Effective medium theory principles and applications

CERN Document Server

Choy, Tuck C

2015-01-01

Effective medium theory dates back to the early days of the theory of electricity. Faraday in 1837 proposed one of the earliest models for a composite metal-insulator dielectric and around 1870 Maxwell and later Garnett (1904) developed models to describe a composite or mixed material medium. The subject has been developed considerably since and while the results are useful for predicting materials performance, the theory can also be used in a wide range of problems in physics and materials engineering. This book develops the topic of effective medium theory by bringing together the essentials of both the static and the dynamical theory. Electromagnetic systems are thoroughly dealt with, as well as related areas such as the CPA theory of alloys, liquids, the density functional theory etc., with applications to ultrasonics, hydrodynamics, superconductors, porous media and others, where the unifying aspects of the effective medium concept are emphasized. In this new second edition two further chapters have been...

Center-symmetric effective theory for high-temperature SU(2) Yang-Mills theory

International Nuclear Information System (INIS)

Forcrand, Ph. de; Kurkela, A.; Vuorinen, A.

2008-01-01

We construct and study a dimensionally reduced effective theory for high-temperature SU(2) Yang-Mills theory that respects all the symmetries of the underlying theory. Our main motivation is to study whether the correct treatment of the center symmetry can help extend the applicability of the dimensional reduction procedure towards the confinement transition. After performing perturbative matching to the full theory at asymptotically high temperatures, we map the phase diagram of the effective theory using nonperturbative lattice simulations. We find that at lower temperature the theory undergoes a second-order confining phase transition, in complete analogy with the full theory, which is a direct consequence of having incorporated the center symmetry

Effective quantum field theories

International Nuclear Information System (INIS)

Georgi, H.M.

1989-01-01

Certain dimensional parameters play a crucial role in the understanding of weak and strong interactions based on SU(2) x U(1) and SU(3) symmetry group theories and of grand unified theories (GUT's) based on SU(5). These parameters are the confinement scale of quantum chromodynamics and the breaking scales of SU(2) x U(1) and SU(5). The concepts of effective quantum field theories and renormalisability are discussed with reference to the economics and ethics of research. (U.K.)

Effective actions for F-theory compactifications and tensor theories

International Nuclear Information System (INIS)

Bonetti, Federico

2014-01-01

In this thesis we study the low-energy effective dynamics emerging from a class of F-theory compactifications in four and six dimensions. We also investigate six-dimensional supersymmetric quantum field theories with self-dual tensors, motivated by the problem of describing the long-wavelength regime of a stack of M5-branes in M-theory. These setups share interesting common features. They both constitute examples of intrinsically non-perturbative physics. On the one hand, in the context of F-theory the non-perturbative character is encoded in the geometric formulation of this class of string vacua, which allows the complexified string coupling to vary in space. On the other hand, the dynamics of a stack of multiple M5-branes flows in the infrared to a novel kind of superconformal field theories in six dimensions - commonly referred to as (2,0) theories - that are expected to possess no perturbative weakly coupled regime and have resisted a complete understanding so far. In particular, no Lagrangian description is known for these models. The strategy we employ to address these two problems is also analogous. A recurring Leitmotif of our work is a transdimensional treatment of the system under examination: in order to extract information about dynamics in d dimensions we consider a (d-1)-dimensional setup. As far as F-theory compactifications are concerned, this is a consequence of the duality between M-theory and F-theory, which constitutes our main tool in the derivation of the effective action of F-theory compactifications. We apply it to six-dimensional F-theory vacua, obtained by taking the internal space to be an elliptically fibered Calabi-Yau threefold, but we also employ it to explore a novel kind of F-theory constructions in four dimensions based on manifolds with Spin(7) holonomy. With reference to six-dimensional (2,0) theories, the transdimensional character of our approach relies in the idea of studying these theories in five dimensions. Indeed, we

Effective Field Theory on Manifolds with Boundary

Science.gov (United States)

Albert, Benjamin I.

In the monograph Renormalization and Effective Field Theory, Costello made two major advances in rigorous quantum field theory. Firstly, he gave an inductive position space renormalization procedure for constructing an effective field theory that is based on heat kernel regularization of the propagator. Secondly, he gave a rigorous formulation of quantum gauge theory within effective field theory that makes use of the BV formalism. In this work, we extend Costello's renormalization procedure to a class of manifolds with boundary and make preliminary steps towards extending his formulation of gauge theory to manifolds with boundary. In addition, we reorganize the presentation of the preexisting material, filling in details and strengthening the results.

An introduction to effective field theory

International Nuclear Information System (INIS)

Donoghue, John F.

1999-01-01

In these lectures I describe the main ideas of effective field theory. These are first illustrated using QED and the linear sigma model as examples. Calculational techniques using both Feynman diagrams and dispersion relations are introduced. Within QCD, chiral perturbation theory is a complete effective field theory, and I give a guide to some calculations in the literature which illustrates key ideas. (author)

Effective medium theory for anisotropic metamaterials

KAUST Repository

Zhang, Xiujuan

2015-01-20

Materials with anisotropic material parameters can be utilized to fabricate many fascinating devices, such as hyperlenses, metasolids, and one-way waveguides. In this study, we analyze the effects of geometric anisotropy on a two-dimensional metamaterial composed of a rectangular array of elliptic cylinders and derive an effective medium theory for such a metamaterial. We find that it is possible to obtain a closed-form analytical solution for the anisotropic effective medium parameters, provided the aspect ratio of the lattice and the eccentricity of the elliptic cylinder satisfy certain conditions. The derived effective medium theory not only recovers the well-known Maxwell-Garnett results in the quasi-static regime, but is also valid beyond the long-wavelength limit, where the wavelength in the host medium is comparable to the size of the lattice so that previous anisotropic effective medium theories fail. Such an advance greatly broadens the applicable realm of the effective medium theory and introduces many possibilities in the design of structures with desired anisotropic material characteristics. A real sample of a recently theoretically proposed anisotropic medium, with a near-zero index to control the flux, is achieved using the derived effective medium theory, and control of the electromagnetic waves in the sample is clearly demonstrated.

Soft collinear effective theory for gravity

Science.gov (United States)

Okui, Takemichi; Yunesi, Arash

2018-03-01

We present how to construct a soft collinear effective theory (SCET) for gravity at the leading and next-to-leading powers from the ground up. The soft graviton theorem and decoupling of collinear gravitons at the leading power are manifest from the outset in the effective symmetries of the theory. At the next-to-leading power, certain simple structures of amplitudes, which are completely obscure in Feynman diagrams of the full theory, are also revealed, which greatly simplifies calculations. The effective Lagrangian is highly constrained by effectively multiple copies of diffeomorphism invariance that are inevitably present in gravity SCET due to mode separation, an essential ingredient of any SCET. Further explorations of effective theories of gravity with mode separation may shed light on Lagrangian-level understandings of some of the surprising properties of gravitational scattering amplitudes. A gravity SCET with an appropriate inclusion of Glauber modes may serve as a powerful tool for studying gravitational scattering in the Regge limit.

Renormalons in effective field theories

International Nuclear Information System (INIS)

Luke, M.; Manohar, A.V.; Savage, M.J.

1995-01-01

We investigate the high-order behavior of perturbative matching conditions in effective field theories. These series are typically badly divergent, and are not Borel summable due to infrared and ultraviolet renormalons which introduce ambiguities in defining the sum of the series. We argue that, when treated consistently, there is no physical significance to these ambiguities. Although nonperturbative matrix elements and matching conditions are in general ambiguous, the ambiguity in any physical observable is always higher order in 1/M than the theory has been defined. We discuss the implications for the recently noticed infrared renormalon in the pole mass of a heavy quark. We show that a ratio of form factors in exclusive Λ b decays (which is related to the pole mass) is free from renormalon ambiguities regardless of the mass used as the expansion parameter of heavy quark effective theory. The renormalon ambiguities also cancel in inclusive heavy hadron decays. Finally, we demonstrate the cancellation of renormalons in a four-Fermi effective theory obtained by integrating out a heavy colored scalar

Effective field theory for NN interactions

International Nuclear Information System (INIS)

Tran Duy Khuong; Vo Hanh Phuc

2003-01-01

The effective field theory of NN interactions is formulated and the power counting appropriate to this case is reviewed. It is more subtle than in most effective field theories since in the limit that the S-wave NN scattering lengths go to infinity. It is governed by nontrivial fixed point. The leading two body terms in the effective field theory for nucleon self interactions are scale invariant and invariant under Wigner SU(4) spin-isospin symmetry in this limit. Higher body terms with no derivatives (i.e. three and four body terms) are automatically invariant under Wigner symmetry. (author)

Boundary effects in super-Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Shah, Mushtaq B.; Ganai, Prince A. [National Institute of Technology, Department of Physics, Srinagar, Kashmir (India); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Alberta (Canada); Zaz, Zaid [University of Kashmir, Department of Electronics and Communication Engineering, Srinagar, Kashmir (India); Bhat, Anha [National Institute of Technology, Department of Metallurgical and Materials Engineering, Srinagar, Kashmir (India); Masood, Syed [International Islamic University, Department of Physics, Islamabad (Pakistan)

2017-05-15

In this paper, we shall analyze a three dimensional supersymmetry theory with N = 2 supersymmetry. We will analyze the quantization of this theory, in the presence of a boundary. The effective Lagrangian used in the path integral quantization of this theory, will be given by the sum of the gauge fixing term and the ghost term with the original classical Lagrangian. Even though the supersymmetry of this effective Lagrangian will also be broken due to the presence of a boundary, it will be demonstrated that half of the supersymmetry of this theory can be preserved by adding a boundary Lagrangian to the effective bulk Lagrangian. The supersymmetric transformation of this new boundary Lagrangian will exactly cancel the boundary term generated from the supersymmetric transformation of the effective bulk Lagrangian. We will analyze the Slavnov-Taylor identity for this N = 2 Yang-Mills theory with a boundary. (orig.)

Boundary effects in super-Yang-Mills theory

International Nuclear Information System (INIS)

Shah, Mushtaq B.; Ganai, Prince A.; Faizal, Mir; Zaz, Zaid; Bhat, Anha; Masood, Syed

2017-01-01

In this paper, we shall analyze a three dimensional supersymmetry theory with N = 2 supersymmetry. We will analyze the quantization of this theory, in the presence of a boundary. The effective Lagrangian used in the path integral quantization of this theory, will be given by the sum of the gauge fixing term and the ghost term with the original classical Lagrangian. Even though the supersymmetry of this effective Lagrangian will also be broken due to the presence of a boundary, it will be demonstrated that half of the supersymmetry of this theory can be preserved by adding a boundary Lagrangian to the effective bulk Lagrangian. The supersymmetric transformation of this new boundary Lagrangian will exactly cancel the boundary term generated from the supersymmetric transformation of the effective bulk Lagrangian. We will analyze the Slavnov-Taylor identity for this N = 2 Yang-Mills theory with a boundary. (orig.)

Gravitational effects in field gravitation theory

International Nuclear Information System (INIS)

Denisov, V.I.; Logunov, A.A.; Mestvirishvili, M.A.; Vlasov, A.A.

1979-01-01

The possibilities to describe various gravitation effects of field gravitation theory (FGT) are considered. Past-Newtonian approximation of the FGT has been constructed and on the basis of this approximation it has been shown that the field theory allows one to describe the whole set of experimental facts. The comparison of post-Newtonian parameters in FGT with those in the Einstein's theory makes it clear that these two; theories are undistinguishable from the viewpoint of any experiments, realized with post-Newtonian accuracy. Gravitational field of an island type source with spherically symmetrical distribution of matter and unstationary homogeneous model of Universe, which allows to describe the effect of cosmological red shift, are considered

Effective Field Theories and Strong Interactions. Final Technical Report

International Nuclear Information System (INIS)

Fleming, Sean

2011-01-01

The framework of Effective Field Theories (EFTs) allows us to describe strong interactions in terms of degrees of freedom relevant to the energy regimes of interest, in the most general way consistent with the symmetries of QCD. Observables are expanded systematically in powers of M lo /M hi , where M lo (M hi ) denotes a low-(high-)energy scale. This organizational principle is referred to as 'power counting'. Terms of increasing powers in the expansion parameter are referred to as leading order (LO), next-to-leading order (NLO), etc. Details of the QCD dynamics not included explicitly are encoded in interaction parameters, or 'low-energy constants' (LECs), which can in principle be calculated from an explicit solution of QCD - for example via lattice simulations- but can also be determined directly from experimental data. QCD has an intrinsic scale M QCD ≅ 1 GeV, at which the QCD coupling constant α s (M QCD ) becomes large and the dynamics becomes non-perturbative. As a consequence M QCD sets the scale for the masses of most hadrons, such as the nucleon mass m N ≅ 940 MeV. EFTs can roughly be divided into two categories: those that can be matched onto QCD in perturbation theory, which we call high-energy EFTs, and those that cannot be matched perturbatively, which we call low-energy EFTs. In high-energy EFTs, M QCD typically sets the low-energy scale, and all the dynamics associated with this scale reside in matrix elements of EFT operators. These non-perturbative matrix elements are the LECs and are also referred to as long-distance contributions. Each matrix element is multiplied by a short-distance coefficient, which contains the dynamics from the high scale M hi . Since M hi >> M QCD , α s (M hi ) hi ∼ M Q , the heavy-quark mass, and in addition to M QCD there are low scales associated with the typical relative momentum ∼ M Q v and energy ∼ M Q v 2 of the heavy quarks. Depending on the sizes of M Q and the heavy-quark velocity v these scales can

Effective potentials in gauge field theories

International Nuclear Information System (INIS)

Caldas, P.S.S.; Fleming, H.; Garcia, R.L.

An elementary and very efficient method for computing the effective potential of any theory containing scalar bosons is described. Examples include massless scalar electrodynamics and Yang-Mills theories [pt

Spectator interactions in soft-collinear effective theory

International Nuclear Information System (INIS)

Hill, Richard J.; Neubert, Matthias

2003-01-01

Soft-collinear effective theory is generalized to include soft massless quarks in addition to collinear fields. This extension is necessary for the treatment of interactions with the soft spectator quark in a heavy meson. The power counting of the relevant fields and the construction of the effective Lagrangian are discussed at leading order in Λ/m b . Several novel effects occur in the matching of full-theory amplitudes onto effective-theory operators containing soft light quarks, such as the appearance of an intermediate mass scale and large non-localities of operators on scales of order 1/Λ. Important examples of effective-theory operators with soft light quarks are studied and their renormalization properties explored. The formalism presented here forms the basis for a systematic analysis of factorization and power corrections for any exclusive B-meson decay into light particles

Spectator Interactions in Soft-Collinear Effective Theory

International Nuclear Information System (INIS)

Hill, Richard J

2002-01-01

Soft-collinear effective theory is generalized to include soft massless quarks in addition to collinear fields. This extension is necessary for the treatment of interactions with the soft spectator quark in a heavy meson. The power counting of the relevant fields and the construction of the effective Lagrangian are discussed at leading order in Λ/m b . Several novel effects occur in the matching of full-theory amplitudes onto effective-theory operators containing soft light quarks, such as the appearance of an intermediate mass scale and large non-localities of operators on scales of order 1/Λ. Important examples of effective-theory operators with soft light quarks are studied and their renormalization properties explored. The formalism presented here forms the basis for a systematic analysis of factorization and power corrections for any exclusive B-meson decay into light particles

Renormalization (and power counting) of effective field theories for the nuclear force

International Nuclear Information System (INIS)

Timoteo, Varese S.; Szpigel, Sergio; Duraes, Francisco O.

2011-01-01

The most common scheme used to regularize the Lippman-Schwinger (LS) equation is to introduce a sharp or smooth regularizing function that suppresses the contributions from the potential matrix elements for momenta larger than a given cutoff scale, which separates high-energy/short-distance scales and low-energy/long-distance scales, thus eliminating the ultraviolet divergences in the momentum integrals. Then, one needs determine the strengths of the contact interactions, the so called low-energy constants (LEC), by fitting a set of low-energy scattering data. Once the LECs are fixed for a given cutoff, the LS equation can be solved to evaluate other observables. Such a procedure, motivated by Wilsons renormalization group, relies on the fundamental premise of EFT that physics at low-energy/long-distance scales is insensitive with respect to the details of the dynamics at high-energy/short-distance scales, i.e. the relevant high-energy/short- distance effects for describing the low-energy observables can be captured in the cutoff-dependent LECs. The NN interaction can be considered properly renormalized when the calculated observables are independent of the cutoff scale within the range of validity of the ChEFT or involves a small residual cutoff dependence due to the truncation of the chiral expansion. In the language of Wilsons renormalization group, this means that the LECs must run with the cutoff scale in such a way that the scattering amplitude becomes renormalization group invariant (RGI). Here we consider pionless EFT up to NNLO and chiral EFT up to NNLO and use a subtractive renormalization scheme to describe the NN scattering channels with. We fix the strength of the contact interactions at a reference scale, chosen to be the one the provides the best fit, and then evolve the driving terms with a non-relativistic Callan-Symanzik equation to slide the renormalization scale. By computing phase shift relative differences, we show that the method is RGI. We

Introduction to soft-collinear effective theory

CERN Document Server

Becher, Thomas; Ferroglia, Andrea

2015-01-01

Among resummation techniques for perturbative QCD in the context of collider and flavor physics, soft-collinear effective theory (SCET) has emerged as both a powerful and versatile tool, having been applied to a large variety of processes, from B-meson decays to jet production at the LHC.  This book provides a concise, pedagogical introduction to this technique. It discusses the expansion of Feynman diagrams around the high-energy limit, followed by the explicit construction of the effective Lagrangian - first for a scalar theory, then for QCD. The underlying concepts are illustrated with the quark vector form factor at large momentum transfer, and the formalism is applied to compute soft-gluon resummation and to perform transverse-momentum resummation for the Drell-Yan process utilizing renormalization group evolution in SCET. Finally, the infrared structure of n-point gauge-theory amplitudes is analyzed by relating them to effective-theory operators. This text is suitable for graduate students and non-spe...

