using an approach based on state-space representations and matrix-fraction descriptions. Chapters are devoted to characteristic lambda matrices and canonical descriptions of MIMO systems; spectral analysis, divisors, and spectral factors of nonsingular lambda matrices; feedback control of MV systems; and structural decomposition theories and their application to MV control systems.
NASA Technical Reports Server (NTRS)
Middleton, W. D.; Lundry, J. L.
1975-01-01
An integrated system of computer programs has been developed for the design and analysis of supersonic configurations. The system uses linearized theory methods for the calculation of surface pressures and supersonic area rule concepts in combination with linearized theory for calculation of aerodynamic force coefficients. Interactive graphics are optional at the user's request. This part presents a general description of the system and describes the theoretical methods used.
Quadratic canonical transformation theory and higher order density matrices.
Neuscamman, Eric; Yanai, Takeshi; Chan, Garnet Kin-Lic
2009-03-28
Canonical transformation (CT) theory provides a rigorously size-extensive description of dynamic correlation in multireference systems, with an accuracy superior to and cost scaling lower than complete active space second order perturbation theory. Here we expand our previous theory by investigating (i) a commutator approximation that is applied at quadratic, as opposed to linear, order in the effective Hamiltonian, and (ii) incorporation of the three-body reduced density matrix in the operator and density matrix decompositions. The quadratic commutator approximation improves CT's accuracy when used with a single-determinant reference, repairing the previous formal disadvantage of the single-reference linear CT theory relative to singles and doubles coupled cluster theory. Calculations on the BH and HF binding curves confirm this improvement. In multireference systems, the three-body reduced density matrix increases the overall accuracy of the CT theory. Tests on the H(2)O and N(2) binding curves yield results highly competitive with expensive state-of-the-art multireference methods, such as the multireference Davidson-corrected configuration interaction (MRCI+Q), averaged coupled pair functional, and averaged quadratic coupled cluster theories.
NASA Astrophysics Data System (ADS)
Amorim, B.
2018-04-01
We develop a general theory to model the angle-resolved photoemission spectroscopy (ARPES) of commensurate and incommensurate van der Waals (vdW) structures, formed by lattice mismatched and/or misaligned stacked layers of two-dimensional materials. The present theory is based on a tight-binding description of the structure and the concept of generalized umklapp processes, going beyond previous descriptions of ARPES in incommensurate vdW structures, which are based on continuous, low-energy models, being limited to structures with small lattice mismatch/misalignment. As applications of the general formalism, we study the ARPES bands and constant energy maps for two structures: twisted bilayer graphene and twisted bilayer MoS2. The present theory should be useful in correctly interpreting experimental results of ARPES of vdW structures and other systems displaying competition between different periodicities, such as two-dimensional materials weakly coupled to a substrate and materials with density wave phases.
Structure induction in diagnostic causal reasoning.
Meder, Björn; Mayrhofer, Ralf; Waldmann, Michael R
2014-07-01
Our research examines the normative and descriptive adequacy of alternative computational models of diagnostic reasoning from single effects to single causes. Many theories of diagnostic reasoning are based on the normative assumption that inferences from an effect to its cause should reflect solely the empirically observed conditional probability of cause given effect. We argue against this assumption, as it neglects alternative causal structures that may have generated the sample data. Our structure induction model of diagnostic reasoning takes into account the uncertainty regarding the underlying causal structure. A key prediction of the model is that diagnostic judgments should not only reflect the empirical probability of cause given effect but should also depend on the reasoner's beliefs about the existence and strength of the link between cause and effect. We confirmed this prediction in 2 studies and showed that our theory better accounts for human judgments than alternative theories of diagnostic reasoning. Overall, our findings support the view that in diagnostic reasoning people go "beyond the information given" and use the available data to make inferences on the (unobserved) causal rather than on the (observed) data level. (c) 2014 APA, all rights reserved.
NASA Astrophysics Data System (ADS)
Koval, N. E.; Borisov, A. G.; Rosa, L. F. S.; Stori, E. M.; Dias, J. F.; Grande, P. L.; Sánchez-Portal, D.; Muiño, R. Díez
2017-06-01
We present a combined theoretical and experimental study of the energy loss of H2+ molecular ions interacting with thin oxide and carbon films. As a result of quantum mechanical interference of the target electrons, the energy loss of a molecular projectile differs from the sum of the energy losses of individual atomic projectiles. This difference is known as the vicinage effect. Calculations based on the time-dependent density functional theory allow the first-principles description of the dynamics of target excitations produced by the correlated motion of the nucleons forming the molecule. We investigate in detail the dependence of the vicinage effect on the speed and charge state of the projectile and find an excellent agreement between calculated and measured data.
Yu, Nan; Ahern, Lee A; Connolly-Ahern, Colleen; Shen, Fuyuan
2010-12-01
Health messages can be either informative or descriptive, and can emphasize either potential losses or gains. This study, guided by message framing theory and exemplification theory, specifically investigated the combined effects of messages with loss-gain frames mixed with statistics or exemplar appeals. The findings revealed a series of main effects and interactions for loss-gain frames and statistics-exemplar appeals on fetal alcohol spectrum disorder (FASD) prevention intention, intention to know more, perceived severity, perceived fear, perceived external efficacy, and perceived internal efficacy. The gain-statistics appeal showed an advantage in promoting perceived efficacy toward FASD, while the loss-exemplar appeal revealed an advantage in increasing prevention intention, perceived severity, and perceived fear toward FASD. Limitations and implications for future research are discussed.
Diffractive Scattering and Gauge/String Duality
Tan, Chung-I
2018-05-11
High-energy diffractive scattering will be discussed based on Gauge/String duality. As shown by Brower, Polchinski, Strassler and Tan, the ubiquitous Pomeron emerges naturally in gauge theories with string-theoretical descriptions. Its existence is intimately tied to gluons, and also to the energy-momentum tensor. With a confining dual background metric, the Pomeron can be interpreted as a 'massive graviton'. In a single unified step, both its infrared and ultraviolet properties are dealt with, reflecting confinement and conformal symmetry respectively. An effective field theory for high-energy scattering can be constructed. Applications based on this approach will also be described.
Refined geometric transition and qq-characters
NASA Astrophysics Data System (ADS)
Kimura, Taro; Mori, Hironori; Sugimoto, Yuji
2018-01-01
We show the refinement of the prescription for the geometric transition in the refined topological string theory and, as its application, discuss a possibility to describe qq-characters from the string theory point of view. Though the suggested way to operate the refined geometric transition has passed through several checks, it is additionally found in this paper that the presence of the preferred direction brings a nontrivial effect. We provide the modified formula involving this point. We then apply our prescription of the refined geometric transition to proposing the stringy description of doubly quantized Seiberg-Witten curves called qq-characters in certain cases.
First moments of nucleon generalized parton distributions
Wang, P.; Thomas, A. W.
2010-06-01
We extrapolate the first moments of the generalized parton distributions using heavy baryon chiral perturbation theory. The calculation is based on the one loop level with the finite range regularization. The description of the lattice data is satisfactory, and the extrapolated moments at physical pion mass are consistent with the results obtained with dimensional regularization, although the extrapolation in the momentum transfer to t=0 does show sensitivity to form factor effects, which lie outside the realm of chiral perturbation theory. We discuss the significance of the results in the light of modern experiments as well as QCD inspired models.
Harmonic oscillator representation in the theory of scattering and nuclear reactions
NASA Technical Reports Server (NTRS)
Smirnov, Yuri F.; Shirokov, A. M.; Lurie, Yuri, A.; Zaitsev, S. A.
1995-01-01
The following questions, concerning the application of the harmonic oscillator representation (HOR) in the theory of scattering and reactions, are discussed: the formulation of the scattering theory in HOR; exact solutions of the free motion Schroedinger equation in HOR; separable expansion of the short range potentials and the calculation of the phase shifts; 'isolated states' as generalization of the Wigner-von Neumann bound states embedded in continuum; a nuclear coupled channel problem in HOR; and the description of true three body scattering in HOR. As an illustration the soft dipole mode in the (11)Li nucleus is considered in a frame of the (9)Li+n+n cluster model taking into account of three body continuum effects.
A continuum theory for multicomponent chromatography modeling.
Pfister, David; Morbidelli, Massimo; Nicoud, Roger-Marc
2016-05-13
A continuum theory is proposed for modeling multicomponent chromatographic systems under linear conditions. The model is based on the description of complex mixtures, possibly involving tens or hundreds of solutes, by a continuum. The present approach is shown to be very efficient when dealing with a large number of similar components presenting close elution behaviors and whose individual analytical characterization is impossible. Moreover, approximating complex mixtures by continuous distributions of solutes reduces the required number of model parameters to the few ones specific to the characterization of the selected continuous distributions. Therefore, in the frame of the continuum theory, the simulation of large multicomponent systems gets simplified and the computational effectiveness of the chromatographic model is thus dramatically improved. Copyright © 2016 Elsevier B.V. All rights reserved.
A Fifth Force: Generalized through Superconductors
NASA Technical Reports Server (NTRS)
Robertson, Glen A.
1999-01-01
The connection between the Biefield-Brown Effect, the recent repeat of the 1902 Trouton-Noble (TN) experiments, and the gravity shielding experiments was explored. This connection is visualized through high capacitive electron concentrations. From this connection, a theory is proposed that connects mass energy to gravity and a fifth force. The theory called the Gravi-Atomic Energy theory presents two new terms: Gravi-atomic energy and quantum vacuum pressure (QVP). Gravi-atomic energy is defined as the radiated mass energy, which acts on vacuum energy to create a QVP about a mass, resulting in gravity and the fifth force. The QVP emission from a superconductor was discussed followed by the description of a test for QVP from a superconductor using a Cavendish balance.
The nuclear contacts and short range correlations in nuclei
NASA Astrophysics Data System (ADS)
Weiss, R.; Cruz-Torres, R.; Barnea, N.; Piasetzky, E.; Hen, O.
2018-05-01
Atomic nuclei are complex strongly interacting systems and their exact theoretical description is a long-standing challenge. An approximate description of nuclei can be achieved by separating its short and long range structure. This separation of scales stands at the heart of the nuclear shell model and effective field theories that describe the long-range structure of the nucleus using a mean-field approximation. We present here an effective description of the complementary short-range structure using contact terms and stylized two-body asymptotic wave functions. The possibility to extract the nuclear contacts from experimental data is presented. Regions in the two-body momentum distribution dominated by high-momentum, close-proximity, nucleon pairs are identified and compared to experimental data. The amount of short-range correlated (SRC) nucleon pairs is determined and compared to measurements. Non-combinatorial isospin symmetry for SRC pairs is identified. The obtained one-body momentum distributions indicate dominance of SRC pairs above the nuclear Fermi-momentum.
Non-Markovian quantum processes: Complete framework and efficient characterization
NASA Astrophysics Data System (ADS)
Pollock, Felix A.; Rodríguez-Rosario, César; Frauenheim, Thomas; Paternostro, Mauro; Modi, Kavan
2018-01-01
Currently, there is no systematic way to describe a quantum process with memory solely in terms of experimentally accessible quantities. However, recent technological advances mean we have control over systems at scales where memory effects are non-negligible. The lack of such an operational description has hindered advances in understanding physical, chemical, and biological processes, where often unjustified theoretical assumptions are made to render a dynamical description tractable. This has led to theories plagued with unphysical results and no consensus on what a quantum Markov (memoryless) process is. Here, we develop a universal framework to characterize arbitrary non-Markovian quantum processes. We show how a multitime non-Markovian process can be reconstructed experimentally, and that it has a natural representation as a many-body quantum state, where temporal correlations are mapped to spatial ones. Moreover, this state is expected to have an efficient matrix-product-operator form in many cases. Our framework constitutes a systematic tool for the effective description of memory-bearing open-system evolutions.
How to heat up from the cold: examining the preconditions for (unconscious) mood effects.
Ruys, Kirsten I; Stapel, Diederik A
2008-05-01
What are the necessary preconditions to make people feel good or bad? In this research, the authors aimed to uncover the bare essentials of mood induction. Several induction techniques exist, and most of these techniques demand a relatively high amount of cognitive capacity. Moreover, to be effective, most techniques require conscious awareness. The authors proposed that the common and defining element in all effective mood induction techniques is the dominating salience of evaluative tone over descriptive meaning. This evaluative-tone hypothesis was tested in two paradigms in which the evaluative meaning of the "primed" concept was more salient than its descriptive meaning (i.e., when subliminal stimulus exposure was so short that mainly the evaluative meaning was activated [see D. A. Stapel, W. Koomen, & K. I. Ruys, 2002] and when the primed concepts were sufficiently extreme such that evaluative meaning always dominated descriptive meaning). Explicit and implicit mood measures showed that the activation of a dominating evaluative tone affected people's mood states. Implications of these findings for theories on unconscious mood induction are discussed. (c) 2008 APA, all rights reserved
Åstrøm, Anne N; Lie, Stein Atle; Gülcan, Ferda
2018-05-31
Understanding factors that affect dental attendance behavior helps in constructing effective oral health campaigns. A socio-cognitive model that adequately explains variance in regular dental attendance has yet to be validated among younger adults in Norway. Focusing a representative sample of younger Norwegian adults, this cross-sectional study provided an empirical test of the Theory of Planned Behavior (TPB) augmented with descriptive norm and action planning and estimated direct and indirect effects of attitudes, subjective norms, descriptive norms, perceived behavioral control and action planning on intended and self-reported regular dental attendance. Self-administered questionnaires provided by 2551, 25-35 year olds, randomly selected from the Norwegian national population registry were used to assess socio-demographic factors, dental attendance as well as the constructs of the augmented TPB model (attitudes, subjective norms, descriptive norms, intention, action planning). A two-stage process of structural equation modelling (SEM) was used to test the augmented TPB model. Confirmatory factor analysis, CFA, confirmed the proposed correlated 6-factor measurement model after re-specification. SEM revealed that attitudes, perceived behavioral control, subjective norms and descriptive norms explained intention. The corresponding standardized regression coefficients were respectively (β = 0.70), (β =0.18), (β = - 0.17) and (β =0.11) (p < 0.001). Intention (β =0.46) predicted action planning and action planning (β =0.19) predicted dental attendance behavior (p < 0.001). The model revealed indirect effects of intention and perceived behavioral control on behavior through action planning and through intention and action planning, respectively. The final model explained 64 and 41% of the total variance in intention and dental attendance behavior. The findings support the utility of the TPB, the expanded normative component and action planning in predicting younger adults' intended- and self-reported dental attendance. Interventions targeting young adults' dental attendance might usefully focus on positive consequences following this behavior accompanied with modeling and group performance.
The Chaos Theory of Careers: A User's Guide
ERIC Educational Resources Information Center
Bright, Jim E. H.; Pryor, Robert G. L.
2005-01-01
The purpose of this article is to set out the key elements of the Chaos Theory of Careers. The complexity of influences on career development presents a significant challenge to traditional predictive models of career counseling. Chaos theory can provide a more appropriate description of career behavior, and the theory can be applied with clients…
Chaos Theory and Post Modernism
ERIC Educational Resources Information Center
Snell, Joel
2009-01-01
Chaos theory is often associated with post modernism. However, one may make the point that both terms are misunderstood. The point of this article is to define both terms and indicate their relationship. Description: Chaos theory is associated with a definition of a theory dealing with variables (butterflies) that are not directly related to a…
The Effect of Descriptive Norms on Pregaming Frequency: Tests of Five Moderators
Merrill, Jennifer E.; Kenney, Shannon R.; Carey, Kate B.
2016-01-01
Background Pregaming is highly prevalent on college campuses and associated with heightened levels of intoxication and risk of alcohol consequences. However, research examining the correlates of pregaming behavior is limited. Descriptive norms (i.e., perceptions about the prevalence or frequency of a behavior) are reliable and comparatively strong predictors of general drinking behavior, with recent evidence indicating that they are also associated with pregaming. Objectives We tested the hypothesis that higher descriptive norms for pregaming frequency would be associated with personal pregaming frequency. We also tested whether this effect would be stronger in the context of several theory-based moderators: female gender, higher injunctive norms (i.e., perceptions of others' attitudes toward a particular behavior), a more positive attitude toward pregaming, a stronger sense of identification with the drinking habits of other students, and stronger social comparison tendencies. Methods College student drinkers (N=198, 63% female) participated in an online survey assessing frequency of pregaming, descriptive norms, and hypothesized moderators. Results A multiple regression model revealed that higher descriptive norms, a more positive attitude toward pregaming, and stronger peer identification were significantly associated with greater pregaming frequency among drinkers. However, no moderators of the association between descriptive norms and pregaming frequency were observed. Conclusions/Importance Descriptive norms are robust predictors of pregaming behavior, for both genders and across levels of several potential moderators. Future research seeking to understand pregaming behavior should consider descriptive norms, as well as personal attitudes and identification with student peers, as targets of interventions designed to reduce pregaming. PMID:27070494
Rimal, Rajiv N.; Mollen, Saar
2013-01-01
Background Scholars in a variety of disciplines are interested in understanding the conditions under which social norms affect human behavior. Following the distinction made between descriptive and injunctive norms by the focus theory of normative conduct, the theory of normative social behavior predicts that the influence of descriptive norms on behavior is moderated by injunctive norms, outcome expectations, and group identity. We extended the theory by testing the proposition that the influence of descriptive norms on behavior would be greater under conditions of greater issue familiarity, defined as the ease with which one can cognitively access the behavior or behavioral issue. Design and Methods The model was tested in the domain of alcohol consumption intentions by conducting a survey among incoming students (n=719) to a large university in the United States. Data indicated that students in the sample were well representative of the university population. Results The influence of descriptive norms on behavioral intentions was moderated by issue familiarity, as predicted. Familiarity was a facilitator of behavior: the influence of descriptive norms on behavioral intentions was greater under conditions of high, rather than low, familiarity. The overall model explained 53% of the variance in alcohol consumption intentions. Conclusions Public health interventions promoting health behaviors need to take into account the extent to which the behaviors are familiar to the target audience. The influence of norms appears to be weaker when the behavior is unfamiliar or novel. Implications for theory and interventions for reducing alcohol consumption are discussed. PMID:25170478
Anderson, Lara B.; Gray, James; Raghuram, Nikhil; ...
2016-04-13
In this study, we explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, wheremore » a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.« less
Guido, Ciro A; Jacquemin, Denis; Adamo, Carlo; Mennucci, Benedetta
2015-12-08
We critically analyze the performances of continuum solvation models when coupled to time-dependent density functional theory (TD-DFT) to predict solvent effects on both absorption and emission energies of chromophores in solution. Different polarization schemes of the polarizable continuum model (PCM), such as linear response (LR) and three different state specific (SS) approaches, are considered and compared. We show the necessity of introducing a SS model in cases where large electron density rearrangements are involved in the excitations, such as charge-transfer transitions in both twisted and quadrupolar compounds, and underline the very delicate interplay between the selected polarization method and the chosen exchange-correlation functional. This interplay originates in the different descriptions of the transition and ground/excited state multipolar moments by the different functionals. As a result, the choice of both the DFT functional and the solvent polarization scheme has to be consistent with the nature of the studied electronic excitation.
Coupled-cluster based R-matrix codes (CCRM): Recent developments
NASA Astrophysics Data System (ADS)
Sur, Chiranjib; Pradhan, Anil K.
2008-05-01
We report the ongoing development of the new coupled-cluster R-matrix codes (CCRM) for treating electron-ion scattering and radiative processes within the framework of the relativistic coupled-cluster method (RCC), interfaced with the standard R-matrix methodology. The RCC method is size consistent and in principle equivalent to an all-order many-body perturbation theory. The RCC method is one of the most accurate many-body theories, and has been applied for several systems. This project should enable the study of electron-interactions with heavy atoms/ions, utilizing not only high speed computing platforms but also improved theoretical description of the relativistic and correlation effects for the target atoms/ions as treated extensively within the RCC method. Here we present a comprehensive outline of the newly developed theoretical method and a schematic representation of the new suite of CCRM codes. We begin with the flowchart and description of various stages involved in this development. We retain the notations and nomenclature of different stages as analogous to the standard R-matrix codes.
Dichotomy between theory and practice in chest radiography and its impact on students.
Botwe, Benard O; Arthur, Lawrence; Tenkorang, Michael K K; Anim-Sampong, Samuel
2017-06-01
It is important that theory is synchronous with clinical practices that students engage in. Lack of congruence between theory and practice presents serious problems to students. This study was therefore conducted to determine if there was a theory-practice gap in chest radiography during clinical rotations, and any associated causes and effects on radiography students. A descriptive survey design was used to conduct this study from 2 February to 27 July 2014. A semi-structured questionnaire consisting of open- and close-ended questions was used to purposively collect data from 26 radiography students in Ghana who had completed theory lessons in chest radiography and had either completed or were undertaking clinical rotations in chest radiography. Twenty-five (96%) respondents indicated the presence of theory-practice gap in chest radiography during clinical rotations, where differences between theory and clinical practice were observed. Lack of working materials 16 (62%), heavy workload 14 (54%), equipment breakdowns 14 (54%) and supervisory factors 11 (43%) were identified as the causes. Many students (81%) experienced diverse adverse effects such as confusion 10 (38%), poor performance during clinical examinations 6 (23%) and entire loss of interest in the professional training 1 (4%) of this dichotomy. Dichotomy between theory and practice found in chest radiography has diverse adverse effects on students. Regular feedback on the quality of clinical practice received by students should be encouraged to determine the existence of any gaps between theory and practice in order to promote effective clinical rotation programmes in radiography. © 2016 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.
Generalized thermodynamics of phase equilibria in scalar active matter
NASA Astrophysics Data System (ADS)
Solon, Alexandre P.; Stenhammar, Joakim; Cates, Michael E.; Kafri, Yariv; Tailleur, Julien
2018-02-01
Motility-induced phase separation (MIPS) arises generically in fluids of self-propelled particles when interactions lead to a kinetic slowdown at high densities. Starting from a continuum description of scalar active matter akin to a generalized Cahn-Hilliard equation, we give a general prescription for the mean densities of coexisting phases in flux-free steady states that amounts, at a hydrodynamics scale, to extremizing an effective free energy. We illustrate our approach on two well-known models: self-propelled particles interacting either through a density-dependent propulsion speed or via direct pairwise forces. Our theory accounts quantitatively for their phase diagrams, providing a unified description of MIPS.
NASA Technical Reports Server (NTRS)
Paine, D. A.; Kaplan, M. L.
1976-01-01
Potential vorticity theory is developed in a description of an equivalent potential temperature topography, and a new theory suited to the description of scale interaction is elaborated. Macroscale triggering of ageostrophic flow fields at the mesoscale, in turn leading to release of convective instability along narrow zones at the microscale, is examined. Correlation of appreciable decrease in potential vorticity with such phenomena as cumulonimbi, tornados, and duststorms is examined. The relevance of a multiscale energy-momentum cascade in numerical prediction of severe mesoscale and microscale phenomena from radiosonde data is reviewed. Hypotheses for mesoscale dynamics are constructed.
Bojowald, Martin
2008-01-01
Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time. Supplementary material is available for this article at 10.12942/lrr-2008-4.
Baudu, M; Raveau, D; Guibaud, G
2004-07-01
The study of natural organic matter (NOM) adsorption on an activated carbon showed that equilibrium cannot be described according to a simple model such as a Freundlich isotherm and confirms the need for a closer description of the organic matter to simulate the competitive adsorption with micropollutants. A representation of the organic matter in three fractions is chosen: non-adsorbable, weak and strong adsorbable. The Ideal Adsorbed Solution Theory (IAST) can, under restrictive conditions, be used to effectively predict the competition between the pesticides and the organic matter. Therefore, it was noted that the model simulated with good precision the competition between atrazine or diuron and natural organic matter in aqueous solution for two activated carbons (A and B). The same parameters for the modeling of organic matter adsorption (Freudlich constants for two absorbable fractions) are used with the two pesticides. However, IAST does not allow correct modeling of pesticide adsorption onto two other (C and D) activated carbons in solution in natural water to be described. IAS theory does not reveal competition between diuron and NOM and pore blockage mechanism by the NOM is proposed as the major effect for the adsorption capacity reduction. However, the difference observed between the two pesticides could be due to in addition to the pore blockage effect, a particular phenomenon with the diuron, especially with D activated carbon. We can suppose specific interactions between the diuron and the adsorbed organic matter and a competition between adsorption sites of NOM and activated carbon surface.
Intensive psychotherapy of schizophrenia.
Keats, C. J.; McGlashan, T. H.
1985-01-01
The literature on strategies of investigative psychotherapy of schizophrenia is selectively reviewed, and a case history is presented. The format is modelled on the authors' research technique of contrasting theory with practice. While long-term observation of single cases does not address cause and effect, descriptions of cases with a variety of known outcomes can help to build a typology of treatment processes. PMID:4049907
New dualities and misleading anomaly matchings from outer-automorphism twists
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pal, Sridip; Song, Jaewon
We study four-dimensional N=1, 2 superconformal theories in class S obtained by compactifying the 6d N=(2, 0) theory on a Riemann surface C with outer-automorphism twist lines. From the pair-of-pants decompositions of C, we find various dual descriptions for the same theory having distinct gauge groups. We show that the various configurations of the twist line give rise to dual descriptions for the identical theory. We compute the ’t Hooft anomaly coefficients and the superconformal indices to test dualities. Surprisingly, we find that the class S theories with twist lines wrapping 1-cycles of C have the identical ’t Hooft anomaliesmore » as the ones without the twist line, whereas the superconformal indices differ. As a result, this provides a large set of examples where the anomaly matching is insufficient to test dualities.« less
Beauchaine, Theodore P.; Gatzke-Kopp, Lisa; Mead, Hilary K.
2007-01-01
In science, theories lend coherence to vast amounts of descriptive information. However, current diagnostic approaches in psychopathology are primarily atheoretical, emphasizing description over etiological mechanisms. We describe the importance of Polyvagal Theory toward understanding the etiology of emotion dysregulation, a hallmark of psychopathology. When combined with theories of social reinforcement and motivation, Polyvagal Theory specifies etiological mechanisms through which distinct patterns of psychopathology emerge. In this paper, we summarize three studies evaluating autonomic nervous system functioning in children with conduct problems, ages 4-18. At all age ranges, these children exhibit attenuated sympathetic nervous system responses to reward, suggesting deficiencies in approach motivation. By middle school, this reward insensitivity is met with inadequate vagal modulation of cardiac output, suggesting additional deficiencies in emotion regulation. We propose a biosocial developmental model of conduct problems in which inherited impulsivity is amplified through social reinforcement of emotional lability. Implications for early intervention are discussed. PMID:17045726
New dualities and misleading anomaly matchings from outer-automorphism twists
Pal, Sridip; Song, Jaewon
2017-03-29
We study four-dimensional N=1, 2 superconformal theories in class S obtained by compactifying the 6d N=(2, 0) theory on a Riemann surface C with outer-automorphism twist lines. From the pair-of-pants decompositions of C, we find various dual descriptions for the same theory having distinct gauge groups. We show that the various configurations of the twist line give rise to dual descriptions for the identical theory. We compute the ’t Hooft anomaly coefficients and the superconformal indices to test dualities. Surprisingly, we find that the class S theories with twist lines wrapping 1-cycles of C have the identical ’t Hooft anomaliesmore » as the ones without the twist line, whereas the superconformal indices differ. As a result, this provides a large set of examples where the anomaly matching is insufficient to test dualities.« less
NASA Astrophysics Data System (ADS)
Qiu, Yiheng; Henderson, Thomas M.; Scuseria, Gustavo E.