Radiative neutron capture on a proton at big-bang nucleosynthesis energies

International Nuclear Information System (INIS)

Ando, S.; Cyburt, R. H.; Hong, S. W.; Hyun, C. H.

2006-01-01

The total cross section for radiative neutron capture on a proton, np→dγ, is evaluated at big-bang nucleosynthesis (BBN) energies. The electromagnetic transition amplitudes are calculated up to next-to-leading-order within the framework of pionless effective field theory with dibaryon fields. We also calculate the dγ→np cross section and the photon analyzing power for the dγ(vector sign)→np process from the amplitudes. The values of low-energy constants that appear in the amplitudes are estimated by a Markov Chain Monte Carlo analysis using the relevant low-energy experimental data. Our result agrees well with those of other theoretical calculations except for the np→dγ cross section at some energies estimated by an R-matrix analysis. We also study the uncertainties in our estimation of the np→dγ cross section at relevant BBN energies and find that the estimated cross section is reliable to within ∼1% error

Effective theories with broken flavour symmetry

International Nuclear Information System (INIS)

Miller, R.D.C.; McKellar, B.H.J.

1981-07-01

The work of Ovrut and Schnitzer on effective theories derived from a non Abelian Gauge Theory is generalised to include the physically interesting case of broken flavour symmetry. The calculations are performed at the 1-loop level. It is shown that at an intermediate stage in the calculations two distinct renormalised gauge coupling constants appear, one describing gauge field coupling to heavy particles and the other describing coupling to light particles. Appropriately modified Slavnov-Taylor identities are shown to hold. A simple alternative to the Ovrut-Schnitzer rules for calculating with effective theories is also considered

Matrix effective theories of the fractional quantum Hall effect

International Nuclear Information System (INIS)

Cappelli, Andrea; Rodriguez, Ivan D

2009-01-01

The present understanding of nonperturbative ground states in the fractional quantum Hall effect is based on effective theories of the Jain 'composite fermion' excitations. We review the approach based on matrix variables, i.e. D0 branes, originally introduced by Susskind and Polychronakos. We show that the Maxwell-Chern-Simons matrix gauge theory provides a matrix generalization of the quantum Hall effect, where the composite-fermion construction naturally follows from gauge invariance. The matrix ground states obtained by suitable projections of higher Landau levels are found to be in one-to-one correspondence with the Laughlin and Jain hierarchical states. The matrix theory possesses a physical limit for commuting matrices that could be reachable while staying in the same phase.

Boundary effects on quantum field theories

International Nuclear Information System (INIS)

Lee, Tae Hoon

1991-01-01

Quantum field theory in the S 1 *R 3 space-time is simply described by the imaginary time formalism. We generalize Schwinger-DeWitt proper-time technique which is very useful in zero temperature field theories to this case. As an example we calculate the one-loop effective potential of the finite temperature scala field theory by this technique.(Author)

Playing with QCD I: effective field theories

International Nuclear Information System (INIS)

Fraga, Eduardo S.

2009-01-01

The building blocks of hadrons are quarks and gluons, although color is confined into singlet states. QCD is believed to be the fundamental theory of strong interactions. Its asymptotically free nature puts the vacuum out of reach for perturbation theory. The Lagrangian of QCD and the Feynman rules associated were built by using the Gauge Principle, starting from the quark matter fields and obtaining gluons as connections. A simpler, and sometimes necessary or complementary, approach is provided by effective field theories or effective models, especially when one has to deal with the nonperturbative sector of the theory. (author)

One-particle reducibility in effective scattering theory

International Nuclear Information System (INIS)

Vereshagin, V.

2016-01-01

To construct the reasonable renormalization scheme suitable for the effective theories one needs to resolve the “problem of couplings” because the number of free parameters in a theory should be finite. Otherwise the theory would loose its predictive power. In the case of effective theory already the first step on this way shows the necessity to solve the above-mentioned problem for the 1-loop 2-leg function traditionally called self energy. In contrast to the customary renormalizable models the corresponding Feynman graph demonstrates divergencies that require introducing of an infinite number of prescriptions. In the recent paper [1] it has been shown that the way out of this difficulty requires the revision of the notion of one-particle reducibility. The point is that in effective scattering theory one can introduce two different notions: the graphic reducibility and the analytic one. Below we explain the main ideas of the paper [1] and recall some notions and definitions introduced earlier in [2] and [3

Holographic effective field theories

Energy Technology Data Exchange (ETDEWEB)

Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)

2016-06-28

We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

Effective field theory and the quark model

International Nuclear Information System (INIS)

Durand, Loyal; Ha, Phuoc; Jaczko, Gregory

2001-01-01

We analyze the connections between the quark model (QM) and the description of hadrons in the low-momentum limit of heavy-baryon effective field theory in QCD. By using a three-flavor-index representation for the effective baryon fields, we show that the 'nonrelativistic' constituent QM for baryon masses and moments is completely equivalent through O(m s ) to a parametrization of the relativistic field theory in a general spin-flavor basis. The flavor and spin variables can be identified with those of effective valence quarks. Conversely, the spin-flavor description clarifies the structure and dynamical interpretation of the chiral expansion in effective field theory, and provides a direct connection between the field theory and the semirelativistic models for hadrons used in successful dynamical calculations. This allows dynamical information to be incorporated directly into the chiral expansion. We find, for example, that the striking success of the additive QM for baryon magnetic moments is a consequence of the relative smallness of the non-additive spin-dependent corrections

On supersymmetric effective theories of axion

Energy Technology Data Exchange (ETDEWEB)

Higaki, Tetsutaro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kitano, Ryuichiro [Tohoku Univ., Sendai (Japan). Dept. of Physics

2011-04-15

We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. (orig.)

Exchange effects in Relativistic Schroedinger Theory

International Nuclear Information System (INIS)

Sigg, T.; Sorg, M.

1998-01-01

The Relativistic Schroedinger Theory predicts the occurrence of exchange and overlap effects in many-particle systems. For a 2-particle system, the interaction energy of the two particles consists of two contributions: Coulomb energy and exchange energy, where the first one is revealed to be the same as in standard quantum theory. However the exchange energy is mediated by an exchange potential, contrary to the kinematical origin of the exchange term in the standard theory

Infrared and ultraviolet behaviour of effective scalar field theory

International Nuclear Information System (INIS)

Ball, R.D.; Thorne, R.S.

1995-01-01

We consider the infrared and ultraviolet behaviour of the effective quantum field theory of a single Z 2 symmetric scalar field. In a previous paper we proved to all orders in perturbation theory the renormalizability of massive effective scalar field theory using Wilson's exact renormalization group equation. Here we show that away from exceptional momenta the massless theory is similarly renormalizable, and we prove detailed bounds on Green's functions as arbitrary combinations of exceptional Euclidean momenta are approached. As a corollary we also Weinberg's Theorem for the massive effective theory, n the form of bounds on Green's functions at Euclidean momenta much greater than the particle mass but below the naturalness scale of theory. 12 refs

Infrared and ultraviolet behaviour of effective scalar field theory

CERN Document Server

Ball, R D

1995-01-01

We consider the infrared and ultraviolet behaviour of the effective quantum field theory of a single Z_2 symmetric scalar field. In a previous paper we proved to all orders in perturbation theory the renormalizability of massive effective scalar field theory using Wilson's exact renormalization group equation. Here we show that away from exceptional momenta the massless theory is similarly renormalizable, and we prove detailed bounds on Green's functions as arbitrary combinations of exceptional Euclidean momenta are approached. As a corollary we also prove Weinberg's Theorem for the massive effective theory, in the form of bounds on Green's functions at Euclidean momenta much greater than the particle mass but below the naturalness scale of the theory.

Effective field theory: A modern approach to anomalous couplings

International Nuclear Information System (INIS)

Degrande, Céline; Greiner, Nicolas; Kilian, Wolfgang; Mattelaer, Olivier; Mebane, Harrison; Stelzer, Tim; Willenbrock, Scott; Zhang, Cen

2013-01-01

We advocate an effective field theory approach to anomalous couplings. The effective field theory approach is the natural way to extend the standard model such that the gauge symmetries are respected. It is general enough to capture any physics beyond the standard model, yet also provides guidance as to the most likely place to see the effects of new physics. The effective field theory approach also clarifies that one need not be concerned with the violation of unitarity in scattering processes at high energy. We apply these ideas to pair production of electroweak vector bosons. -- Highlights: •We discuss the advantages of effective field theories compared to anomalous couplings. •We show that one need not be concerned with unitarity violation at high energy. •We discuss the application of effective field theory to weak boson physics

Soft-Collinear Effective Theory

CERN Multimedia

CERN. Geneva

2017-01-01

I will review the basic principles about Soft-Collinear Effective Theory. I will focus on how it can be used to understand factorization properties and how one can resum large logarithms arising from infrared physics using the renormalization group evolution.

Issues of effective field theories with resonances

International Nuclear Information System (INIS)

Gegelia, J.; Japaridze, G.

2014-01-01

We address some issues of renormalization and symmetries of effective field theories with unstable particles - resonances. We also calculate anomalous contributions in the divergence of the singlet axial current in an effective field theory of massive SU(N) Yang-Mills fields interacting with fermions and discuss their possible relevance to the strong CP problem. (author)

More effective field theory for non-relativistic scattering

International Nuclear Information System (INIS)

Kaplan, D.B.

1997-01-01

An effective field theory treatment of nucleon-nucleon scattering at low energy shows much promise and could prove to be a useful tool in the study of nuclear matter at both ordinary and extreme densities. The analysis is complicated by the existence a large length scale - the scattering length -which arises due to couplings in the short distance theory being near critical values. I show how this can be dealt with by introducing an explicit s-channel state in the effective field theory. The procedure is worked out analytically in a toy example. I then demonstrate that a simple effective field theory excellently reproduces the 1 S 0 np phase shift up to the pion production threshold. (orig.)

Towards a comprehensive theory of monadic effects

DEFF Research Database (Denmark)

Filinski, Andrzej

2011-01-01

It has been more than 20 years since monads were proposed as a unifying concept for computational effects, in both formal semantics and functional programs. Over that period, there has been substantial incremental progress on several fronts within the ensuing research area, including denotational....... Some stronger-than-expected ties between the research topics mentioned above also instill hope that there is indeed a natural, comprehensive theory of monadic effects, waiting to be fully explicated......., and attempts to assess our collective progress towards the goal of a broad yet coherent theory of monadic effects. We are not quite there yet, but intriguingly, many potential ingredients of such a theory have been repeatedly discovered and developed, with only minor variations, in seemingly unrelated contexts...

Renormalizable Abelian-projected effective gauge theory derived from quantum chromodynamics

International Nuclear Information System (INIS)

Kondo, Kei-ichi; Shinohara, Toru

2001-01-01

We show that an effective Abelian gauge theory can be obtained as a renormalizable theory from QCD in the maximal Abelian gauge. The derivation improves in a systematic manner the previous version that was obtained by one of the authors and was referred to as the Abelian-projected effective gauge theory. This result supports the view that we can construct an effective Abelian gauge theory from QCD without losing characteristic features of the original non-Abelian gauge theory. In fact, it is shown that the effective coupling constant in the resulting renormalizable theory has a renormalization-scale dependence governed by the β-function that is exactly the same as that of the original Yang-Mills theory, irrespective of the choice of gauge fixing parameters of the maximal Abelian gauge and the parameters used for identifying the dual variables. Moreover, we evaluate the anomalous dimensions of the fields and parameters in the resultant theory. By choosing the renormalized parameters appropriately, we can switch the theory into an electric or a magnetic theory. (author)

Conceptual Models and Theory-Embedded Principles on Effective Schooling.

Science.gov (United States)

Scheerens, Jaap

1997-01-01

Reviews models and theories on effective schooling. Discusses four rationality-based organization theories and a fifth perspective, chaos theory, as applied to organizational functioning. Discusses theory-embedded principles flowing from these theories: proactive structuring, fit, market mechanisms, cybernetics, and self-organization. The…

Effective field theory for magnetic compactifications

Energy Technology Data Exchange (ETDEWEB)

Buchmuller, Wilfried; Dierigl, Markus [Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany); Dudas, Emilian [Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay,F-91128 Palaiseau (France); Schweizer, Julian [Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany)

2017-04-10

Magnetic flux plays an important role in compactifications of field and string theories in two ways, it generates a multiplicity of chiral fermion zero modes and it can break supersymmetry. We derive the complete four-dimensional effective action for N=1 supersymmetric Abelian and non-Abelian gauge theories in six dimensions compactified on a torus with flux. The effective action contains the tower of charged states and it accounts for the mass spectrum of bosonic and fermionic fields as well as their level-dependent interactions. This allows us to compute quantum corrections to the mass and couplings of Wilson lines. We find that the one-loop corrections vanish, contrary to the case without flux. This can be traced back to the spontaneous breaking of symmetries of the six-dimensional theory by the background gauge field, with the Wilson lines as Goldstone bosons.

Effective field theory for triaxially deformed nuclei

Energy Technology Data Exchange (ETDEWEB)

Chen, Q.B. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Kaiser, N. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Institute for Advanced Simulation, Institut fuer Kernphysik, Juelich Center for Hadron Physics and JARA-HPC, Forschungszentrum Juelich, Juelich (Germany); Meng, J. [Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); University of Stellenbosch, Department of Physics, Stellenbosch (South Africa)

2017-10-15

Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation. (orig.)

Correlated effective field theory in transition metal compounds

International Nuclear Information System (INIS)

Mukhopadhyay, Subhasis; Chatterjee, Ibha

2004-01-01

Mean field theory is good enough to study the physical properties at higher temperatures and in higher dimensions. It explains the critical phenomena in a restricted sense. Near the critical temperatures, when fluctuations become important, it may not give the correct results. Similarly in low dimensions, the correlations become important and the mean field theory seems to be inadequate to explain the physical phenomena. At low-temperatures too, the quantum correlations become important and these effects are to be treated in an appropriate way. In 1974, Prof. M.E. Lines of Bell Laboratories, developed a theory which goes beyond the mean field theory and is known as the correlated effective field (CEF) theory. It takes into account the fluctuations in a semiempirical way. Lines and his collaborators used this theory to explain the short-range correlations and their anisotropy in the paramagnetic phase. Later Suzuki et al., Chatterjee and Desai, Mukhopadhyay and Chatterjee applied this theory to the magnetically ordered phase and a tremendous success of the theory has been found in real systems. The success of the CEF theory is discussed in this review. In order to highlight the success of this theory, earlier effective field theories and their improvements over mean field theories e.g., Bethe-Peierls-Weiss method, reaction field approximation, etc., are also discussed in this review for completeness. The beauty of the CEF theory is that it is mean field-like, but captures the essential physics of real systems to a great extent. However, this is a weak correlated theory and as a result is inappropriate for the metallic phase when strong correlations become important. In recent times, transition metal oxides become important due to the discovery of the high-temperature superconductivity and the colossal magnetoresistance phenomena. These oxides seem to be Mott insulators and undergo an insulator to metal transition by applying magnetic field, pressure and by changing

Exploring CRM effectiveness: an institutional theory perspective

NARCIS (Netherlands)

B. Hillebrand (Bas); J.J. Nijholt (Jurriaan); E.J. Nijssen (Edwin)

2011-01-01

textabstractThis study identifies the potential contribution that institutional theory can make to understanding the success of marketing practices. Based on institutional theory, we argue that the effectiveness of marketing practices decreases when firms are motivated to adopt such practices under

Exploring CRM effectiveness : an institutional theory perspective

NARCIS (Netherlands)

Hillebrand, B.; Nijholt, J.J.; Nijssen, E.J.

2011-01-01

This study identifies the potential contribution that institutional theory can make to understanding the success of marketing practices. Based on institutional theory, we argue that the effectiveness of marketing practices decreases when firms are motivated to adopt such practices under the

Perturbation theory of effective Hamiltonians

International Nuclear Information System (INIS)

Brandow, B.H.

1975-01-01

This paper constitutes a review of the many papers which have used perturbation theory to derive ''effective'' or ''model'' Hamiltonians. It begins with a brief review of nondegenerate and non-many-body perturbation theory, and then considers the degenerate but non-many-body problem in some detail. It turns out that the degenerate perturbation problem is not uniquely defined, but there are some practical criteria for choosing among the various possibilities. Finally, the literature dealing with the linked-cluster aspects of open-shell many-body systems is reviewed. (U.S.)

Could reggeon field theory be an effective theory for QCD in the Regge limit?

Energy Technology Data Exchange (ETDEWEB)

Bartels, Jochen [II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany); Contreras, Carlos [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Avda. España 1680, Casilla 110-V, Valparaiso (Chile); Vacca, G.P. [INFN Sezione di Bologna, DIFA, Via Irnerio 46, I-40126 Bologna (Italy)

2016-03-30

In this paper we investigate the possibility whether, in the extreme limit of high energies and large transverse distances, reggeon field theory might serve as an effective theory of high energy scattering for strong interactions. We analyse the functional renormalization group equations (flow equations) of reggeon field theory and search for fixed points in the space of (local) reggeon field theories. We study in complementary ways the candidate for the scaling solution, investigate its main properties and briefly discuss possible physical interpretations.

Globally and locally supersymmetric effective theories for light fields

CERN Document Server

Brizi, Leonardo; Scrucca, Claudio A

2009-01-01

We reconsider the general question of how to characterize most efficiently the low-energy effective theory obtained by integrating out heavy modes in globally and locally supersymmetric theories. We consider theories with chiral and vector multiplets and identify the conditions under which an approximately supersymmetric low-energy effective theory can exist. These conditions translate into the requirements that all the derivatives, fermions and auxiliary fields should be small in units of the heavy mass scale. They apply not only to the matter sector, but also to the gravitational one if present, and imply in that case that the gravitino mass should be small. We then show how to determine the unique exactly supersymmetric theory that approximates this effective theory at the lowest order in the counting of derivatives, fermions and auxiliary fields, by working both at the superfield level and with component fields. As a result we give a simple prescription for integrating out heavy superfields in an algebrai...

Effective Gravitational Theories in String Theory and the AdS/CFT Correspondence

DEFF Research Database (Denmark)

Pedersen, Andreas Vigand

an effective theory for higher dimensional extended black holes in a uid/elastic perturbative derivative expansion. Moreover, we show that the approach is quite universal and can be extended to various supergravities. Finally, we consider a new generalization of the method, which allows us to treat (SUGRA...... as low/high spin. As a byproduct of our analysis, we find a new stationary dipole-charged black hole solution on the AdS S backgrounds of type IIB/M-theory. We finally consider, via a double scaling extremal limit, a novel null-wave zero-temperature giant graviton exhibiting a BPS spectrum. Finally......We consider various aspects of effective gravitational theories, including supergravity, within the framework of the blackfold approach. The thesis is naturally split into three parts. In the first part of the thesis, we explore the blackfold approach and explain how it is possible to write down...

Boundary operators in effective string theory

Energy Technology Data Exchange (ETDEWEB)

Hellerman, Simeon [Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan); Swanson, Ian [Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan)

2017-04-13

Various universal features of relativistic rotating strings depend on the organization of allowed local operators on the worldsheet. In this paper, we study the set of Neumann boundary operators in effective string theory, which are relevant for the controlled study of open relativistic strings with freely moving endpoints. Relativistic open strings are thought to encode the dynamics of confined quark-antiquark pairs in gauge theories in the planar approximation. Neumann boundary operators can be organized by their behavior under scaling of the target space coordinates X{sup μ}, and the set of allowed X-scaling exponents is bounded above by +1/2 and unbounded below. Negative contributions to X-scalings come from powers of a single invariant, or “dressing' operator, which is bilinear in the embedding coordinates. In particular, we show that all Neumann boundary operators are dressed by quarter-integer powers of this invariant, and we demonstrate how this rule arises from various ways of regulating the short-distance singularities of the effective theory.

The Theory of Effectiveness of the State: Institutional Aspect

Directory of Open Access Journals (Sweden)

Kolesnichenko Irina M.

2016-02-01

Full Text Available The article is devoted to one of the most urgent problems of modern economic theory and practice — effectiveness of the state. The aim of the paper is a comprehensive analysis of institutional aspects of the formation of a new economic theory of effectiveness of the state. To achieve this aim, the author first summarizes the evolution and theoretical and methodological characteristics of the economic theories of the state paying a special attention to the essence of the concept of “state” and focusing on “effectiveness of the state” as a major category of the new economic theory. Then he proceeds to institutional aspects of effectiveness of the state considering it as a specific organization and system of institutions of power and control; defines components of effectiveness of the state generalizing the existing methodological approaches and most importantly — the modern criteria for assessing the effectiveness of the state.

Effective field theory of interactions on the lattice

DEFF Research Database (Denmark)

Valiente, Manuel; Zinner, Nikolaj T.

2015-01-01

We consider renormalization of effective field theory interactions by discretizing the continuum on a tight-binding lattice. After studying the one-dimensional problem, we address s-wave collisions in three dimensions and relate the bare lattice coupling constants to the continuum coupling consta...... constants. Our method constitutes a very simple avenue for the systematic renormalization in effective field theory, and is especially useful as the number of interaction parameters increases.......We consider renormalization of effective field theory interactions by discretizing the continuum on a tight-binding lattice. After studying the one-dimensional problem, we address s-wave collisions in three dimensions and relate the bare lattice coupling constants to the continuum coupling...

Effective medium theory for anisotropic metamaterials

KAUST Repository

Zhang, Xiujuan; Wu, Ying

2015-01-01

-dimensional metamaterial composed of a rectangular array of elliptic cylinders and derive an effective medium theory for such a metamaterial. We find that it is possible to obtain a closed-form analytical solution for the anisotropic effective medium parameters, provided

Scattering theory and effective medium approximations to heterogeneous materials

International Nuclear Information System (INIS)

Gubernatis, J.E.

1977-01-01

The formal analogy existing between problems studied in the microscopic theory of disordered alloys and problems concerned with the effective (macroscopic) behavior of heterogeneous materials is discussed. Attention is focused on (1) analogous approximations (effective medium approximations) developed for the microscopic problems by scattering theory concepts and techniques, but for the macroscopic problems principally by intuitive means, (2) the link, provided by scattering theory, of the intuitively developed approximations to a well-defined perturbative analysis, (3) the possible presence of conditionally convergent integrals in effective medium approximations

Is the effective field theory of dark energy effective?

Energy Technology Data Exchange (ETDEWEB)

Linder, Eric V. [Berkeley Center for Cosmological Physics and Berkeley Lab, University of California, New Campbell Hall 341, Berkeley, CA, 94720 (United States); Sengör, Gizem; Watson, Scott, E-mail: evlinder@lbl.gov, E-mail: gsengor@syr.edu, E-mail: gswatson@syr.edu [Department of Physics, Syracuse University, 201 Physics Building, Syracuse, NY, 13244 (United States)

2016-05-01

The effective field theory of cosmic acceleration systematizes possible contributions to the action, accounting for both dark energy and modifications of gravity. Rather than making model dependent assumptions, it includes all terms, subject to the required symmetries, with four (seven) functions of time for the coefficients. These correspond respectively to the Horndeski and general beyond Horndeski class of theories. We address the question of whether this general systematization is actually effective, i.e. useful in revealing the nature of cosmic acceleration when compared with cosmological data. The answer is no and yes: there is no simple time dependence of the free functions —assumed forms in the literature are poor fits, but one can derive some general characteristics in early and late time limits. For example, we prove that the gravitational slip must restore to general relativity in the de Sitter limit of Horndeski theories, and why it doesn't more generally. We also clarify the relation between the tensor and scalar sectors, and its important relation to observations; in a real sense the expansion history H ( z ) or dark energy equation of state w ( z ) is 1/5 or less of the functional information! In addition we discuss the de Sitter, Horndeski, and decoupling limits of the theory utilizing Goldstone techniques.

Elementary theory of quantum Hall effect

Directory of Open Access Journals (Sweden)

Keshav N. Shrivastava

2008-04-01

Full Text Available The Hall effect is the generation of a current perpendicular to both the direction of the applied electric as well as magnetic field in a metal or in a semiconductor. It is used to determine the concentration of electrons. The quantum Hall effect with integer quantization was discovered by von Klitzing and fractionally charged states were found by Tsui, Stormer and Gossard. Robert Laughlin explained the quantization of Hall current by using “flux quantization” and introduced incompressibility to obtain the fractional charge. We have developed the theory of the quantum Hall effect by using the theory of angular momentum. Our predicted fractions are in accord with those measured. We emphasize our explanation of the observed phenomena. We use spin to explain the fractional charge and hence we discover spin-charge locking.

Application of Canonical Effective Methods to Background-Independent Theories

Science.gov (United States)

Buyukcam, Umut

Effective formalisms play an important role in analyzing phenomena above some given length scale when complete theories are not accessible. In diverse exotic but physically important cases, the usual path-integral techniques used in a standard Quantum Field Theory approach seldom serve as adequate tools. This thesis exposes a new effective method for quantum systems, called the Canonical Effective Method, which owns particularly wide applicability in backgroundindependent theories as in the case of gravitational phenomena. The central purpose of this work is to employ these techniques to obtain semi-classical dynamics from canonical quantum gravity theories. Application to non-associative quantum mechanics is developed and testable results are obtained. Types of non-associative algebras relevant for magnetic-monopole systems are discussed. Possible modifications of hypersurface deformation algebra and the emergence of effective space-times are presented. iii.

Complete set of essential parameters of an effective theory

Science.gov (United States)

Ioffe, M. V.; Vereshagin, V. V.

2018-04-01

The present paper continues the series [V. V. Vereshagin, True self-energy function and reducibility in effective scalar theories, Phys. Rev. D 89, 125022 (2014); , 10.1103/PhysRevD.89.125022A. Vereshagin and V. Vereshagin, Resultant parameters of effective theory, Phys. Rev. D 69, 025002 (2004); , 10.1103/PhysRevD.69.025002K. Semenov-Tian-Shansky, A. Vereshagin, and V. Vereshagin, S-matrix renormalization in effective theories, Phys. Rev. D 73, 025020 (2006), 10.1103/PhysRevD.73.025020] devoted to the systematic study of effective scattering theories. We consider matrix elements of the effective Lagrangian monomials (in the interaction picture) of arbitrary high dimension D and show that the full set of corresponding coupling constants contains parameters of both kinds: essential and redundant. Since it would be pointless to formulate renormalization prescriptions for redundant parameters, it is necessary to select the full set of the essential ones. This is done in the present paper for the case of the single scalar field.

A periodic table of effective field theories

Energy Technology Data Exchange (ETDEWEB)

Cheung, Clifford [Walter Burke Institute for Theoretical Physics,California Institute of Technology,Pasadena, CA (United States); Kampf, Karol; Novotny, Jiri [Institute of Particle and Nuclear Physics,Faculty of Mathematics and Physics, Charles University,Prague (Czech Republic); Shen, Chia-Hsien [Walter Burke Institute for Theoretical Physics,California Institute of Technology,Pasadena, CA (United States); Trnka, Jaroslav [Center for Quantum Mathematics and Physics (QMAP),Department of Physics, University of California,Davis, CA (United States)

2017-02-06

We systematically explore the space of scalar effective field theories (EFTs) consistent with a Lorentz invariant and local S-matrix. To do so we define an EFT classification based on four parameters characterizing 1) the number of derivatives per interaction, 2) the soft properties of amplitudes, 3) the leading valency of the interactions, and 4) the spacetime dimension. Carving out the allowed space of EFTs, we prove that exceptional EFTs like the non-linear sigma model, Dirac-Born-Infeld theory, and the special Galileon lie precisely on the boundary of allowed theory space. Using on-shell momentum shifts and recursion relations, we prove that EFTs with arbitrarily soft behavior are forbidden and EFTs with leading valency much greater than the spacetime dimension cannot have enhanced soft behavior. We then enumerate all single scalar EFTs in d<6 and verify that they correspond to known theories in the literature. Our results suggest that the exceptional theories are the natural EFT analogs of gauge theory and gravity because they are one-parameter theories whose interactions are strictly dictated by properties of the S-matrix.

Low-energy operators in effective theories

International Nuclear Information System (INIS)

Felline, C.; Piekarewicz, J.; Mehta, N.P.; Shepard, J.R.

2003-01-01

Modern effective-theory techniques are applied to the nuclear many-body problem. A novel approach is proposed for the renormalization of operators in a manner consistent with the construction of the effective potential. To test this approach, a one-dimensional, yet realistic, nucleon-nucleon potential is introduced. An effective potential is then constructed by tuning its parameters to reproduce the exact effective-range expansion and a variety of bare operators are renormalized in a fashion compatible with this construction. Predictions for the expectation values of these effective operators in the ground state reproduce the results of the exact theory with remarkable accuracy (at the 0.5% level). This represents a marked improvement over a widely practiced approach that uses effective interactions but retains bare operators. Further, it is shown that this improvement is more impressive as the operator becomes more sensitive to the short-range structure of the potential. We illustrate the main ideas of this work using the elastic form factor of the deuteron as an example

Effective description of higher-order scalar-tensor theories

Energy Technology Data Exchange (ETDEWEB)

Langlois, David [APC—Astroparticule et Cosmologie, Université Paris Diderot Paris 7, 75013 Paris (France); Mancarella, Michele; Vernizzi, Filippo [Institut de physique théorique, Université Paris Saclay, CEA, CNRS, 91191 Gif-sur-Yvette (France); Noui, Karim, E-mail: langlois@apc.univ-paris7.fr, E-mail: michele.mancarella@cea.fr, E-mail: karim.noui@lmpt.univ-tours.fr, E-mail: filippo.vernizzi@cea.fr [Laboratoire de Mathématiques et Physique Théorique, Université François Rabelais, Parc de Grandmont, 37200 Tours (France)

2017-05-01

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 initial 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.

Consistency relations in effective field theory

Energy Technology Data Exchange (ETDEWEB)

Munshi, Dipak; Regan, Donough, E-mail: D.Munshi@sussex.ac.uk, E-mail: D.Regan@sussex.ac.uk [Astronomy Centre, School of Mathematical and Physical Sciences, University of Sussex, Brighton BN1 9QH (United Kingdom)

2017-06-01

The consistency relations in large scale structure relate the lower-order correlation functions with their higher-order counterparts. They are direct outcome of the underlying symmetries of a dynamical system and can be tested using data from future surveys such as Euclid. Using techniques from standard perturbation theory (SPT), previous studies of consistency relation have concentrated on continuity-momentum (Euler)-Poisson system of an ideal fluid. We investigate the consistency relations in effective field theory (EFT) which adjusts the SPT predictions to account for the departure from the ideal fluid description on small scales. We provide detailed results for the 3D density contrast δ as well as the scaled divergence of velocity 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.

The N=1 effective action of F-theory compactifications

International Nuclear Information System (INIS)

Grimm, Thomas W.

2011-01-01

The four-dimensional N=1 effective action of F-theory compactified on a Calabi-Yau fourfold is studied by lifting a three-dimensional M-theory compactification. The lift is performed by using T-duality realized via a Legendre transform on the level of the effective action, and the application of vector-scalar duality in three dimensions. The leading order Kaehler potential and gauge-kinetic coupling functions are determined. In these compactifications two sources of gauge theories are present. Space-time filling non-Abelian seven-branes arise at the singularities of the elliptic fibration of the fourfold. Their couplings are included by resolving the singular fourfold. Generically a U(1) r gauge theory arises from the R-R bulk sector if the base of the elliptically fibered Calabi-Yau fourfold supports 2r harmonic three-forms. The gauge coupling functions depend holomorphically on the complex structure moduli of the fourfold, comprising closed and open string degrees of freedom. The four-dimensional electro-magnetic duality is studied in the three-dimensional effective theory obtained after M-theory compactification. A discussion of matter couplings transforming in the adjoint of the seven-brane gauge group is included.

Soft-collinear factorization in effective field theory

International Nuclear Information System (INIS)

Bauer, Christian W.; Pirjol, Dan; Stewart, Iain W.

2002-01-01

The factorization of soft and ultrasoft gluons from collinear particles is shown at the level of operators in an effective field theory. Exclusive hadronic factorization and inclusive partonic factorization follow as special cases. The leading-order Lagrangian is derived using power counting and gauge invariance in the effective theory. Several species of gluons are required, and softer gluons appear as background fields to gluons with harder momenta. Two examples are given: the factorization of soft gluons in B→Dπ and the soft-collinear convolution for the B→X s γ spectrum

Unraveling the Structure of Hadrons with Effective Field Theories of QCD

International Nuclear Information System (INIS)

Iain Stewart

2004-01-01

Effective Field theory is a powerful framework based on controlled expansions for problems with a natural separation of energy scales. This technique is particularly important for QCD, the theory of strong interactions, due to the vast diversity of phenomena that it describes. Stewart and collaborators have invented a new class of effective theories that can be used in processes with energetic hadrons. These Soft-Collinear Effective Theories provide a unified framework for describing hadronic processes which involve hard probes or the release of a large amount of energy. Many interesting issues about hadronic physics can be addressed with the soft-collinear effective theory. Examples include the size and shape of hadronic form factors, the universality of hadronic distribution functions for a plethora of processes, and the importance of subleading corrections at intermediate energy scales. Effective field theories allow these issues to be addressed using only the underlying symmetries and scales in QCD. Understanding these issues also has a direct impact on other areas of physics, such as on devising clean methods for the measurement of CP violation in the decay of B-mesons. Current progress on the soft-collinear effective theory and related methods is discussed in this report

Quasiconfigurations and the theory of effective interactions

International Nuclear Information System (INIS)

Poves, A.; Zuker, A.

1980-01-01

Perturbation theory is reformulated. Schroedinger's equation is recast as a non linear integral equation which yields by Neumann expansion a linked cluster series for the degenerate, quasi degenerate or non degenerate problem. An effective interaction theory emerges that can be formulated in a biorthogonal basis leading to a non Hermitian secular problem. Hermiticity can be recovered in a clear and rigorous way. As the mathematical form of the theory is dictated by the request of physical clarity the latter is obtained naturally. When written in diagrammatic many body language, the integral equation produces a set of linked coupled equations for the degenerate case. The classic summations (Brueckner, Bethe-Faddeev and RPA) emerge naturally. Possible extensions of nuclear matter theory are suggested

Globally and locally supersymmetric effective theories for light fields

International Nuclear Information System (INIS)

Brizi, Leonardo; Gomez-Reino, Marta; Scrucca, Claudio A.