2017-05-01
Projected Hartree-Fock theory provides an accurate description of many kinds of strong correlations but does not properly describe weakly correlated systems. Coupled cluster theory, in contrast, does the opposite. It therefore seems natural to combine the two so as to describe both strong and weak correlations with high accuracy in a relatively black-box manner. Combining the two approaches, however, is made more difficult by the fact that the two techniques are formulated very differently. In earlier work, we showed how to write spin-projected Hartree-Fock in a coupled-cluster-like language. Here, we fill in the gaps in that earlier work. Further, we combine projected Hartree-Fock and coupled cluster theory in a variational formulation and show how the combination performs for the description of the Hubbard Hamiltonian and for several small molecular systems.
Beauchaine, Theodore P; Gatzke-Kopp, Lisa; Mead, Hilary K
2007-02-01
In science, theories lend coherence to vast amounts of descriptive information. However, current diagnostic approaches in psychopathology are primarily atheoretical, emphasizing description over etiological mechanisms. We describe the importance of Polyvagal Theory toward understanding the etiology of emotion dysregulation, a hallmark of psychopathology. When combined with theories of social reinforcement and motivation, Polyvagal Theory specifies etiological mechanisms through which distinct patterns of psychopathology emerge. In this paper, we summarize three studies evaluating autonomic nervous system functioning in children with conduct problems, ages 4-18. At all age ranges, these children exhibit attenuated sympathetic nervous system responses to reward, suggesting deficiencies in approach motivation. By middle school, this reward insensitivity is met with inadequate vagal modulation of cardiac output, suggesting additional deficiencies in emotion regulation. We propose a biosocial developmental model of conduct problems in which inherited impulsivity is amplified through social reinforcement of emotional lability. Implications for early intervention are discussed.
Bulk viscous cosmology with causal transport theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Piattella, Oliver F.; Fabris, Júlio C.; Zimdahl, Winfried, E-mail: oliver.piattella@gmail.com, E-mail: fabris@pq.cnpq.br, E-mail: winfried.zimdahl@pq.cnpq.br
2011-05-01
We consider cosmological scenarios originating from a single imperfect fluid with bulk viscosity and apply Eckart's and both the full and the truncated Müller-Israel-Stewart's theories as descriptions of the non-equilibrium processes. Our principal objective is to investigate if the dynamical properties of Dark Matter and Dark Energy can be described by a single viscous fluid and how such description changes when a causal theory (Müller-Israel-Stewart's, both in its full and truncated forms) is taken into account instead of Eckart's non-causal one. To this purpose, we find numerical solutions for the gravitational potential and compare its behaviour with the corresponding ΛCDMmore » case. Eckart's and the full causal theory seem to be disfavoured, whereas the truncated theory leads to results similar to those of the ΛCDM model for a bulk viscous speed in the interval 10{sup −11} || cb{sup 2} ∼< 10{sup −8}.« less
Building Rate Into a Dynamic Theory of Linguistic Description.
ERIC Educational Resources Information Center
Bailey, Charles-James N.
1970-01-01
This study of linguistic change is done within the "dynamic paradigm" of linguistic description, in which the strict dichotomy between diachronic and synchronic linguistics found in "static paradigms" is not maintained. The chief purpose here is to indicate how rate could be built into a linguistic description of sound change, such change being…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Silberman, E.; Morgan, H.W.
1977-01-01
Application of the mathematical theory of groups to the symmetry of molecules is a powerful method which permits the prediction, classification, and qualitative description of many molecular properties. In the particular case of vibrational molecular spectroscopy, applications of group theory lead to simple methods for the prediction of the number of bands to be found in the infrared and Raman spectra, their shape and polarization, and the qualitative description of the normal modes with which they are associated. The tables necessary for the application of group theory to vibrational spectroscopy and instructions on how to use them for molecular gases,more » liquids, and solutions are presented. A brief introduction to the concepts, definitions, nomenclature, and formulae is also included.« less
NASA Astrophysics Data System (ADS)
May, Volkhard; Megow, Jörg; Zelinskyi, Iaroslav
2012-04-01
Excitation energy transfer (EET) in molecular systems is studied theoretically. Chromophore complexes are considered which are formed by a butanediamine dendrimer with four pheophorbide-a molecules. To achieve a description with an atomic resolution and to account for the effect of an ethanol solvent a mixed quantum classical methodology is utilized. Details of the EET and spectra of transient anisotropy showing signatures of EET are presented. A particular control of intermolecular EET is achieved by surface plasmons of nearby placed metal nanoparticles (MNP). To attain a quantum description of the molecule-MNP system a microscopic theory is introduced. As a particular application surface plasmon affected absorption spectra of molecular complexes placed in the proximity of a spherical MNP are discussed.
On theory in ecology: Another perspective
Houlahan, Jeff E.; McKinney, Shawn T.; Rochette, Rémy
2015-01-01
We agree with Marquet and colleagues (2014) that the balance between theory and data is an important one. However, their description of what constitutes good theory in ecology ignores the most important characteristic of successful theory—that it accurately and precisely describes the way the world works.
Open quantum system approach to the modeling of spin recombination reactions.
Tiersch, M; Steiner, U E; Popescu, S; Briegel, H J
2012-04-26
In theories of spin-dependent radical pair reactions, the time evolution of the radical pair, including the effect of the chemical kinetics, is described by a master equation in the Liouville formalism. For the description of the chemical kinetics, a number of possible reaction operators have been formulated in the literature. In this work, we present a framework that allows for a unified description of the various proposed mechanisms and the forms of reaction operators for the spin-selective recombination processes. On the basis of the concept that master equations can be derived from a microscopic description of the spin system interacting with external degrees of freedom, it is possible to gain insight into the underlying microscopic processes and develop a systematic approach toward determining the specific form of the reaction operator in concrete scenarios.
Five roles for using theory and evidence in the design and testing of behavior change interventions.
Bartholomew, L Kay; Mullen, Patricia Dolan
2011-01-01
The prevailing wisdom in the field of health-related behavior change is that well-designed and effective interventions are guided by theory. Using the framework of intervention mapping, we describe and provide examples of how investigators can effectively select and use theory to design, test, and report interventions. We propose five roles for theory and evidence about theories: a) identification of behavior and determinants of behavior related to a specified health problem (i.e., the logic model of the problem); b) explication of a causal model that includes theoretical constructs for producing change in the behavior of interest (i.e., the logic model of change); c) selection of intervention methods and delivery of practical applications to achieve changes in health behavior; d) evaluation of the resulting intervention including theoretical mediating variables; and e) reporting of the active ingredients of the intervention together with the evaluation results. In problem-driven applied behavioral or social science, researchers use one or multiple theories, empiric evidence, and new research, both to assess a problem and to solve or prevent a problem. Furthermore, the theories for description of the problem may differ from the theories for its solution. In an applied approach, the main focus is on solving problems regarding health behavior change and improvement of health outcomes, and the criteria for success are formulated in terms of the problem rather than the theory. Resulting contributions to theory development may be quite useful, but they are peripheral to the problem-solving process.
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.
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. PMID:22413059
Weak values in collision theory
NASA Astrophysics Data System (ADS)
de Castro, Leonardo Andreta; Brasil, Carlos Alexandre; Napolitano, Reginaldo de Jesus
2018-05-01
Weak measurements have an increasing number of applications in contemporary quantum mechanics. They were originally described as a weak interaction that slightly entangled the translational degrees of freedom of a particle to its spin, yielding surprising results after post-selection. That description often ignores the kinetic energy of the particle and its movement in three dimensions. Here, we include these elements and re-obtain the weak values within the context of collision theory by two different approaches, and prove that the results are compatible with each other and with the results from the traditional approach. To provide a more complete description, we generalize weak values into weak tensors and use them to provide a more realistic description of the Stern-Gerlach apparatus.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baumgart, Matthew; Cohen, Timothy; Moult, Ian
We construct an effective field theory (EFT) description of the hard photon spectrum for heavy WIMP annihilation. This facilitates precision predictions relevant for line searches, and allows the incorporation of non-trivial energy resolution effects. Our framework combines techniques from non-relativistic EFTs and soft-collinear effective theory (SCET), as well as its multi-scale extensions that have been recently introduced for studying jet substructure. We find a number of interesting features, including the simultaneous presence of SCET I and SCET II modes, as well as collinear-soft modes at the electroweak scale. We derive a factorization formula that enables both the resummation of themore » leading large Sudakov double logarithms that appear in the perturbative spectrum, and the inclusion of Sommerfeld enhancement effects. Consistency of this factorization is demonstrated to leading logarithmic order through explicit calculation. Our final result contains both the exclusive and the inclusive limits, thereby providing a unifying description of these two previously-considered approximations. We estimate the impact on experimental sensitivity, focusing for concreteness on an SU(2) W triplet fermion dark matter — the pure wino — where the strongest constraints are due to a search for gamma-ray lines from the Galactic Center. Here, we find numerically significant corrections compared to previous results, thereby highlighting the importance of accounting for the photon spectrum when interpreting data from current and future indirect detection experiments.« less
Resummed photon spectra for WIMP annihilation
Baumgart, Matthew; Cohen, Timothy; Moult, Ian; ...
2018-03-20
We construct an effective field theory (EFT) description of the hard photon spectrum for heavy WIMP annihilation. This facilitates precision predictions relevant for line searches, and allows the incorporation of non-trivial energy resolution effects. Our framework combines techniques from non-relativistic EFTs and soft-collinear effective theory (SCET), as well as its multi-scale extensions that have been recently introduced for studying jet substructure. We find a number of interesting features, including the simultaneous presence of SCET I and SCET II modes, as well as collinear-soft modes at the electroweak scale. We derive a factorization formula that enables both the resummation of themore » leading large Sudakov double logarithms that appear in the perturbative spectrum, and the inclusion of Sommerfeld enhancement effects. Consistency of this factorization is demonstrated to leading logarithmic order through explicit calculation. Our final result contains both the exclusive and the inclusive limits, thereby providing a unifying description of these two previously-considered approximations. We estimate the impact on experimental sensitivity, focusing for concreteness on an SU(2) W triplet fermion dark matter — the pure wino — where the strongest constraints are due to a search for gamma-ray lines from the Galactic Center. Here, we find numerically significant corrections compared to previous results, thereby highlighting the importance of accounting for the photon spectrum when interpreting data from current and future indirect detection experiments.« less
Doubly Special Relativity: A New Relativity or Not
NASA Astrophysics Data System (ADS)
Jafari, Nosratollah; Shariati, Ahmad
2006-06-01
Double Special Relativity theories are the relativistic theories in which the transformations between inertial observers are characterized by two observer-independent scales of the light speed and the Planck length. We study two main examples of these theories and want to show that these theories are not the new theories of relativity, but only are re-descriptions of Einstein's special relativity in the non-conventional coordinates.
An Overview of Cultural Historical Activity Theory (CHAT) Use in Classroom Research 2000 to 2009
ERIC Educational Resources Information Center
Nussbaumer, Doris
2012-01-01
Western educational researchers have eagerly accepted activity theory (AT) also known as cultural historical activity theory (CHAT) to collect and analyze data in rich description of complex situations. As this theory is applicable to a wide variety of disciplines, this review is limited to education and specifically to qualitative studies of…
ERIC Educational Resources Information Center
Francis, Becky
1999-01-01
Discusses the extent to which poststructuralist theory can be applied to feminist research. Explores why some feminist researchers are attracted to poststructuralist theory and others are not. Distinguishes between application of poststructuralist theory to descriptive theory and to emancipatory research. Argues that pure poststructuralism is not…
Realising effective theories of tribrid inflation: are there effects from messenger fields?
NASA Astrophysics Data System (ADS)
Antusch, Stefan; Nolde, David
2015-09-01
Tribrid inflation is a variant of supersymmetric hybrid inflation in which the inflaton is a matter field (which can be charged under gauge symmetries) and inflation ends by a GUT-scale phase transition of a waterfall field. These features make tribrid inflation a promising framework for realising inflation with particularly close connections to particle physics. Superpotentials of tribrid inflation involve effective operators suppressed by some cutoff scale, which is often taken as the Planck scale. However, these operators may also be generated by integrating out messenger superfields with masses below the Planck scale, which is in fact quite common in GUT and/or flavour models. The values of the inflaton field during inflation can then lie above this mass scale, which means that for reliably calculating the model predictions one has to go beyond the effective theory description. We therefore discuss realisations of effective theories of tribrid inflation and specify in which cases effects from the messenger fields are expected, and under which conditions they can safely be neglected. In particular, we point out how to construct realisations where, despite the fact that the inflaton field values are above the messenger mass scale, the predictions for the observables are (to a good approximation) identical to the ones calculated in the effective theory treatment where the messenger mass scale is identified with the (apparent) cutoff scale.
Realising effective theories of tribrid inflation: are there effects from messenger fields?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Antusch, Stefan; Max-Planck-Institut für Physik; Nolde, David
2015-09-22
Tribrid inflation is a variant of supersymmetric hybrid inflation in which the inflaton is a matter field (which can be charged under gauge symmetries) and inflation ends by a GUT-scale phase transition of a waterfall field. These features make tribrid inflation a promising framework for realising inflation with particularly close connections to particle physics. Superpotentials of tribrid inflation involve effective operators suppressed by some cutoff scale, which is often taken as the Planck scale. However, these operators may also be generated by integrating out messenger superfields with masses below the Planck scale, which is in fact quite common in GUTmore » and/or flavour models. The values of the inflaton field during inflation can then lie above this mass scale, which means that for reliably calculating the model predictions one has to go beyond the effective theory description. We therefore discuss realisations of effective theories of tribrid inflation and specify in which cases effects from the messenger fields are expected, and under which conditions they can safely be neglected. In particular, we point out how to construct realisations where, despite the fact that the inflaton field values are above the messenger mass scale, the predictions for the observables are (to a good approximation) identical to the ones calculated in the effective theory treatment where the messenger mass scale is identified with the (apparent) cutoff scale.« less
Realising effective theories of tribrid inflation: are there effects from messenger fields?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Antusch, Stefan; Nolde, David, E-mail: stefan.antusch@unibas.ch, E-mail: david.nolde@unibas.ch
2015-09-01
Tribrid inflation is a variant of supersymmetric hybrid inflation in which the inflaton is a matter field (which can be charged under gauge symmetries) and inflation ends by a GUT-scale phase transition of a waterfall field. These features make tribrid inflation a promising framework for realising inflation with particularly close connections to particle physics. Superpotentials of tribrid inflation involve effective operators suppressed by some cutoff scale, which is often taken as the Planck scale. However, these operators may also be generated by integrating out messenger superfields with masses below the Planck scale, which is in fact quite common in GUTmore » and/or flavour models. The values of the inflaton field during inflation can then lie above this mass scale, which means that for reliably calculating the model predictions one has to go beyond the effective theory description. We therefore discuss realisations of effective theories of tribrid inflation and specify in which cases effects from the messenger fields are expected, and under which conditions they can safely be neglected. In particular, we point out how to construct realisations where, despite the fact that the inflaton field values are above the messenger mass scale, the predictions for the observables are (to a good approximation) identical to the ones calculated in the effective theory treatment where the messenger mass scale is identified with the (apparent) cutoff scale.« less
Operational Indistinguishably of Varying Speed of Light Theories
NASA Astrophysics Data System (ADS)
Jafari, Nosratollah; Shariati, Ahmad
The varying speed of light theories have been recently proposed to solve the standard model problems and anomalies in the ultra high energy cosmic rays. These theories try to formulate a new relativity with no assumptions about the constancy of the light speed. In this regard, we study two theories and want to show that these theories are not the new theories of relativity, but only re-descriptions of Einstein's special relativity.
NASA Astrophysics Data System (ADS)
van Westen, Thijs; Gross, Joachim
2017-07-01
The Helmholtz energy of a fluid interacting by a Lennard-Jones pair potential is expanded in a perturbation series. Both the methods of Barker-Henderson (BH) and of Weeks-Chandler-Andersen (WCA) are evaluated for the division of the intermolecular potential into reference and perturbation parts. The first four perturbation terms are evaluated for various densities and temperatures (in the ranges ρ*=0 -1.5 and T*=0.5 -12 ) using Monte Carlo simulations in the canonical ensemble. The simulation results are used to test several approximate theoretical methods for describing perturbation terms or for developing an approximate infinite order perturbation series. Additionally, the simulations serve as a basis for developing fully analytical third order BH and WCA perturbation theories. The development of analytical theories allows (1) a careful comparison between the BH and WCA formalisms, and (2) a systematic examination of the effect of higher-order perturbation terms on calculated thermodynamic properties of fluids. Properties included in the comparison are supercritical thermodynamic properties (pressure, internal energy, and chemical potential), vapor-liquid phase equilibria, second virial coefficients, and heat capacities. For all properties studied, we find a systematically improved description upon using a higher-order perturbation theory. A result of particular relevance is that a third order perturbation theory is capable of providing a quantitative description of second virial coefficients to temperatures as low as the triple-point of the Lennard-Jones fluid. We find no reason to prefer the WCA formalism over the BH formalism.
Retarded correlators in kinetic theory: branch cuts, poles and hydrodynamic onset transitions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Romatschke, Paul
In this paper, the collective modes of an effective kinetic theory description based on the Boltzmann equation in a relaxation-time approximation applicable to gauge theories at weak but finite coupling and low frequencies are studied. Real time retarded two-point correlators of the energy-momentum tensor and the R-charge current are calculated at finite temperature in flat space-times for large N gauge theories. It is found that the real-time correlators possess logarithmic branch cuts which in the limit of large coupling disappear and give rise to non-hydrodynamic poles that are reminiscent of quasi-normal modes in black holes. In addition to branch cuts,more » correlators can have simple hydrodynamic poles, generalizing the concept of hydrodynamic modes to intermediate wavelength. Surprisingly, the hydrodynamic poles cease to exist for some critical value of the wavelength and coupling reminiscent of the properties of onset transitions.« less
Retarded correlators in kinetic theory: branch cuts, poles and hydrodynamic onset transitions
Romatschke, Paul
2016-06-24
In this paper, the collective modes of an effective kinetic theory description based on the Boltzmann equation in a relaxation-time approximation applicable to gauge theories at weak but finite coupling and low frequencies are studied. Real time retarded two-point correlators of the energy-momentum tensor and the R-charge current are calculated at finite temperature in flat space-times for large N gauge theories. It is found that the real-time correlators possess logarithmic branch cuts which in the limit of large coupling disappear and give rise to non-hydrodynamic poles that are reminiscent of quasi-normal modes in black holes. In addition to branch cuts,more » correlators can have simple hydrodynamic poles, generalizing the concept of hydrodynamic modes to intermediate wavelength. Surprisingly, the hydrodynamic poles cease to exist for some critical value of the wavelength and coupling reminiscent of the properties of onset transitions.« less
Deformations of superconformal theories
Córdova, Clay; Dumitrescu, Thomas T.; Intriligator, Kenneth
2016-11-22
Here, we classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in d ≥ 3 dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and noncentral charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact thatmore » short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformations can be used to derive known and new constraints on moduli-space effective actions.« less
The effect of implied orientation derived from verbal context on picture recognition.
Stanfield, R A; Zwaan, R A
2001-03-01
Perceptual symbol systems assume an analogue relationship between a symbol and its referent, whereas amodal symbol systems assume an arbitrary relationship between a symbol and its referent. According to perceptual symbol theories, the complete representation of an object, called a simulation, should reflect physical characteristics of the object. Amodal theories, in contrast, do not make this prediction. We tested the hypothesis, derived from perceptual symbol theories, that people mentally represent the orientation of an object implied by a verbal description. Orientation (vertical-horizontal) was manipulated by having participants read a sentence that implicitly suggested a particular orientation for an object. Then recognition latencies to pictures of the object in each of the two orientations were measured. Pictures matching the orientation of the object implied by the sentence were responded to faster than pictures that did not match the orientation. This finding is interpreted as offering support for theories positing perceptual symbol systems.
Particle-hole symmetry and composite fermions in fractional quantum Hall states
NASA Astrophysics Data System (ADS)
Nguyen, Dung Xuan; Golkar, Siavash; Roberts, Matthew M.; Son, Dam Thanh
2018-05-01
We study fractional quantum Hall states at filling fractions in the Jain sequences using the framework of composite Dirac fermions. Synthesizing previous work, we write an effective field theory consistent with all symmetry requirements, including Galilean invariance and particle-hole symmetry. Employing a Fermi-liquid description, we demonstrate the appearance of the Girvin-Macdonald-Platzman algebra and compute the dispersion relation of neutral excitations and various response functions. Our results satisfy requirements of particle-hole symmetry. We show that while the dispersion relation obtained from the modified random-phase approximation (MRPA) of the Halperin-Lee-Read (HLR) theory is particle-hole symmetric, correlation functions obtained from this scheme are not. The results of the Dirac theory are shown to be consistent with the Haldane bound on the projected structure factor, while those of the MPRA of the HLR theory violate it.
Psychology and Adult Learning. Second Edition.
ERIC Educational Resources Information Center
Tennant, Mark
This book provides a critical account of the psychological theories that have informed contemporary adult education theory and practice. Chapter 1 discusses the importance of balancing description, critique, and comments on each theory's influence on adult education and the need to understand psychological development throughout the life span. The…
Educational Theory and Practice in an Aristotelian Perspective.
ERIC Educational Resources Information Center
Saugstad, Tone
2002-01-01
Uses an Aristotelian perspective to discuss the relationship between educational theory and practice. Draws on Aristotle's Nichomachean ethics and his description of three forms of knowledge to show that educational theory and practice are of qualitatively different categories and thus cannot automatically enter into a "fruitful…
Description of Adsorption in Liquid Chromatography under Nonideal Conditions.
Ortner, Franziska; Ruppli, Chantal; Mazzotti, Marco
2018-05-15
A thermodynamically consistent description of binary adsorption in reversed-phase chromatography is presented, accounting for thermodynamic nonidealities in the liquid and adsorbed phases. The investigated system involves the adsorbent Zorbax 300SB-C18, as well as phenetole and 4- tert-butylphenol as solutes and methanol and water as inert components forming the eluent. The description is based on adsorption isotherms, which are a function of the liquid-phase activities, to account for nonidealities in the liquid phase. Liquid-phase activities are calculated with a UNIQUAC model established in this work, based on experimental phase equilibrium data. The binary interaction in the adsorbed phase is described by the adsorbed solution theory, assuming an ideal (ideal adsorbed solution theory) or real (real adsorbed solution theory) adsorbed phase. Implementation of the established adsorption model in a chromatographic code achieves a quantitative description of experimental elution profiles, with feed compositions exploiting the entire miscible region, and involving a broad range of different eluent compositions (methanol/water). The quantitative agreement of the model and experimental data serves as a confirmation of the underlying physical (thermodynamic) concepts and of their applicability to a broad range of operating conditions.
Towards timelike singularity via AdS dual
NASA Astrophysics Data System (ADS)
Bhowmick, Samrat; Chatterjee, Soumyabrata
2017-07-01
It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore, one can study field theory on this Kasner space via its gravity dual. In this paper, we show that there exists a Kasner-like geometry with timelike singularity for which one can construct a dual gravity description. We then study various extremal surfaces including spacelike geodesics in the dual gravity description. Finally, we compute correlators of highly massive operators in the boundary field theory with a geodesic approximation.
Vakonomic Constraints in Higher-Order Classical Field Theory
NASA Astrophysics Data System (ADS)
Campos, Cédric M.
2010-07-01
We propose a differential-geometric setting for the dynamics of a higher-order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both, the Lagrangian and the Hamiltonian description, since the field equations are formulated using the Lagrangian on a higher-order jet bundle and the canonical multisymplectic form on its affine dual. The result is that we obtain a unique and global intrinsic description of the dynamics. The case of vakonomic constraints is also studied within this formalism.
Executable Architecture of Net Enabled Operations: State Machine of Federated Nodes
2009-11-01
verbal descriptions from operators) of the current Command and Control (C2) practices into model form. In theory these should be Standard Operating...faudra une grande quantité de données pour faire en sorte que le modèle reflète les processus véritables, les auteurs recommandent que la machine à...descriptions from operators) of the current C2 practices into model form. In theory these should be SOPs that execute as a thread from start to finish. The
Plasmonics simulations including nonlocal effects using a boundary element method approach
NASA Astrophysics Data System (ADS)
Trügler, Andreas; Hohenester, Ulrich; García de Abajo, F. Javier
2017-09-01
Spatial nonlocality in the photonic response of metallic nanoparticles is actually known to produce near-field quenching and significant plasmon frequency shifts relative to local descriptions. As the control over size and morphology of fabricated nanostructures is truly reaching the nanometer scale, understanding and accounting for nonlocal phenomena is becoming increasingly important. Recent advances clearly point out the need to go beyond the local theory. We here present a general formalism for incorporating spatial dispersion effects through the hydrodynamic model and generalizations for arbitrary surface morphologies. Our method relies on the boundary element method, which we supplement with a nonlocal interaction potential. We provide numerical examples in excellent agreement with the literature for individual and paired gold nanospheres, and critically examine the accuracy of our approach. The present method involves marginal extra computational cost relative to local descriptions and facilitates the simulation of spatial dispersion effects in the photonic response of complex nanoplasmonic structures.
NASA Astrophysics Data System (ADS)
Cygorek, M.; Axt, V. M.
2015-08-01
Starting from a quantum kinetic theory for the spin dynamics in diluted magnetic semiconductors, we derive simplified equations that effectively describe the spin transfer between carriers and magnetic impurities for an arbitrary initial impurity magnetization. Taking the Markov limit of these effective equations, we obtain good quantitative agreement with the full quantum kinetic theory for the spin dynamics in bulk systems at high magnetic doping. In contrast, the standard rate description where the carrier-dopant interaction is treated according to Fermi’s golden rule, which involves the assumption of a short memory as well as a perturbative argument, has been shown previously to fail if the impurity magnetization is non-zero. The Markov limit of the effective equations is derived, assuming only a short memory, while higher order terms are still accounted for. These higher order terms represent the precession of the carrier-dopant correlations in the effective magnetic field due to the impurity spins. Numerical calculations show that the Markov limit of our effective equations reproduces the results of the full quantum kinetic theory very well. Furthermore, this limit allows for analytical solutions and for a physically transparent interpretation.