2009-01-01

We reconsider the general question of how to characterize most efficiently the low-energy effective theory obtained by integrating out heavy modes in globally and locally supersymmetric theories. We consider theories with chiral and vector multiplets and identify the conditions under which an approximately supersymmetric low-energy effective theory can exist. These conditions translate into the requirements that all the derivatives, fermions and auxiliary fields should be small in units of the heavy mass scale. They apply not only to the matter sector, but also to the gravitational one if present, and imply in that case that the gravitino mass should be small. We then show how to determine the unique exactly supersymmetric theory that approximates this effective theory at the lowest order in the counting of derivatives, fermions and auxiliary fields, by working both at the superfield level and with component fields. As a result we give a simple prescription for integrating out heavy superfields in an algebraic and manifestly supersymmetric way, which turns out to hold in the same form both for globally and locally supersymmetric theories, meaning that the process of integrating out heavy modes commutes with the process of switching on gravity. More precisely, for heavy chiral and vector multiplets one has to impose respectively stationarity of the superpotential and the Kaehler potential.

Effective Field Theory with Two Higgs Doublets

CERN Document Server

Crivellin, Andreas; Procura, Massimiliano

2016-01-01

In this article we extend the effective field theory framework describing new physics effects to the case where the underlying low-energy theory is a Two-Higgs-Doublet model. We derive a complete set of independent operators up to dimension six assuming a $Z_2$-invariant CP-conserving Higgs potential. The effects on Higgs and gauge boson masses, mixing angles in the Higgs sector as well as couplings to fermions and gauge bosons are computed. At variance with the case of a single Higgs doublet, we find that pair production of SM-like Higgses, arising through dimension-six operators, is not fixed by fermion-fermion-Higgs couplings and can therefore be sizable.

Correlation theory of crystal field and anisotropic exchange effects

DEFF Research Database (Denmark)

Lindgård, Per-Anker

1985-01-01

A general theory for including correlation effects in static and dynamic properties is presented in terms of Raccah or Stevens operators. It is explicitly developed for general crystal fields and anisotropic interactions and systems with several sublattices, like the rare earth compounds....... The theory gives explicitly a temperature dependent renormalization of both the crystal field and the interactions, and a damping of the excitations and in addition a central park component. The general theory is illustrated by a discussion of the singlet-doublet system. The correlation effects...

On the derivation of effective field theories

International Nuclear Information System (INIS)

Uzunov, Dimo I.

2004-12-01

A general self-consistency approach allows a thorough treatment of the corrections to the standard mean-field approximation (MFA). The natural extension of standard MFA with the help of cumulant expansion leads to a new point of view on the effective field theories. The proposed approach can be used for a systematic treatment of fluctuation effects of various length scales and, perhaps, for the development of a new coarse graining procedure. We outline and justify our method by some preliminary calculations. Concrete results are given for the critical temperature and the Landau parameters of the φ 4 -theory - the field counterpart of the Ising model. An important unresolved problem of the modern theory of phase transitions - the problem for the calculation of the true critical temperature, is considered within the framework of the present approach. A comprehensive description of the ground state properties of many-body systems is also demonstrated. (author)

Z(3)-symmetric effective theory for pure gauge QCD at high temperature

International Nuclear Information System (INIS)

Vuorinen, A.

2007-01-01

We review the construction and basic properties of a three-dimensional effective field theory for high-temperature SU(3) Yang-Mills theory, which respects its center symmetry and was introduced in Ref. [A. Vuorinen, L.G. Yaffe, Z(3)-symmetric effective theory for SU(3) Yang-Mills theory at high, Phys. Rev. D 74 (2006) 025011, hep-ph/0604100]. We explain why the phase diagram of the new theory is expected to closely resemble the one of the full theory and argue that this implies that it is applicable down to considerably lower temperatures than the usual non-Z(3)-symmetric 3d effective theory EQCD

Renormalization in Large Momentum Effective Theory of Parton Physics.

Science.gov (United States)

Ji, Xiangdong; Zhang, Jian-Hui; Zhao, Yong

2018-03-16

In the large-momentum effective field theory approach to parton physics, the matrix elements of nonlocal operators of quark and gluon fields, linked by straight Wilson lines in a spatial direction, are calculated in lattice quantum chromodynamics as a function of hadron momentum. Using the heavy-quark effective theory formalism, we show a multiplicative renormalization of these operators at all orders in perturbation theory, both in dimensional and lattice regularizations. The result provides a theoretical basis for extracting parton properties through properly renormalized observables in Monte Carlo simulations.

Effective theory of brane world with small tension

Science.gov (United States)

Hisano, Junji; Okada, Nobuchika

2000-05-01

The five dimensional theory compactified on S1 with two ``branes'' (two domain walls) embedded in it is constructed, based on the field-theoretic mechanism to generate the ``brane.'' Some light states localized in the ``brane'' appear in the theory. One is the Nambu-Goldstone boson, which corresponds to the breaking of the translational invariance in the transverse direction of the ``brane.'' In addition, if the tension of the ``brane'' is smaller than the fundamental scale of the original theory, it is found that there may exist not only massless states but also some massive states lighter than the fundamental scale in the ``brane.'' We analyze the four dimensional effective theory by integrating out the freedom of the fifth dimension. We show that some effective couplings can be explicitly calculated. As one of our results, some effective couplings of the state localized in the ``brane'' to the higher Kaluza-Klein modes in the bulk are found to be suppressed by the width of the ``brane.'' The resultant suppression factor can be quantitatively different from the one analyzed by Bando et al. using the Nambu-Goto action, while they are qualitatively the same.

Theory and application of a gauge invariant effective action to the multi-loop renormalization of non-Abelian gauge theories

International Nuclear Information System (INIS)

Hart, C.F.

1981-01-01

A gauge invariant effective action which generalizes the usual background field method is applied to quantum non-Abelian gauge theories. The gauge properties of the theory as well as its equivalence to the conventional theory are presented. Solutions to the new effective field equations are found to be physical and it is shown how S-matrix elements may be computed in terms of this new effective action. Feynman rules are given and the renormalization theory is discussed using minimal subtraction and dimensional regularization. The resulting computation of counterterms is found to be simpler than that of the usual method. A complete two-loop calculation of the β function for pure Yang-Mills theory is given as a specific example of this approach

Introduction to non-perturbative heavy quark effective theory

International Nuclear Information System (INIS)

Sommer, R.

2010-08-01

My lectures on the effective field theory for heavy quarks, an expansion around the static limit, concentrate on the motivation and formulation of HQET, its renormalization and discretization. This provides the basis for understanding that and how this effective theory can be formulated fully non-perturbatively in the QCD coupling, while by the very nature of an effective field theory, it is perturbative in the expansion parameter 1/m. After the couplings in the effective theory have been determined, the result at a certain order in 1/m is unique up to higher order terms in 1/m. In particular the continuum limit of the lattice regularized theory exists and leaves no trace of how it was regularized. In other words, the theory yields an asymptotic expansion of the QCD observables in 1/m - as usual in a quantum field theory modified by powers of logarithms. None of these properties has been shown rigorously (e.g. to all orders in perturbation theory) but perturbative computations and recently also non-perturbative lattice results give strong support to this ''standard wisdom''. A subtle issue is that a theoretically consistent formulation of the theory is only possible through a non-perturbative matching of its parameters with QCD at finite values of 1/m. As a consequence one finds immediately that the splitting of a result for a certain observable into, for example, lowest order and first order is ambiguous. Depending on how the matching between effective theory and QCD is done, a first order contribution may vanish and appear instead in the lowest order. For example, the often cited phenomenological HQET parameters anti Λ and λ 1 lack a unique non-perturbative definition. But this does not affect the precision of the asymptotic expansion in 1/m. The final result for an observable is correct up to order (1/m) n+1 if the theory was treated including (1/m) n terms. Clearly, the weakest point of HQET is that it intrinsically is an expansion. In practise, carrying it

Effective field theory approach to nuclear matter

International Nuclear Information System (INIS)

Saviankou, P.; Gruemmer, F.; Epelbaum, E.; Krewald, S.; Meissner, Ulf-G.

2006-01-01

Effective field theory provides a systematic approach to hardon physics and few-nucleon systems. It allows one to determine the effective two-, three-, and more-nucleon interactions which are consistent with each other. We present a project to derive bulk properties of nuclei from the effective nucleonic interactions

Global effects in quaternionic quantum field theory

International Nuclear Information System (INIS)

Brumby, S.P.; Joshi, G.C.

1997-01-01

A local quaternionic gauge structure is introduced onto space-time. It is a theory of vector bosons and dimensionless scalar fields, which recalls semi-classical treatments of gravity. After transforming to the 'i' gauge, it was found that the quaternionic symmetry takes the form of an exotic SU (2) gauge theory in the standard complex framework, with global phenomena appearing in the form of cosmic strings. Coupling this quaternionic sector to the Standard Model sector has only been achieved at the level of an effective theory, which is constrained by the quaternionic origin of the bosons to be of a nonrenormalisable form. 14 refs.,

Strong field effects on binary systems in Einstein-aether theory

International Nuclear Information System (INIS)

Foster, Brendan Z.

2007-01-01

'Einstein-aether' theory is a generally covariant theory of gravity containing a dynamical preferred frame. This article continues an examination of effects on the motion of binary pulsar systems in this theory, by incorporating effects due to strong fields in the vicinity of neutron star pulsars. These effects are included through an effective approach, by treating the compact bodies as point particles with nonstandard, velocity dependent interactions parametrized by dimensionless sensitivities. Effective post-Newtonian equations of motion for the bodies and the radiation damping rate are determined. More work is needed to calculate values of the sensitivities for a given fluid source; therefore, precise constraints on the theory's coupling constants cannot yet be stated. It is shown, however, that strong field effects will be negligible given current observational uncertainties if the dimensionless couplings are less than roughly 0.1 and two conditions that match the PPN parameters to those of pure general relativity are imposed. In this case, weak field results suffice. There then exists a one-parameter family of Einstein-aether theories with 'small-enough' couplings that passes all current observational tests. No conclusion can be reached for larger couplings until the sensitivities for a given source can be calculated

arXiv Chiral Effective Theory of Dark Matter Direct Detection

CERN Document Server

Bishara, Fady

2017-02-03

We present the effective field theory for dark matter interactions with the visible sector that is valid at scales of O(1 GeV). Starting with an effective theory describing the interactions of fermionic and scalar dark matter with quarks, gluons and photons via higher dimension operators that would arise from dimension-five and dimension-six operators above electroweak scale, we perform a nonperturbative matching onto a heavy baryon chiral perturbation theory that describes dark matter interactions with light mesons and nucleons. This is then used to obtain the coefficients of the nuclear response functions using a chiral effective theory description of nuclear forces. Our results consistently keep the leading contributions in chiral counting for each of the initial Wilson coefficients.

Generalized uncertainty principle as a consequence of the effective field theory

Energy Technology Data Exchange (ETDEWEB)

Faizal, Mir, E-mail: mirfaizalmir@gmail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia – Okanagan, Kelowna, British Columbia V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Ali, Ahmed Farag, E-mail: ahmed.ali@fsc.bu.edu.eg [Department of Physics, Faculty of Science, Benha University, Benha, 13518 (Egypt); Netherlands Institute for Advanced Study, Korte Spinhuissteeg 3, 1012 CG Amsterdam (Netherlands); Nassar, Ali, E-mail: anassar@zewailcity.edu.eg [Department of Physics, Zewail City of Science and Technology, 12588, Giza (Egypt)

2017-02-10

We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counter terms for this scalar field theory deformed by generalized uncertainty principle, and show that the generalized uncertainty principle contributes to the matter conformal anomaly.

Generalized uncertainty principle as a consequence of the effective field theory

Directory of Open Access Journals (Sweden)

Mir Faizal

2017-02-01

Full Text Available We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counter terms for this scalar field theory deformed by generalized uncertainty principle, and show that the generalized uncertainty principle contributes to the matter conformal anomaly.

A gluon cluster solution of effective Yang-Mills theory

CERN Document Server

Pavlovsky, O V

2001-01-01

A classical solution of the effective Yang-Mills (YM) theory with a finite energy and nonstandard Lagrangian was obtained. Influence of vacuum polarization on gluon cluster formation was discussed. Appearance of cluster solutions in the theory of non-Abelian fields can take place only if the result goes beyond the framework of pure YM theory. It is shown that account of quantum effects of polarized vacuum in the presence of a classical gluon field can also result in formation of the solutions. Solutions with the finite intrinsic energy are provided. Besides, fields of colour groups SU(2) were studied

Effective potential kinetic theory for strongly coupled plasmas

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2016-11-01

The effective potential theory (EPT) is a recently proposed method for extending traditional plasma kinetic and transport theory into the strongly coupled regime. Validation from experiments and molecular dynamics simulations have shown it to be accurate up to the onset of liquid-like correlation parameters (corresponding to Γ ≃ 10-50 for the one-component plasma, depending on the process of interest). Here, this theory is briefly reviewed along with comparisons between the theory and molecular dynamics simulations for self-diffusivity and viscosity of the one-component plasma. A number of new results are also provided, including calculations of friction coefficients, energy exchange rates, stopping power, and mobility. The theory is also cast in the Landau and Fokker-Planck kinetic forms, which may prove useful for enabling efficient kinetic computations.

Theory of fractional quantum hall effect

International Nuclear Information System (INIS)

Kostadinov, I.Z.

1985-08-01

A theory of the Fractional Quantum Hall Effect is constructed based on magnetic flux fractionization, which lead to instability of the system against selfcompression. A theorem is proved stating that arbitrary potentials fail to lift a specific degeneracy of the Landau level. For the case of 1/3 fractional filling a model 3-particles interaction is constructed breaking the symmetry. The rigid 3-particles wave function plays the role of order parameter. In a BCS type of theory the gap in the single particles spectrum is produced by the 3-particles interaction. The mean field critical behaviour and critical parameters are determined as well as the Ginsburg-Landau equation coefficients. The Hall conductivity is calculated from the first principles and its temperature dependence is found. The simultaneous tunnelling of 3,5,7 etc. electrons and quantum interference effects are predicted. (author)

The Application of Persuasion Theory to Placebo Effects.

Science.gov (United States)

Geers, Andrew L; Briñol, Pablo; Vogel, Erin A; Aspiras, Olivia; Caplandies, Fawn C; Petty, Richard E

2018-01-01

Placebo effects, or positive outcomes resulting from expectations about a treatment, are powerful components of modern medical care. In this chapter, we suggest that our understanding of placebo effects may benefit from more explicitly connecting this phenomenon to the existing empirical psychological literature on persuasion. Persuasion typically involves an attempt to bring about a change in beliefs or attitudes as a result of providing information on a topic. We begin by providing a brief overview of the psychological literature on placebo effects. We then point to connections between this literature and research on persuasive communication. Although some links have been made, these initial connections have predominantly relied on classic theories of persuasion rather than on more contemporary and comprehensive models. Next, we describe a modern theory of persuasion that may facilitate the study of placebo effects and analyze two issues pertinent to the literature on placebo effects from the lens of this model. Specifically, we consider how and when characteristics of a practitioner (e.g., variables such as perceptions of a practitioner's confidence or competence) can influence the magnitude of placebo effects, and how modern persuasion theory can help in understanding the durability of placebo effects over time. We conclude that examining placebo effects as an outcome of persuasive communication would be a fruitful line of future research. © 2018 Elsevier Inc. All rights reserved.

Many-body theory of effective mass in degenerate semiconductors

Science.gov (United States)

Tripathi, G. S.; Shadangi, S. K.

2018-03-01

We derive the many-body theory of the effective mass in the effective mass representation (EMR). In the EMR, we need to solve the equation of motion of an electron in the presence of electron-electron interactions, where the wavefunction is expanded over a complete set of Luttinger-Kohn wavefunctions. We use the Luttinger-Ward thermodynamic potential and the Green’s function perturbation to derive an expression for the band effective mass by taking into account the electron-electron interactions. Both quasi-particle and the correlation contributions are considered. We show that had we considered only the quasi-particle contribution, we would have missed important cancellations. Thus the correlated motion of electrons has important effects in the renormalization of the effective mass. Considering the exchange self-energy in the band model, we derive a tractable expression for the band effective mass. We apply the theory to n-type degenerate semiconductors, PbTe and SnTe, and analyze the impact of the theory on the anisotropic effective mass of the conduction bands in these systems.

Einstein-aether as a quantum effective field theory

International Nuclear Information System (INIS)

Withers, Benjamin

2009-01-01

The possibility that Lorentz symmetry is violated in gravitational processes is relatively unconstrained by experiment, in stark contrast with the level of accuracy to which Lorentz symmetry has been confirmed in the matter sector. One model of Lorentz violation in the gravitational sector is Einstein-aether theory, in which Lorentz symmetry is broken by giving a vacuum expectation value to a dynamical vector field. In this paper, we analyse the effective theory for quantized gravitational and aether perturbations. We show that this theory possesses a controlled effective expansion within dimensional regularization, that is, for any process there are a finite number of Feynman diagrams which will contribute to a given order of accuracy. We find that there is no log running of the 2-derivative phenomenological parameters, justifying the use of experimental constraints for these parameters obtained over many orders of magnitude in energy scale. Given the stringent experimental bounds on 2-derivative Lorentz-violating operators, we estimate the size of matter Lorentz violation which arises due to loop effects. This amounts to an estimation of the natural size of coefficients for Lorentz-violating dimension-6 matter operators, which in turn can be used to obtain a new bound on the 2-derivative parameters of this theory.

Experiment, theory and the Casimir effect

International Nuclear Information System (INIS)

Mostepanenko, V M

2009-01-01

Several problems at the interface between the field-theoretical description of the Casimir effect and experiments on measuring the Casimir force are discussed. One of these problems is connected with the definition of the Casimir free energy in ideal metal rectangular boxes satisfying the general physical requirements. It is shown that the consideration of rectangular boxes with a partition (piston) does not negate the previously known results obtained for boxes without a piston. Both sets of results are found to be in mutual agreement. Another problem is related to the use of the proximity force approximation for the interpretation of the experimental data and to the search of analytical results beyond the PFA based on the first principles of quantum field theory. Next, we discuss concepts of experimental precision and of the measure of agreement between experiment and theory. The fundamental difference between these two concepts is clarified. Finally, recent approach to the thermal Casimir force taking screening effects into account is applied to real metals. It is shown that this approach is thermodynamically and experimentally inconsistent. The physical reasons of this inconsistency are connected with the violation of thermal equilibrium which is the basic applicability condition of the Lifshitz theory.

Introduction to non-perturbative heavy quark effective theory

Energy Technology Data Exchange (ETDEWEB)

Sommer, R. [DESY, Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

2010-08-15

My lectures on the effective field theory for heavy quarks, an expansion around the static limit, concentrate on the motivation and formulation of HQET, its renormalization and discretization. This provides the basis for understanding that and how this effective theory can be formulated fully non-perturbatively in the QCD coupling, while by the very nature of an effective field theory, it is perturbative in the expansion parameter 1/m. After the couplings in the effective theory have been determined, the result at a certain order in 1/m is unique up to higher order terms in 1/m. In particular the continuum limit of the lattice regularized theory exists and leaves no trace of how it was regularized. In other words, the theory yields an asymptotic expansion of the QCD observables in 1/m - as usual in a quantum field theory modified by powers of logarithms. None of these properties has been shown rigorously (e.g. to all orders in perturbation theory) but perturbative computations and recently also non-perturbative lattice results give strong support to this ''standard wisdom''. A subtle issue is that a theoretically consistent formulation of the theory is only possible through a non-perturbative matching of its parameters with QCD at finite values of 1/m. As a consequence one finds immediately that the splitting of a result for a certain observable into, for example, lowest order and first order is ambiguous. Depending on how the matching between effective theory and QCD is done, a first order contribution may vanish and appear instead in the lowest order. For example, the often cited phenomenological HQET parameters anti {lambda} and {lambda}{sub 1} lack a unique non-perturbative definition. But this does not affect the precision of the asymptotic expansion in 1/m. The final result for an observable is correct up to order (1/m){sup n+1} if the theory was treated including (1/m){sup n} terms. Clearly, the weakest point of HQET is that it

Transformation properties of the effective action for gauge theories

International Nuclear Information System (INIS)

Otten, C.M.E.

1978-01-01

The main purpose of this thesis is to investigate the gauge invariance properties of the effective action. In fact, the Slavnov-Taylor identities for the effective action are nothing but a compact formulation of the gauge symmetry properties of the theory. Chapter II of this thesis focuses on the derivation of the Slavnov-Taylor identities for a general gauge theory, especially the identities for proper vertices. An analysis of the group- and invariance structure of the effective action is given, using both diagrammatic and functional techniques. Moreover, the Slavnov-Taylor identities are written out explicitely up to the order g 4 , where g is the coupling constant of the theory. The general theory outlined in chapter II is applied to an SU(2) model containing vector bosons, scalar particles and leptons. Specifically, the interplay between finite one-loop effects and the invariance structure of the model is studied in a certain limit (the so-called large Higgs mass limit). It is shown that the results can be fully interpreted on the basis of the Slavnov-Taylor identities for proper vertices. This is done in chapter III. (Auth.)

Partially massless higher-spin theory II: one-loop effective actions

Energy Technology Data Exchange (ETDEWEB)

Brust, Christopher [Perimeter Institute for Theoretical Physics,31 Caroline St. N, Waterloo, Ontario, N2L 2Y5 (Canada); Hinterbichler, Kurt [CERCA, Department of Physics, Case Western Reserve University,10900 Euclid Ave, Cleveland, OH, 44106 (United States)

2017-01-30

We continue our study of a generalization of the D-dimensional linearized Vasiliev higher-spin equations to include a tower of partially massless (PM) fields. We compute one-loop effective actions by evaluating zeta functions for both the “minimal” and “non-minimal” parity-even versions of the theory. Specifically, we compute the log-divergent part of the effective action in odd-dimensional Euclidean AdS spaces for D=7 through 19 (dual to the a-type conformal anomaly of the dual boundary theory), and the finite part of the effective action in even-dimensional Euclidean AdS spaces for D=4 through 8 (dual to the free energy on a sphere of the dual boundary theory). We pay special attention to the case D=4, where module mixings occur in the dual field theory and subtlety arises in the one-loop computation. The results provide evidence that the theory is UV complete and one-loop exact, and we conjecture and provide evidence for a map between the inverse Newton’s constant of the partially massless higher-spin theory and the number of colors in the dual CFT.

Partially massless higher-spin theory II: one-loop effective actions

International Nuclear Information System (INIS)

Brust, Christopher; Hinterbichler, Kurt

2017-01-01

We continue our study of a generalization of the D-dimensional linearized Vasiliev higher-spin equations to include a tower of partially massless (PM) fields. We compute one-loop effective actions by evaluating zeta functions for both the “minimal” and “non-minimal” parity-even versions of the theory. Specifically, we compute the log-divergent part of the effective action in odd-dimensional Euclidean AdS spaces for D=7 through 19 (dual to the a-type conformal anomaly of the dual boundary theory), and the finite part of the effective action in even-dimensional Euclidean AdS spaces for D=4 through 8 (dual to the free energy on a sphere of the dual boundary theory). We pay special attention to the case D=4, where module mixings occur in the dual field theory and subtlety arises in the one-loop computation. The results provide evidence that the theory is UV complete and one-loop exact, and we conjecture and provide evidence for a map between the inverse Newton’s constant of the partially massless higher-spin theory and the number of colors in the dual CFT.

Effective potential in Lorentz-breaking field theory models

Energy Technology Data Exchange (ETDEWEB)

Baeta Scarpelli, A.P. [Centro Federal de Educacao Tecnologica, Nova Gameleira Belo Horizonte, MG (Brazil); Setor Tecnico-Cientifico, Departamento de Policia Federal, Belo Horizonte, MG (Brazil); Brito, L.C.T. [Universidade Federal de Lavras, Departamento de Fisica, Lavras, MG (Brazil); Felipe, J.C.C. [Universidade Federal de Lavras, Departamento de Fisica, Lavras, MG (Brazil); Universidade Federal dos Vales do Jequitinhonha e Mucuri, Instituto de Engenharia, Ciencia e Tecnologia, Veredas, Janauba, MG (Brazil); Nascimento, J.R.; Petrov, A.Yu. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil)

2017-12-15

We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, the one-loop corrections to the effective potential in all the cases we study depend on the background tensors responsible for the Lorentz-symmetry violation. This has consequences for physical quantities like, for example, in the induced mass due to the Coleman-Weinberg mechanism. (orig.)

Effective potential in Lorentz-breaking field theory models

International Nuclear Information System (INIS)

Baeta Scarpelli, A.P.; Brito, L.C.T.; Felipe, J.C.C.; Nascimento, J.R.; Petrov, A.Yu.

2017-01-01

We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, the one-loop corrections to the effective potential in all the cases we study depend on the background tensors responsible for the Lorentz-symmetry violation. This has consequences for physical quantities like, for example, in the induced mass due to the Coleman-Weinberg mechanism. (orig.)

String perturbation theory and effective Lagrangians

International Nuclear Information System (INIS)

Klebanov, I.

1987-09-01

We isolate logarithmic divergences from bosonic string amplitudes on a disc. These divergences are compared with 'tadpole' divergences in the effective field theory with a cosmological term, which also contains an effective potential for the dilation. Also, corrections to β-functions are compared with variations of the effective action. In both cases we find an inconsistency between the two. This is a serious problem which could undermine our ability to remove divergences from the bosonic string

Effective potential for spontaneously broken gauge theories and gauge hierarchies

International Nuclear Information System (INIS)

Hagiwara, T.; Ovrut, B.

1979-01-01

The Appelquist-Carazzone effective-field-theory method, where one uses effective light-field coupling constants dependent on the heavy-field sector, is explicitly shown to be valid for the discussion of the gauge-hierarchy problem in grand unified gauge models. Using the method of functionals we derive an expression for the one-loop approximation to the scalar-field effective potential for spontaneously broken theories in an arbitrary R/sub xi/ gauge. We argue that this potential generates, through its derivatives, valid zero-momentum, one-particle-irreducible vertices for any value of xi (not just the xi→infinity Landau gauge). The equation that the one-loop vacuum correction must satisfy is presented, and we solve this equation for a number of spontaneously broken theories including gauge theories with gauge groups U(1) and SO(3). We find that a one-loop vacuum shift in a massless, non-Goldstone direction occurs via the Coleman-Weinberg mechanism with an effective coupling constant dependent on the heavy-field sector

Effective string theory and QCD scattering amplitudes

International Nuclear Information System (INIS)

Makeenko, Yuri

2011-01-01

QCD string is formed at distances larger than the confinement scale and can be described by the Polchinski-Strominger effective string theory with a nonpolynomial action, which has nevertheless a well-defined semiclassical expansion around a long-string ground state. We utilize modern ideas about the Wilson-loop/scattering-amplitude duality to calculate scattering amplitudes and show that the expansion parameter in the effective string theory is small in the Regge kinematical regime. For the amplitudes we obtain the Regge behavior with a linear trajectory of the intercept (d-2)/24 in d dimensions, which is computed semiclassically as a momentum-space Luescher term, and discuss an application to meson scattering amplitudes in QCD.

Towards a chiral effective field theory of nuclear matter

International Nuclear Information System (INIS)

Mallik, S.

2008-01-01

As a preliminary attempt to formulate an effective theory of nuclear matter, we undertake to calculate the effective pole parameters of nucleon in such a medium. We begin with the virial expansion of these parameters to leading order in nucleon number density in terms of the on-shell NN scattering amplitude. We then proceed to calculate the same parameters in the effective theory, getting a formula for the nucleon mass-shift to leading order, that was known already to give too large a value to be acceptable at normal nuclear density. At this point the virial expansion suggests a modification of this formula, which we carry out following Weinberg's method for the two-nucleon system in the effective theory. The results are encouraging enough to attempt a complete, next-to-leading order calculation of the off-shell nucleon spectral function in nuclear medium. (author)

Consistent constraints on the Standard Model Effective Field Theory

International Nuclear Information System (INIS)

Berthier, Laure; Trott, Michael

2016-01-01

We develop the global constraint picture in the (linear) effective field theory generalisation of the Standard Model, incorporating data from detectors that operated at PEP, PETRA, TRISTAN, SpS, Tevatron, SLAC, LEPI and LEP II, as well as low energy precision data. We fit one hundred and three observables. We develop a theory error metric for this effective field theory, which is required when constraints on parameters at leading order in the power counting are to be pushed to the percent level, or beyond, unless the cut off scale is assumed to be large, Λ≳ 3 TeV. We more consistently incorporate theoretical errors in this work, avoiding this assumption, and as a direct consequence bounds on some leading parameters are relaxed. We show how an S,T analysis is modified by the theory errors we include as an illustrative example.

Quasi-effective medium theory for multi-layered magneto-dielectric structures

International Nuclear Information System (INIS)

Genov, Dentcho A; Mundru, Pattabhiraju C

2014-01-01

We present a quasi-effective medium theory that determines the optical properties of multi-layered composites beyond the quasi-static limit. The proposed theory exactly reproduces the far field scattering/extinction cross sections through an iterative process in which mode-dependent quasi-effective impedances of the composite system are introduced. In the large wavelength limit our theory is consistent with the Maxwell–Garnett formalism. Possible applications in determining the hybridization particle resonances of multi-shell structures and electromagnetic cloaking are identified. (paper)

Constraints on four dimensional effective field theories from string and F-theory

Energy Technology Data Exchange (ETDEWEB)

Baume, Florent

2017-06-21

This thesis is a study of string theory compactifications to four dimensions and the constraints the Effective Field theories must exhibit, exploring both the closed and open sectors. In the former case, we focus on axion monodromy scenarios and the impact the backreaction of the energy density induced by the vev of an axion has on its field excursions. For all the cases studied, we find that the backreaction is small up to a critical value, and the proper field distance is flux independent and at most logarithmic in the axion vev. We then move to the open sector, where we use the framework of F-theory. We first explore the relation between the spectra arising from F-theory GUTs and those coming from a decomposition of the adjoint of E{sub 8} to SU(5) x U(1){sup n}. We find that extending the latter spectrum with new SU(5)-singlet fields, and classifying all possible ways of breaking the Abelian factors, all the spectra coming from smooth elliptic fibration constructed in the literature fit in our classification. We then explore generic properties of the spectra arising when breaking SU(5) to the Standard Model gauge group while retaining some anomaly properties. We finish by a study of F-theory compactications on a singular elliptic fibration via Matrix Factorisation, and find the charged spectrum of two non-Abelian examples.

Constraints on four dimensional effective field theories from string and F-theory

International Nuclear Information System (INIS)

Baume, Florent

2017-01-01

This thesis is a study of string theory compactifications to four dimensions and the constraints the Effective Field theories must exhibit, exploring both the closed and open sectors. In the former case, we focus on axion monodromy scenarios and the impact the backreaction of the energy density induced by the vev of an axion has on its field excursions. For all the cases studied, we find that the backreaction is small up to a critical value, and the proper field distance is flux independent and at most logarithmic in the axion vev. We then move to the open sector, where we use the framework of F-theory. We first explore the relation between the spectra arising from F-theory GUTs and those coming from a decomposition of the adjoint of E 8 to SU(5) x U(1) n . We find that extending the latter spectrum with new SU(5)-singlet fields, and classifying all possible ways of breaking the Abelian factors, all the spectra coming from smooth elliptic fibration constructed in the literature fit in our classification. We then explore generic properties of the spectra arising when breaking SU(5) to the Standard Model gauge group while retaining some anomaly properties. We finish by a study of F-theory compactications on a singular elliptic fibration via Matrix Factorisation, and find the charged spectrum of two non-Abelian examples.

Neutralino dark matter in BMSSM effective theory

International Nuclear Information System (INIS)

Berg, Marcus; Edsjö, Joakim; Lundström, Erik; Sjörs, Stefan; Gondolo, Paolo

2009-01-01

We study thermal neutralino dark matter in an effective field theory extension of the MSSM, called ''Beyond the MSSM'' (BMSSM) in Dine, Seiberg and Thomas (2007). In this class of effective field theories, the field content of the MSSM is unchanged, but the little hierarchy problem is alleviated by allowing small corrections to the Higgs/higgsino part of the Lagrangian. We perform parameter scans and compute the dark matter relic density. The light higgsino LSP scenario is modified the most; we find new regions of parameter space compared to the standard MSSM. This involves interesting interplay between the WMAP dark matter bounds and the LEP chargino bound. We also find some changes for gaugino LSPs, partly due to annihilation through a Higgs resonance, and partly due to coannihilation with light top squarks in models that are ruled in by the new effective terms

Strong coupling gauge theories and effective field theories. Proceedings of the 2002 international workshop

International Nuclear Information System (INIS)

Harada, Masayasu; Kikukawa, Yoshio; Yamawaki, Koichi

2003-01-01

This issue presents the important recent progress in both theoretical and phenomenological issues of strong coupling gauge theories, with/without supersymmetry and extra dimensions, etc. Emphasis in a placed on dynamical symmetry breaking with large anomalous dimensions governed by the dynamics near the nontrivial fixed point. Also presented are recent developments of the corresponding effective field theories. The 43 of the presented papers are indexed individually. (J.P.N)

Baryon non-invariant couplings in Higgs effective field theory

International Nuclear Information System (INIS)

Merlo, Luca; Saa, Sara; Sacristan-Barbero, Mario

2017-01-01

The basis of leading operators which are not invariant under baryon number is constructed within the Higgs effective field theory. This list contains 12 dimension six operators, which preserve the combination B - L, to be compared to only 6 operators for the standard model effective field theory. The discussion of the independent flavour contractions is presented in detail for a generic number of fermion families adopting the Hilbert series technique. (orig.)

Fluid analog model for boundary effects in field theory

International Nuclear Information System (INIS)

Ford, L. H.; Svaiter, N. F.

2009-01-01

Quantum fluctuations in the density of a fluid with a linear phonon dispersion relation are studied. In particular, we treat the changes in these fluctuations due to nonclassical states of phonons and to the presence of boundaries. These effects are analogous to similar effects in relativistic quantum field theory, and we argue that the case of the fluid is a useful analog model for effects in field theory. We further argue that the changes in the mean squared density are, in principle, observable by light scattering experiments.

Effective Hamiltonian theory: recent formal results and non-nuclear applications

International Nuclear Information System (INIS)

Brandow, B.H.

1981-01-01

Effective Hamiltonian theory is discussed from the points of view of the unitary transformation method and degenerate perturbation theory. It is shown that the two approaches are identical term by term. The main features of a formulation of the coupled-cluster method for open-shell systems are outlined. Finally, recent applications of the many-body linked-cluster form of degenerate perturbation theory are described: the derivation of effective spin Hamiltonians in magnetic insulator systems, the derivation and calculation ab initio of effective π-electron Hamiltonians for planar conjugated hydrocarbon molecules, and understanding the so-called valence fluctuation phenomenon exhibited by certain rare earth compounds

The Faraday effect revisited: General theory

DEFF Research Database (Denmark)

Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse...