Generalized uncertainty principle and quantum gravity phenomenology
NASA Astrophysics Data System (ADS)
Bosso, Pasquale
The fundamental physical description of Nature is based on two mutually incompatible theories: Quantum Mechanics and General Relativity. Their unification in a theory of Quantum Gravity (QG) remains one of the main challenges of theoretical physics. Quantum Gravity Phenomenology (QGP) studies QG effects in low-energy systems. The basis of one such phenomenological model is the Generalized Uncertainty Principle (GUP), which is a modified Heisenberg uncertainty relation and predicts a deformed canonical commutator. In this thesis, we compute Planck-scale corrections to angular momentum eigenvalues, the hydrogen atom spectrum, the Stern-Gerlach experiment, and the Clebsch-Gordan coefficients. We then rigorously analyze the GUP-perturbed harmonic oscillator and study new coherent and squeezed states. Furthermore, we introduce a scheme for increasing the sensitivity of optomechanical experiments for testing QG effects. Finally, we suggest future projects that may potentially test QG effects in the laboratory.
On the effective field theory for quasi-single field inflation
NASA Astrophysics Data System (ADS)
Tong, Xi; Wang, Yi; Zhou, Siyi
2017-11-01
We study the effective field theory (EFT) description of the virtual particle effects in quasi-single field inflation, which unifies the previous results on large mass and large mixing cases. By using a horizon crossing approximation and matching with known limits, approximate expressions for the power spectrum and the spectral index are obtained. The error of the approximate solution is within 10% in dominate parts of the parameter space, which corresponds to less-than-0.1% error in the ns-r diagram. The quasi-single field corrections on the ns-r diagram are plotted for a few inflation models. Especially, the quasi-single field correction drives m2phi2 inflation to the best fit region on the ns-r diagram, with an amount of equilateral non-Gaussianity which can be tested in future experiments.
McDowell, J J; Calvin, Olivia L; Hackett, Ryan; Klapes, Bryan
2017-07-01
Two competing predictions of matching theory and an evolutionary theory of behavior dynamics, and one additional prediction of the evolutionary theory, were tested in a critical experiment in which human participants worked on concurrent schedules for money (Dallery et al., 2005). The three predictions concerned the descriptive adequacy of matching theory equations, and of equations describing emergent equilibria of the evolutionary theory. Tests of the predictions falsified matching theory and supported the evolutionary theory. Copyright © 2017 Elsevier B.V. All rights reserved.
Electron collection theory for a D-region subsonic blunt electrostatic probe
NASA Technical Reports Server (NTRS)
Wai-Kwong Lai, T.
1974-01-01
Blunt probe theory for subsonic flow in a weakly ionized and collisional gas is reviewed, and an electron collection theory for the relatively unexplored case, Deybye length approximately 1, which occurs in the lower ionosphere (D-region), is developed. It is found that the dimensionless Debye length is no longer an electric field screening parameter, and the space charge field effect can be negelected. For ion collection, Hoult-Sonin theory is recognized as a correct description of the thin, ion density-perturbed layer adjacent the blunt probe surface. The large volume with electron density perturbed by a positively biased probe renders the usual thin boundary layer analysis inapplicable. Theories relating free stream conditions to the electron collection rate for both stationary and moving blunt probes are obtained. A model based on experimental nonlinear electron drift velocity data is proposed. For a subsonically moving probe, it is found that the perturbed region can be divided into four regions with distinct collection mechanisms.
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.
Fleeson, William; Jayawickreme, Eranda
2014-01-01
Personality researchers should modify models of traits to include mechanisms of differential reaction to situations. Whole Trait Theory does so via five main points. First, the descriptive side of traits should be conceptualized as density distributions of states. Second, it is important to provide an explanatory account of the Big 5 traits. Third, adding an explanatory account to the Big 5 creates two parts to traits, an explanatory part and a descriptive part, and these two parts should be recognized as separate entities that are joined into whole traits. Fourth, Whole Trait Theory proposes that the explanatory side of traits consists of social-cognitive mechanisms. Fifth, social-cognitive mechanisms that produce Big-5 states should be identified. PMID:26097268
NASA Astrophysics Data System (ADS)
Jeon, Imtak; Lambert, Neil; Richmond, Paul
2012-11-01
We consider periodic arrays of M2-branes in the ABJM model in the spirit of a circle compactification to D2-branes in type IIA string theory. The result is a curious formulation of three-dimensional maximally supersymmetric Yang-Mills theory in terms of fermions, seven transverse scalars, a non-dynamical gauge field and an additional scalar `dual gluon'. Upon further T-duality on a transverse torus we obtain a non-manifest- Lorentz-invariant description of five-dimensional maximally supersymmetric Yang-Mills. Here the additional scalar field can be thought of as the components of a two-form along the torus. This action can be viewed as an M-theory description of M5-branes on {{{T}}^3}.
Sum-rule corrections: a route to error cancellations in correlation matrix renormalisation theory
NASA Astrophysics Data System (ADS)
Liu, C.; Liu, J.; Yao, Y. X.; Wang, C. Z.; Ho, K. M.
2017-03-01
We recently proposed the correlation matrix renormalisation (CMR) theory to efficiently and accurately calculate ground state total energy of molecular systems, based on the Gutzwiller variational wavefunction (GWF) to treat the electronic correlation effects. To help reduce numerical complications and better adapt the CMR to infinite lattice systems, we need to further refine the way to minimise the error originated from the approximations in the theory. This conference proceeding reports our recent progress on this key issue, namely, we obtained a simple analytical functional form for the one-electron renormalisation factors, and introduced a novel sum-rule correction for a more accurate description of the intersite electron correlations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.
Non-equilibrium magnetic interactions in strongly correlated systems
NASA Astrophysics Data System (ADS)
Secchi, A.; Brener, S.; Lichtenstein, A. I.; Katsnelson, M. I.
2013-06-01
We formulate a low-energy theory for the magnetic interactions between electrons in the multi-band Hubbard model under non-equilibrium conditions determined by an external time-dependent electric field which simulates laser-induced spin dynamics. We derive expressions for dynamical exchange parameters in terms of non-equilibrium electronic Green functions and self-energies, which can be computed, e.g., with the methods of time-dependent dynamical mean-field theory. Moreover, we find that a correct description of the system requires, in addition to exchange, a new kind of magnetic interaction, that we name twist exchange, which formally resembles Dzyaloshinskii-Moriya coupling, but is not due to spin-orbit, and is actually due to an effective three-spin interaction. Our theory allows the evaluation of the related time-dependent parameters as well.
Children's Accounts of Sibling Jealousy and Their Implicit Theories about Relationships
ERIC Educational Resources Information Center
Thompson, Julie A.; Halberstadt, Amy G.
2008-01-01
In two studies, fifth- and sixth-grade children's descriptive accounts of sibling jealousy were related to their implicit theories about relationships. Children's jealousy accounts were collected via structured interviews; their implicit theories were assessed by questionnaire. In both studies, children reported experiencing mild to moderate…
Constrained variational calculus for higher order classical field theories
NASA Astrophysics Data System (ADS)
Campos, Cédric M.; de León, Manuel; Martín de Diego, David
2010-11-01
We develop an intrinsic geometrical setting for higher order constrained field theories. As a main tool we use an appropriate generalization of the classical Skinner-Rusk formalism. Some examples of applications are studied, in particular to the geometrical description of optimal control theory for partial differential equations.
A Critique of the Controversy about the Stability of Consumers' Tastes.
ERIC Educational Resources Information Center
Daniel, Coldwell, III
1988-01-01
Examines the role of the stability of consumer tastes in descriptive theory. Summarizes the traditional approach to the derivation of the consumer's preference structure, considers ways in which the conventional theory has been extended, presents the Stigler-Becker theory of consumer choice, and evaluates both approaches. (GEA)
ERIC Educational Resources Information Center
Dulberg, Nancy
2005-01-01
Recent research on children's historical thinking has produced rich descriptions of instruction. However, the research literature is largely lacking a theoretical model of learning. This article asserts that developmental constructivist theory informs research design and interpretation, provides explanatory power, and promises more useful…
Smith, Gregory T.; McCarthy, Denis M.; Zapolski, Tamika C. B.
2010-01-01
The authors argue for a significant shift in how clinical psychology researchers conduct construct validation and theory validation tests. They argue that sound theory and validation tests can best be conducted on measures of unidimensional or homogeneous constructs. Hierarchical organizations of such constructs are useful descriptively and theoretically, but higher order composites do not refer to definable psychological processes. Application of this perspective to the approach of the Diagnostic and Statistical Manual of Mental Disorders to describing psychopathology calls into doubt the traditional use of the syndromal approach, in which single scores reflect the presence of multidimensional disorders. For many forms of psychological dysfunction, this approach does not appear optimal and may need to be discarded. The authors note that their perspective represents a straightforward application of existing psychometric theory, they demonstrate the practical value of adopting this perspective, and they provide evidence that this shift is already under way among clinical researchers. Description in terms of homogeneous dimensions provides improved validity, utility, and parsimony. In contrast, the use of composite diagnoses can retard scientific progress and hamper clinicians' efforts to understand and treat dysfunction. PMID:19719340
Metaphor, Model, and Theory in Education Research.
ERIC Educational Resources Information Center
Dickmeyer, Nathan
1989-01-01
The concepts of metaphor, model, and theory are defined and used to show how social science research in general, and education research in particular, has differed from Popper's description of natural science research. (IAH)
Felix P. Ratcliff; James Bartolome; Michele Hammond; Sheri Spiegal; Michael White
2015-01-01
Ecological site descriptions and associated state-and-transition models are useful tools for understanding the variable effects of management and environment on range resources. Models for woody riparian sites have yet to be fully developed. At Tejon Ranch, in the southern San Joaquin Valley of California, we are using ecological site theory to investigate the role of...
ERIC Educational Resources Information Center
Silyvier, Tsindoli; Nyandusi, Charles
2015-01-01
The purpose of the study was to assess the effect of teacher characteristics on their competence in developing resilience in vulnerable primary school children. A descriptive survey research design was used. This study was based on resiliency theory as proposed by Krovetz (1998). Simple random sampling was used to select a sample size of 108…
High-Frequency Sound Interaction in Ocean Sediments
2002-09-30
sediment attenuation (10-300 kHz) and sound speed (10-300 kHz) and determine constraints imposed on sediment acoustic models , such as poroelastic (Biot...by poroelastic seafloors: First-order theory,” accepted for publication in J. Acoust . Soc. Am. 5. K. L. Williams, “An effective density fluid model ... poroelastic sediment models , the appropriateness of stochastic descriptions of sediment heterogeneities, the importance of single versus multiple
ERIC Educational Resources Information Center
Shearer, Rick L.
2009-01-01
Theory building is complex and ongoing. Theories need to be constantly tested and the underlying constructs explored, as knowledge of a field evolves. This study, which is in support of Moore's (1980, 1993) theory of transactional distance, is exploratory and descriptive, and focuses on one of the key variables in the theory dialogue. As…
A Report on Two Views of the Deficit Theory of Language.
ERIC Educational Resources Information Center
Yellin, David
The views of proponents and opponents of the language deficit theory--the theory that nonstandard dialect is a deficient form of language--are presented in this paper. Following a description of the work of Basil Bernstein, a British educator who is considered the key figure among proponents of the theory, the paper presents an overview of the…
A hybrid approach to simulation of electron transfer in complex molecular systems
Kubař, Tomáš; Elstner, Marcus
2013-01-01
Electron transfer (ET) reactions in biomolecular systems represent an important class of processes at the interface of physics, chemistry and biology. The theoretical description of these reactions constitutes a huge challenge because extensive systems require a quantum-mechanical treatment and a broad range of time scales are involved. Thus, only small model systems may be investigated with the modern density functional theory techniques combined with non-adiabatic dynamics algorithms. On the other hand, model calculations based on Marcus's seminal theory describe the ET involving several assumptions that may not always be met. We review a multi-scale method that combines a non-adiabatic propagation scheme and a linear scaling quantum-chemical method with a molecular mechanics force field in such a way that an unbiased description of the dynamics of excess electron is achieved and the number of degrees of freedom is reduced effectively at the same time. ET reactions taking nanoseconds in systems with hundreds of quantum atoms can be simulated, bridging the gap between non-adiabatic ab initio simulations and model approaches such as the Marcus theory. A major recent application is hole transfer in DNA, which represents an archetypal ET reaction in a polarizable medium. Ongoing work focuses on hole transfer in proteins, peptides and organic semi-conductors. PMID:23883952
Recent progress in the microscopic description of small and large amplitude collective motion
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lacroix, D., E-mail: lacroix@ipno.in2p3.fr; Tanimura, Y.; Ayik, S.
2015-10-15
Dynamical mean-field theory has recently attracted much interests to provide a unified framework for the description of many aspects of nuclear dynamics [1, 2, 3, 4, 5] (for recent reviews see [6, 7]). In particular, the inclusion of pairing correlation has opened new perspectives [8, 9, 10, 11, 12]. A summary of recent applications including giant resonances and transfer reactions will be made in this talk [13, 14, 15, 16]. While new progresses have been made with the use of sophisticated effective interactions and the development of symmetry unrestricted applications, mean-field dynamics suffer from the poor treatment of quantum fluctuationsmore » in collective space. As a consequence, these theories are successful in describing average properties of many different experimental observations but generally fail to account realistically for the width of experimental distribution. The increase of predictive power of dynamical mean-field theory is facing the difficulty of going beyond the independent particle or quasi-particle picture. Nevertheless, in the last decade, novel methods have been proposed to prepare the next generation of microscopic mean-field codes able to account for both average properties and fluctuations around the average. A review of recent progresses in this direction as well as recent applications to heavy-ion collisions will be given [17, 18].« less
Perturbation theory for water with an associating reference fluid
NASA Astrophysics Data System (ADS)
Marshall, Bennett D.
2017-11-01
The theoretical description of the thermodynamics of water is challenged by the structural transition towards tetrahedral symmetry at ambient conditions. As perturbation theories typically assume a spherically symmetric reference fluid, they are incapable of accurately describing the liquid properties of water at ambient conditions. In this paper we address this problem by introducing the concept of an associated reference perturbation theory (APT). In APT we treat the reference fluid as an associating hard sphere fluid which transitions to tetrahedral symmetry in the fully hydrogen bonded limit. We calculate this transition in a theoretically self-consistent manner without appealing to molecular simulations. This associated reference provides the reference fluid for a second order Barker-Henderson perturbative treatment of the long-range attractions. We demonstrate that this approach gives a significantly improved description of water as compared to standard perturbation theories.
Generating functionals and Gaussian approximations for interruptible delay reactions
NASA Astrophysics Data System (ADS)
Brett, Tobias; Galla, Tobias
2015-10-01
We develop a generating functional description of the dynamics of non-Markovian individual-based systems in which delay reactions can be terminated before completion. This generalizes previous work in which a path-integral approach was applied to dynamics in which delay reactions complete with certainty. We construct a more widely applicable theory, and from it we derive Gaussian approximations of the dynamics, valid in the limit of large, but finite, population sizes. As an application of our theory we study predator-prey models with delay dynamics due to gestation or lag periods to reach the reproductive age. In particular, we focus on the effects of delay on noise-induced cycles.
Reformulations of Yang–Mills theories with space–time tensor fields
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guo, Zhi-Qiang, E-mail: gzhqedu@gmail.com
2016-01-15
We provide the reformulations of Yang–Mills theories in terms of gauge invariant metric-like variables in three and four dimensions. The reformulations are used to analyze the dimension two gluon condensate and give gauge invariant descriptions of gluon polarization. In three dimensions, we obtain a non-zero dimension two gluon condensate by one loop computation, whose value is similar to the square of photon mass in the Schwinger model. In four dimensions, we obtain a Lagrangian with the dual property, which shares the similar but different property with the dual superconductor scenario. We also make discussions on the effectiveness of one loopmore » approximation.« less
A theory of ring formation around Be stars
NASA Technical Reports Server (NTRS)
Huang, S.-S.
1976-01-01
A theory for the formation of gaseous rings around Be stars is developed which involves the combined effect of stellar rotation and radiation pressure. A qualitative scenario of ring formation is outlined in which the envelope formed about a star from ejected material is in the form of a disk in the equatorial plane, collisions between ejected gas blobs are inevitable, and particles with high angular momenta form a rotating ring around the star. A quantitative description of this process is then formulated by considering the angular momentum and dynamical energy of the ejected matter as well as those of the ring alone, without introducing any other assumptions.
Traffic Games: Modeling Freeway Traffic with Game Theory
Cortés-Berrueco, Luis E.; Gershenson, Carlos; Stephens, Christopher R.
2016-01-01
We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers’ interactions. PMID:27855176
Traffic Games: Modeling Freeway Traffic with Game Theory.
Cortés-Berrueco, Luis E; Gershenson, Carlos; Stephens, Christopher R
2016-01-01
We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers' interactions.
1956-05-01
in this par- t.cular instance was not a parameter of importance in the etiology of fatigue. Many of the animals received significant doses of ionizing...noise levels in the range of 150 to i60 db is clearly etiologic in the production of the fatigue syndrome., Much less is known about the effects on...I.i Primary . . . . . . . . . . . . . i 2 :condary . . . . . . . . . . . . CHAPTER 2 THEORY AND BACKGROUND . . . . . . . 12 2.1 Description of the
NASA Astrophysics Data System (ADS)
Nold, Andreas; Goddard, Ben; Sibley, David; Kalliadasis, Serafim
2014-03-01
Multiscale effects play a predominant role in wetting phenomena such as the moving contact line. An accurate description is of paramount interest for a wide range of industrial applications, yet it is a matter of ongoing research, due to the difficulty of incorporating different physical effects in one model. Important small-scale phenomena are corrections to the attractive fluid-fluid and wall-fluid forces in inhomogeneous density distributions, which often previously have been accounted for by the disjoining pressure in an ad-hoc manner. We systematically derive a novel model for the description of a single-component liquid-vapor multiphase system which inherently incorporates these nonlocal effects. This derivation, which is inspired by statistical mechanics in the framework of colloidal density functional theory, is critically discussed with respect to its assumptions and restrictions. The model is then employed numerically to study a moving contact line of a liquid fluid displacing its vapor phase. We show how nonlocal physical effects are inherently incorporated by the model and describe how classical macroscopic results for the contact line motion are retrieved. We acknowledge financial support from ERC Advanced Grant No. 247031 and Imperial College through a DTG International Studentship.
NASA Technical Reports Server (NTRS)
Lutzky, D.; Bjorkman, W. S.
1973-01-01
The Mission Analysis Evaluation and Space Trajectory Operations program known as MAESTRO is described. MAESTRO is an all FORTRAN, block style, computer program designed to perform various mission control tasks. This manual is a guide to MAESTRO, providing individuals the capability of modifying the program to suit their needs. Descriptions are presented of each of the subroutines descriptions consist of input/output description, theory, subroutine description, and a flow chart where applicable. The programmer's manual also contains a detailed description of the common blocks, a subroutine cross reference map, and a general description of the program structure.
NASA Astrophysics Data System (ADS)
Ruiz-Cabello, F. Javier Montes; Maroni, Plinio; Borkovec, Michal
2013-06-01
Force measurements between three types of latex particles of diameters down to 1 μm with sulfate and carboxyl surface functionalities were carried out with the multi-particle colloidal probe technique. The experiments were performed in monovalent electrolyte up to concentrations of about 5 mM. The force profiles could be quantified with the theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO) by invoking non-retarded van der Waals forces and the Poisson-Boltzmann description of double layer forces within the constant regulation approximation. The forces measured in the symmetric systems were used to extract particle and surface properties, namely, the Hamaker constant, surface potentials, and regulation parameters. The regulation parameter is found to be independent of solution composition. With these values at hand, the DLVO theory is capable to accurately predict the measured forces in the asymmetric systems down to distances of 2-3 nm without adjustable parameters. This success indicates that DLVO theory is highly reliable to quantify interaction forces in such systems. However, charge regulation effects are found to be important, and they must be considered to obtain correct description of the forces. The use of the classical constant charge or constant potential boundary conditions may lead to erroneous results. To make reliable predictions of the force profiles, the surface potentials must be extracted from direct force measurements too. For highly charged surfaces, the commonly used electrophoresis techniques are found to yield incorrect estimates of this quantity.
Montes Ruiz-Cabello, F Javier; Maroni, Plinio; Borkovec, Michal
2013-06-21
Force measurements between three types of latex particles of diameters down to 1 μm with sulfate and carboxyl surface functionalities were carried out with the multi-particle colloidal probe technique. The experiments were performed in monovalent electrolyte up to concentrations of about 5 mM. The force profiles could be quantified with the theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO) by invoking non-retarded van der Waals forces and the Poisson-Boltzmann description of double layer forces within the constant regulation approximation. The forces measured in the symmetric systems were used to extract particle and surface properties, namely, the Hamaker constant, surface potentials, and regulation parameters. The regulation parameter is found to be independent of solution composition. With these values at hand, the DLVO theory is capable to accurately predict the measured forces in the asymmetric systems down to distances of 2-3 nm without adjustable parameters. This success indicates that DLVO theory is highly reliable to quantify interaction forces in such systems. However, charge regulation effects are found to be important, and they must be considered to obtain correct description of the forces. The use of the classical constant charge or constant potential boundary conditions may lead to erroneous results. To make reliable predictions of the force profiles, the surface potentials must be extracted from direct force measurements too. For highly charged surfaces, the commonly used electrophoresis techniques are found to yield incorrect estimates of this quantity.
Thermodynamics sheds light on black hole dynamics
NASA Astrophysics Data System (ADS)
Cárdenas, Marcela; Julié, Félix-Louis; Deruelle, Nathalie
2018-06-01
We propose to unify two a priori distinct aspects of black hole physics: their thermodynamics, and their description as point particles, which is an essential starting point in the post-Newtonian approach to their dynamics. We will find that, when reducing a black hole to a point particle endowed with its specific effective mass, one in fact describes a black hole satisfying the first law of thermodynamics, such that its global charges, and hence its entropy, remain constant. This gives a thermodynamical interpretation of its effective mass, thus opening a promising synergy between black hole thermodynamics and the analytical approaches to the two-body problems in gravity theories. To illustrate this relationship, the Einstein-Maxwell-dilaton theory, which contains simple examples of asympotically flat, hairy black hole solutions, will serve as a laboratory.
ERIC Educational Resources Information Center
Gunter, Helen M.
2013-01-01
This article reports on a seminar by the Critical Educational Policy and Leadership Research Interest Group in June 2012. The article reports on the papers and our engagement with the need to use theory to develop descriptions and understandings.
NASA Technical Reports Server (NTRS)
Ellis, J. R.
1988-01-01
Complex states of stress and strain are introduced into components during service in engineering applications. It follows that analysis of such components requires material descriptions, or constitutive theories, which reflect the tensorial nature of stress and strain. For applications involving stress levels above yield, the situation is more complex in that material response is both nonlinear and history dependent. This has led to the development of viscoplastic constitutive theories which introduce time by expressing the flow and evolutionary equation in the form of time derivatives. Models were developed here which can be used to analyze high temperature components manufactured from advanced composite materials. In parallel with these studies, effort was directed at developing multiaxial testing techniques to verify the various theories. Recent progress in the development of constitutive theories from both the theoretical and experimental viewpoints are outlined. One important aspect is that material descriptions for advanced composite materials which can be implemented in general purpose finite element codes and used for practical design are verified.
FRW Solutions and Holography from Uplifted AdS/CFT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dong, Xi; Horn, Bart; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC
2012-02-15
Starting from concrete AdS/CFT dual pairs, one can introduce ingredients which produce cosmological solutions, including metastable de Sitter and its decay to non-accelerating FRW. We present simple FRW solutions sourced by magnetic flavor branes and analyze correlation functions and particle and brane dynamics. To obtain a holographic description, we exhibit a time-dependent warped metric on the solution and interpret the resulting redshifted region as a Lorentzian low energy effective field theory in one fewer dimension. At finite times, this theory has a finite cutoff, a propagating lower dimensional graviton and a finite covariant entropy bound, but at late times themore » lower dimensional Planck mass and entropy go off to infinity in a way that is dominated by contributions from the low energy effective theory. This opens up the possibility of a precise dual at late times. We reproduce the time-dependent growth of the number of degrees of freedom in the system via a count of available microscopic states in the corresponding magnetic brane construction.« less
FRW solutions and holography from uplifted AdS/CFT systems
NASA Astrophysics Data System (ADS)
Dong, Xi; Horn, Bart; Matsuura, Shunji; Silverstein, Eva; Torroba, Gonzalo
2012-05-01
Starting from concrete AdS/CFT dual pairs, one can introduce ingredients which produce cosmological solutions, including metastable de Sitter and its decay to nonaccelerating Friedmann-Robertson-Walker. We present simple Friedmann-Robertson-Walker solutions sourced by magnetic flavor branes and analyze correlation functions and particle and brane dynamics. To obtain a holographic description, we exhibit a time-dependent warped metric on the solution and interpret the resulting redshifted region as a Lorentzian low energy effective field theory in one fewer dimension. At finite times, this theory has a finite cutoff, a propagating lower-dimensional graviton, and a finite covariant entropy bound, but at late times the lower-dimensional Planck mass and entropy go off to infinity in a way that is dominated by contributions from the low energy effective theory. This opens up the possibility of a precise dual at late times. We reproduce the time-dependent growth of the number of degrees of freedom in the system via a count of available microscopic states in the corresponding magnetic brane construction.
Understanding medical practice team roles.
Hills, Laura
2015-01-01
Do you believe that the roles your employees play on your medical practice team are identical to their job titles or job descriptions? Do you believe that team roles are determined by personality type? This article suggests that a more effective way to build and manage your medical practice team is to define team roles through employee behaviors. It provides 10 rules of behavioral team roles that can help practice managers to select and build high-performing teams, build more productive team relationships, improve the employee recruitment process, build greater team trust and understanding; and increase their own effectiveness. This article describes in detail Belbin's highly regarded and widely used team role theory and summarizes four additional behavioral team role theories and systems. It offers lessons learned when applying team role theory to practice. Finally, this article offers an easy-to-implement method for assessing current team roles. It provides a simple four-question checklist that will help practice managers balance an imbalanced medical practice team.
Second-order dissipative hydrodynamics for plasma with chiral asymmetry and vorticity
NASA Astrophysics Data System (ADS)
Gorbar, E. V.; Rybalka, D. O.; Shovkovy, I. A.
2017-05-01
By making use of the chiral kinetic theory in the relaxation-time approximation, we derive an Israel-Stewart type formulation of the hydrodynamic equations for a chiral relativistic plasma made of neutral particles (e.g., neutrinos). The effects of chiral asymmetry are captured by including an additional continuity equation for the axial charge, as well as the leading-order quantum corrections due to the spin of particles. In a formulation of the chiral kinetic theory used, we introduce a symmetric form of the energy-momentum tensor that is suitable for the description of a weakly nonuniform chiral plasma. By construction, the energy and momentum are conserved to the same leading order in the Planck constant as the kinetic equation itself. By making use of such a chiral kinetic theory and the Chapman-Enskog approach, we obtain a set of second-order dissipative hydrodynamic equations. The effects of the fluid vorticity and velocity fluctuations on the dispersion relations of chiral vortical waves are analyzed.