Structure functions of hadrons in the QCD effective theory

International Nuclear Information System (INIS)

Shigetani, Takayuki

1996-01-01

We study the structure functions of hadrons with the low energy effective theory of QCD. We try to clarify a link between the low energy effective theory, where non-perturbative dynamics is essential, and the high energy deep inelastic scattering experiment. We calculate the leading twist matrix elements of the structure function at the low energy model scale within the effective theory. Calculated structure functions are evoluted to the high momentum scale with the help of the perturbative QCD, and compared with the experimental data. Through the comparison of the model calculations with the experiment, we discuss how the non-perturbative dynamics of the effective theory is reflected in the deep inelastic phenomena. We first evaluate the structure functions of the pseudoscalar mesons using the NJL model. The resulting structure functions show reasonable agreements with experiments. We study then the quark distribution functions of the nucleon using a covariant quark-diquark model. We calculate three leading twist distribution functions, spin-independent f 1 (x), longitudinal spin distribution g 1 (x), and chiral-odd transversity spin distribution h 1 (x). The results for f 1 (x) and g 1 (x) turn out to be consistent with available experiments because of the strong spin-0 diquark correlation. (author)

Classical and non-classical effective medium theories: New perspectives

International Nuclear Information System (INIS)

Tsukerman, Igor

2017-01-01

Highlights: • Advanced non-asymptotic and nonlocal homogenization theories of metamaterials, valid in electrostatics and electrodynamics. • Classical theories (Clausius–Mossotti, Lorenz–Lorentz, Maxwell Garnett) fit well into the proposed framework. • Nonlocal effects can be included in the model, making order-of-magnitude accuracy improvements possible. • A challenging problem for future research is to determine what effective tensors are attainable for given constituents of a metamaterial. - Abstract: Future research in electrodynamics of periodic electromagnetic composites (metamaterials) can be expected to produce sophisticated homogenization theories valid for any composition and size of the lattice cell. The paper outlines a promising path in that direction, leading to non-asymptotic and nonlocal homogenization models, and highlights aspects of homogenization that are often overlooked: the finite size of the sample and the role of interface boundaries. Classical theories (e.g. Clausius–Mossotti, Maxwell Garnett), while originally derived from a very different set of ideas, fit well into the proposed framework. Nonlocal effects can be included in the model, making an order-of-magnitude accuracy improvements possible. One future challenge is to determine what effective parameters can or cannot be obtained for a given set of constituents of a metamaterial lattice cell, thereby delineating the possible from the impossible in metamaterial design.

Classical and non-classical effective medium theories: New perspectives

Energy Technology Data Exchange (ETDEWEB)

Tsukerman, Igor, E-mail: igor@uakron.edu

2017-05-18

Highlights: • Advanced non-asymptotic and nonlocal homogenization theories of metamaterials, valid in electrostatics and electrodynamics. • Classical theories (Clausius–Mossotti, Lorenz–Lorentz, Maxwell Garnett) fit well into the proposed framework. • Nonlocal effects can be included in the model, making order-of-magnitude accuracy improvements possible. • A challenging problem for future research is to determine what effective tensors are attainable for given constituents of a metamaterial. - Abstract: Future research in electrodynamics of periodic electromagnetic composites (metamaterials) can be expected to produce sophisticated homogenization theories valid for any composition and size of the lattice cell. The paper outlines a promising path in that direction, leading to non-asymptotic and nonlocal homogenization models, and highlights aspects of homogenization that are often overlooked: the finite size of the sample and the role of interface boundaries. Classical theories (e.g. Clausius–Mossotti, Maxwell Garnett), while originally derived from a very different set of ideas, fit well into the proposed framework. Nonlocal effects can be included in the model, making an order-of-magnitude accuracy improvements possible. One future challenge is to determine what effective parameters can or cannot be obtained for a given set of constituents of a metamaterial lattice cell, thereby delineating the possible from the impossible in metamaterial design.

Generalized Effective Medium Theory for Particulate Nanocomposite Materials

Directory of Open Access Journals (Sweden)

Muhammad Usama Siddiqui

2016-08-01

Full Text Available The thermal conductivity of particulate nanocomposites is strongly dependent on the size, shape, orientation and dispersion uniformity of the inclusions. To correctly estimate the effective thermal conductivity of the nanocomposite, all these factors should be included in the prediction model. In this paper, the formulation of a generalized effective medium theory for the determination of the effective thermal conductivity of particulate nanocomposites with multiple inclusions is presented. The formulated methodology takes into account all the factors mentioned above and can be used to model nanocomposites with multiple inclusions that are randomly oriented or aligned in a particular direction. The effect of inclusion dispersion non-uniformity is modeled using a two-scale approach. The applications of the formulated effective medium theory are demonstrated using previously published experimental and numerical results for several particulate nanocomposites.

The Faraday effect revisited: General theory

DEFF Research Database (Denmark)

Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

2006-01-01

This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. At zero temperature and zero frequency...

Heavy Quark Effective Theory

Science.gov (United States)

Manohar, A. V.

2003-02-01

These lecture notes present some of the basic ideas of heavy quark effective theory. The topics covered include the classification of states, the derivation of the HQET Lagrangian at tree level, hadron masses, meson form factors, Luke's theorem, reparameterization invariance and inclusive decays. Radiative corrections are discussed in some detail, including an explicit computation of a matching correction for HQET. Borel summability, renormalons, and their connection with the QCD perturbation series is covered, as well as the use of the upsilon expansion to improve the convergence of the perturbation series.

Higgs Effective Field Theories

CERN Document Server

2016-01-01

The main focus of this meeting is to present new theoretical advancements related to effective field theories, evaluate the impact of initial results from the LHC Run2, and discuss proposals for data interpretation/presentation during Run2. A crucial role of the meeting is to bring together theorists from different backgrounds and with different viewpoints and to extend bridges towards the experimental community. To this end, we would like to achieve a good balance between senior and junior speakers, enhancing the visibility of younger scientists while keeping some overview talks.

When effective theories predict: the inevitability of Mercury's anomalous perihelion precession

CERN Document Server

Wells, James D

2012-01-01

If the concepts underlying Effective Theory were appreciated from the earliest days of Newtonian gravity, Le Verrier's announcement in 1845 of the anomalous perihelion precession of Mercury would have been no surprise. Furthermore, the size of the effect could have been anticipated through "naturalness" arguments well before the definitive computation in General Relativity. Thus, we have an illustration of how Effective Theory concepts can guide us in extending our knowledge to "new physics", and not just in how to reduce larger theories to restricted (e.g., lower energy) domains.

Versatility of field theory motivated nuclear effective Lagrangian approach

International Nuclear Information System (INIS)

Arumugam, P.; Sharma, B.K.; Sahu, P.K.; Patra, S.K.; Sil, Tapas; Centelles, M.; Vinas, X.

2004-01-01

We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei

Vibrational nonadiabaticity and tunneling effects in transition state theory

International Nuclear Information System (INIS)

Marcus, R.A.

1979-01-01

The usual quantum mechanical derivation of transition state theory is a statistical one (a quasi-equilibrium is assumed) or dynamical. The typical dynamical one defines a set of internal states and assumes vibrational adiabaticity. Effects of nonadiabaticity before and after the transition state are included in the present derivation, assuming a classical treatment of the reaction coordinate. The relation to a dynamical derivation of classical mechanical transition state theory is described, and tunneling effects are considered

Effective field theory of cosmological perturbations

International Nuclear Information System (INIS)

Piazza, Federico; Vernizzi, Filippo

2013-01-01

The effective field theory of cosmological perturbations stems from considering a cosmological background solution as a state displaying spontaneous breaking of time translations and (adiabatic) perturbations as the related Nambu–Goldstone modes. With this insight, one can systematically develop a theory for the cosmological perturbations during inflation and, with minor modifications, also describe in full generality the gravitational interactions of dark energy, which are relevant for late-time cosmology. The formalism displays a unique set of Lagrangian operators containing an increasing number of cosmological perturbations and derivatives. We give an introductory description of the unitary gauge formalism for theories with broken gauge symmetry—that allows us to write down the most general Lagrangian—and of the Stückelberg ‘trick’—that allows to recover gauge invariance and to make the scalar field explicit. We show how to apply this formalism to gravity and cosmology and we reproduce the detailed analysis of the action in the ADM variables. We also review some basic applications to inflation and dark energy. (paper)

Effective field theory of cosmological perturbations

Science.gov (United States)

Piazza, Federico; Vernizzi, Filippo

2013-11-01

The effective field theory of cosmological perturbations stems from considering a cosmological background solution as a state displaying spontaneous breaking of time translations and (adiabatic) perturbations as the related Nambu-Goldstone modes. With this insight, one can systematically develop a theory for the cosmological perturbations during inflation and, with minor modifications, also describe in full generality the gravitational interactions of dark energy, which are relevant for late-time cosmology. The formalism displays a unique set of Lagrangian operators containing an increasing number of cosmological perturbations and derivatives. We give an introductory description of the unitary gauge formalism for theories with broken gauge symmetry—that allows us to write down the most general Lagrangian—and of the Stückelberg ‘trick’—that allows to recover gauge invariance and to make the scalar field explicit. We show how to apply this formalism to gravity and cosmology and we reproduce the detailed analysis of the action in the ADM variables. We also review some basic applications to inflation and dark energy.

Effective medium theories of inhomogeneous media from modern perspective

International Nuclear Information System (INIS)

Gubernatis, J.E.

1977-01-01

In the study of disordered alloys, theorists have stated the physics of the problem in terms of an integral equation and analyzed this equation by techniques developed in the quantum mechanical theory of scattering. The application of the scattering theory approach to the computation of the effective dielectric constant of a polycrystal is discussed. The problem is framed in the form of an integral equation. Several well-known intuitive approximations are recovered, and the connection of the approximations to perturbation theory is indicated

Effective-field-theory model for the fractional quantum Hall effect

International Nuclear Information System (INIS)

Zhang, S.C.; Hansson, T.H.; Kivelson, S.

1989-01-01

Starting directly from the microscopic Hamiltonian, we derive a field-theory model for the fractional quantum hall effect. By considering an approximate coarse-grained version of the same model, we construct a Landau-Ginzburg theory similar to that of Girvin. The partition function of the model exhibits cusps as a function of density and the Hall conductance is quantized at filling factors ν = (2k-1)/sup -1/ with k an arbitrary integer. At these fractions the ground state is incompressible, and the quasiparticles and quasiholes have fractional charge and obey fractional statistics. Finally, we show that the collective density fluctuations are massive

Quantum optical effective-medium theory and transformation quantum optics for metamaterials

DEFF Research Database (Denmark)

Wubs, Martijn; Amooghorban, Ehsan; Zhang, Jingjing

2016-01-01

electrodynamics of media with both loss and gain. In the second part of this paper, we present a new application of transformation optics whereby local spontaneous-emission rates of quantum emitters can be designed. This follows from an analysis how electromagnetic Green functions transform under coordinate......While typically designed to manipulate classical light, metamaterials have many potential applications for quantum optics as well. We argue why a quantum optical effective-medium theory is needed. We present such a theory for layered metamaterials that is valid for light propagation in all spatial...... directions, thereby generalizing earlier work for one-dimensional propagation. In contrast to classical effective-medium theory there is an additional effective parameter that describes quantum noise. Our results for metamaterials are based on a rather general Lagrangian theory for the quantum...

The Effects of Integrating Laboratory Work with Theory on Academic ...

African Journals Online (AJOL)

The Effects of Integrating Laboratory Work with Theory on Academic Achievement in Secondary School Physics. ... Journal Home > Vol 4, No 4 (2010) > ... better than those taught by treating practical work after and separate from theory.

QCD Effective Field Theories for Heavy Quarkonium

International Nuclear Information System (INIS)

Brambilla, Nora

2006-01-01

QCD nonrelativistic effective field theories (NREFT) are the modern and most suitable frame to describe heavy quarkonium properties. Here I summarize few relevant concepts and some of the interesting physical applications (spectrum, decays, production) of NREFT

Effective field theory approach to structure functions at small xBj

International Nuclear Information System (INIS)

Nachtmann, O.

2003-01-01

We relate the structure functions of deep inelastic lepton-nucleon scattering to current-current correlation functions in a Euclidean field theory depending on a parameter r. The r-dependent Hamiltonian of the theory is P 0 -(1-r)P 3 , with P 0 the usual Hamiltonian and P 3 the third component of the momentum operator. We show that a small x Bj in the structure functions corresponds to the small r limit of the effective theory. We argue that for r→0 there is a critical regime of the theory where simple scaling relations should hold. We show that in this framework Regge behaviour of the structure functions obtained with the hard pomeron ansatz corresponds to a scaling behaviour of the matrix elements in the effective theory where the intercept of the hard pomeron appears as a critical index. Explicit expressions for various analytic continuations of the structure functions and matrix elements are given as well as path integral representations for the matrix elements in the effective theory. Our aim is to provide a framework for truly non-perturbative calculations of the structure functions at small x Bj for arbitrary Q 2 . (orig.)

Inadequate Evidence for Multiple Intelligences, Mozart Effect, and Emotional Intelligence Theories

Science.gov (United States)

Waterhouse, Lynn

2006-01-01

I (Waterhouse, 2006) argued that, because multiple intelligences, the Mozart effect, and emotional intelligence theories have inadequate empirical support and are not consistent with cognitive neuroscience findings, these theories should not be applied in education. Proponents countered that their theories had sufficient empirical support, were…

Realising effective theories of tribrid inflation: are there effects from messenger fields?

International Nuclear Information System (INIS)

Antusch, Stefan; Nolde, David

2015-01-01

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?

Science.gov (United States)

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?

Energy Technology Data Exchange (ETDEWEB)

Antusch, Stefan [Department of Physics, University of Basel,Klingelbergstr. 82, CH-4056 Basel (Switzerland); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805 München (Germany); Nolde, David [Department of Physics, University of Basel,Klingelbergstr. 82, CH-4056 Basel (Switzerland)

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 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.

Phenomenological theory of synergistic effects in plasma-wall interaction

International Nuclear Information System (INIS)

Itoh, N.; Hasebe, Y.

1986-01-01

A phenomenological theory for synergistic effects under multi-species particle bombardement has been developed. The theory is based on a model in which two free-energy minima are assumed to be overcome under actions of radiation for a process to be completed. The synergistic factor, the ratio of the yield of the process under irradiation with two species of particles to the summation of the yields of the process under irradiation with each of two component species, is obtained as a function of the beam flux for several parameters relevant to thermodynamic and radiation-enhanced processes. The criterion for the synergistic effect is obtained. The theory has been shown to be able to explain the yield-flux relation obtained by Haasz et al. for hydrogen-induced methane formation from graphite. (orig.)

Uses of Effective Field Theory in Lattice QCD

OpenAIRE

Kronfeld, Andreas S.

2002-01-01

Several physical problems in particle physics, nuclear physics, and astrophysics require information from non-perturbative QCD to gain a full understanding. In some cases the most reliable technique for quantitative results is to carry out large-scale numerical calculations in lattice gauge theory. As in any numerical technique, there are several sources of uncertainty. This chapter explains how effective field theories are used to keep them under control and, then, obtain a sensible error ba...

Baryons in the heavy quark effective theory

International Nuclear Information System (INIS)

Mannel, T.; Roberts, W.; Ryzak, Z.

1990-08-01

We show how to incorporate baryons in the heavy quark effective theory. A convenient formalism is exhibited and applied to semileptonic weak decays of heavy baryons and to exclusive production of heavy baryons in e + e - annihilation. (orig.)

Factorization of heavy-to-light form factors in soft-collinear effective theory

CERN Document Server

Beneke, Martin; Feldmann, Th.

2004-01-01

Heavy-to-light transition form factors at large recoil energy of the light meson have been conjectured to obey a factorization formula, where the set of form factors is reduced to a smaller number of universal form factors up to hard-scattering corrections. In this paper we extend our previous investigation of heavy-to-light currents in soft-collinear effective theory to final states with invariant mass Lambda^2 as is appropriate to exclusive B meson decays. The effective theory contains soft modes and two collinear modes with virtualities of order m_b*Lambda (`hard-collinear') and Lambda^2. Integrating out the hard-collinear modes results in the hard spectator-scattering contributions to exclusive B decays. We discuss the representation of heavy-to-light currents in the effective theory after integrating out the hard-collinear scale, and show that the previously conjectured factorization formula is valid to all orders in perturbation theory. The naive factorization of matrix elements in the effective theory ...

A new formulation of the effective theory for heavy particles

International Nuclear Information System (INIS)

Aglietti, U.; Capitani, S.

1994-01-01

We derive the effective theories for heavy particles with a functional integral approach by integrating away the states with high velocity and with high virtuality. This formulation is non-perturbative and has a close connection with the Wilson renormalization group transformation. The fixed point hamiltonian of our transformation coincides with the static hamiltonian and irrelevant operators can be identified with the usual 1/M corrections to the static theory. No matching condition has to be imposed between the full and the static theory operators with our approach. The values of the matching constants come out as a dynamical effect of the renormalization group flow. ((orig.))

On the effective field theory of intersecting D3-branes

Science.gov (United States)

Abbaspur, Reza

2018-05-01

We study the effective field theory of two intersecting D3-branes with one common dimension along the lines recently proposed in ref. [1]. We introduce a systematic way of deriving the classical effective action to arbitrary orders in perturbation theory. Using a proper renormalization prescription to handle logarithmic divergencies arising at all orders in the perturbation series, we recover the first order renormalization group equation of ref. [1] plus an infinite set of higher order equations. We show the consistency of the higher order equations with the first order one and hence interpret the first order result as an exact RG flow equation in the classical theory.

Effective field theory dimensional regularization

International Nuclear Information System (INIS)

Lehmann, Dirk; Prezeau, Gary

2002-01-01

A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed

Effective field theory dimensional regularization

Science.gov (United States)

Lehmann, Dirk; Prézeau, Gary

2002-01-01

A Lorentz-covariant regularization scheme for effective field theories with an arbitrary number of propagating heavy and light particles is given. This regularization scheme leaves the low-energy analytic structure of Greens functions intact and preserves all the symmetries of the underlying Lagrangian. The power divergences of regularized loop integrals are controlled by the low-energy kinematic variables. Simple diagrammatic rules are derived for the regularization of arbitrary one-loop graphs and the generalization to higher loops is discussed.

The effects of anti-vaccine conspiracy theories on vaccination intentions.

Directory of Open Access Journals (Sweden)

Daniel Jolley

Full Text Available The current studies investigated the potential impact of anti-vaccine conspiracy beliefs, and exposure to anti-vaccine conspiracy theories, on vaccination intentions. In Study 1, British parents completed a questionnaire measuring beliefs in anti-vaccine conspiracy theories and the likelihood that they would have a fictitious child vaccinated. Results revealed a significant negative relationship between anti-vaccine conspiracy beliefs and vaccination intentions. This effect was mediated by the perceived dangers of vaccines, and feelings of powerlessness, disillusionment and mistrust in authorities. In Study 2, participants were exposed to information that either supported or refuted anti-vaccine conspiracy theories, or a control condition. Results revealed that participants who had been exposed to material supporting anti-vaccine conspiracy theories showed less intention to vaccinate than those in the anti-conspiracy condition or controls. This effect was mediated by the same variables as in Study 1. These findings point to the potentially detrimental consequences of anti-vaccine conspiracy theories, and highlight their potential role in shaping health-related behaviors.

Threshold resummation for Higgs production in effective field theory

International Nuclear Information System (INIS)

Idilbi, Ahmad; Ji Xiangdong; Ma Jianping; Yuan Feng

2006-01-01

We present an effective field theory approach to resum the large double logarithms originated from soft-gluon radiations at small final-state hadron invariant masses in Higgs and vector boson (γ*,W,Z) production at hadron colliders. The approach is conceptually simple, independent of details of an effective field theory formulation, and valid to all orders in subleading logarithms. As an example, we show the result of summing the next-to-next-to-next-to leading logarithms is identical to that of the standard pQCD factorization method

Scattering of decuplet baryons in chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Haidenbauer, J. [Institut fuer Kernphysik, Institute for Advanced Simulation and Juelich Center for Hadron Physics, Juelich (Germany); Petschauer, S.; Kaiser, N.; Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Meissner, Ulf G. [Institut fuer Kernphysik, Institute for Advanced Simulation and Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany)

2017-11-15

A formalism for treating the scattering of decuplet baryons in chiral effective field theory is developed. The minimal Lagrangian and potentials in leading-order SU(3) chiral effective field theory for the interactions of octet baryons (B) and decuplet baryons (D) for the transitions BB → BB, BB <-> DB, DB → DB, BB <-> DD, DB <-> DD, and DD → DD are provided. As an application of the formalism we compare with results from lattice QCD simulations for ΩΩ and NΩ scattering. Implications of our results pertinent to the quest for dibaryons are discussed. (orig.)

Theory of fractional quantum Hall effect

International Nuclear Information System (INIS)

Kostadinov, I.Z.

1984-09-01

A theory of the fractional quantum Hall effect is constructed by introducing 3-particle interactions breaking the symmetry for ν=1/3 according to a degeneracy theorem proved here. An order parameter is introduced and a gap in the single particle spectrum is found. The critical temperature, critical filling number and critical behaviour are determined as well as the Ginzburg-Landau equation coefficients. A first principle calculation of the Hall current is given. 3, 5, 7 electron tunneling and Josephson interference effects are predicted. (author)

String creation, D-branes and effective field theory

International Nuclear Information System (INIS)

Hung Lingyan

2008-01-01

This paper addresses several unsettled issues associated with string creation in systems of orthogonal Dp-D(8-p) branes. The interaction between the branes can be understood either from the closed string or open string picture. In the closed string picture it has been noted that the DBI action fails to capture an extra RR exchange between the branes. We demonstrate how this problem persists upon lifting to M-theory. These D-brane systems are analysed in the closed string picture by using gauge-fixed boundary states in a non-standard lightcone gauge, in which RR exchange can be analysed precisely. The missing piece in the DBI action also manifests itself in the open string picture as a mismatch between the Coleman-Weinberg potential obtained from the effective field theory and the corresponding open string calculation. We show that this difference can be reconciled by taking into account the superghosts in the (0+1) effective theory of the chiral fermion, that arises from gauge fixing the spontaneously broken world-line local supersymmetries

Kohn-Luttinger effect in gauge theories

International Nuclear Information System (INIS)

Schaefer, T.

2006-01-01

Kohn and Luttinger showed that a many body system of fermions interacting via short range forces becomes superfluid even if the interaction is repulsive in all partial waves. In gauge theories such as QCD the interaction between fermions is long range and the assumptions of Kohn and Luttinger are not satisfied. We show that in a U(1) gauge theory the Kohn-Luttinger phenomenon does not take place. In QCD attractive channels always exist, but there are cases in which the primary pairing channel leaves some fermions ungapped. As an example we consider the unpaired fermion in the 2SC phase of QCD with two flavors. We show that it acquires a very small gap via a mechanism analogous to the Kohn-Luttinger effect. The gap is too small to be phenomenologically relevant

Strong decays and dipion transitions of Y(5S)

International Nuclear Information System (INIS)

Simonov, Yu.A.; Veselov, A.I.

2009-01-01

Dipion transitions of Y(nS) with n=5, n ' =1,2,3 are studied using the Field Correlator Method, applied previously to dipion transitions with n=2,3,4. The only two parameters of effective Lagrangian were fixed in that earlier study, and total widths Γ ππ (5,n ' ) as well as pionless decay widths Γ BB (5S), Γ BB* (5S), Γ B*B* (5S) and Γ KK (5,n ' ) were calculated and are in a reasonable agreement with experiment. The experimental ππ spectra for (5,1) and (5,2) transitions are well reproduced taking into account FSI in the ππ

The exact effective couplings of 4D N=2 gauge theories

Energy Technology Data Exchange (ETDEWEB)

Mitev, Vladimir [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Mathematik; Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Pomoni, Elli [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); National Technical Univ. Athens (Greece). Physics Division

2014-07-15

The anomalous dimensions of operators in the purely gluonic SU(2,1 vertical stroke 2) sector of any planar conformal N=2 theory can be read off from the N=4 SYM results by replacing the N=4 coupling constant by an interpolating function of the N=2 coupling constants, to which we refer to as the effective coupling. For a large class of N=2 theories we compute the weak coupling expansion of these functions as well as the leading strong coupling term by employing supersymmetric localization. Via Feynman diagrams, we interpret our results as the relative (between N=2 and N=4) finite renormalization of the coupling constant. Using the AdS/CFT dictionary, we identify the effective couplings with the effective string tensions of the corresponding gravity dual theories. Thus, any observable in the SU(2,1 vertical stroke 2) sector can be obtained from its N=4 counterpart by replacing the N=4 coupling constant by the universal, for a given theory, effective coupling.

The exact effective couplings of 4D N=2 gauge theories

International Nuclear Information System (INIS)

Mitev, Vladimir; Humboldt-Universitaet, Berlin; Pomoni, Elli; National Technical Univ. Athens

2014-07-01

The anomalous dimensions of operators in the purely gluonic SU(2,1 vertical stroke 2) sector of any planar conformal N=2 theory can be read off from the N=4 SYM results by replacing the N=4 coupling constant by an interpolating function of the N=2 coupling constants, to which we refer to as the effective coupling. For a large class of N=2 theories we compute the weak coupling expansion of these functions as well as the leading strong coupling term by employing supersymmetric localization. Via Feynman diagrams, we interpret our results as the relative (between N=2 and N=4) finite renormalization of the coupling constant. Using the AdS/CFT dictionary, we identify the effective couplings with the effective string tensions of the corresponding gravity dual theories. Thus, any observable in the SU(2,1 vertical stroke 2) sector can be obtained from its N=4 counterpart by replacing the N=4 coupling constant by the universal, for a given theory, effective coupling.

Analysis of self-consistency effects in range-separated density-functional theory with Møller-Plesset perturbation theory

DEFF Research Database (Denmark)

Fromager, Emmanuel; Jensen, Hans Jørgen Aagaard

2011-01-01

Range-separated density-functional theory combines wave function theory for the long-range part of the two-electron interaction with density-functional theory for the short-range part. When describing the long-range interaction with non-variational methods, such as perturbation or coupled......-cluster theories, self-consistency effects are introduced in the density functional part, which for an exact solution requires iterations. They are generally assumed to be small but no detailed study has been performed so far. Here, the authors analyze self-consistency when using Møller-Plesset-type (MP......) perturbation theory for the long range interaction. The lowest-order self-consistency corrections to the wave function and the energy, that enter the perturbation expansions at the second and fourth order, respectively, are both expressed in terms of the one-electron reduced density matrix. The computational...

Hořava-Lifshitz gravity and effective theory of the fractional quantum Hall effect

Energy Technology Data Exchange (ETDEWEB)

Wu, Chaolun [Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States); Wu, Shao-Feng [Department of Physics, Shanghai University,Shanghai 200444 (China); Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States)

2015-01-22

We show that Hořava-Lifshitz gravity theory can be employed as a covariant framework to build an effective field theory for the fractional quantum Hall effect that respects all the spacetime symmetries such as non-relativistic diffeomorphism invariance and anisotropic Weyl invariance as well as the gauge symmetry. The key to this formalism is a set of correspondence relations that maps all the field degrees of freedom in the Hořava-Lifshitz gravity theory to external background (source) fields among others in the effective action of the quantum Hall effect, according to their symmetry transformation properties. We originally derive the map as a holographic dictionary, but its form is independent of the existence of holographic duality. This paves the way for the application of Hořava-Lifshitz holography on fractional quantum Hall effect. Using the simplest holographic Chern-Simons model, we compute the low energy effective action at leading orders and show that it captures universal electromagnetic and geometric properties of quantum Hall states, including the Wen-Zee shift, Hall viscosity, angular momentum density and their relations. We identify the shift function in Hořava-Lifshitz gravity theory as minus of guiding center velocity and conjugate to guiding center momentum. This enables us to distinguish guiding center angular momentum density from the internal one, which is the sum of Landau orbit spin and intrinsic (topological) spin of the composite particles. Our effective action shows that Hall viscosity is minus half of the internal angular momentum density and proportional to Wen-Zee shift, and Hall bulk viscosity is half of the guiding center angular momentum density.

Effective-field theory on the kinetic Ising model

International Nuclear Information System (INIS)

Shi Xiaoling; Wei Guozhu; Li Lin

2008-01-01

As an analytical method, the effective-field theory (EFT) is used to study the dynamical response of the kinetic Ising model in the presence of a sinusoidal oscillating field. The effective-field equations of motion of the average magnetization are given for the square lattice (Z=4) and the simple cubic lattice (Z=6), respectively. The dynamic order parameter, the hysteresis loop area and the dynamic correlation are calculated. In the field amplitude h 0 /ZJ-temperature T/ZJ plane, the phase boundary separating the dynamic ordered and the disordered phase has been drawn, and the dynamical tricritical point has been observed. We also make the compare results of EFT with that given by using the mean field theory (MFT)

Surface effect theory in binary alloys: surfaces with cut-off

International Nuclear Information System (INIS)

Kumar, V.; Silva, C.E.T.G. da; Moran-Lopez, J.L.

1981-01-01

A surface effect theory in binary alloys which ore ordered with surfaces with cut-off is presented. This theory is based in a model of pair interaction between first neighbours and includes long and short range effects. The (120) surface with sup(-) (110) monoatomic cut-off and terrace in the (110) planes of an alloy with body centered cubic structure is presented as example. Results for the concentrations in all the different surface sites are given. (L.C.) [pt

A Guide to Effective School Leadership Theories

Science.gov (United States)

Lynch, Matthew

2012-01-01

Educational administrators know that leadership requires hundreds of judgments each day that require a sensitivity and understanding of various leadership strategies. Bridging the gap between the academic and practical world, "A Guide to Effective School Leadership Theories" provides an exploration of ten dominant leadership strategies to give…

Minding one's P's and Q's: From the one loop effective action in quantum field theory to classical transport theory

International Nuclear Information System (INIS)

Jalilian-Marian, Jamal; Jeon, Sangyong; Venugopalan, Raju; Wirstam, Jens

2000-01-01

The one loop effective action in quantum field theory can be expressed as a quantum mechanical path integral over world lines, with internal symmetries represented by Grassmanian variables. In this paper, we develop a real time, many body, world line formalism for the one loop effective action. In particular, we study hot QCD and obtain the classical transport equations which, as Litim and Manuel have shown, reduce in the appropriate limit to the non-Abelian Boltzmann-Langevin equation first obtained by Boedeker. In the Vlasov limit, the classical kinetic equations are those that correspond to the hard thermal loop effective action. We also discuss the imaginary time world line formalism for a hot φ 4 theory, and elucidate its relation to classical transport theory. (c) 2000 The American Physical Society

Tissue Acoustoelectric Effect Modeling From Solid Mechanics Theory.

Science.gov (United States)

Song, Xizi; Qin, Yexian; Xu, Yanbin; Ingram, Pier; Witte, Russell S; Dong, Feng

2017-10-01

The acoustoelectric (AE) effect is a basic physical phenomenon, which underlies the changes made in the conductivity of a medium by the application of focused ultrasound. Recently, based on the AE effect, several biomedical imaging techniques have been widely studied, such as ultrasound-modulated electrical impedance tomography and ultrasound current source density imaging. To further investigate the mechanism of the AE effect in tissue and to provide guidance for such techniques, we have modeled the tissue AE effect using the theory of solid mechanics. Both bulk compression and thermal expansion of tissue are considered and discussed. Computation simulation shows that the muscle AE effect result, conductivity change rate, is 3.26×10 -3 with 4.3-MPa peak pressure, satisfying the theoretical value. Bulk compression plays the main role for muscle AE effect, while thermal expansion makes almost no contribution to it. In addition, the AE signals of porcine muscle are measured at different focal positions. With the same magnitude order and the same change trend, the experiment result confirms that the simulation result is effective. Both simulation and experimental results validate that tissue AE effect modeling using solid mechanics theory is feasible, which is of significance for the further development of related biomedical imaging techniques.

A flexoelectric theory with rotation gradient effects for elastic dielectrics

International Nuclear Information System (INIS)

Anqing, Li; Shenjie, Zhou; Lu, Qi; Xi, Chen

2016-01-01

In this paper, a general flexoelectric theory in the framework of couple stress theory is proposed for isotropic dielectrics, in which the rotation gradient and the polarization gradient are involved to represent the nonlocal mechanical and electrical effects, respectively. The present flexoelectric theory shows only the anti-symmetric part of rotation gradient can induce polarization, while the symmetric part of rotation gradient cannot induce polarization in isotropic dielectrics. The electrostatic stress is obtained naturally in the governing equations and boundary conditions in terms of the variational principle, which is composed of two parts: the Maxwell stress corresponding to the polarization and the remainder relating to the polarization gradient. The current theory is able to account for the effects of size, direct and inverse flexoelectricities, and electrostatic force. To illustrate this theory, a simple application of Bernoulli–Euler cantilever beam is discussed. The numerical results demonstrate neither the higher-order constant l 1 nor the higher-order constant l 2 associated with the symmetric and anti-symmetric parts of rotation gradient, respectively, can be ignored in the flexoelectric theory. In addition, the induced deflection increases as the increase of the flexoelectric coefficient. The polarization is no longer constant and the potential is no longer linear along the thickness direction of beam because of the influence of polarization gradient. (paper)

Reconstructing inflationary paradigm within Effective Field Theory framework

Science.gov (United States)

Choudhury, Sayantan

2016-03-01

In this paper my prime objective is to analyse the constraints on a sub-Planckian excursion of a single inflaton field within Effective Field Theory framework in a model independent fashion. For a generic single field inflationary potential, using the various parameterization of the primordial power spectrum I have derived the most general expression for the field excursion in terms of various inflationary observables, applying the observational constraints obtained from recent Planck 2015 and Planck 2015 + BICEP2/Keck Array data. By explicit computation I have reconstructed the structural form of the inflationary potential by constraining the Taylor expansion co-efficients appearing in the generic expansion of the potential within the Effective Field Theory. Next I have explicitly derived, a set of higher order inflationary consistency relationships, which would help us to break the degeneracy between various class of inflationary models by differentiating them. I also provided two simple examples of Effective Theory of inflation- inflection-point model and saddle-point model to check the compatibility of the prescribed methodology in the light of Planck 2015 and Planck 2015 + BICEP2/Keck Array data. Finally, I have also checked the validity of the prescription by estimating the cosmological parameters and fitting the theoretical CMB TT, TE and EE angular power spectra with the observed data within the multipole range 2 < l < 2500.