ERIC Educational Resources Information Center
Sensevy, Gérard; Gruson, Brigitte; Forest, Dominique
2015-01-01
In this paper, we first sketch the joint action theory paradigm from a general viewpoint in sciences of culture. Then we specify this generic description by focusing on the joint action theory in didactics (JATD). We elaborate on three currently developed elements of the theory: the reticence-expression dialectics; the contract-milieu dialectics,…
Thinking about Theory in Educational Research: Fieldwork in Philosophy
ERIC Educational Resources Information Center
Lingard, Bob
2015-01-01
This article responds to and reflects upon the articles in this special issue. Specifically, it deals with the usage of theory in each of the articles, what we might see, as examples of re-descriptive usage in autonomous theorizing. The articles utilize different theories and varying intellectual resources--Foucault and Deleuze (Richard Niesche),…
How Often Are Theories Developed through Empirical Research into Higher Education?
ERIC Educational Resources Information Center
Ashwin, Paul
2012-01-01
This article reports on a review of empirical research published in selected higher education journals in 2008, which was focused on examining how often theories are developed through research. This review found relatively little evidence of theory development. Drawing on the notions of internal and external languages of description, it is argued…
A Partial Theory of Executive Succession.
ERIC Educational Resources Information Center
Thiemann, Francis C.
This study has two purposes: (1) To construct a partial theory of succession, and (2) to utilize a method of theory construction which combines some of the concepts of Hans Zetterberg with the principles of formal symbolic logic. A bibliography on succession in complex organizations with entries on descriptive and empirical studies from various…
Controlling Communication: A Prescriptive Approach to Communication Studies.
ERIC Educational Resources Information Center
Garner, Mark; Johnson, Edward
If the discussions of communication can be divided into those concerned with a description or theory and those concerned with prescription, then it must be understood that the former can never by itself improve communication. As a field, communication studies does not yet know enough about prescriptive language theory; that is, theory concerned…
Mind and Meaning: Piaget and Vygotsky on Causal Explanation.
ERIC Educational Resources Information Center
Beilin, Harry
1996-01-01
Piaget's theory has been characterized as descriptive and not explanatory, not qualifying as causal explanation. Piaget was consistent in showing how his theory was both explanatory and causal. Vygotsky also endorsed causal-genetic explanation but, on the basis of knowledge of only Piaget's earliest works, he claimed that Piaget's theory was not…
Ali Morowatisharifabad, Mohammad; Abdolkarimi, Mahdi; Asadpour, Mohammad; Fathollahi, Mahmood Sheikh; Balaee, Parisa
2018-04-15
Theory-based education tailored to target behaviour and group can be effective in promoting physical activity. The purpose of this study was to examine the predictive power of Protection Motivation Theory on intent and behaviour of Physical Activity in Patients with Type 2 Diabetes. This descriptive study was conducted on 250 patients in Rafsanjan, Iran. To examine the scores of protection motivation theory structures, a researcher-made questionnaire was used. Its validity and reliability were confirmed. The level of physical activity was also measured by the International Short - form Physical Activity Inventory. Its validity and reliability were also approved. Data were analysed by statistical tests including correlation coefficient, chi-square, logistic regression and linear regression. The results revealed that there was a significant correlation between all the protection motivation theory constructs and the intention to do physical activity. The results showed that the Theory structures were able to predict 60% of the variance of physical activity intention. The results of logistic regression demonstrated that increase in the score of physical activity intent and self - efficacy increased the chance of higher level of physical activity by 3.4 and 1.5 times, respectively OR = (3.39, 1.54). Considering the ability of protection motivation theory structures to explain the physical activity behaviour, interventional designs are suggested based on the structures of this theory, especially to improve self -efficacy as the most powerful factor in predicting physical activity intention and behaviour.
NASA Technical Reports Server (NTRS)
Bodley, C. S.; Devers, D. A.; Park, C. A.
1975-01-01
A theoretical development and associated digital computer program system is presented. The dynamic system (spacecraft) is modeled as an assembly of rigid and/or flexible bodies not necessarily in a topological tree configuration. The computer program system may be used to investigate total system dynamic characteristics including interaction effects between rigid and/or flexible bodies, control systems, and a wide range of environmental loadings. Additionally, the program system may be used for design of attitude control systems and for evaluation of total dynamic system performance including time domain response and frequency domain stability analyses. Volume 1 presents the theoretical developments including a description of the physical system, the equations of dynamic equilibrium, discussion of kinematics and system topology, a complete treatment of momentum wheel coupling, and a discussion of gravity gradient and environmental effects. Volume 2, is a program users' guide and includes a description of the overall digital program code, individual subroutines and a description of required program input and generated program output. Volume 3 presents the results of selected demonstration problems that illustrate all program system capabilities.
NASA Astrophysics Data System (ADS)
Dunklin, Jeremy R.; Forcherio, Gregory T.; Berry, Keith R.; Roper, D. Keith
2016-09-01
Polymer films containing plasmonic nanostructures are of increasing interest for development of responsive energy, sensing, and therapeutic systems. A series of novel gold nanoparticle (AuNP)-polydimethylsiloxane (PDMS) films were fabricated to elucidate enhanced optical extinction from diffractive and scattering induced internal reflection. AuNPs with dramatically different scattering-to-absorption ratios were compared at variable interparticle separations to differentiate light trapping from optical diffraction and Mie scattering. Description of interfacial optical and thermal effects due to these interrelated contributions has progressed beyond Mie theory, Beer's law, effective media, and conventional heat transfer descriptions. Thermal dissipation rates in AuNP-PDMS with this interfacial optical reflection was enhanced relative to films containing heterogeneous AuNPs and a developed thermal dissipation description. This heuristic, which accounts for contributions of both internal and external thermal dissipations, has been shown to accurately predict thermal dissipation rates from AuNP-containing insulating and conductive substrates in both two and three-dimensional systems. Enhanced thermal response rates could enable design and adaptive control of thermoplasmonic materials for a variety of implementations.
Phase transitions in Yang-Mills theories and their gravity duals
NASA Astrophysics Data System (ADS)
Marsano, Joseph Daniel
This thesis is a study of the thermal phase structure of systems that admit dual gauge theory and string theory descriptions. In a pair of examples, we explore the connection between perturbative Yang-Mills and gravitational thermodynamics which arises from the fact that these descriptions probe different corners of a single phase diagram. The structure that emerges from a detailed study of these isolated regions generally suggests a natural conjecture how they may be connected to one another within the full phase diagram. This permits the identification of interesting phenomena in the gauge and gravity regimes under a continuous change in parameters. We begin by studying the AdS5/CFT 4 system which, when the supergravity description is valid, exhibits a first order Hawking-Page phase transition as a function of temperature from a thermal gas of gravitons to a large black hole. In the perturbative Yang-Mills regime, we find that the free theory exhibits a weakly first order deconfinement transition whose precise nature at small nonzero coupling depends on the result of a nontrivial perturbative computation. It is conjectured that this deconfinement transition is continuously connected in the full phase diagram to the Hawking-Page transition at strong coupling, with the confined phase identified with the graviton gas and the deconfined phase identified with the black hole. We then turn to the study of Gregory-Laflamme (GL) black hole/black string transitions in supergravity and their realization in a setup that admits a dual description via the maximally supersymmetric Yang-Mills theory on T2. The thermodynamics of Yang-Mills theories on low dimensional tori is studied in detail revealing an intricate structure of which the GL transition at strong coupling is a small piece. We are led to conjecture that GL physics is continuously connected to deconfinement in maximally supersymmetric 0 + 1-dimensional gauged matrix quantum mechanics. This identification will then permit us to probe GL transitions from the gauge theory point of view and comment on some puzzles regarding their precise nature.
Logic Dynamics for Deductive Inference -- Its Stability and Neural Basis
NASA Astrophysics Data System (ADS)
Tsuda, Ichiro
2014-12-01
We propose a dynamical model that represents a process of deductive inference. We discuss the stability of logic dynamics and a neural basis for the dynamics. We propose a new concept of descriptive stability, thereby enabling a structure of stable descriptions of mathematical models concerning dynamic phenomena to be clarified. The present theory is based on the wider and deeper thoughts of John S. Nicolis. In particular, it is based on our joint paper on the chaos theory of human short-term memories with a magic number of seven plus or minus two.
Many-Body Theory of Pyrochlore Iridates and Related Materials
NASA Astrophysics Data System (ADS)
Wang, Runzhi
In this thesis we focus on two problems. First we propose a numerical method for generating optimized Wannier functions with desired properties. Second we perform the state of the art density functional plus dynamical mean-field calculations in pyrochlore iridates, to investigate the physics induced by the cooperation of spin-orbit coupling and electron correlation. We begin with the introduction for maximally localized Wannier functions and other related extensions. Then we describe the current research in the field of spin-orbit coupling and its interplay with correlation effects, followed by a brief introduction of the `hot' materials of iridates. Before the end of the introduction, we discuss the numerical methods employed in our work, including the density functional theory; dynamical mean-field theory and its combination with the exact diagonalization impurity solver. Then we propose our approach for constructing an optimized set of Wannier functions, which is a generalization of the functionality of the classic maximal localization method put forward by Marzari and Vanderbilt. Our work is motivated by the requirement of the effective description of the local subspace of the Hamiltonian by the beyond density functional theory methods. In extensions of density functional theory such as dynamical mean-field theory, one may want highly accurate description of particular local orbitals, including correct centers and symmetries; while the basis for the remaining degrees of freedom is unimportant. Therefore, we develop the selectively localized Wannier function approach which allows for a greater localization in the selected subset of Wannier functions and at the same time allows us to fix the centers and ensure the point symmetries. Applications in real materials are presented to demonstrate the power of our approach. Next we move to the investigation of pyrochlore iridates, focussing on the metal-insulator transition and material dependence in these compounds. We perform combined density functional plus dynamical mean-field calculations in Lu2Ir2O7, Y2Ir2O 7, Eu2Ir2O7, with spin-orbit coupling included and both single-site and cluster approximations appiled. A broad range of Weyl metal is predicted as the intervening phase in the metal-insulator transition. By comparing to experiments, we find that the single-site approximation fails to predict the gap values and substantial difference between the Y and Eu-compound, demonstrating the inadequacy of this approximation and indicating the key role played by the intersite effects. Finally, we provide a more accurate description of the vicinity of the metal-insulator and topological transitions implied by density functional plus cluster dynamical mean-field calculations of pyrochlore iridates. We find definitive evidence of the Weyl semimetal phase, the electronic structure of which can be approximately described as ``Weyl rings" with an extremely flat dispersion of one of the Weyl bands. This Weyl semimetal phase is further investigated by the k • p analysis fitting to the numerical results. We find that this unusual structure leads to interesting behavior in the optical conductivity including a Hall effect in the interband component, and to an enhanced susceptibility.
Consistency relations in effective field theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Munshi, Dipak; Regan, Donough, E-mail: D.Munshi@sussex.ac.uk, E-mail: D.Regan@sussex.ac.uk
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 δmore » as well as the scaled divergence of velocity θ-bar . Assuming a ΛCDM background cosmology, we find the correction to SPT results becomes important at k ∼> 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.« less
ERIC Educational Resources Information Center
Fulei-Szanto, Andres
1974-01-01
A description of a contrastive linguistics project in Hungary aiming to augment linguistic theories in the Spanish language and propound theories for scientific and artistic translation. (Text is in Spanish.) (CK)
Chemical Principles Revisited: Updating the Atomic Theory in General Chemistry.
ERIC Educational Resources Information Center
Whitman, Mark
1984-01-01
Presents a descriptive overview of recent achievements in atomic structure to provide instructors with the background necessary to enhance their classroom presentations. Topics considered include hadrons, quarks, leptons, forces, and the unified fields theory. (JN)
Prospect theory for online financial trading.
Liu, Yang-Yu; Nacher, Jose C; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv
2014-01-01
Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the "reflection effect". People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called "loss aversion". Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior.
Pristine Inner Experience and Descriptive Experience Sampling: Implications for Psychology
Lapping-Carr, Leiszle R.; Heavey, Christopher L.
2017-01-01
Pristine inner experience is that which is directly present in awareness before it is distorted by attempts at observation or interpretation. Many psychological methods, including most introspective methods, attempt to measure some aspect of pristine inner experience (thoughts, feelings, mental imagery, sensations, etc.). We believe, however, that these methods produce unspecifiable combinations of pristine inner experience, beliefs about the self, beliefs about what inner experience should be like, inaccurate recollections, miscommunications, and other confounding influences. We argue that descriptive experience sampling (DES) can produce high fidelity descriptions of pristine inner experience. These descriptions are used to create idiographic profiles, carefully crafted, in-depth characterizations of the pristine inner experience of individuals. We believe these profiles, because they are built from moments apprehended via a method that confronts the challenges inherent in examining inner experience, are uniquely valuable in advancing the science of inner experience and psychology broadly. For example, DES observations raise important questions about the veracity of results gathered via questionnaires and other introspective methods, like casual introspection. DES findings also provide high fidelity phenomenological data that can be useful for those developing psychological theories, such as theories of emotional processing. Additionally, DES procedures may allow clinicians and clients to practice valuable skills, like bracketing presuppositions and attending to internal experiences. This paper will describe difficulties inherent in the study of pristine inner experience and discuss implications of high fidelity descriptions of pristine inner experience for psychological research, theory development, and clinical practice. PMID:29312047
A gauge-theoretic approach to gravity.
Krasnov, Kirill
2012-08-08
Einstein's general relativity (GR) is a dynamical theory of the space-time metric. We describe an approach in which GR becomes an SU(2) gauge theory. We start at the linearized level and show how a gauge-theoretic Lagrangian for non-interacting massless spin two particles (gravitons) takes a much more simple and compact form than in the standard metric description. Moreover, in contrast to the GR situation, the gauge theory Lagrangian is convex. We then proceed with a formulation of the full nonlinear theory. The equivalence to the metric-based GR holds only at the level of solutions of the field equations, that is, on-shell. The gauge-theoretic approach also makes it clear that GR is not the only interacting theory of massless spin two particles, in spite of the GR uniqueness theorems available in the metric description. Thus, there is an infinite-parameter class of gravity theories all describing just two propagating polarizations of the graviton. We describe how matter can be coupled to gravity in this formulation and, in particular, how both the gravity and Yang-Mills arise as sectors of a general diffeomorphism-invariant gauge theory. We finish by outlining a possible scenario of the ultraviolet completion of quantum gravity within this approach.
BEC-BCS crossover and the liquid-gas phase transition in hot and dense nuclear matter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jin Meng; Urban, Michael; Schuck, Peter
2010-08-15
The effect of nucleon-nucleon correlations in symmetric nuclear matter at finite temperature is studied beyond BCS theory. Starting from a Hartree-Fock description of nuclear matter with the Gogny effective interaction, we add correlations corresponding to the formation of preformed pairs and scattering states above the superfluid critical temperature within the in-medium T-matrix approach, which is analogous to the Nozieres-Schmitt-Rink theory. We calculate the critical temperature for a BEC superfluid of deuterons, of a BCS superfluid of nucleons, and in the crossover between these limits. The effect of the correlations on thermodynamic properties (equation of state, energy, entropy) and the liquid-gasmore » phase transition is discussed. Our results show that nucleon-nucleon correlations beyond BCS play an important role for the properties of nuclear matter, especially in the low-density region.« less
NASA Astrophysics Data System (ADS)
Ohlsson, Stellan; Cosejo, David G.
2014-07-01
The problem of how people process novel and unexpected information— deep learning (Ohlsson in Deep learning: how the mind overrides experience. Cambridge University Press, New York, 2011)—is central to several fields of research, including creativity, belief revision, and conceptual change. Researchers have not converged on a single theory for conceptual change, nor has any one theory been decisively falsified. One contributing reason is the difficulty of collecting informative data in this field. We propose that the commonly used methodologies of historical analysis, classroom interventions, and developmental studies, although indispensible, can be supplemented with studies of laboratory models of conceptual change. We introduce re- categorization, an experimental paradigm in which learners transition from one definition of a categorical concept to another, incompatible definition of the same concept, a simple form of conceptual change. We describe a re-categorization experiment, report some descriptive findings pertaining to the effects of category complexity, the temporal unfolding of learning, and the nature of the learner's final knowledge state. We end with a brief discussion of ways in which the re-categorization model can be improved.
Single electron relativistic clock interferometer
NASA Astrophysics Data System (ADS)
Bushev, P. A.; Cole, J. H.; Sholokhov, D.; Kukharchyk, N.; Zych, M.
2016-09-01
Although time is one of the fundamental notions in physics, it does not have a unique description. In quantum theory time is a parameter ordering the succession of the probability amplitudes of a quantum system, while according to relativity theory each system experiences in general a different proper time, depending on the system's world line, due to time dilation. It is therefore of fundamental interest to test the notion of time in the regime where both quantum and relativistic effects play a role, for example, when different amplitudes of a single quantum clock experience different magnitudes of time dilation. Here we propose a realization of such an experiment with a single electron in a Penning trap. The clock can be implemented in the electronic spin precession and its time dilation then depends on the radial (cyclotron) state of the electron. We show that coherent manipulation and detection of the electron can be achieved already with present day technology. A single electron in a Penning trap is a technologically ready platform where the notion of time can be probed in a hitherto untested regime, where it requires a relativistic as well as quantum description.
Flavor and baryon quantum numbers and their nondiffractive renormalizations of the Pomeron
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dash, J.W.; Jones, S.T.; Manesis, E.K.
We present a theoretical review and a detailed phonomenological description of the ''flavoring'' of the bare Pomeron pole at t = 0 (i.e., the nondiffractive renormalization of its multiperipheral unitarity sum by strange quarks, charmed quarks, diquarks,...) from an ''unflavored'' intercept alpha-circumflex = 0.85 to a ''flavored'' intercept ..cap alpha.. approx. = 1.08. Experimentally, flavoring effects seem to converge rapidly; hence this number is probably close to the bare intercept of the Reggeon field theory. We treat NN, ..pi..N, and KN total cross sections and real to imaginary amplitude ratios. We do not observe oscillations. We pay particular attention tomore » 2sigma/sub K/N - sigma/sub piN/ which rises monotonically. We present a closely related combination of inelastic diffraction cross sections which decreases monotonically, indicating that vacuum amplitudes are not simply the sum of a Pomeron pole and an ideally mixed f. In fact we argue that a Pomeron + f structure is neither compatible with flavoring nor with schemes in which flavoring is somehow absorbed away. In contrast, flavoring is required for consistency with experiment by the Chew-Rosenzweig hypothesis of the Pomeron-f identity. We close with a description of flavoring threshold effects on the Reggeon field theory at current energies.« less
Hadron collider tests of neutrino mass-generating mechanisms
NASA Astrophysics Data System (ADS)
Ruiz, Richard Efrain
The Standard Model of particle physics (SM) is presently the best description of nature at small distances and high energies. However, with tiny but nonzero neutrino masses, a Higgs boson mass unstable under radiative corrections, and little guidance on understanding the hierarchy of fermion masses, the SM remains an unsatisfactory description of nature. Well-motivated scenarios that resolve these issues exist but also predict extended gauge (e.g., Left-Right Symmetric Models), scalar (e.g., Supersymmetry), and/or fermion sectors (e.g., Seesaw Models). Hence, discovering such new states would have far-reaching implications. After reviewing basic tenets of the SM and collider physics, several beyond the SM (BSM) scenarios that alleviate these shortcomings are investigated. Emphasis is placed on the production of a heavy Majorana neutrinos at hadron colliders in the context of low-energy, effective theories that simultaneously explain the origin of neutrino masses and their smallness compared to other elementary fermions, the so-called Seesaw Mechanisms. As probes of new physics, rare top quark decays to Higgs bosons in the context of the SM, the Types I and II Two Higgs Doublet Model (2HDM), and the semi-model independent framework of Effective Field Theory (EFT) have also been investigated. Observation prospects and discovery potentials of these models at current and future collider experiments are quantified.
NASA Astrophysics Data System (ADS)
Miller, Steven D.
1995-05-01
Standard Monte Carlo methods used in photon diffusion score absorbed photons or statistical weight deposited within voxels comprising a mesh. An alternative approach to a stochastic description is considered for rapid surface flux calculations and finite medias. Matrix elements are assigned to a spatial lattice whose function is to score vector intersections of scattered photons making transitions into either the forward or back solid angle half spaces. These complete matrix elements can be related to the directional fluxes within the lattice space. This model differentiates between ballistic, quasi-ballistic, and highly diffuse photon contributions, and effectively models the subsurface generation of a scattered light flux from a ballistic source. The connection between a path integral and diffusion is illustrated. Flux perturbations can be effectively illustrated for tissue-tumor-tissue and for 3 layer systems with strong absorption in one or more layers. For conditions where the diffusion theory has difficulties such as strong absorption, highly collimated sources, small finite volumes, and subsurface regions, the computation time of the algorithm is rapid with good accuracy and compliments other description of photon diffusion. The model has the potential to do computations relevant to photodynamic therapy (PDT) and analysis of laser beam interaction with tissues.
Jiang, Kang; Ling, Feiyang; Feng, Zhongxiang; Wang, Kun; Guo, Lei
2017-02-17
As the prevalence of mobile phone use has increased globally, experts have verified the effects of mobile phone distraction on traffic safety. However, the psychological factors underlying pedestrians' decisions to use their mobile phones while crossing the street have received little attention. The present study employed the theory of planned behavior (TPB) to investigate the psychological factors that influence pedestrians' intentions to use a mobile phone while crossing the street. The additional predictors of descriptive norms, moral norms, risk perception, mobile phone involvement, and perceived ability to compensate are included. Approximately 40% of participants reported having used a mobile phone while crossing during the previous week and 5.4% had been involved in crossing accidents due to mobile phone distractions. Hierarchical multiple regression analyses revealed overall support for the predictive utility of the TPB. The standard TPB variables accounted for 13.3% of variance in intentions after demographic variables were controlled, and the extended predictors contributed an additional 7.6% beyond the standard constructs. The current study revealed that attitude, perceived behavior control, descriptive norms, mobile phone involvement, and perceived ability to compensate all emerged as significant predictors of intentions. The findings could support the design of more effective safety campaigns and interventions to reduce pedestrians' distracted crossing behaviors.
Transport Phenomena of Water in Molecular Fluidic Channels
Vo, Truong Quoc; Kim, BoHung
2016-01-01
In molecular-level fluidic transport, where the discrete characteristics of a molecular system are not negligible (in contrast to a continuum description), the response of the molecular water system might still be similar to the continuum description if the time and ensemble averages satisfy the ergodic hypothesis and the scale of the average is enough to recover the classical thermodynamic properties. However, even in such cases, the continuum description breaks down on the material interfaces. In short, molecular-level liquid flows exhibit substantially different physics from classical fluid transport theories because of (i) the interface/surface force field, (ii) thermal/velocity slip, (iii) the discreteness of fluid molecules at the interface and (iv) local viscosity. Therefore, in this study, we present the result of our investigations using molecular dynamics (MD) simulations with continuum-based energy equations and check the validity and limitations of the continuum hypothesis. Our study shows that when the continuum description is subjected to the proper treatment of the interface effects via modified boundary conditions, the so-called continuum-based modified-analytical solutions, they can adequately predict nanoscale fluid transport phenomena. The findings in this work have broad effects in overcoming current limitations in modeling/predicting the fluid behaviors of molecular fluidic devices. PMID:27650138
Riebl, Shaun K; Estabrooks, Paul A; Dunsmore, Julie C; Savla, Jyoti; Frisard, Madlyn I; Dietrich, Andrea M; Peng, Yiming; Zhang, Xiang; Davy, Brenda M
2015-08-01
Efforts to reduce unhealthy dietary intake behaviors in youth are urgently needed. Theory-based interventions can be effective in promoting behavior change; one promising model is the Theory of Planned Behavior (TPB). The aim of this study was to determine, using a systematic literature review, how the TPB has been applied to investigate dietary behaviors, and to evaluate which constructs are associated with dietary behavioral intentions and behaviors in youth. Publications were identified by searching electronic databases, contacting experts in the field, and examining an evolving Internet-based TPB-specific bibliography. Studies including participants aged 2-18years, all TPB constructs discernible and measured with a description of how the variables were assessed and analyzed, were published in English and peer-reviewed journals, and focused on nutrition-related behaviors in youth were identified. Accompanying a descriptive statistical analysis was the calculation of effect sizes where possible, a two-stage meta-analysis, and a quality assessment using tenants from the Consolidated Standards of Reporting Trials (CONSORT) and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statements. Thirty-four articles, including three intervention studies, were reviewed. The TPB was most often used to evaluate healthy eating and sugary snack and beverage consumption. Attitude had the strongest relationship with dietary behavioral intention (mean r=0.52), while intention was the most common predictor of behavior performance (mean r=0.38; both p<0.001). All three interventions revealed beneficial outcomes when using the TPB (e.g. η(2)=0.51 and ds=0.91, 0.89, and 0.79); extending the Theory with implementation intentions may enhance its effectiveness (e.g. η(2)=0.76). Overall, the TPB may be an effective framework to identify and understand child and adolescent nutrition-related behaviors, allowing for the development of tailored initiatives targeting poor dietary practices in youth. However, support from the literature is primarily from observational studies and a greater effort towards examining these relationships within intervention studies is needed. Copyright © 2015 Elsevier Ltd. All rights reserved.
Sum-rule corrections: A route to error cancellations in correlation matrix renormalisation theory
Liu, C.; Liu, J.; Yao, Y. X.; ...
2017-01-16
Here, we recently proposed the correlation matrix renormalisation (CMR) theory to efficiently and accurately calculate ground state total energy of molecular systems, based on the Gutzwiller variational wavefunction (GWF) to treat the electronic correlation effects. To help reduce numerical complications and better adapt the CMR to infinite lattice systems, we need to further refine the way to minimise the error originated from the approximations in the theory. This conference proceeding reports our recent progress on this key issue, namely, we obtained a simple analytical functional form for the one-electron renormalisation factors, and introduced a novel sum-rule correction for a moremore » accurate description of the intersite electron correlations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.« less
Sum-rule corrections: A route to error cancellations in correlation matrix renormalisation theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, C.; Liu, J.; Yao, Y. X.
Here, we recently proposed the correlation matrix renormalisation (CMR) theory to efficiently and accurately calculate ground state total energy of molecular systems, based on the Gutzwiller variational wavefunction (GWF) to treat the electronic correlation effects. To help reduce numerical complications and better adapt the CMR to infinite lattice systems, we need to further refine the way to minimise the error originated from the approximations in the theory. This conference proceeding reports our recent progress on this key issue, namely, we obtained a simple analytical functional form for the one-electron renormalisation factors, and introduced a novel sum-rule correction for a moremore » accurate description of the intersite electron correlations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.« less
Microdosimetry and Katz's track structure theory. I. One-hit detectors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zaider, M.
1990-10-01
A microdosimetric treatment of the response of one-hit detectors to radiation is formulated and compared with the model proposed by R. Katz, S. C. Sharma, and M. Homayoonfar within the framework of their track-structure theory. It is shown that radial dose distributions (on which the track structure theory is based) are generally poor substitutes for the exact microdosimetric distributions except when (a) the target is much larger than the radial extent of the track or (b) the effective specific energy in the target (alpha z) is negligibly small. Since neither one of these conditions is generally satisfied, it is suggestedmore » that a meaningful search for one-hit detectors be based on a microdosimetric description of the stochastics of energy deposition. An analysis of the phi x-174 bacteriophage inactivation data is presented.« less
[Theory of Mind in a child with autism: how to train her?].
Martín García, María J; Gómez Becerra, Inmaculada; Garro Espín, María J
2012-11-01
Theory of Mind is a metacognitive skill that, in many cases, is deficient in autism. In this paper, we present a clinical study conducted with a child diagnosed with autism, which verifies the effectiveness of a training protocol testing false beliefs, which has been considered to measure the Theory of Mind. Basically, the protocol incorporates a number of verbal prompts (such as emphasizing the elements of the narratives that indicate situational or temporary changes), trains many examples, extending the tests incorporating some games with more familiar objects from the child's daily life, applies differential contingencies to discriminate right from wrong in each child's responses and provides descriptive feedback. The results show that the training protocol achieved the highest level of correct trials and the child generalizes the ability to take the perspective of her natural context.
Daveson, Barbara; O'Callaghan, Clare
2011-01-01
Many references to time or temporality are located within music therapy literature, however little research has been completed regarding this phenomenon. Findings from a modified grounded theory study about clients' experiences and descriptions of time within the context of music therapy are presented here. The study was informed by the constructivist-interpretive paradigm and a grounded-descriptive statement finding resulted. A 2-staged research methodology was used, comprising a deductive-inductive content analysis of information from the public domain, followed by data-mining of information from a minimum of 160 clients and analysis of data from at least 43 of these 160 clients. Information regarding memory experiences, the duration of music therapy effects, recall and retrieval, and experiences of time are identified. Implications for practice are emphasized, in particular the following is stressed (a) the importance of time orientation and temporal connectedness in relation to identity development, (b) temporal strategies within music experience to assist integration, recall, and retrieval of information, and (c) the importance of and the elements involved in time modification. New explanations for music therapy phenomena are shared, and areas for research highlighted. Benefits of using time dynamically to aid therapeutic process are proposed, and it is concluded that temporal experience within the context of music therapy is important in relation to both practice and research.
Nonadiabatic molecular dynamics simulations: synergies between theory and experiments.
Tavernelli, Ivano
2015-03-17
Recent developments in nonadiabatic dynamics enabled ab inito simulations of complex ultrafast processes in the condensed phase. These advances have opened new avenues in the study of many photophysical and photochemical reactions triggered by the absorption of electromagnetic radiation. In particular, theoretical investigations can be combined with the most sophisticated femtosecond experimental techniques to guide the interpretation of measured time-resolved observables. At the same time, the availability of experimental data at high (spatial and time) resolution offers a unique opportunity for the benchmarking and the improvement of those theoretical models used to describe complex molecular systems in their natural environment. The established synergy between theory and experiments can produce a better understanding of new ultrafast physical and chemical processes at atomistic scale resolution. Furthermore, reliable ab inito molecular dynamics simulations can already be successfully employed as predictive tools to guide new experiments as well as the design of novel and better performing materials. In this paper, I will give a concise account on the state of the art of molecular dynamics simulations of complex molecular systems in their excited states. The principal aim of this approach is the description of a given system of interest under the most realistic ambient conditions including all environmental effects that influence experiments, for instance, the interaction with the solvent and with external time-dependent electric fields, temperature, and pressure. To this end, time-dependent density functional theory (TDDFT) is among the most efficient and accurate methods for the representation of the electronic dynamics, while trajectory surface hopping gives a valuable representation of the nuclear quantum dynamics in the excited states (including nonadiabatic effects). Concerning the environment and its effects on the dynamics, the quantum mechanics/molecular mechanics (QM/MM) approach has the advantage of providing an atomistic (even though approximated) description of the solvent molecules, which is crucial for the characterization of all ultrafast relaxation phenomena that depend on the geometrical arrangement at the interface between a molecule and the solvent, for example, the hydrogen bond network. After a short description of the TDDFT-based implementation of Ehrenfest and trajectory surface hopping dynamics, I will present applications in different domains of molecular chemistry and physics: the analysis and the understanding of (time-resolved) X-ray absorption spectra, the interpretation of the ultrafast relaxation dynamics of photoexcited dyes in solution, and the design of specific laser pulses (capable of inducing desired chemical reactions) using local control theory.
A higher-order theory for geometrically nonlinear analysis of composite laminates
NASA Technical Reports Server (NTRS)
Reddy, J. N.; Liu, C. F.
1987-01-01
A third-order shear deformation theory of laminated composite plates and shells is developed, the Navier solutions are derived, and its finite element models are developed. The theory allows parabolic description of the transverse shear stresses, and therefore the shear correction factors of the usual shear deformation theory are not required in the present theory. The theory also accounts for the von Karman nonlinear strains. Closed-form solutions of the theory for rectangular cross-ply and angle-ply plates and cross-ply shells are developed. The finite element model is based on independent approximations of the displacements and bending moments (i.e., mixed finite element model), and therefore, only C sup o -approximation is required. The finite element model is used to analyze cross-ply and angle-ply laminated plates and shells for bending and natural vibration. Many of the numerical results presented here should serve as references for future investigations. Three major conclusions resulted from the research: First, for thick laminates, shear deformation theories predict deflections, stresses and vibration frequencies significantly different from those predicted by classical theories. Second, even for thin laminates, shear deformation effects are significant in dynamic and geometrically nonlinear analyses. Third, the present third-order theory is more accurate compared to the classical and firt-order theories in predicting static and dynamic response of laminated plates and shells made of high-modulus composite materials.
Beyond the Five Conceptual Frameworks: A Decade of Development in Family Theory
ERIC Educational Resources Information Center
Broderick, Carlfred B.
1971-01-01
The review presents a brief and somewhat personal and impressionistic description of the status of the field in 1960, deals with the fortunes of some of the general broadguage theories and conceptual frameworks which have dominated the family literature over the decade, and offers survey of some of the substantive theories which dealt with more…
NASA Astrophysics Data System (ADS)
Menthe, R. W.; McColgan, C. J.; Ladden, R. M.
1991-05-01
The Unified AeroAcoustic Program (UAAP) code calculates the airloads on a single rotation prop-fan, or propeller, and couples these airloads with an acoustic radiation theory, to provide estimates of near-field or far-field noise levels. The steady airloads can also be used to calculate the nonuniform velocity components in the propeller wake. The airloads are calculated using a three dimensional compressible panel method which considers the effects of thin, cambered, multiple blades which may be highly swept. These airloads may be either steady or unsteady. The acoustic model uses the blade thickness distribution and the steady or unsteady aerodynamic loads to calculate the acoustic radiation. The users manual for the UAAP code is divided into five sections: general code description; input description; output description; system description; and error codes. The user must have access to IMSL10 libraries (MATH and SFUN) for numerous calls made for Bessel functions and matrix inversion. For plotted output users must modify the dummy calls to plotting routines included in the code to system-specific calls appropriate to the user's installation.
NASA Technical Reports Server (NTRS)
Menthe, R. W.; Mccolgan, C. J.; Ladden, R. M.
1991-01-01
The Unified AeroAcoustic Program (UAAP) code calculates the airloads on a single rotation prop-fan, or propeller, and couples these airloads with an acoustic radiation theory, to provide estimates of near-field or far-field noise levels. The steady airloads can also be used to calculate the nonuniform velocity components in the propeller wake. The airloads are calculated using a three dimensional compressible panel method which considers the effects of thin, cambered, multiple blades which may be highly swept. These airloads may be either steady or unsteady. The acoustic model uses the blade thickness distribution and the steady or unsteady aerodynamic loads to calculate the acoustic radiation. The users manual for the UAAP code is divided into five sections: general code description; input description; output description; system description; and error codes. The user must have access to IMSL10 libraries (MATH and SFUN) for numerous calls made for Bessel functions and matrix inversion. For plotted output users must modify the dummy calls to plotting routines included in the code to system-specific calls appropriate to the user's installation.
Hydrodynamic description of spin Calogero-Sutherland model
NASA Astrophysics Data System (ADS)
Abanov, Alexander; Kulkarni, Manas; Franchini, Fabio
2009-03-01
We study a non-linear collective field theory for an integrable spin-Calogero-Sutherland model. The hydrodynamic description of this SU(2) model in terms of charge density, charge velocity and spin currents is used to study non-perturbative solutions (solitons) and examine their correspondence with known quantum numbers of elementary excitations [1]. A conventional linear bosonization or harmonic approximation is not sufficient to describe, for example, the physics of spin-charge (non)separation. Therefore, we need this new collective bosonic field description that captures the effects of the band curvature. In the strong coupling limit [2] this model reduces to integrable SU(2) Haldane-Shastry model. We study a non-linear coupling of left and right spin currents which form a Kac-Moody algebra. Our quantum hydrodynamic description for the spin case is an extension for the one found in the spinless version in [3].[3pt] [1] Y. Kato,T. Yamamoto, and M. Arikawa, J. Phys. Soc. Jpn. 66, 1954-1961 (1997).[0pt] [2] A. Polychronakos, Phys Rev Lett. 70,2329-2331(1993).[0pt] [3] A.G.Abanov and P.B. Wiegmann, Phys Rev Lett 95, 076402(2005)
Thompson, Cheryl Bagley
2009-01-01
This 13th article of the Basics of Research series is first in a short series on statistical analysis. These articles will discuss creating your statistical analysis plan, levels of measurement, descriptive statistics, probability theory, inferential statistics, and general considerations for interpretation of the results of a statistical analysis.
NASA Astrophysics Data System (ADS)
Kotliar, Gabriel
2005-01-01
Dynamical mean field theory (DMFT) relates extended systems (bulk solids, surfaces and interfaces) to quantum impurity models (QIM) satisfying a self-consistency condition. This mapping provides an economic description of correlated electron materials. It is currently used in practical computations of physical properties of real materials. It has also great conceptual value, providing a simple picture of correlated electron phenomena on the lattice, using concepts derived from quantum impurity models such as the Kondo effect. DMFT can also be formulated as a first principles electronic structure method and is applicable to correlated materials.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dine, Michael; Draper, Patrick; Stephenson-Haskins, Laurel
Here, we study the large N θ dependence and the η' potential in supersymmetric QCD with small soft SUSY-breaking terms. Known exact results in SUSY QCD are found to reflect a variety of expectations from large N perturbation theory, including the presence of branches and the behavior of theories with matter (both with N f << N and N f ~ N ). But, there are also striking departures from ordinary QCD and the conventional large N description: instanton effects, when under control, are not exponentially suppressed at large N , and branched structure in supersymmetric QCD is always associatedmore » with approximate discrete symmetries. We suggest that these differences motivate further study of large N QCD on the lattice.« less
Sbraga, T P; O'Donohue, W
2000-01-01
We review the current state of sexual harassment theory, research, treatment, and prevention. Definitional problems and implications are discussed. An examination of the epidemiology of sexual harassment is presented, highlighting correlates that include characteristics of the organizational environment, the perpetrator, and the recipient of unwanted sexual behavior. Normative responses to sexual harassment and consequences are discussed. Descriptions of the most prevalent models of sexual harassment are offered and the empirical evidence for them is briefly reviewed. From there, the effect of model development and evaluation on the prevention and treatment of sexual harassment is considered. We comment on the steps that would need to be taken to develop viable prevention and treatment programs. Suggestions for fruitful avenues of research and theory development are offered.
Robust controller design for flexible structures using normalized coprime factor plant descriptions
NASA Technical Reports Server (NTRS)
Armstrong, Ernest S.
1993-01-01
Stabilization is a fundamental requirement in the design of feedback compensators for flexible structures. The search for the largest neighborhood around a given design plant for which a single controller produces closed-loop stability can be formulated as an H(sub infinity) control problem. The use of normalized coprime factor plant descriptions, in which the plant perturbations are defined as additive modifications to the coprime factors, leads to a closed-form expression for the maximum neighborhood boundary allowing optimal and suboptimal H(sub infinity) compensators to be computed directly without the usual gamma iteration. A summary of the theory on robust stabilization using normalized coprime factor plant descriptions is presented, and the application of the theory to the computation of robustly stable compensators for the phase version of the Control-Structures Interaction (CSI) Evolutionary Model is described. Results from the application indicate that the suboptimal version of the theory has the potential of providing the bases for the computation of low-authority compensators that are robustly stable to expected variations in design model parameters and additive unmodeled dynamics.
Enhancement of Supersymmetry via Renormalization Group Flow and the Superconformal Index
NASA Astrophysics Data System (ADS)
Maruyoshi, Kazunobu; Song, Jaewon
2017-04-01
We find a four-dimensional N =1 gauge theory which flows to the minimal interacting N =2 superconformal field theory, the Argyres-Douglas theory, in the infrared up to the extra free chiral multiplets. The gauge theory is obtained from a certain N =1 preserving deformation of the N =2 S U (2 ) gauge theory with four fundamental hypermultiplets. From this description, we compute the full superconformal index and find agreements with the known results in special limits.
Harris, Tina
2015-04-29
Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.
NASA Astrophysics Data System (ADS)
Lonardoni, D.; Gandolfi, S.; Lynn, J. E.; Petrie, C.; Carlson, J.; Schmidt, K. E.; Schwenk, A.
2018-04-01
Quantum Monte Carlo methods have recently been employed to study properties of nuclei and infinite matter using local chiral effective-field-theory interactions. In this work, we present a detailed description of the auxiliary field diffusion Monte Carlo algorithm for nuclei in combination with local chiral two- and three-nucleon interactions up to next-to-next-to-leading order. We show results for the binding energy, charge radius, charge form factor, and Coulomb sum rule in nuclei with 3 ≤A ≤16 . Particular attention is devoted to the effect of different operator structures in the three-body force for different cutoffs. The outcomes suggest that local chiral interactions fit to few-body observables give a very good description of the ground-state properties of nuclei up to 16O, with the exception of one fit for the softer cutoff which predicts overbinding in larger nuclei.
Branes and the Kraft-Procesi transition: classical case
NASA Astrophysics Data System (ADS)
Cabrera, Santiago; Hanany, Amihay
2018-04-01
Moduli spaces of a large set of 3 d N=4 effective gauge theories are known to be closures of nilpotent orbits. This set of theories has recently acquired a special status, due to Namikawa's theorem. As a consequence of this theorem, closures of nilpotent orbits are the simplest non-trivial moduli spaces that can be found in three dimensional theories with eight supercharges. In the early 80's mathematicians Hanspeter Kraft and Claudio Procesi characterized an inclusion relation between nilpotent orbit closures of the same classical Lie algebra. We recently [1] showed a physical realization of their work in terms of the motion of D3-branes on the Type IIB superstring embedding of the effective gauge theories. This analysis is restricted to A-type Lie algebras. The present note expands our previous discussion to the remaining classical cases: orthogonal and symplectic algebras. In order to do so we introduce O3-planes in the superstring description. We also find a brane realization for the mathematical map between two partitions of the same integer number known as collapse. Another result is that basic Kraft-Procesi transitions turn out to be described by the moduli space of orthosymplectic quivers with varying boundary conditions.
Antimatter Production at a Potential Boundary
NASA Technical Reports Server (NTRS)
LaPointe, Michael R.; Reddy, Dhanireddy (Technical Monitor)
2001-01-01
Current antiproton production techniques rely on high-energy collisions between beam particles and target nuclei to produce particle and antiparticle pairs, but inherently low production and capture efficiencies render these techniques impractical for the cost-effective production of antimatter for space propulsion and other commercial applications. Based on Dirac's theory of the vacuum field, a new antimatter production concept is proposed in which particle-antiparticle pairs are created at the boundary of a steep potential step formed by the suppression of the local vacuum fields. Current antimatter production techniques are reviewed, followed by a description of Dirac's relativistic quantum theory of the vacuum state and corresponding solutions for particle tunneling and reflection from a potential barrier. The use of the Casimir effect to suppress local vacuum fields is presented as a possible technique for generating the sharp potential gradients required for particle-antiparticle pair creation.
NASA Astrophysics Data System (ADS)
Das, Ashok
2007-01-01
It is not usual for someone to write a book on someone else's Ph.D. thesis, but then Feynman was not a usual physicist. He was without doubt one of the most original physicists of the twentieth century, who has strongly influenced the developments in quantum field theory through his many ingenious contributions. Path integral approach to quantum theories is one such contribution which pervades almost all areas of physics. What is astonishing is that he developed this idea as a graduate student for his Ph.D. thesis which has been printed, for the first time, in the present book along with two other related articles. The early developments in quantum theory, by Heisenberg and Schrödinger, were based on the Hamiltonian formulation, where one starts with the Hamiltonian description of a classical system and then promotes the classical observables to noncommuting quantum operators. However, Dirac had already stressed in an article in 1932 (this article is also reproduced in the present book) that the Lagrangian is more fundamental than the Hamiltonian, at least from the point of view of relativistic invariance and he wondered how the Lagrangian may enter into the quantum description. He had developed this idea through his 'transformation matrix' theory and had even hinted on how the action of the classical theory may enter such a description. However, although the brief paper by Dirac contained the basic essential ideas, it did not fully develop the idea of a Lagrangian description in detail in the functional language. Feynman, on the other hand, was interested in the electromagnetic interactions of the electron from a completely different point of view rooted in a theory involving action-at-a-distance. His theory (along with John Wheeler) did not have a Hamiltonian description and, in order to quantize such a theory, he needed an alternative formulation of quantum mechanics. When the article by Dirac was brought to his attention, he immediately realized what he was looking for and developed fully what is known today as the path integral approach to quantum theories. Although his main motivation was in the study of theories involving the concept of action-at-a-distance, as he emphasizes in his thesis, his formulation of quantum theories applies to any theory in general. The thesis develops quite systematically and in detail all the concepts of functionals necessary for this formulation. The motivation and the physical insights are described in the brilliant 'Feynman' style. It is incredible that even at that young age, the signs of his legendary teaching style were evident in his presentation of the material in the thesis. The path integral approach is now something that every graduate student in theoretical physics is supposed to know. There are several books on the subject, even one by Feynman himself (and Hibbs). Nonetheless, the thesis provides a very good background for the way these ideas came about. The two companion articles, although available in print, also gives a complete picture of the development of this line of thinking. The helpful introductory remarks by the editor also puts things in the proper historical perspective. This book would be very helpful to anyone interested in the development of modern ideas in physics.
NASA Astrophysics Data System (ADS)
Derendinger, J.-P.; Scrucca, C. A.; Uranga, A. M.
2006-11-01
This special issue is devoted to the proceedings of the conference 'Winter School on Strings, Supergravity and Gauge Theories', which took place at CERN, the European Centre for Nuclear Research, in Geneva, Switzerland, from the 16 to the 20 of January 2006. This event was organized in the framework of the European Mobility Research and Training Network entitled 'Constituents, Fundamental Forces and Symmetries of the Universe'. It is part of a yearly series of scientific schools which have become a traditional rendezvous for young researchers of the community. The previous one was held at SISSA, in Trieste, Italy, in February 2005, and the next one will take place again at CERN, in January 2007. The school was primarily meant for young doctoral students and postdoctoral researchers working in the area of string theory. It consisted of five general lectures of four hours each, whose notes are published in the present proceedings, and five working group discussion sessions, focused on specific topics of the network research program. It was attended by approximately 250 participants. The topics of the lectures were chosen to provide an introduction to some of the areas of recent progress and to the open problems in string theory. String theory is expected to provide insights into the description of systems where the role of gravity is crucial. One prominent example of such systems are time-dependent backgrounds with big bang singularities, whose status in string theory is reviewed in the lecture notes by Ben Craps. In another main problem in quantum gravity, string theory gives a fascinating microscopic description of black holes and their properties. The lectures by Shiraz Minwalla review the thermal properties of black holes from their microscopic description in terms of a holographically dual large N field theory. Progress in the description of black hole microstates, and its interplay with the macroscopic description in terms of supergravity solutions via the attractor mechanism, are covered by the lectures by Atish Dabholkar and Boris Pioline. A final important mainstream topic in string theory, being a higher-dimensional theory, is its compactification to four dimensions, and the computation of four-dimensional physical properties in terms of the properties of the internal space. The lectures by Mariana Graña review recent progress in the classification of the most general supersymmetric backgrounds describing the compactified dimensions, and their role in determining the number of massless scalar moduli fields in four dimensions. The conference was financially supported by the European Commission under contract MRTN-CT-2004-005104 and by CERN. It was jointly organized by the Physics Institute of the University of Neuchâtel and the Theory Unit of the Physics Division of CERN. It is a great pleasure for us to warmly thank the Theory Unit of CERN for its very kind hospitality and for the high quality of the services and infrastructure that it has provided. We also acknowledge helpful administrative assistance from the Physics Institute of the University of Neuchâtel. Special thanks go finally to Denis Frank for his very valuable help in preparing the conference web pages, and to J Rostant, A-M Perrin and M-S Vascotto for their continuous and very reliable assistance.
Riddlesperger, K L; Beard, M; Flowers, D L; Hisley, S M; Pfeifer, K A; Stiller, J J
1996-09-01
Since the 1980s the electronic domain has become the primary method for academic and professional communication of research and information. Papers relating to theory construction in nursing are a frequently occurring phenomenon within the electronic domain. Theory construction provides the underpinning for the advancement of professional nursing, facilitating the conceptualization of nursing actions leading to theory-based practice and research. The purpose of this study was to address the research question, 'What are the similarities and differences among theory construction papers that are accessible electronically in nursing literature today?' The Cumulative Index to Nursing and Allied Health Literature (CINAHL) was accessed to obtain a listing of papers from which an overall description of the type of theory construction papers being published in the nursing literature today could be determined. A literature search was conducted using the description 'theory construction'. Papers were limited to publication years from 1990 onwards. A total of 125 papers were obtained and read by one of the six authors. Using grounded theory, categories emerged by identification of similarities and differences among the papers. The findings are discussed here along with suggestions for further study. A second purpose of this paper was to present both traditional and non-traditional methods of tapping into the electronic domain when searching for assistance with theory construction.
Unsuppressed primordial standard clocks in warm quasi-single field inflation
NASA Astrophysics Data System (ADS)
Tong, Xi; Wang, Yi; Zhou, Siyi
2018-06-01
We study the non-Gaussianities in quasi-single field inflation with a warm inflation background. The thermal effects at small scales can sufficiently enhance the magnitude of the primordial standard clock signal. This scenario offers us the possibility of probing the UV physics of the very early universe without the exponentially small Boltzmann factor when the mass of the isocurvaton is much heavier than Hubble. The thermal effects at small scales can be studied using the flat space thermal field theory, connected to an effective description using non-Bunch-Davies vacuum at large scales, with large clock signal.
Continuum theory for cluster morphologies of soft colloids.
Kosmrlj, A; Pauschenwein, G J; Kahl, G; Ziherl, P
2011-06-09
We introduce a continuum description of the thermodynamics of colloids with a core-corona architecture. In the case of thick coronas, their overlap can be treated approximately by replacing the exact one-particle density distribution by a suitably shaped step profile, which provides a convenient way of modeling the spherical, columnar, lamellar, and inverted cluster morphologies predicted by numerical simulations and the more involved theories. We use the model to study monodisperse particles with the hard-core/square-shoulder pair interaction as the simplest representatives of the core-corona class. We derive approximate analytical expressions for the enthalpies of the cluster morphologies which offer a clear insight into the mechanisms at work, and we calculate the lattice spacing and the cluster size for all morphologies of the phase sequence as well as the phase-transition pressures. By comparing the results with the exact crystalline minimum-enthalpy configurations, we show that the accuracy of the theory increases with shoulder width. We discuss possible extensions of the theory that could account for the finite-temperature effects.
Spontaneous symmetry breaking, conformal anomaly and incompressible fluid turbulence
NASA Astrophysics Data System (ADS)
Oz, Yaron
2017-11-01
We propose an effective conformal field theory (CFT) description of steady state incompressible fluid turbulence at the inertial range of scales in any number of spatial dimensions. We derive a KPZ-type equation for the anomalous scaling of the longitudinal velocity structure functions and relate the intermittency parameter to the boundary Euler (A-type) conformal anomaly coefficient. The proposed theory consists of a mean field CFT that exhibits Kolmogorov linear scaling (K41 theory) coupled to a dilaton. The dilaton is a Nambu-Goldstone gapless mode that arises from a spontaneous breaking due to the energy flux of the separate scale and time symmetries of the inviscid Navier-Stokes equations to a K41 scaling with a dynamical exponent z=2/3 . The dilaton acts as a random measure that dresses the K41 theory and introduces intermittency. We discuss the two, three and large number of space dimensions cases and how entanglement entropy can be used to characterize the intermittency strength.
Erdmann, G; Janke, W
1978-01-01
This study investigated the interaction between physiological arousal and situation-derived cognitions in the determination of feeling states that is proposed in Schachter's theory of emotions. The degree of bodily arousal was varied by disguised oral administration of a placebo or the sympathicomimetic agent ephedrine. The situational circumstances were varied by instructions offering cues for (a) no emotions ('neutral' control), or the feeling states called (b) 'anger', (c) 'happiness', and (d) anxiety'. The subjects were 72 male students. The dependent variables were blood pressure, heart rate, a list of bodily symptoms, and an adjective check list. The results within the 'anger' and 'happiness' condition were in accordance with Schachter's theory: depending on the type of situation, ephedrine-induced arousal either decreased or increased positive descriptions of mood. The emotional effects of the 'anxiety' condition, however, were independent of the drug-induced arousal level. Contrary to Schachter's theory, anxiety reactions occured also in a state of low physiological arousal and did not increase with increasing arousal.
On Flexible Tubes Conveying Fluid: Geometric Nonlinear Theory, Stability and Dynamics
NASA Astrophysics Data System (ADS)
Gay-Balmaz, François; Putkaradze, Vakhtang
2015-08-01
We derive a fully three-dimensional, geometrically exact theory for flexible tubes conveying fluid. The theory also incorporates the change of the cross section available to the fluid motion during the dynamics. Our approach is based on the symmetry-reduced, exact geometric description for elastic rods, coupled with the fluid transport and subject to the volume conservation constraint for the fluid. We first derive the equations of motion directly, by using an Euler-Poincaré variational principle. We then justify this derivation with a more general theory elucidating the interesting mathematical concepts appearing in this problem, such as partial left (elastic) and right (fluid) invariance of the system, with the added holonomic constraint (volume). We analyze the fully nonlinear behavior of the model when the axis of the tube remains straight. We then proceed to the linear stability analysis and show that our theory introduces important corrections to previously derived results, both in the consistency at all wavelength and in the effects arising from the dynamical change of the cross section. Finally, we derive and analyze several analytical, fully nonlinear solutions of traveling wave type in two dimensions.
Education as Simulation Game: A Critical Hermeneutic.
ERIC Educational Resources Information Center
Palermo, James
1979-01-01
This paper examines a specific educational game called "Popcorn Factory." First, it gives a detailed description of the game, then shifts the description into a critical hermeneutical framework, analyzing the deep structures at work in the "Popcorn Factory" according to the theories of Freud and Marcuse. (Author/SJL)
The Manu-Facturing of a Language.
ERIC Educational Resources Information Center
Washabaugh, William
1980-01-01
Discusses Providence Island Sign Language (PSL), an autochthonous and relatively immature language of about 20 speakers. It is a nascent and evolving language whose description can produce rich results for linguistic theory. Such a description will also be an explanation of the phylogeny of a linguistic system. (Author/PJM)
Small collision systems: Theory overview on cold nuclear matter effects
NASA Astrophysics Data System (ADS)
Armesto, Néstor
2018-02-01
Many observables measured at the Relativistic Heavy Ion Collider and the Large Hadron Collider show a smooth transition between proton-proton and protonnucleus collisions (small systems), and nucleus-nucleus collisions (large systems), when represented versus some variable like the multiplicity in the event. In this contribution I review some of the physics mechanisms, named cold nuclear matter effects, that may lead to a collective-like behaviour in small systems beyond the macroscopic description provided by relativistic hydrodynamics. I focus on the nuclear modification of parton densities, single inclusive particle production and correlations.
Intervalley scattering induced by Coulomb interaction and disorder in carbon-nanotube quantum dots
NASA Astrophysics Data System (ADS)
Secchi, Andrea; Rontani, Massimo
2013-09-01
We develop a theory of intervalley Coulomb scattering in semiconducting carbon-nanotube quantum dots, taking into account the effects of curvature and chirality. Starting from the effective mass description of single-particle states, we study the two-electron system by fully including Coulomb interaction, spin-orbit coupling, and short-range disorder. We find that the energy level splittings associated with intervalley scattering are nearly independent of the chiral angle and, while smaller than those due to spin-orbit interaction, large enough to be measurable.
NASA Astrophysics Data System (ADS)
Reichman, David R.; Charbonneau, Patrick
2005-05-01
In this set of lecture notes we review the mode-coupling theory of the glass transition from several perspectives. First, we derive mode-coupling equations for the description of density fluctuations from microscopic considerations with the use the Mori Zwanzig projection operator technique. We also derive schematic mode-coupling equations of a similar form from a field-theoretic perspective. We review the successes and failures of mode-coupling theory, and discuss recent advances in the applications of the theory.
A Novel Approach to Anharmonicity for a Wealth of Applications in Nonlinear Science Technologies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hanusse, Patrick
2011-04-19
We present a new theory of the anharmonicity of nonlinear oscillations that are exhibited by many physical systems. New physical quantities are introduced that describe the departure from linear or harmonic behavior and as far as extremely anharmonic situations. In order to solve the nonlinear phase equation, the key notion of our theory, which controls the anharmonic behavior, a new and fascinating nonlinear trigonometry is designed. These results provide a general and accurate yet compact description of such signals, by far better than the Fourier description, both quantitatively and qualitatively and will benefit many application fields.
Improved formalism for precision Higgs coupling fits
NASA Astrophysics Data System (ADS)
Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; Karl, Robert; List, Jenny; Ogawa, Tomohisa; Peskin, Michael E.; Tian, Junping
2018-03-01
Future e+e- colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e+e- data, based on the effective field theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e+e- colliders.
NASA Astrophysics Data System (ADS)
Guerrero-García, Guillermo Iván; González-Mozuelos, Pedro; de la Cruz, Mónica Olvera
2011-10-01
In a previous theoretical and simulation study [G. I. Guerrero-García, E. González-Tovar, and M. Olvera de la Cruz, Soft Matter 6, 2056 (2010)], it has been shown that an asymmetric charge neutralization and electrostatic screening depending on the charge polarity of a single nanoparticle occurs in the presence of a size-asymmetric monovalent electrolyte. This effect should also impact the effective potential between two macroions suspended in such a solution. Thus, in this work we study the mean force and the potential of mean force between two identical charged nanoparticles immersed in a size-asymmetric monovalent electrolyte, showing that these results go beyond the standard description provided by the well-known Derjaguin-Landau-Verwey-Overbeek theory. To include consistently the ion-size effects, molecular dynamics (MD) simulations and liquid theory calculations are performed at the McMillan-Mayer level of description in which the solvent is taken into account implicitly as a background continuum with the suitable dielectric constant. Long-range electrostatic interactions are handled properly in the simulations via the well established Ewald sums method and the pre-averaged Ewald sums approach, originally proposed for homogeneous ionic fluids. An asymmetric behavior with respect to the colloidal charge polarity is found for the effective interactions between two identical nanoparticles. In particular, short-range attractions are observed between two equally charged nanoparticles, even though our model does not include specific interactions; these attractions are greatly enhanced for anionic nanoparticles immersed in standard electrolytes where cations are smaller than anions. Practical implications of some of the presented results are also briefly discussed. A good accord between the standard Ewald method and the pre-averaged Ewald approach is attained, despite the fact that the ionic system studied here is certainly inhomogeneous. In general, good agreement between the liquid theory approach and MD simulations is also found.
USDA-ARS?s Scientific Manuscript database
The theory of planned behavior (TPB) has received its fair share of criticism lately, including calls for it to retire. We contributed to improving the theory by testing extensions such as the model of goal-directed behavior (MGDB, which adds desire and anticipated positive and negative emotions) ap...
ERIC Educational Resources Information Center
Major, Jason T.; Johnson, Wendy; Deary, Ian J.
2012-01-01
Three prominent theories of intelligence, the Cattell-Horn-Carroll (CHC), extended fluid-crystallized (Gf-Gc) and verbal-perceptual-image rotation (VPR) theories, provide differing descriptions of the structure of intelligence (McGrew, 2009; Horn & Blankson, 2005; Johnson & Bouchard, 2005b). To compare these theories, models representing them were…
Geometric foundations of the theory of feedback equivalence
NASA Technical Reports Server (NTRS)
Hermann, R.
1987-01-01
A description of feedback control is presented within the context of differential equations, differential geometry, and Lie theory. Work related to the integration of differential geometry with the control techniques of feedback linearization is summarized. Particular attention is given to the application of the theory of vector field systems. Feedback invariants for control systems in state space form are also addressed.
ERIC Educational Resources Information Center
Töman, Ufuk; Karatas, Faik Özgür; Çimer, Sabiha Odabasi
2014-01-01
In this study, we investigate of science and technology teachers' opinions about the theory of evolution and the evolution teaching. The aim of this study, we investigate of science and technology teachers' opinions about the theory of evolution and the evolution teaching. This study is a descriptive study. Open-ended questions were used to…
Low Endogenous Neural Noise in Autism
ERIC Educational Resources Information Center
Davis, Greg; Plaisted-Grant, Kate
2015-01-01
"Heuristic" theories of autism postulate that a single mechanism or process underpins the diverse psychological features of autism spectrum disorder. Although no such theory can offer a comprehensive account, the parsimonious descriptions they provide are powerful catalysts to autism research. One recent proposal holds that…
Building a functional multiple intelligences theory to advance educational neuroscience.
Cerruti, Carlo
2013-01-01
A key goal of educational neuroscience is to conduct constrained experimental research that is theory-driven and yet also clearly related to educators' complex set of questions and concerns. However, the fields of education, cognitive psychology, and neuroscience use different levels of description to characterize human ability. An important advance in research in educational neuroscience would be the identification of a cognitive and neurocognitive framework at a level of description relatively intuitive to educators. I argue that the theory of multiple intelligences (MI; Gardner, 1983), a conception of the mind that motivated a past generation of teachers, may provide such an opportunity. I criticize MI for doing little to clarify for teachers a core misunderstanding, specifically that MI was only an anatomical map of the mind but not a functional theory that detailed how the mind actually processes information. In an attempt to build a "functional MI" theory, I integrate into MI basic principles of cognitive and neural functioning, namely interregional neural facilitation and inhibition. In so doing I hope to forge a path toward constrained experimental research that bears upon teachers' concerns about teaching and learning.
Ali Morowatisharifabad, Mohammad; Abdolkarimi, Mahdi; Asadpour, Mohammad; Fathollahi, Mahmood Sheikh; Balaee, Parisa
2018-01-01
INTRODUCTION: Theory-based education tailored to target behaviour and group can be effective in promoting physical activity. AIM: The purpose of this study was to examine the predictive power of Protection Motivation Theory on intent and behaviour of Physical Activity in Patients with Type 2 Diabetes. METHODS: This descriptive study was conducted on 250 patients in Rafsanjan, Iran. To examine the scores of protection motivation theory structures, a researcher-made questionnaire was used. Its validity and reliability were confirmed. The level of physical activity was also measured by the International Short - form Physical Activity Inventory. Its validity and reliability were also approved. Data were analysed by statistical tests including correlation coefficient, chi-square, logistic regression and linear regression. RESULTS: The results revealed that there was a significant correlation between all the protection motivation theory constructs and the intention to do physical activity. The results showed that the Theory structures were able to predict 60% of the variance of physical activity intention. The results of logistic regression demonstrated that increase in the score of physical activity intent and self - efficacy increased the chance of higher level of physical activity by 3.4 and 1.5 times, respectively OR = (3.39, 1.54). CONCLUSION: Considering the ability of protection motivation theory structures to explain the physical activity behaviour, interventional designs are suggested based on the structures of this theory, especially to improve self -efficacy as the most powerful factor in predicting physical activity intention and behaviour. PMID:29731945
Quantum criticality and black holes.
Sachdev, Subir; Müller, Markus
2009-04-22
Many condensed matter experiments explore the finite temperature dynamics of systems near quantum critical points. Often, there are no well-defined quasiparticle excitations, and so quantum kinetic equations do not describe the transport properties completely. The theory shows that the transport coefficients are not proportional to a mean free scattering time (as is the case in the Boltzmann theory of quasiparticles), but are completely determined by the absolute temperature and by equilibrium thermodynamic observables. Recently, explicit solutions of this quantum critical dynamics have become possible via the anti-de Sitter/conformal field theory duality discovered in string theory. This shows that the quantum critical theory provides a holographic description of the quantum theory of black holes in a negatively curved anti-de Sitter space, and relates its transport coefficients to properties of the Hawking radiation from the black hole. We review how insights from this connection have led to new results for experimental systems: (i) the vicinity of the superfluid-insulator transition in the presence of an applied magnetic field, and its possible application to measurements of the Nernst effect in the cuprates, (ii) the magnetohydrodynamics of the plasma of Dirac electrons in graphene and the prediction of a hydrodynamic cyclotron resonance.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Riseborough, P. S.; Lawrence, Jon M.
Here, we review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effectmore » and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger's theorem, the Friedel sum rule, the Schrieffer–Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Nozieres exhaustion principle, Doniach's diagram, the Anderson lattice model, the Slave-Boson method, etc.« less
Riseborough, P. S.; Lawrence, Jon M.
2016-07-04
Here, we review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effectmore » and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger's theorem, the Friedel sum rule, the Schrieffer–Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Nozieres exhaustion principle, Doniach's diagram, the Anderson lattice model, the Slave-Boson method, etc.« less
A gauge-theoretic approach to gravity
Krasnov, Kirill
2012-01-01
Einstein's general relativity (GR) is a dynamical theory of the space–time metric. We describe an approach in which GR becomes an SU(2) gauge theory. We start at the linearized level and show how a gauge-theoretic Lagrangian for non-interacting massless spin two particles (gravitons) takes a much more simple and compact form than in the standard metric description. Moreover, in contrast to the GR situation, the gauge theory Lagrangian is convex. We then proceed with a formulation of the full nonlinear theory. The equivalence to the metric-based GR holds only at the level of solutions of the field equations, that is, on-shell. The gauge-theoretic approach also makes it clear that GR is not the only interacting theory of massless spin two particles, in spite of the GR uniqueness theorems available in the metric description. Thus, there is an infinite-parameter class of gravity theories all describing just two propagating polarizations of the graviton. We describe how matter can be coupled to gravity in this formulation and, in particular, how both the gravity and Yang–Mills arise as sectors of a general diffeomorphism-invariant gauge theory. We finish by outlining a possible scenario of the ultraviolet completion of quantum gravity within this approach. PMID:22792040
The Large-Scale Structure of Scientific Method
ERIC Educational Resources Information Center
Kosso, Peter
2009-01-01
The standard textbook description of the nature of science describes the proposal, testing, and acceptance of a theoretical idea almost entirely in isolation from other theories. The resulting model of science is a kind of piecemeal empiricism that misses the important network structure of scientific knowledge. Only the large-scale description of…
Returning to Roots: On Social Information Processing and Moral Development
ERIC Educational Resources Information Center
Dodge, Kenneth A.; Rabiner, David L.
2004-01-01
Social information processing theory has been posited as a description of how mental operations affect behavioral responding in social situations. Arsenio and Lemerise (this issue) proposed that consideration of concepts and methods from moral domain models could enhance this description. This paper agrees with their proposition, although it…
Water Resource Management. [Student Guide] and Teacher's Guide.
ERIC Educational Resources Information Center
Young, Donald B.; Pottenger, Francis M.
This student guide and accompanying teacher's guide are a product of the Foundational Approaches in Science Teaching (FAST) curriculum development project at the University of Hawaii. In the teaching guide, the introduction gives a description of the underlying theory and practice in FAST and includes the FAST instructional model, descriptions of…
Malheiro, Carine; Mendiboure, Bruno; Plantier, Frédéric; Blas, Felipe J; Miqueu, Christelle
2014-04-07
As a first step of an ongoing study of thermodynamic properties and adsorption of complex fluids in confined media, we present a new theoretical description for spherical monomers using the Statistical Associating Fluid Theory for potential of Variable Range (SAFT-VR) and a Non-Local Density Functional Theory (NLDFT) with Weighted Density Approximations (WDA). The well-known Modified Fundamental Measure Theory is used to describe the inhomogeneous hard-sphere contribution as a reference for the monomer and two WDA approaches are developed for the dispersive terms from the high-temperature Barker and Henderson perturbation expansion. The first approach extends the dispersive contributions using the scalar and vector weighted densities introduced in the Fundamental Measure Theory (FMT) and the second one uses a coarse-grained (CG) approach with a unique weighted density. To test the accuracy of this new NLDFT/SAFT-VR coupling, the two versions of the theoretical model are compared with Grand Canonical Monte Carlo (GCMC) molecular simulations using the same molecular model. Only the version with the "CG" approach for the dispersive terms provides results in excellent agreement with GCMC calculations in a wide range of conditions while the "FMT" extension version gives a good representation solely at low pressures. Hence, the "CG" version of the theoretical model is used to reproduce methane adsorption isotherms in a Carbon Molecular Sieve and compared with experimental data after a characterization of the material. The whole results show an excellent agreement between modeling and experiments. Thus, through a complete and consistent comparison both with molecular simulations and with experimental data, the NLDFT/SAFT-VR theory has been validated for the description of monomers.
Who uses nursing theory? A univariate descriptive analysis of five years' research articles.
Bond, A Elaine; Eshah, Nidal Farid; Bani-Khaled, Mohammed; Hamad, Atef Omar; Habashneh, Samira; Kataua', Hussein; al-Jarrah, Imad; Abu Kamal, Andaleeb; Hamdan, Falastine Rafic; Maabreh, Roqia
2011-06-01
Since the early 1950s, nursing leaders have worked diligently to build the Scientific Discipline of Nursing, integrating Theory, Research and Practice. Recently, the role of theory has again come into question, with some scientists claiming nurses are not using theory to guide their research, with which to improve practice. The purposes of this descriptive study were to determine: (i) Were nursing scientists' research articles in leading nursing journals based on theory? (ii) If so, were the theories nursing theories or borrowed theories? (iii) Were the theories integrated into the studies, or were they used as organizing frameworks? Research articles from seven top ISI journals were analysed, excluding regularly featured columns, meta-analyses, secondary analysis, case studies and literature reviews. The authors used King's dynamic Interacting system and Goal Attainment Theory as an organizing framework. They developed consensus on how to identify the integration of theory, searching the Title, Abstract, Aims, Methods, Discussion and Conclusion sections of each research article, whether quantitative or qualitative. Of 2857 articles published in the seven journals from 2002 to, and including, 2006, 2184 (76%) were research articles. Of the 837 (38%) authors who used theories, 460 (55%) used nursing theories, 377 (45%) used other theories: 776 (93%) of those who used theory integrated it into their studies, including qualitative studies, while 51 (7%) reported they used theory as an organizing framework for their studies. Closer analysis revealed theory principles were implicitly implied, even in research reports that did not explicitly report theory usage. Increasing numbers of nursing research articles (though not percentagewise) continue to be guided by theory, and not always by nursing theory. Newer nursing research methods may not explicitly state the use of nursing theory, though it is implicitly implied. © 2010 The Authors. Scandinavian Journal of Caring Sciences © 2010 Nordic College of Caring Science.
Quantum many-body intermetallics: Phase stability of Fe3Al and small-gap formation in Fe2VAl
NASA Astrophysics Data System (ADS)
Kristanovski, Oleg; Richter, Raphael; Krivenko, Igor; Lichtenstein, Alexander I.; Lechermann, Frank
2017-01-01
Various intermetallic compounds harbor subtle electronic correlation effects. To elucidate this fact for the Fe-Al system, we perform a realistic many-body investigation based on a combination of density functional theory with dynamical mean-field theory in a charge self-consistent manner. A better characterization and understanding of the phase stability of bcc-based D 03-Fe3Al through an improved description of the correlated charge density and the magnetic energy is achieved. Upon replacement of one Fe sublattice with V, the Heusler compound Fe2VAl is realized, known to display bad-metal behavior and increased specific heat. Here we document a charge-gap opening at low temperatures in line with previous experimental work. The gap structure does not match conventional band theory and is reminiscent of (pseudo)gap characteristics in correlated oxides.
Theory of resonant x-ray emission spectra in compounds with localized f electrons
NASA Astrophysics Data System (ADS)
Kolorenč, Jindřich
2018-05-01
I discuss a theoretical description of the resonant x-ray emission spectroscopy (RXES) that is based on the Anderson impurity model. The parameters entering the model are determined from material-specific LDA+DMFT calculations. The theory is applicable across the whole f series, not only in the limits of nearly empty (La, Ce) or nearly full (Yb) valence f shell. Its performance is illustrated on the pressure-enhanced intermediate valency of elemental praseodymium. The obtained results are compared to the usual interpretation of RXES, which assumes that the spectrum is a superposition of several signals, each corresponding to one configuration of the 4f shell. The present theory simplifies to such superposition only if nearly all effects of hybridization of the 4f shell with the surrounding states are neglected. Although the assumption of negligible hybridization sounds reasonable for lanthanides, the explicit calculations show that it substantially distorts the analysis of the RXES data.
Clayton, Deborah A; Griffith, Christopher J
2008-04-01
The main aim of this study was to determine the factors which influence caterers' hand hygiene practices using social cognitive theory. One hundred and fifteen food handlers from 29 catering businesses were observed carrying out 31,050 food preparation actions in their workplace. Caterers subsequently completed the Hand Hygiene Instrument (HHI), which ascertained attitudes towards hand hygiene using constructs from the Theory of Planned Behaviour (TPB) and the Health Belief Model. The TPB provided a useful framework for understanding caterers' implementation of hand hygiene practices, explaining 34% of the variance in hand hygiene malpractices (p < 0.05). Five components were identified as significant predictors of hand hygiene malpractices: attitudes, subjective norms, descriptive norms, perceived behavioural control and intention (p < 0.05). Thus, suggesting that hand hygiene practices cannot be improved solely through the provision of information to individuals. Effective interventions may need to focus on changing the organisational food safety culture.
2016-06-01
theories of the mammalian visual system, and exploiting descriptive text that may accompany a still image for improved inference. The focus of the Brown...test, computer vision, semantic description , street scenes, belief propagation, generative models, nonlinear filtering, sufficient statistics 16...visual system, and exploiting descriptive text that may accompany a still image for improved inference. The focus of the Brown team was on single images
Testing neoclassical and turbulent effects on poloidal rotation in the core of DIII-D
Chrystal, Colin; Burrell, Keith H.; Grierson, Brian A.; ...
2014-07-09
Experimental tests of ion poloidal rotation theories have been performed on DIII-D using a novel impurity poloidal rotation diagnostic. These tests show significant disagreements with theoretical predictions in various conditions, including L-mode plasmas with internal transport barriers (ITB), H-mode plasmas, and QH-mode plasmas. The theories tested include standard neoclassical theory, turbulence driven Reynolds stress, and fast-ion friction on the thermal ions. Poloidal rotation is observed to spin up at the formation of an ITB and makes a significant contribution to the measurement of themore » $$\\vec{E}$$ × $$\\vec{B}$$ shear that forms the ITB. In ITB cases, neoclassical theory agrees quantitatively with the experimental measurements only in the steep gradient region. Significant quantitative disagreement with neoclassical predictions is seen in the cores of ITB, QH-, and H-mode plasmas, demonstrating that neoclassical theory is an incomplete description of poloidal rotation. The addition of turbulence driven Reynolds stress does not remedy this disagreement; linear stability calculations and Doppler backscattering measurements show that disagreement increases as turbulence levels decline. Furthermore, the effect of fast-ion friction, by itself, does not lead to improved agreement; in QH-mode plasmas, neoclassical predictions are closest to experimental results in plasmas with the largest fast ion friction. Finally, predictions from a new model that combines all three effects show somewhat better agreement in the H-mode case, but discrepancies well outside the experimental error bars remain.« less
F-theoretic vs microscopic description of a conformal mathcal{N} = 2 SYM theory
NASA Astrophysics Data System (ADS)
Billò, Marco; Gallot, Laurent; Lerda, Alberto; Pesando, Igor
2010-11-01
The F-theory background of four D7 branes in a type I' orientifold was conjectured to be described by the Seiberg-Witten curve for the superconformal SU(2) gauge theory with four flavors. This relation was explained by considering in this background a probe D3 brane, which supports this theory with SU(2) realized as Sp(1). Here we explicitly compute the non-perturbative corrections to the D7/D3 system in type I' due to D-instantons. This computation provides both the quartic effective action on the D7 branes and the quadratic effective action on the D3 brane; the latter agrees with the F-theoretic prediction. The action obtained in this way is related to the one derived from the usual instanton calculus à la Nekrasov (or from its AGT realization in terms of Liouville conformal blocks) by means of a non-perturbative redefinition of the coupling constant. We also point out an intriguing relation between the four-dimensional theory on the probe D3 brane with SO(8) flavor symmetry and the eight-dimensional dynamics on the D7 branes. On the latter, SO(8) represents a gauge group and the flavor masses correspond to the vacuum expectation values of an adjoint scalar field m: what we find is that the exact effective coupling in four dimensions is obtained from its perturbative part by taking into account in its mass dependence the full quantum dynamics of the field m in eight dimensions.
Feedback produces divergence from prospect theory in descriptive choice.
Jessup, Ryan K; Bishara, Anthony J; Busemeyer, Jerome R
2008-10-01
A recent study demonstrated that individuals making experience-based choices underweight small probabilities, in contrast to the overweighting observed in a typical descriptive paradigm. We tested whether trial-by-trial feedback in a repeated descriptive paradigm would engender choices more correspondent with experiential or descriptive paradigms. The results of a repeated gambling task indicated that individuals receiving feedback underweighted small probabilities, relative to their no-feedback counterparts. These results implicate feedback as a critical component during the decision-making process, even in the presence of fully specified descriptive information. A model comparison at the individual-subject level suggested that feedback drove individuals' decision weights toward objective probability weighting.
A kinetic theory description of the viscosity of dense fluids consisting of chain molecules.
de Wijn, Astrid S; Vesovic, Velisa; Jackson, George; Trusler, J P Martin
2008-05-28
An expression for the viscosity of a dense fluid is presented that includes the effect of molecular shape. The molecules of the fluid are approximated by chains of equal-sized, tangentially jointed, rigid spheres. It is assumed that the collision dynamics in such a fluid can be approximated by instantaneous collisions between two rigid spheres belonging to different chains. The approach is thus analogous to that of Enskog for a fluid consisting of rigid spheres. The description is developed in terms of two molecular parameters, the diameter sigma of the spherical segment and the chain length (number of segments) m. It is demonstrated that an analysis of viscosity data of a particular pure fluid alone cannot be used to obtain independently effective values of both sigma and m. Nevertheless, the chain lengths of n-alkanes are determined by assuming that the diameter of each rigid sphere making up the chain can be represented by the diameter of a methane molecule. The effective chain lengths of n-alkanes are found to increase linearly with the number C of carbon atoms present. The dependence can be approximated by a simple relationship m=1+(C-1)3. The same relationship was reported within the context of a statistical associating fluid theory equation of state treatment of the fluid, indicating that both the equilibrium thermodynamic properties and viscosity yield the same value for the chain lengths of n-alkanes.
Analysing Exemplary Science Teaching
ERIC Educational Resources Information Center
Alsop, Steve, Ed.; Bencze, Larry, Ed.; Pedretti, Erminia, Ed.
2004-01-01
How might exemplary practice be represented by teachers' narratives? How might such representations be analyzed? How might theory and practice be related? "Analyzing Exemplary Science Teaching" is a text that seeks to combine educational theory and practice through analysis of a series of teachers' descriptions of "exemplary"…
An Application of General System Theory (GST) to Group Therapy.
ERIC Educational Resources Information Center
Matthews, Charles O.
1992-01-01
Demonstrates the compatibility of General System Theory (GST) with the traditional counseling literature in explicating a therapy group's progression through Tuckman's (1965, 1977) developmental stages (forming, storming, norming, performing, and adjourning). Description uses both traditional group literature and GST concepts. (Author/NB)
The Language of Qualitative Issues. AIR Forum 1982 Paper.
ERIC Educational Resources Information Center
Duckwall, Julia M.; Johnson, F. Craig
The communication of research findings among collegiate institutional researchers is considered in relation to the contribution of qualitative language in general, and catastrophe theory in particular. The qualitative language of catastrophe theory may help reduce the arbitrariness of description, through identification of qualitative features…
Are Prospective English Teachers Linguistically Intelligent?
ERIC Educational Resources Information Center
Tezel, Kadir Vefa
2017-01-01
Language is normally associated with linguistic capabilities of individuals. In the theory of multiple intelligences, language is considered to be related primarily to linguistic intelligence. Using the theory of Multiple Intelligences as its starting point, this descriptive survey study investigated to what extent prospective English teachers'…
Census taking in the hat: FRW/CFT duality
NASA Astrophysics Data System (ADS)
Sekino, Yasuhiro; Susskind, Leonard
2009-10-01
In this paper a holographic description of eternal inflation is developed. We focus on the description of an open Friedmann-Robertson-Walker (FRW) universe that results from a tunneling event in which a false vacuum with positive vacuum energy decays to a supersymmetric vacuum with vanishing cosmological constant. The observations of a “census taker” in the final vacuum can be organized into a holographic dual conformal field theory that lives on the asymptotic boundary of space. We refer to this bulk-boundary correspondence as FRW/CFT duality. The dual conformal field theory (CFT) is a Euclidean two-dimensional theory that includes a Liouville 2D gravity sector describing geometric fluctuations of the boundary. The renormalization-group flow of the theory is richer than in the AdS/CFT correspondence, and generates two space-time dimensions—one spacelike and one timelike. We discuss a number of phenomena such as bubble collisions, and the Garriga, Guth Vilenkin “persistence of memory,” from the dual viewpoint.
Empirical Monod-Beuneu relation of spin relaxation revisited for elemental metals
NASA Astrophysics Data System (ADS)
Szolnoki, L.; Kiss, A.; Forró, L.; Simon, F.
2014-03-01
Monod and Beuneu [P. Monod and F. Beuneu, Phys. Rev. B 19, 911 (1979), 10.1103/PhysRevB.19.911] established the validity of the Elliott-Yafet theory for elemental metals through correlating the experimental electron spin resonance linewidth with the so-called spin-orbit admixture coefficients and the momentum-relaxation theory. The spin-orbit admixture coefficients data were based on atomic spin-orbit splitting. We highlight two shortcomings of the previous description: (i) the momentum-relaxation involves the Debye temperature and the electron-phonon coupling whose variation among the elemental metals was neglected, (ii) the Elliott-Yafet theory involves matrix elements of the spin-orbit coupling (SOC), which are however not identical to the SOC induced energy splitting of the atomic levels, even though the two have similar magnitudes. We obtain the empirical spin-orbit admixture parameters for the alkali metals by considering the proper description of the momentum relaxation theory. In addition we present a model calculation, which highlights the difference between the SOC matrix element and energy splitting.
NASA Astrophysics Data System (ADS)
le Roux, J. A.; Zank, G. P.; Khabarova, O.; Webb, G. M.
2016-12-01
Simulations of charged particle acceleration in turbulent plasma regions with numerous small-scale contracting and merging (reconnecting) magnetic islands/flux ropes emphasize the key role of temporary particle trapping in these structures for efficient acceleration that can result in power-law spectra. In response, a comprehensive kinetic transport theory framework was developed by Zank et al. and le Roux et al. to capture the essential physics of energetic particle acceleration in solar wind regions containing numerous dynamic small-scale flux ropes. Examples of test particle solutions exhibiting hard power-law spectra for energetic particles were presented in recent publications by both Zank et al. and le Roux et al.. However, the considerable pressure in the accelerated particles suggests the need for expanding the kinetic transport theory to enable a self-consistent description of energy exchange between energetic particles and small-scale flux ropes. We plan to present the equations of an expanded kinetic transport theory framework that will enable such a self-consistent description.
Coarse graining atomistic simulations of plastically deforming amorphous solids
NASA Astrophysics Data System (ADS)
Hinkle, Adam R.; Rycroft, Chris H.; Shields, Michael D.; Falk, Michael L.
2017-05-01
The primary mode of failure in disordered solids results from the formation and persistence of highly localized regions of large plastic strains known as shear bands. Continuum-level field theories capable of predicting this mechanical response rely upon an accurate representation of the initial and evolving states of the amorphous structure. We perform molecular dynamics simulations of a metallic glass and propose a methodology for coarse graining discrete, atomistic quantities, such as the potential energies of the elemental constituents. A strain criterion is established and used to distinguish the coarse-grained degrees-of-freedom inside the emerging shear band from those of the surrounding material. A signal-to-noise ratio provides a means of evaluating the strength of the signal of the shear band as a function of the coarse graining. Finally, we investigate the effect of different coarse graining length scales by comparing a two-dimensional, numerical implementation of the effective-temperature description in the shear transformation zone (STZ) theory with direct molecular dynamics simulations. These comparisons indicate the coarse graining length scale has a lower bound, above which there is a high level of agreement between the atomistics and the STZ theory, and below which the concept of effective temperature breaks down.
4d $$ \\mathcal{N}=1 $$ from 6d $$ \\mathcal{N}=\\left(1,0\\right) $$ on a torus with fluxes
Bah, Ibrahima; Hanany, Amihay; Maruyoshi, Kazunobu; ...
2017-06-05
Compactifying N = (1, 0) theories on a torus, with additional fluxes for global symmetries, we obtain N = 1 supersymmetric theories in four dimensions. It is shown that for many choices of flux these models are toric quiver gauge theories with singlet fields. Particularly we compare the anomalies deduced from the description of the six dimensional theory and the anomalies of the quiver gauge theories. Also, we give predictions for anomalies of four-dimensional theories corresponding to general compactifi cations of M5-branes probing C 2/Z k singularities.
Prospect Theory for Online Financial Trading
NASA Astrophysics Data System (ADS)
Liu, Yang-Yu; Nacher, Jose C.; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv
2014-03-01
Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people make decisions based on the potential value of losses and gains rather than the final outcome. People are risk-averse with respect to gains and risk-seeking with respect to losses, a phenomenon called ``loss aversion''. Despite of the fact that prospect theory has been well studied in behavioral economics at the theoretical level, there exist very few empirical research and most of them has been undertaken with micro-panel data. Here we analyze the trading activities of over 1.5 million members of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behaviour of ``winners'' and ``losers'', i.e., traders with positive or negative final net profit, we find clear evidence of the loss aversion phenomenon, an essence in prospect theory. This work demonstrates an unprecedented large-scale empirical evidence of prospect theory. It has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the effect of loss aversion. It also provides opportunity to augment online social trading, where users are allowed to watch and follow the trading activity of others, by predicting potential winners based on their historical trading behaviour.
Getting the Picture: The Role of Metaphors in Teaching Electronics Theory
ERIC Educational Resources Information Center
Pitcher, Rod
2014-01-01
In this paper, I report my investigation of the use of metaphors in teaching theory in electronic engineering. I give a description of the nature of metaphors, how they are used in teaching the theory and some of the problems that might arise in the process. I investigate how some people react to the metaphors and how others forget the metaphors…
ERIC Educational Resources Information Center
Feliciano-Torres, Hector L.
2017-01-01
The purpose of this quantitative, descriptive non experimental study was to investigate the use of wireless mobile network devices at a post-secondary institution using the innovation diffusion theory (IDT) and technology acceptance model (TAM) as background theories. The researcher intended to explore how students and personnel of the institution…
ERIC Educational Resources Information Center
Cutright, Marc, Ed.
This anthology considers some ways that chaos theory might be not only a descriptive metaphor for the conditions of leadership, planning, and policy in higher education, but also a prescriptive metaphor that might be used to improve these functions and others. The essays are: (1) "Introduction: Metaphor, Chaos Theory, and This Book" (Marc…
Rotorcraft control system design for uncertain vehicle dynamics using quantitative feedback theory
NASA Technical Reports Server (NTRS)
Hess, R. A.
1994-01-01
Quantitative Feedback Theory describes a frequency-domain technique for the design of multi-input, multi-output control systems which must meet time or frequency domain performance criteria when specified uncertainty exists in the linear description of the vehicle dynamics. This theory is applied to the design of the longitudinal flight control system for a linear model of the BO-105C rotorcraft. Uncertainty in the vehicle model is due to the variation in the vehicle dynamics over a range of airspeeds from 0-100 kts. For purposes of exposition, the vehicle description contains no rotor or actuator dynamics. The design example indicates the manner in which significant uncertainty exists in the vehicle model. The advantage of using a sequential loop closure technique to reduce the cost of feedback is demonstrated by example.
Intermolecular symmetry-adapted perturbation theory study of large organic complexes.
Heßelmann, Andreas; Korona, Tatiana
2014-09-07
Binding energies for the complexes of the S12L database by Grimme [Chem. Eur. J. 18, 9955 (2012)] were calculated using intermolecular symmetry-adapted perturbation theory combined with a density-functional theory description of the interacting molecules. The individual interaction energy decompositions revealed no particular change in the stabilisation pattern as compared to smaller dimer systems at equilibrium structures. This demonstrates that, to some extent, the qualitative description of the interaction of small dimer systems may be extrapolated to larger systems, a method that is widely used in force-fields in which the total interaction energy is decomposed into atom-atom contributions. A comparison of the binding energies with accurate experimental reference values from Grimme, the latter including thermodynamic corrections from semiempirical calculations, has shown a fairly good agreement to within the error range of the reference binding energies.
Phases of five-dimensional theories, monopole walls, and melting crystals
NASA Astrophysics Data System (ADS)
Cherkis, Sergey A.
2014-06-01
Moduli spaces of doubly periodic monopoles, also called monopole walls or monowalls, are hyperkähler; thus, when four-dimensional, they are self-dual gravitational instantons. We find all monowalls with lowest number of moduli. Their moduli spaces can be identified, on the one hand, with Coulomb branches of five-dimensional supersymmetric quantum field theories on 3 × T 2 and, on the other hand, with moduli spaces of local Calabi-Yau metrics on the canonical bundle of a del Pezzo surface. We explore the asymptotic metric of these moduli spaces and compare our results with Seiberg's low energy description of the five-dimensional quantum theories. We also give a natural description of the phase structure of general monowall moduli spaces in terms of triangulations of Newton polygons, secondary polyhedra, and associahedral projections of secondary fans.
Improved multidimensional semiclassical tunneling theory.
Wagner, Albert F
2013-12-12
We show that the analytic multidimensional semiclassical tunneling formula of Miller et al. [Miller, W. H.; Hernandez, R.; Handy, N. C.; Jayatilaka, D.; Willets, A. Chem. Phys. Lett. 1990, 172, 62] is qualitatively incorrect for deep tunneling at energies well below the top of the barrier. The origin of this deficiency is that the formula uses an effective barrier weakly related to the true energetics but correctly adjusted to reproduce the harmonic description and anharmonic corrections of the reaction path at the saddle point as determined by second order vibrational perturbation theory. We present an analytic improved semiclassical formula that correctly includes energetic information and allows a qualitatively correct representation of deep tunneling. This is done by constructing a three segment composite Eckart potential that is continuous everywhere in both value and derivative. This composite potential has an analytic barrier penetration integral from which the semiclassical action can be derived and then used to define the semiclassical tunneling probability. The middle segment of the composite potential by itself is superior to the original formula of Miller et al. because it incorporates the asymmetry of the reaction barrier produced by the known reaction exoergicity. Comparison of the semiclassical and exact quantum tunneling probability for the pure Eckart potential suggests a simple threshold multiplicative factor to the improved formula to account for quantum effects very near threshold not represented by semiclassical theory. The deep tunneling limitations of the original formula are echoed in semiclassical high-energy descriptions of bound vibrational states perpendicular to the reaction path at the saddle point. However, typically ab initio energetic information is not available to correct it. The Supporting Information contains a Fortran code, test input, and test output that implements the improved semiclassical tunneling formula.
Improved formalism for precision Higgs coupling fits
DOE Office of Scientific and Technical Information (OSTI.GOV)
Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon
Future e +e – colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e +e – data, based on the effective field theory description of corrections to the Standard Model. Lastly, we apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e +e – colliders.
Improved formalism for precision Higgs coupling fits
Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; ...
2018-03-20
Future e +e – colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e +e – data, based on the effective field theory description of corrections to the Standard Model. Lastly, we apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e +e – colliders.
Pedophilia: an update on theory and practice.
Travin, S; Bluestone, H; Coleman, E; Cullen, K; Melella, J
1985-01-01
The number of sexual attacks on children is staggering, yet it is extremely difficult to understand what effective treatments are available for the pedophile by reviewing the literature. Therefore, the authors present an update of the changing conceptualizations regarding the offenders and their victims. An overview of the currently used modalities to treat the pedophile is presented with emphasis on the promising cognitive-behavioral approach. A brief description of this approach is given with two case illustrations.
Schmeichel, Brandon J; Gailliot, Matthew T; Filardo, Emily-Ana; McGregor, Ian; Gitter, Seth; Baumeister, Roy F
2009-05-01
Three studies tested the roles of implicit and/or explicit self-esteem in reactions to mortality salience. In Study 1, writing about death versus a control topic increased worldview defense among participants low in implicit self-esteem but not among those high in implicit self-esteem. In Study 2, a manipulation to boost implicit self-esteem reduced the effect of mortality salience on worldview defense. In Study 3, mortality salience increased the endorsement of positive personality descriptions but only among participants with the combination of low implicit and high explicit self-esteem. These findings indicate that high implicit self-esteem confers resilience against the psychological threat of death, and therefore the findings provide direct support for a fundamental tenet of terror management theory regarding the anxiety-buffering role of self-esteem. Copyright (c) 2009 APA, all rights reserved.
Quantum theory of atoms in molecules: results for the SR-ZORA Hamiltonian.
Anderson, James S M; Ayers, Paul W
2011-11-17
The quantum theory of atoms in molecules (QTAIM) is generalized to include relativistic effects using the popular scalar-relativistic zeroth-order regular approximation (SR-ZORA). It is usually assumed that the definition of the atom as a volume bounded by a zero-flux surface of the electron density is closely linked to the form of the kinetic energy, so it is somewhat surprising that the atoms corresponding to the relativistic kinetic-energy operator in the SR-ZORA Hamiltonian are also bounded by zero-flux surfaces. The SR-ZORA Hamiltonian should be sufficient for qualitative descriptions of molecular electronic structure across the periodic table, which suggests that QTAIM-based analysis can be useful for molecules and solids containing heavy atoms.
θ and the η ' in large N supersymmetric QCD
Dine, Michael; Draper, Patrick; Stephenson-Haskins, Laurel; ...
2017-05-22
Here, we study the large N θ dependence and the η' potential in supersymmetric QCD with small soft SUSY-breaking terms. Known exact results in SUSY QCD are found to reflect a variety of expectations from large N perturbation theory, including the presence of branches and the behavior of theories with matter (both with N f << N and N f ~ N ). But, there are also striking departures from ordinary QCD and the conventional large N description: instanton effects, when under control, are not exponentially suppressed at large N , and branched structure in supersymmetric QCD is always associatedmore » with approximate discrete symmetries. We suggest that these differences motivate further study of large N QCD on the lattice.« less
Large-D gravity and low-D strings.
Emparan, Roberto; Grumiller, Daniel; Tanabe, Kentaro
2013-06-21
We show that in the limit of a large number of dimensions a wide class of nonextremal neutral black holes has a universal near-horizon limit. The limiting geometry is the two-dimensional black hole of string theory with a two-dimensional target space. Its conformal symmetry explains the properties of massless scalars found recently in the large-D limit. For black branes with string charges, the near-horizon geometry is that of the three-dimensional black strings of Horne and Horowitz. The analogies between the α' expansion in string theory and the large-D expansion in gravity suggest a possible effective string description of the large-D limit of black holes. We comment on applications to several subjects, in particular to the problem of critical collapse.
NASA Astrophysics Data System (ADS)
Gloor, Guy J.; Jackson, George; Blas, Felipe J.; del Río, Elvira Martín; de Miguel, Enrique
2004-12-01
A Helmholtz free energy density functional is developed to describe the vapor-liquid interface of associating chain molecules. The functional is based on the statistical associating fluid theory with attractive potentials of variable range (SAFT-VR) for the homogenous fluid [A. Gil-Villegas, A. Galindo, P. J. Whitehead, S. J. Mills, G. Jackson, and A. N. Burgess, J. Chem. Phys. 106, 4168 (1997)]. A standard perturbative density functional theory (DFT) is constructed by partitioning the free energy density into a reference term (which incorporates all of the short-range interactions, and is treated locally) and an attractive perturbation (which incorporates the long-range dispersion interactions). In our previous work [F. J. Blas, E. Martín del Río, E. de Miguel, and G. Jackson, Mol. Phys. 99, 1851 (2001); G. J. Gloor, F. J. Blas, E. Martín del Río, E. de Miguel, and G. Jackson, Fluid Phase Equil. 194, 521 (2002)] we used a mean-field version of the theory (SAFT-HS) in which the pair correlations were neglected in the attractive term. This provides only a qualitative description of the vapor-liquid interface, due to the inadequate mean-field treatment of the vapor-liquid equilibria. Two different approaches are used to include the correlations in the attractive term: in the first, the free energy of the homogeneous fluid is partitioned such that the effect of correlations are incorporated in the local reference term; in the second, a density averaged correlation function is incorporated into the perturbative term in a similar way to that proposed by Toxvaerd [S. Toxvaerd, J. Chem. Phys. 64, 2863 (1976)]. The latter is found to provide the most accurate description of the vapor-liquid surface tension on comparison with new simulation data for a square-well fluid of variable range. The SAFT-VR DFT is used to examine the effect of molecular chain length and association on the surface tension. Different association schemes (dimerization, straight and branched chain formation, and network structures) are examined separately. The surface tension of the associating fluid is found to be bounded between the nonassociating and fully associated limits (both of which correspond to equivalent nonassociating systems). The temperature dependence of the surface tension is found to depend strongly on the balance between the strength and range of the association, and on the particular association scheme. In the case of a system with a strong but very localized association interaction, the surface tension exhibits the characteristic "s shaped" behavior with temperature observed in fluids such as water and alkanols. The various types of curves observed in real substances can be reproduced by the theory. It is very gratifying that a DFT based on SAFT-VR free energy can provide an accurate quantitative description of the surface tension of both the model and experimental systems.
Huang, Emily; Wyles, Susannah M; Chern, Hueylan; Kim, Edward; O'Sullivan, Patricia
2016-07-01
A developmental and descriptive approach to assessing trainee intraoperative performance was explored. Semistructured interviews with 20 surgeon educators were recorded, transcribed, deidentified, and analyzed using a grounded theory approach to identify emergent themes. Two researchers independently coded the transcripts. Emergent themes were also compared to existing theories of skill acquisition. Surgeon educators characterized intraoperative surgical performance as an integrated practice of multiple skill categories and included anticipating, planning for contingencies, monitoring progress, self-efficacy, and "working knowledge." Comments concerning progression through stages, broadly characterized as "technician," "anatomist," "anticipator," "strategist," and "executive," formed a narrative about each stage of development. The developmental trajectory with narrative, descriptive profiles of surgeons working toward mastery provide a standardized vocabulary for communicating feedback, while fostering reflection on trainee progress. Viewing surgical performance as integrated practice rather than the conglomerate of isolated skills enhances authentic assessment. Copyright © 2015 Elsevier Inc. All rights reserved.
Existence of the passage to the limit of an inviscid fluid.
Goldobin, Denis S
2017-11-24
In the dynamics of a viscous fluid, the case of vanishing kinematic viscosity is actually equivalent to the Reynolds number tending to infinity. Hence, in the limit of vanishing viscosity the fluid flow is essentially turbulent. On the other hand, the Euler equation, which is conventionally adopted for the description of the flow of an inviscid fluid, does not possess proper turbulent behaviour. This raises the question of the existence of the passage to the limit of an inviscid fluid for real low-viscosity fluids. To address this question, one should employ the theory of turbulent boundary layer near an inflexible boundary (e.g., rigid wall). On the basis of this theory, one can see how the solutions to the Euler equation become relevant for the description of the flow of low-viscosity fluids, and obtain the small parameter quantifying accuracy of this description for real fluids.
The AP Descriptive Chemistry Question: Student Errors
ERIC Educational Resources Information Center
Crippen, Kent; Brooks, David W.
2005-01-01
For over a decade, the authors have been involved in a design theory experiment providing software for high school students preparing for the descriptive question on the Advanced Placement (AP) chemistry examination. Since 1997, the software has been available as a Web site offering repeatable practice. This study describes a 4-year project during…
Impact of Single-Case Pupil Descriptions on Student Teacher Attitudes towards Inclusive Education
ERIC Educational Resources Information Center
Röhm, Alexander; Schnöring, Annika; Hastall, Matthias R.
2018-01-01
Institutional and individual stigmatization are still major barriers for children with disabilities to access education. Teacher attitudes towards inclusive education play a crucial role in this regard, and are shaped by single-case descriptions from mass media or other sources. Building on exemplification theory and priming, two experiments with…
Phase space deformations in phantom cosmology
NASA Astrophysics Data System (ADS)
López, J. L.; Sabido, M.; Yee-Romero, C.
2018-03-01
We discuss the physical consequences of general phase space deformations on the minisuperspace of phantom cosmology. Based on the principle of physically equivalent descriptions in the deformed theory, we investigate for what values of the deformation parameters the arising descriptions are physically equivalent. We also construct and solve the quantum model and derive the semiclassical dynamics.
Applicability of DFT model in reactive distillation
NASA Astrophysics Data System (ADS)
Staszak, Maciej
2017-11-01
The density functional theory (DFT) applicability to reactive distillation is discussed. Brief modeling techniques description of distillation and rectification with chemical reaction is provided as a background for quantum method usage description. The equilibrium and nonequilibrium distillation models are described for that purpose. The DFT quantum theory is concisely described. The usage of DFT in the modeling of reactive distillation is described in two parts. One of the fundamental and very important component of distillation modeling is vapor-liquid equilibrium description for which the DFT quantum approach can be used. The representative DFT models, namely COSMO-RS (Conductor like Screening Model for Real Solvents), COSMOSPACE (COSMO Surface Pair Activity Coefficient) and COSMO-SAC (SAC - segment activity coefficient) approaches are described. The second part treats the way in which the chemical reaction is described by means of quantum DFT method. The intrinsic reaction coordinate (IRC) method is described which is used to find minimum energy path of substrates to products transition. The DFT is one of the methods which can be used for that purpose. The literature data examples are provided which proves that IRC method is applicable for chemical reaction kinetics description.
Context for Understanding why Particular Nanoscale Crystals Turn-On Faster and Other Lenr Effects
NASA Astrophysics Data System (ADS)
Chubb, Scott R.
Two persistent questions have been: (1) Why is it often necessary to wait for a finite period of time before the Excess Heat effect is observed after palladium (Pd) has been sufficiently loaded with deuterium (D), that the near full-loading condition (PdDx, 0.85 ~ < x → 1) that is required for Excess Heat, has been achieved? (2) Is it possible to identify physical properties of the materials and/or crystals that are used that might be playing a role in the interval of time associated with this phenomenon? Recently, I generalized conventional energy band theory to address both questions. The new theory can explain these experimental results but will be ignored by most scientists. I suggest that this is expected: The context of energy band and Ion Band State (IBS) theory is very different from the context of hot fusion theory. Even within the Low-Energy Nuclear Reactions (LENR) field, hidden, simplifying assumptions exist, which implicitly reflect biases associated with the context of hot fusion. A typical example is the idea that a single, particular form of reaction or environment can explain all LENR phenomena. As opposed to such a picture, involving a single "nuclear active environment" ("NAE"), the context of IBS theory and many-body physics suggests a more realistic and useful description of LENR involves a multiplicity of "nuclear active environments" (NAEs).
Diaconis, Persi; Holmes, Susan; Janson, Svante
2015-01-01
We work out a graph limit theory for dense interval graphs. The theory developed departs from the usual description of a graph limit as a symmetric function W (x, y) on the unit square, with x and y uniform on the interval (0, 1). Instead, we fix a W and change the underlying distribution of the coordinates x and y. We find choices such that our limits are continuous. Connections to random interval graphs are given, including some examples. We also show a continuity result for the chromatic number and clique number of interval graphs. Some results on uniqueness of the limit description are given for general graph limits. PMID:26405368
Columnar mesophases of hexabenzocoronene derivatives. II. Charge carrier mobility
NASA Astrophysics Data System (ADS)
Kirkpatrick, James; Marcon, Valentina; Kremer, Kurt; Nelson, Jenny; Andrienko, Denis
2008-09-01
Combining atomistic molecular dynamic simulations, Marcus-Hush theory description of charge transport rates, and master equation description of charge dynamics, we correlate the temperature-driven change of the mesophase structure with the change of charge carrier mobilities in columnar phases of hexabenzocoronene derivatives. The time dependence of fluctuations in transfer integrals shows that static disorder is predominant in determining charge transport characteristics. Both site energies and transfer integrals are distributed because of disorder in the molecular arrangement. It is shown that the contributions to the site energies from polarization and electrostatic effects are of opposite sign for positive charges. We look at three mesophases of hexabenzocoronene: herringbone, discotic, and columnar disordered. All results are compared to time resolved microwave conductivity data and show excellent agreement with no fitting parameters.
SEACAS Theory Manuals: Part III. Finite Element Analysis in Nonlinear Solid Mechanics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Laursen, T.A.; Attaway, S.W.; Zadoks, R.I.
1999-03-01
This report outlines the application of finite element methodology to large deformation solid mechanics problems, detailing also some of the key technological issues that effective finite element formulations must address. The presentation is organized into three major portions: first, a discussion of finite element discretization from the global point of view, emphasizing the relationship between a virtual work principle and the associated fully discrete system, second, a discussion of finite element technology, emphasizing the important theoretical and practical features associated with an individual finite element; and third, detailed description of specific elements that enjoy widespread use, providing some examples ofmore » the theoretical ideas already described. Descriptions of problem formulation in nonlinear solid mechanics, nonlinear continuum mechanics, and constitutive modeling are given in three companion reports.« less
Columnar mesophases of hexabenzocoronene derivatives. II. Charge carrier mobility.
Kirkpatrick, James; Marcon, Valentina; Kremer, Kurt; Nelson, Jenny; Andrienko, Denis
2008-09-07
Combining atomistic molecular dynamic simulations, Marcus-Hush theory description of charge transport rates, and master equation description of charge dynamics, we correlate the temperature-driven change of the mesophase structure with the change of charge carrier mobilities in columnar phases of hexabenzocoronene derivatives. The time dependence of fluctuations in transfer integrals shows that static disorder is predominant in determining charge transport characteristics. Both site energies and transfer integrals are distributed because of disorder in the molecular arrangement. It is shown that the contributions to the site energies from polarization and electrostatic effects are of opposite sign for positive charges. We look at three mesophases of hexabenzocoronene: herringbone, discotic, and columnar disordered. All results are compared to time resolved microwave conductivity data and show excellent agreement with no fitting parameters.
Skytt, Bernice; Hagerman, Heidi; Strömberg, Annika; Engström, Maria
2015-11-01
To elucidate first-line managers' descriptions and reflections regarding their staff's access to empowering structures using Kanter's theory of structural empowerment. Good structural conditions within workplaces are essential to employees' wellbeing, and their ability to access empowerment structures is largely dependent on the management. Twenty-eight first-line managers in elderly care were interviewed. Deductive qualitative content analysis was used to analyse data. Managers perceived that staff had varying degrees of access to the empowering structures described in Kanter's theory - and that they possessed formal power in their roles as contact persons and representatives. The descriptions mostly started from the managers' own actions, although some started from the needs of staff members. All managers described their staff's access to the empowering structures in Kanter's theory as important, yet it seemed as though this was not always reflected on and discussed as a strategic issue. Managers could make use of performance and appraisal dialogues to keep up to date on staff's access to empowering structures. Recurrent discussions in the management group based on such current information could promote staff's access to power through empowering structures and make job definitions a strategic issue in the organisation. © 2014 John Wiley & Sons Ltd.
Rajah-Kanagasabai, Camilla J.; Roberts, Lynne D.
2015-01-01
This study examined the utility of the Theory of Planned Behavior model, augmented by descriptive norms and justifications, for predicting self-reported research misconduct and questionable research practices in university students. A convenience sample of 205 research active Western Australian university students (47 male, 158 female, ages 18–53 years, M = 22, SD = 4.78) completed an online survey. There was a low level of engagement in research misconduct, with approximately one in seven students reporting data fabrication and one in eight data falsification. Path analysis and model testing in LISREL supported a parsimonious two step mediation model, providing good fit to the data. After controlling for social desirability, the effect of attitudes, subjective norms, descriptive norms and perceived behavioral control on student engagement in research misconduct and questionable research practices was mediated by justifications and then intention. This revised augmented model accounted for a substantial 40.8% of the variance in student engagement in research misconduct and questionable research practices, demonstrating its predictive utility. The model can be used to target interventions aimed at reducing student engagement in research misconduct and questionable research practices. PMID:25983709
Silvestrelli, Pier Luigi; Ambrosetti, Alberto
2014-03-28
The Density Functional Theory (DFT)/van der Waals-Quantum Harmonic Oscillator-Wannier function (vdW-QHO-WF) method, recently developed to include the vdW interactions in approximated DFT by combining the quantum harmonic oscillator model with the maximally localized Wannier function technique, is applied to the cases of atoms and small molecules (X=Ar, CO, H2, H2O) weakly interacting with benzene and with the ideal planar graphene surface. Comparison is also presented with the results obtained by other DFT vdW-corrected schemes, including PBE+D, vdW-DF, vdW-DF2, rVV10, and by the simpler Local Density Approximation (LDA) and semilocal generalized gradient approximation approaches. While for the X-benzene systems all the considered vdW-corrected schemes perform reasonably well, it turns out that an accurate description of the X-graphene interaction requires a proper treatment of many-body contributions and of short-range screening effects, as demonstrated by adopting an improved version of the DFT/vdW-QHO-WF method. We also comment on the widespread attitude of relying on LDA to get a rough description of weakly interacting systems.
A sharp interface model for void growth in irradiated materials
NASA Astrophysics Data System (ADS)
Hochrainer, Thomas; El-Azab, Anter
2015-03-01
A thermodynamic formalism for the interaction of point defects with free surfaces in single-component solids has been developed and applied to the problem of void growth by absorption of point defects in irradiated metals. This formalism consists of two parts, a detailed description of the dynamics of defects within the non-equilibrium thermodynamic frame, and the application of the second law of thermodynamics to provide closure relations for all kinetic equations. Enforcing the principle of non-negative entropy production showed that the description of the problem of void evolution under irradiation must include a relationship between the normal fluxes of defects into the void surface and the driving thermodynamic forces for the void surface motion; these thermodynamic forces are identified for both vacancies and interstitials and the relationships between these forces and the normal point defect fluxes are established using the concepts of transition state theory. The latter theory implies that the defect accommodation into the surface is a thermally activated process. Numerical examples are given to illustrate void growth dynamics in this new formalism and to investigate the effect of the surface energy barriers on void growth. Consequences for phase field models of void growth are discussed.
Rajah-Kanagasabai, Camilla J; Roberts, Lynne D
2015-01-01
This study examined the utility of the Theory of Planned Behavior model, augmented by descriptive norms and justifications, for predicting self-reported research misconduct and questionable research practices in university students. A convenience sample of 205 research active Western Australian university students (47 male, 158 female, ages 18-53 years, M = 22, SD = 4.78) completed an online survey. There was a low level of engagement in research misconduct, with approximately one in seven students reporting data fabrication and one in eight data falsification. Path analysis and model testing in LISREL supported a parsimonious two step mediation model, providing good fit to the data. After controlling for social desirability, the effect of attitudes, subjective norms, descriptive norms and perceived behavioral control on student engagement in research misconduct and questionable research practices was mediated by justifications and then intention. This revised augmented model accounted for a substantial 40.8% of the variance in student engagement in research misconduct and questionable research practices, demonstrating its predictive utility. The model can be used to target interventions aimed at reducing student engagement in research misconduct and questionable research practices.
Polymorphism and Elastic Response of Molecular Materials from First Principles: How Hard Can it Be?
NASA Astrophysics Data System (ADS)
Reilly, Anthony; Tkatchenko, Alexandre
2014-03-01
Molecular materials are of great fundamental and applied importance in science and industry, with numerous applications in pharmaceuticals, electronics, sensing, and catalysis. A key challenge for theory has been the prediction of their stability, polymorphism and response to perturbations. While pairwise models of van der Waals (vdW) interactions have improved the ability of density functional theory (DFT) to model these systems, substantial quantitative and even qualitative failures remain. In this contribution we show how a many-body description of vdW interactions can dramatically improve the accuracy of DFT for molecular materials, yielding quantitative description of stabilities and polymorphism for these challenging systems. Moreover, the role of many-body vdW interactions goes beyond stabilities to response properties. In particular, we have studied the elastic properties of a series of molecular crystals, finding that many-body vdW interactions can account for up to 30% of the elastic response, leading to quantitative and qualitative changes in elastic behavior. We will illustrate these crucial effects with the challenging case of the polymorphs of aspirin, leading to a better understanding of the conflicting experimental and theoretical studies of this system.
Solution to the nonlinear field equations of ten dimensional supersymmetric Yang-Mills theory
NASA Astrophysics Data System (ADS)
Mafra, Carlos R.; Schlotterer, Oliver
2015-09-01
In this paper, we present a formal solution to the nonlinear field equations of ten-dimensional super Yang-Mills theory. It is assembled from products of linearized superfields which have been introduced as multiparticle superfields in the context of superstring perturbation theory. Their explicit form follows recursively from the conformal field theory description of the gluon multiplet in the pure spinor superstring. Furthermore, superfields of higher-mass dimensions are defined and their equations of motion are spelled out.
The Toda lattice hierarchy and deformation of conformal field theories
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fukuma, M.; Takebe, T.
In this paper, the authors point out that the Toda lattice hierarchy known in soliton theory is relevant for the description of the deformations of conformal field theories while the KP hierarchy describes unperturbed conformal theories. It is shown that the holomorphic parts of the conserved currents in the perturbed system (the Toda lattice hierarchy) coincide with the conserved currents in the KP hierarchy and can be written in terms of the W-algebraic currents. Furthermore, their anti-holomorphic counterparts are obtained.
Collective learning modeling based on the kinetic theory of active particles
NASA Astrophysics Data System (ADS)
Burini, D.; De Lillo, S.; Gibelli, L.
2016-03-01
This paper proposes a systems approach to the theory of perception and learning in populations composed of many living entities. Starting from a phenomenological description of these processes, a mathematical structure is derived which is deemed to incorporate their complexity features. The modeling is based on a generalization of kinetic theory methods where interactions are described by theoretical tools of game theory. As an application, the proposed approach is used to model the learning processes that take place in a classroom.
Prospect Theory for Online Financial Trading
Martino, Mauro; Altshuler, Yaniv
2014-01-01
Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the “reflection effect”. People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called “loss aversion”. Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior. PMID:25330203
Clarifying the contribution of subjective norm to predicting leisure-time exercise.
Okun, Morris A; Karoly, Paul; Lutz, Rafer
2002-01-01
To clarify the contribution of subjective norm to exercise intention and behavior by considering the influence of descriptive as well as injunctive social norms related to family and friends. A sample of 530 college students completed a questionnaire that assessed descriptive and injunctive social norms related to family and to friends, perceived behavioral control, attitude, intention, and leisure-time exercise. Friend descriptive social norm was a significant predictor of both intention (p<.05) and leisure-time exercise (p<.001). Descriptive norms should be incorporated into tests of the theory of planned behavior in the exercise domain.
A model for the Pockels effect in distorted liquid crystal blue phases
DOE Office of Scientific and Technical Information (OSTI.GOV)
Castles, F., E-mail: flynn.castles@materials.ox.ac.uk
2015-09-07
Recent experiments have found that a mechanically distorted blue phase can exhibit a primary linear electro-optic (Pockels) effect [F. Castles et al., Nat. Mater. 13, 817 (2014)]. Here, it is shown that flexoelectricity can account for the experimental results and a model, which is based on continuum theory but takes into account the sub-unit-cell structure, is proposed. The model provides a quantitative description of the effect accurate to the nearest order of magnitude and predicts that the Pockels coefficient(s) in an optimally distorted blue phase may be two orders of magnitude larger than in lithium niobate.
Towards a Gender-Inclusive Theory of Educational Administration.
ERIC Educational Resources Information Center
Davies, Lynn
The overrepresentation of men in educational administration may be a result of inappropriate attempts to replicate in education the organizational structures of noneducational enterprises rather than a result of women's interests in or capabilities for administration. This paper opens with a description of the "critical theory" of educational…
Partial Orders Cannot Be Measured
ERIC Educational Resources Information Center
Kyngdon, Andrew
2011-01-01
Black, Wilson, and Yao (this issue) commendably attempt to put descriptive theory at the center of pedagogy, assessment, and curriculum. The thrust of their article is that only through theories of learning will student progression be properly understood. Casting a critical eye over the faddish distinction between "formative" and "summative"…
The Structure-Mapping Engine: Algorithm and Examples.
ERIC Educational Resources Information Center
Falkenhainer, Brian; And Others
This description of the Structure-Mapping Engine (SME), a flexible, cognitive simulation program for studying analogical processing which is based on Gentner's Structure-Mapping theory of analogy, points out that the SME provides a "tool kit" for constructing matching algorithms consistent with this theory. This report provides: (1) a…
Behavioral Variability of Choices versus Structural Inconsistency of Preferences
ERIC Educational Resources Information Center
Regenwetter, Michel; Davis-Stober, Clintin P.
2012-01-01
Theories of rational choice often make the structural consistency assumption that every decision maker's binary strict preference among choice alternatives forms a "strict weak order". Likewise, the very concept of a "utility function" over lotteries in normative, prescriptive, and descriptive theory is mathematically equivalent to strict weak…
[Description of clinical thinking by the dual-process theory].
Peña G, Luis
2012-06-01
Clinical thinking is a very complex process that can be described by the dual-process theory, it has an intuitive part (that recognizes patterns) and an analytical part (that tests hypotheses). It is vulnerable to cognitive bias that professionals must be aware of, to minimize diagnostic errors.
Measurement Scales and Standard Systems in Psychology.
ERIC Educational Resources Information Center
Aftanas, Marion S.
Most discussions of measurement theory are focused on "scales" of measurement, but it is not clear whether reference is made to the mechanisms of measurement or the metric information derived from measurement. This emphasis on scales in measurement theory has not always provided a meaningful or fruitful description of measurement activities in…
Mainstreaming the Non-English Speaking Student.
ERIC Educational Resources Information Center
Rodrigues, Raymond J.; White, Robert H.
As part of a series of sharply focused booklets based on concrete educational needs, this booklet is designed to provide teachers with the best educational theory and research on mainstreaming non-English speaking children in regular classrooms and to present descriptions of classroom activities that are related to the described theory. Section…
Vico's Theory of Knowledge and Some Problems in Genetic Epistemology.
ERIC Educational Resources Information Center
Gash, Hugh
1983-01-01
Argues that Vico's constructivist epistemology is germane to contemporary cognitive developmental psychology, first in clarifying the meaning of the environment in Piaget's theory and second by providing, through the description of mental operations, a way of overcoming directions to the overly formal quality of Piaget's basic concrete-operational…
Recent Trends in Free Speech Theory.
ERIC Educational Resources Information Center
Haiman, Franklyn S.
This syllabus of a convention workshop course on free speech theory consists of descriptions of several United States Supreme Court decisions related to free speech. Some specific areas in which decisions are discussed are: obscene and indecent communication, the definition of a public figure for purposes of libel action, the press versus official…
Getting a Puff: A Social Learning Test of Adolescents Smoking
ERIC Educational Resources Information Center
Monroe, Jacquelyn
2004-01-01
This article is a description of a study that sought to examine the applicability of Ronald Akers' social learning theory. According to Akers' theory, differential associations with smokers, differential reinforcements for smoking, favorable definitions of smoking and the availability of role models (imitation) offer an explanation as to why…
Cultural Descriptions as Political Cultural Acts: An Exploration
ERIC Educational Resources Information Center
Holliday, Adrian
2010-01-01
Interculturality may be something normal which everyone possesses to a degree. However, dominant neo-essentialist theories of culture give the impression that we are too different to easily cross-cultural boundaries. These theories support the development of academic disciplines and the need for professional certainty in intercultural training.…
Electronic wave function and binding effects in M-shell ionization of gold by protons
NASA Astrophysics Data System (ADS)
Pajek, M.; Banaś, D.; Jabłoński, Ł.; Mukoyama, T.
2018-02-01
The measured M-X-ray production cross sections for protons, which are used in the particle induced X-ray emission (PIXE) technique, are systematically underestimated for low impact energies by the ECPSSR and ECUSAR theories. These theories, which are based on the plane wave Born approximation (PWBA) and use the screened hydrogenic wave functions, include corrections for the projectile Coulomb deflection and electron relativistic and binding effects. In the present paper, in order to interpret the observed disagreement at low impact energies, the systematic calculations of the M-shell ionization cross sections for gold were performed using the semiclassical (SCA) and the binary encounter (BEA) approximations in order to identify a role of the electronic wave function and electron binding effects. In these calculations the different wave functions, from nonrelativistic hydrogenic to selfconsistent Dirac-Hartree-Fock, were considered and the binding effect was treated within extreme separated- (SA) and united-atoms (UA) limits. The results are discussed in details and the observed discrepancies are attributed to inadequate description of the electron binding effect at the lowest impact energies for which the molecular approach is required.
Putrov, Pavel; Song, Jaewon; Yan, Wenbin
2016-03-29
We study a class of two-dimensional N = (0; 4) quiver gauge theories that flow to superconformal field theories. We find dualities for the superconformal field theories similar to the 4d N = 2 theories of class S, labelled by a Riemann surface C. The dual descriptions arise from various pair-of-pants decompositions, that involve an analog of the T N theory. Especially, we find the superconformal indices of such theories can be written in terms of a topological field theory on C. In conclusion, we interpret this class of SCFTs as the ones coming from compactifying 6d N = (2;more » 0) theory on CP 1 x C. Moreover, some new dualities of (0; 2) and (2; 2) theories are also discussed.« less
ERIC Educational Resources Information Center
Park, Valerie Darlene
2014-01-01
The purpose of this study was to describe the theories of action, strategic objectives, and strategic initiatives of school systems led by female county superintendents in California and examine their impact on improving system outcomes. Additionally, the factors influencing theory of action, strategic objective, and initiative development were…
A new approach for modular robot system behavioral modeling: Base on Petri net and category theory
NASA Astrophysics Data System (ADS)
Zhang, Yun; Wei, Hongxing; Yang, Bo
2018-04-01
To design modular robot system, Petri nets and category theory are combined and the ability of simulation of Petri net is discussed. According to category theory, the method of describing the category of components in the dynamic characteristics of the system is deduced. Moreover, a modular robot system is analyzed, which provides a verifiable description of the dynamic characteristics of the system.
Aspects of defects in 3d-3d correspondence
Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; ...
2016-10-12
In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2, 0) theory of type A N-1 on a 3-manifold M . The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,C) ) on M and a 3d N=2 theory T N [M ]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T [SU(N )], 5d N=2 SYM, and alsomore » supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N > 2. We also highlight the non-Abelian description of the 3d N=2 T N [M ] theory with defect included, when such a description is available. This paper is a companion to our shorter paper, which summarizes our main results.« less
Quantum nonunital dynamics of spin-bath-assisted Fisher information
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hao, Xiang, E-mail: haoxiang-edu198126@163.com; Wu, Yinzhong
2016-04-15
The nonunital non-Markovian dynamics of qubits immersed in a spin bath is studied without any Markovian approximation. The environmental effects on the precisions of quantum parameter estimation are taken into account. The time-dependent transfer matrix and inhomogeneity vector are obtained for the description of the open dynamical process. The dynamical behaviour of one qubit coupled to a spin bath is geometrically described by the Bloch vector. It is found out that the nonunital non-Markovian effects can engender the improvement of the precision of quantum parameter estimation. This result contributes to the environment-assisted quantum information theory.
Relations between heavy-light meson and quark masses
NASA Astrophysics Data System (ADS)
Brambilla, N.; Komijani, J.; Kronfeld, A. S.; Vairo, A.; Tumqcd Collaboration
2018-02-01
The study of heavy-light meson masses should provide a way to determine renormalized quark masses and other properties of heavy-light mesons. In the context of lattice QCD, for example, it is possible to calculate hadronic quantities for arbitrary values of the quark masses. In this paper, we address two aspects relating heavy-light meson masses to the quark masses. First, we introduce a definition of the renormalized quark mass that is free of both scale dependence and renormalon ambiguities, and discuss its relation to more familiar definitions of the quark mass. We then show how this definition enters a merger of the descriptions of heavy-light masses in heavy-quark effective theory and in chiral perturbation theory (χ PT ). For practical implementations of this merger, we extend the one-loop χ PT corrections to lattice gauge theory with heavy-light mesons composed of staggered fermions for both quarks. Putting everything together, we obtain a practical formula to describe all-staggered heavy-light meson masses in terms of quark masses as well as some lattice artifacts related to staggered fermions. In a companion paper, we use this function to analyze lattice-QCD data and extract quark masses and some matrix elements defined in heavy-quark effective theory.
Relations between heavy-light meson and quark masses
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brambilla, N.; Komijani, J.; Kronfeld, A. S.
Here, the study of heavy-light meson masses should provide a way to determine renormalized quark masses and other properties of heavy-light mesons. In the context of lattice QCD, for example, it is possible to calculate hadronic quantities for arbitrary values of the quark masses. In this paper, we address two aspects relating heavy-light meson masses to the quark masses. First, we introduce a definition of the renormalized quark mass that is free of both scale dependence and renormalon ambiguities, and discuss its relation to more familiar definitions of the quark mass. We then show how this definition enters a mergermore » of the descriptions of heavy-light masses in heavy-quark effective theory and in chiral perturbation theory (χPT). For practical implementations of this merger, we extend the one-loop χPT corrections to lattice gauge theory with heavy-light mesons composed of staggered fermions for both quarks. Putting everything together, we obtain a practical formula to describe all-staggered heavy-light meson masses in terms of quark masses as well as some lattice artifacts related to staggered fermions. In a companion paper, we use this function to analyze lattice-QCD data and extract quark masses and some matrix elements defined in heavy-quark effective theory.« less
NASA Astrophysics Data System (ADS)
Yao, De-Liang; Siemens, D.; Bernard, V.; Epelbaum, E.; Gasparyan, A. M.; Gegelia, J.; Krebs, H.; Meißner, Ulf-G.
2016-05-01
We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the S- and P -partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the D and F waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in order to determine the strangeness content of the nucleon, we calculate the octet baryon masses in the presence of decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral perturbation theory. The octet baryon sigma terms are predicted as a byproduct of this calculation.
Relations between heavy-light meson and quark masses
Brambilla, N.; Komijani, J.; Kronfeld, A. S.; ...
2018-02-07
Here, the study of heavy-light meson masses should provide a way to determine renormalized quark masses and other properties of heavy-light mesons. In the context of lattice QCD, for example, it is possible to calculate hadronic quantities for arbitrary values of the quark masses. In this paper, we address two aspects relating heavy-light meson masses to the quark masses. First, we introduce a definition of the renormalized quark mass that is free of both scale dependence and renormalon ambiguities, and discuss its relation to more familiar definitions of the quark mass. We then show how this definition enters a mergermore » of the descriptions of heavy-light masses in heavy-quark effective theory and in chiral perturbation theory (χPT). For practical implementations of this merger, we extend the one-loop χPT corrections to lattice gauge theory with heavy-light mesons composed of staggered fermions for both quarks. Putting everything together, we obtain a practical formula to describe all-staggered heavy-light meson masses in terms of quark masses as well as some lattice artifacts related to staggered fermions. In a companion paper, we use this function to analyze lattice-QCD data and extract quark masses and some matrix elements defined in heavy-quark effective theory.« less
Byron, M J; Cohen, J E; Frattaroli, S; Gittelsohn, J; Jernigan, D H
2016-12-01
Smoke-free laws, which ban smoking in public venues, can be effective in protecting public health, but it has been difficult to achieve compliance with these laws in low- and middle-income countries. This study was conducted to understand the social norms around public smoking and learn how to improve compliance in Bogor, the first Indonesian city to pass a comprehensive smoke-free law. Eleven stratified focus groups were conducted (n = 89). Data were analyzed using the theory of normative social behavior, which posits that the influence of descriptive norms (perceptions about what other people do) on behavior is moderated by injunctive norms (perceptions about what one is expected to do), outcome expectations and group identity. The findings showed that participants perceived smoking in public to be common for men (descriptive norm). Public smoking is acceptable except in places with air conditioning and around children or pregnant women (injunctive norms). Men smoke without penalty of social or legal sanctions (outcome expectations) and may feel affiliation with other smokers (group identity). Together, these factors support public smoking and inhibit compliance with the smoke-free law. Theory-based communication and policy remedies are suggested that may bolster compliance with Bogor's smoke-free law given the current pro-smoking norms. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Building a functional multiple intelligences theory to advance educational neuroscience
Cerruti, Carlo
2013-01-01
A key goal of educational neuroscience is to conduct constrained experimental research that is theory-driven and yet also clearly related to educators’ complex set of questions and concerns. However, the fields of education, cognitive psychology, and neuroscience use different levels of description to characterize human ability. An important advance in research in educational neuroscience would be the identification of a cognitive and neurocognitive framework at a level of description relatively intuitive to educators. I argue that the theory of multiple intelligences (MI; Gardner, 1983), a conception of the mind that motivated a past generation of teachers, may provide such an opportunity. I criticize MI for doing little to clarify for teachers a core misunderstanding, specifically that MI was only an anatomical map of the mind but not a functional theory that detailed how the mind actually processes information. In an attempt to build a “functional MI” theory, I integrate into MI basic principles of cognitive and neural functioning, namely interregional neural facilitation and inhibition. In so doing I hope to forge a path toward constrained experimental research that bears upon teachers’ concerns about teaching and learning. PMID:24391613
From bosonic topological transition to symmetric fermion mass generation
NASA Astrophysics Data System (ADS)
You, Yi-Zhuang; He, Yin-Chen; Vishwanath, Ashvin; Xu, Cenke
2018-03-01
A bosonic topological transition (BTT) is a quantum critical point between the bosonic symmetry-protected topological phase and the trivial phase. In this work, we investigate such a transition in a (2+1)-dimensional lattice model with the maximal microscopic symmetry: an internal SO (4 ) symmetry. We derive a description for this transition in terms of compact quantum electrodynamics (QED) with four fermion flavors (Nf=4 ). Within a systematic renormalization group analysis, we identify the critical point with the desired O (4 ) emergent symmetry and all expected deformations. By lowering the microscopic symmetry, we recover the previous Nf=2 noncompact QED description of the BTT. Finally, by merging two BTTs we recover a previously discussed theory of symmetric mass generation, as an SU (2 ) quantum chromodynamics-Higgs theory with Nf=4 flavors of SU (2 ) fundamental fermions and one SU (2 ) fundamental Higgs boson. This provides a consistency check on both theories.
Description and Application of a Mathematical Method for the Analysis of Harmony
Zuo, Qiting; Jin, Runfang; Ma, Junxia
2015-01-01
Harmony issues are widespread in human society and nature. To analyze these issues, harmony theory has been proposed as the main theoretical approach for the study of interpersonal relationships and relationships between humans and nature. Therefore, it is of great importance to study harmony theory. After briefly introducing the basic concepts of harmony theory, this paper expounds the five elements that are essential for the quantitative description of harmony issues in water resources management: harmony participant, harmony objective, harmony regulation, harmony factor, and harmony action. A basic mathematical equation for the harmony degree, that is, a quantitative expression of harmony issues, is introduced in the paper: HD = ai − bj, where a is the uniform degree, b is the difference degree, i is the harmony coefficient, and j is the disharmony coefficient. This paper also discusses harmony assessment and harmony regulation and introduces some application examples. PMID:26167535
Magnetic exchange couplings from noncollinear perturbation theory: dinuclear CuII complexes.
Phillips, Jordan J; Peralta, Juan E
2014-08-07
To benchmark the performance of a new method based on noncollinear coupled-perturbed density functional theory [J. Chem. Phys. 138, 174115 (2013)], we calculate the magnetic exchange couplings in a series of triply bridged ferromagnetic dinuclear Cu(II) complexes that have been recently synthesized [Phys. Chem. Chem. Phys. 15, 1966 (2013)]. We find that for any basis-set the couplings from our noncollinear coupled-perturbed methodology are practically identical to those of spin-projected energy-differences when a hybrid density functional approximation is employed. This demonstrates that our methodology properly recovers a Heisenberg description for these systems, and is robust in its predictive power of magnetic couplings. Furthermore, this indicates that the failure of density functional theory to capture the subtle variation of the exchange couplings in these complexes is not simply an artifact of broken-symmetry methods, but rather a fundamental weakness of current approximate density functionals for the description of magnetic couplings.
Research report: a grounded theory description of pastoral counseling.
Townsend, Loren L
2011-01-01
Historically, clerical paradigms of ordained ministry have defined pastoral counseling. However, these fail to describe pastoral counselors in the complex social, theological and medical contexts in which they now work. This study asks the question: How do pastoral counselors in clinical practice describe what is uniquely "pastoral" about the counseling they offer clients? Grounded theory was used to propose a preliminary description and an intermediate theory of how pastoral counselors interpret "pastoral." Eighty-five pastoral counselors were selected for the study over a four year period using criteria to assure maximum variation. Interviews and pastoral identity statements were collected and coded, and theoretical models were organized using NVIVO, a computer assisted qualitative design and analysis software (CAQDAS) package. Results suggest that pastoral counselors share some common ideas regarding "pastoral identity" and clinical practice. How pastoral counselors interpret "pastoral" is highly context sensitive and varies widely.