Dissipative Effects in the Effective Field Theory of Inflation

Energy Technology Data Exchange (ETDEWEB)

Lopez Nacir, Diana; /Buenos Aires, CONICET /Buenos Aires U.; Porto, Rafael A.; /Princeton, Inst. Advanced Study /ISCAP, New York /Columbia U.; Senatore, Leonardo; /Stanford U., ITP /SLAC /KIPAC, Menlo Park; Zaldarriaga, Matias; /Princeton, Inst. Advanced Study

2012-09-14

We generalize the effective field theory of single clock inflation to include dissipative effects. Working in unitary gauge we couple a set of composite operators, {Omicron}{sub {mu}{nu}}..., in the effective action which is constrained solely by invariance under time-dependent spatial diffeomorphisms. We restrict ourselves to situations where the degrees of freedom responsible for dissipation do not contribute to the density perturbations at late time. The dynamics of the perturbations is then modified by the appearance of 'friction' and noise terms, and assuming certain locality properties for the Green's functions of these composite operators, we show that there is a regime characterized by a large friction term {gamma} >> H in which the {zeta}-correlators are dominated by the noise and the power spectrum can be significantly enhanced. We also compute the three point function <{zeta}{zeta}{zeta}> for a wide class of models and discuss under which circumstances large friction leads to an increased level of non-Gaussianities. In particular, under our assumptions, we show that strong dissipation together with the required non-linear realization of the symmetries implies |f{sub NL}| {approx} {gamma}/c{sub s}{sup 2} H >> 1. As a paradigmatic example we work out a variation of the 'trapped inflation' scenario with local response functions and perform the matching with our effective theory. A detection of the generic type of signatures that result from incorporating dissipative effects during inflation, as we describe here, would teach us about the dynamics of the early universe and also extend the parameter space of inflationary models.

Prospect Theory: A Study of the Endowment Effect

Directory of Open Access Journals (Sweden)

Jurandir Sell Macedo

2007-01-01

Full Text Available Behavioral Finance is a recent field of study which contradicts the presupposition supported by Modern Finance that decision makers act rationally. Prospect Theory, developed by Kahneman and Tversky (1979, is presented as an alternative model to the Theory of Expected Utility in relation to the way people decide in face of possibilities of risk. According to Prospect Theory, people define gains and losses based on a given point of reference, which can be established on grounds of a given level of expected gain. This fact leads to the Endowment Effect - a behavioral trend investigated in this study – whereby investors are influenced by a portfolio which they have received as an inheritance or endowment. The reason this occurs is that individuals usually define their expectations of gain according to the future profitability of the portfolio received, and not according to the future profitability of the market. Using an investment simulation, the Endowment Effect was tested among 226 university students taking courses in the subject of capital markets. The results demonstrate that the students were influenced by the different initial portfolios, which were randomly assigned.

The effect of the emotive decisions in prospect theory.

Science.gov (United States)

Bonavia, Tomas

2014-12-29

The main purpose of this paper was to show that the certainty and reflection effects of prospect theory do not occur when stimuli have an affective value. To this end, 160 participants were asked to reply to a series of problems originally designed by Kahneman and Tversky (1979), but modified according to the contributions of Rottenstreich and Hsee (2001). The sample was divided into four experimental conditions, two in a gain situation and two in a loss situation. In both cases, affect-rich and affect-poor stimuli were applied in sure and probable alternatives. The findings showed that, in agreement with our hypotheses, the affective value of the stimuli altered the outcome predicted by prospect theory, showing response patterns contrary to certainty and reflection effects (p ≤ .01 and p ≤ .05 respectively). Therefore, this research supports the influence of the emotions in the decision-making process, and should be extended to other aspects of prospect theory.

Application of spectral distributions in effective interaction theory

International Nuclear Information System (INIS)

Chang, B.D.

1980-01-01

The calculation of observable quantities in a large many-particle space is very complicated and often impractical. In effective interaction theory, to simplify the calculation, the full many-particle space is truncated to a small, manageable model space and the operators associated with the observables are renormalized to accommodate the truncation effects. The operator that has been most extensively studied for renormalization is the Hamiltonian. The renormalized Hamiltonian, often called the effective Hamiltonian, can be defined such that it not only gives the eigenvalues, but also the projections of the full-space (true) eigen-functions onto the model space. These projected wave functions then provide a convenient basis for renormalization of other operators. The usual framework for renormalization is perturbation theory. Unfortunately, the conventional perturbation series for effective Hamiltonians have problems with convergence and their high order terms (especially 4th or higher) are also difficult to calculate. The characteristics of spectral distributions can be helptul in determining the model space and calculating the effective Hamiltonian. In this talk applications of spectral distributions are discussed in the following areas: (1) truncation of many particle spaces by selection of configurations; (2) orthogonal polynomial expansions for the effective Hamiltonian; and (3) establishing new criteria for the effective Hamiltonian

Effects of a strict cutoff on Quantum Field Theory

International Nuclear Information System (INIS)

Sturnfield, J.F.

1987-01-01

Standard Quantum Field Theory has a number of integrals which are infinite. Although these are eliminated for some cases by renormalization, this aspect of the theory is not fully satisfactory. A number of theories with fundamental lengths have been introduced as alternatives and it would be useful to be able to distinguish between them. In particular, the effects that a strict cutoff would have on Quantum Field Theory is studied. It is noted that care must be taken in the method used to apply a strict cutoff. This lead to considering a theory where the cutoffs are defined by restricting each internal line. This theory is only piece-wise analytic. The resulting scattering matrix is frame dependent, yet the theory still satisfies the special relativity view that all frames are subjectively identical. The renormalization of this theory is finite. The change in mass from the electron self-energy will be a spinor operator. The main distinctions of this theory from standard theory will occur at super high energies. New poles and resonances which arise from new endpoint singularities will be found. The locations of these singularities will be frame dependent. Some of these singularities will correspond to creations or interactions of the normal particles with tachyons. It will be shown that for the one loop diagram, the form of the cutoff singularities are closely related to the standard singularities. When there is more than one loop, there can appear some new type of behavior. In particular, a cube root type of behavior in the two loop self-energy diagram will be found. Also the asymptotic behavior of the ladder diagram is studied

Decoupling, effective Lagrangian, and gauge hierarchy in spontaneously broken non-Abelian gauge theories

International Nuclear Information System (INIS)

Kazama, Y.; Yao, Y.

1982-01-01

In spontaneously broken non-Abelian gauge theories which admit gauge hierarchy at the tree level, we show, to all orders in perturbation theory, that (i) the superheavy particles decouple from the light sector at low energies, (ii) an effective low-energy renormalizable theory emerges together with appropriate counterterms, and (iii) the gauge hierarchy can be consistently maintained in the presence of radiative corrections. These assertions are explicitly demonstrated for O(3) gauge theory with two triplets of Higgs particles in a manner easily applicable to more realistic grand unified theories. Furthermore, as a by-product of our analysis, we obtain a systematic method of computing the parameters of the effective low-energy theory via renormalization-group equations to any desired accuracy

Higher fractions theory of fractional hall effect

International Nuclear Information System (INIS)

Kostadinov, I.Z.; Popov, V.N.

1985-07-01

A theory of fractional quantum Hall effect is generalized to higher fractions. N-particle model interaction is used and the gap is expressed through n-particles wave function. The excitation spectrum in general and the mean field critical behaviour are determined. The Hall conductivity is calculated from first principles. (author)

Load theory behind the wheel; perceptual and cognitive load effects.

Science.gov (United States)

Murphy, Gillian; Greene, Ciara M

2017-09-01

Perceptual Load Theory has been proposed as a resolution to the longstanding early versus late selection debate in cognitive psychology. There is much evidence in support of Load Theory but very few applied studies, despite the potential for the model to shed light on everyday attention and distraction. Using a driving simulator, the effect of perceptual and cognitive load on drivers' visual search was assessed. The findings were largely in line with Load Theory, with reduced distractor processing under high perceptual load, but increased distractor processing under high cognitive load. The effect of load on driving behaviour was also analysed, with significant differences in driving behaviour under perceptual and cognitive load. In addition, the effect of perceptual load on drivers' levels of awareness was investigated. High perceptual load significantly increased inattentional blindness and deafness, for stimuli that were both relevant and irrelevant to driving. High perceptual load also increased RTs to hazards. The current study helps to advance Load Theory by illustrating its usefulness outside of traditional paradigms. There are also applied implications for driver safety and roadway design, as the current study suggests that perceptual and cognitive load are important factors in driver attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cancellation of renormalon ambiguities in the heavy quark effective theory

International Nuclear Information System (INIS)

Neubert, M.; Sachrajda, C.T.

1995-01-01

Recently, it has been shown that the concept of the pole mass of a heavy quark becomes ambiguous beyond perturbation theory, because of the presence of infrared renormalons. We argue that the predictions of the heavy quark effective theory, whose construction is based on the pole mass, are free of such ambiguities. In the 1/m Q expansion of physical quantities, infrared and ultraviolet renormalons compensate each other between coefficient functions and matrix elements. We trace the appearance of these compensations for current-induced exclusive heavy-to-heavy and heavy-to-light transitions, and for inclusive decays of heavy hadrons. In particular, we show that the structure of the heavy quark expansion is not obscured by renormalons, and none of the predictions of the heavy quark effective theory are invalidated. ((orig.))

The Faraday effect revisited General theory

CERN Document Server

Cornean, H D; Pedersen, T G

2005-01-01

This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse conductivity can be explicitly computed and coincides with the classical result. In the general case, using magnetic perturbation theory, the conductivity tensor is expanded in powers of the strength of the magnetic field $B$. Then the linear term in $B$ of this expansion is written down in terms of the zero magnetic field Green function and the zero field current operator. In the periodic case, the linear term in $B$ of the conductivity tensor is expressed in terms of zero magnetic field Bloch functions and energies. No derivatives with respect to the quasimomentum appear and thereby all ambiguities are removed, in contrast to earlier work.

Hyperons in nuclear matter from SU(3) chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Petschauer, S.; Kaiser, N. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Haidenbauer, J. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Meissner, Ulf G. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Villa Tambosi, ECT, Villazzano (Trento) (Italy)

2016-01-15

Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. (orig.)

Off-shell renormalization in Higgs effective field theories

Science.gov (United States)

Binosi, Daniele; Quadri, Andrea

2018-04-01

The off-shell one-loop renormalization of a Higgs effective field theory possessing a scalar potential ˜ {({Φ}^{\\dagger}Φ -υ^2/2)}^N with N arbitrary is presented. This is achieved by renormalizing the theory once reformulated in terms of two auxiliary fields X 1,2, which, due to the invariance under an extended Becchi-Rouet-Stora-Tyutin symmetry, are tightly constrained by functional identities. The latter allow in turn the explicit derivation of the mapping onto the original theory, through which the (divergent) multi-Higgs amplitude are generated in a purely algebraic fashion. We show that, contrary to naive expectations based on the loss of power counting renormalizability, the Higgs field undergoes a linear Standard Model like redefinition, and evaluate the renormalization of the complete set of Higgs self-coupling in the N → ∞ case.

Effective theory of rotationally faulted multilayer graphene - the local limit

International Nuclear Information System (INIS)

Kindermann, M; First, P N

2012-01-01

Interlayer coupling in rotationally faulted graphene multilayers breaks the local sublattice-symmetry of the individual layers. Earlier we have presented a theory of this mechanism, which reduces to an effective Dirac model with space-dependent mass in an important limit. It thus makes a wealth of existing knowledge available for the study of rotationally faulted graphene multilayers. Agreement of this theory with a recent experiment in a strong magnetic field was demonstrated. Here we explore some of the predictions of this theory for the system in zero magnetic field at large interlayer bias, when it becomes local in space. We use that theory to illuminate the physics of localization and velocity renormalization in twisted graphene layers. (paper)

When are stakeholder pressures effective? An extension of slack resources theory

NARCIS (Netherlands)

Xiao, Chengyong; Wang, Qian; van Donk, Dirk Pieter; van der Vaart, T.

There has been an intense debate on when stakeholder pressures are effective in driving firms to contribute to sustainable development. Drawing upon institutional theory and slack resources theory, we theorize that country-level sustainability performance interacts with slack resources in shaping

State of Theory and Computer Simulations of Radiation Effects in Ceramics

International Nuclear Information System (INIS)

Corrales, Louis R.; Weber, William J.

2003-01-01

This article presents opinions based on the presentations and discussions at a Workshop on Theory and Computer Simulations of Radiation Effects in Ceramics held in August 2002 at Pacific Northwest National Laboratory in Richland, WA, USA. The workshop was focused on the current state-of-the-art of theory, modeling and simulation of radiation effects in oxide ceramics, directions for future breakthroughs, and creating a close integration with experiment

The effective field theory of cosmological large scale structures

Energy Technology Data Exchange (ETDEWEB)

Carrasco, John Joseph M. [Stanford Univ., Stanford, CA (United States); Hertzberg, Mark P. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Senatore, Leonardo [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

2012-09-20

Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c²_s ≈ 10^–6c² and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)⁴. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc^–1.

The effective field theory of dark matter direct detection

Energy Technology Data Exchange (ETDEWEB)

Fitzpatrick, A. Liam; Haxton, Wick; Katz, Emanuel; Lubbers, Nicholas; Xu, Yiming

2013-02-01

We extend and explore the general non-relativistic effective theory of dark matter (DM) direct detection. We describe the basic non-relativistic building blocks of operators and discuss their symmetry properties, writing down all Galilean-invariant operators up to quadratic order in momentum transfer arising from exchange of particles of spin 1 or less. Any DM particle theory can be translated into the coefficients of an effective operator and any effective operator can be simply related to most general description of the nuclear response. We find several operators which lead to novel nuclear responses. These responses differ significantly from the standard minimal WIMP cases in their relative coupling strengths to various elements, changing how the results from different experiments should be compared against each other. Response functions are evaluated for common DM targets — F, Na, Ge, I, and Xe — using standard shell model techniques. We point out that each of the nuclear responses is familiar from past studies of semi-leptonic electroweak interactions, and thus potentially testable in weak interaction studies. We provide tables of the full set of required matrix elements at finite momentum transfer for a range of common elements, making a careful and fully model-independent analysis possible. Finally, we discuss embedding non-relativistic effective theory operators into UV models of dark matter.

Effective field theory and tunneling currents in the fractional quantum Hall effect

International Nuclear Information System (INIS)

Bieri, Samuel; Fröhlich, Jürg

2012-01-01

We review the construction of a low-energy effective field theory and its state space for “abelian” quantum Hall fluids. The scaling limit of the incompressible fluid is described by a Chern–Simons theory in 2+1 dimensions on a manifold with boundary. In such a field theory, gauge invariance implies the presence of anomalous chiral modes localized on the edge of the sample. We assume a simple boundary structure, i.e., the absence of a reconstructed edge. For the bulk, we consider a multiply connected planar geometry. We study tunneling processes between two boundary components of the fluid and calculate the tunneling current to lowest order in perturbation theory as a function of dc bias voltage. Particular attention is paid to the special cases when the edge modes propagate at the same speed, and when they exhibit two significantly distinct propagation speeds. We distinguish between two “geometries” of interference contours corresponding to the (electronic) Fabry–Perot and Mach–Zehnder interferometers, respectively. We find that the interference term in the current is absent when exactly one hole in the fluid corresponding to one of the two edge components involved in the tunneling processes lies inside the interference contour (i.e., in the case of a Mach–Zehnder interferometer). We analyze the dependence of the tunneling current on the state of the quantum Hall fluid and on the external magnetic flux through the sample. - Highlights: ► We review and extend on the field theoretic construction of the FQHE. ► We calculate tunneling currents between different edge components of a sample. ► We find an absence of interference terms in the currents for some sample geometries. ► No observable Aharonov–Bohm effect is found as the magnetic field is varied. ► Deformation of the edge leads to observable Aharonov–Bohm effect in the currents.

Aspects of statistical spectroscopy relevant to effective-interaction theory

International Nuclear Information System (INIS)

French, J.B.

1975-01-01

The three aspects of statistical spectroscopy discussed in this paper are the information content of complex spectra: procedures for spectroscopy in huge model spaces, useful in effective-interaction theory; and practical ways of identifying and calculating measurable parameters of the effective Hamiltonian and other operators, and of comparing different effective Hamiltonians. (4 figures) (U.S.)

Band mixing effects in mean field theories

International Nuclear Information System (INIS)

Kuyucak, S.; Morrison, I.

1989-01-01

The 1/N expansion method, which is an angular momentum projected mean field theory, is used to investigate the nature of electromagnetic transitions in the interacting boson model (IBM). Conversely, comparison with the exact IBM results sheds light on the range of validity of the mean field theory. It is shown that the projected mean field results for the E2 transitions among the ground, β and γ bands are incomplete for the spin dependent terms and it is essential to include band mixing effect for a correct (Mikhailov) analysis of E2 data. The algebraic expressions derived are general and will be useful in the analysis of experimental data in terms of both the sd and sdg boson models. 17 refs., 7 figs., 8 tabs

Effective action of softly broken supersymmetric theories

International Nuclear Information System (INIS)

Groot Nibbelink, S.; Nyawelo, T.S

2006-12-01

We study the renormalization of (softly) broken supersymmetric theories at the one loop level in detail. We perform this analysis in a superspace approach in which the supersymmetry breaking interactions are parameterized using spurion insertions. We comment on the uniqueness of this parameterization. We compute the one loop renormalization of such theories by calculating superspace vacuum graphs with multiple spurion insertions. To preform this computation efficiently we develop algebraic properties of spurion operators, that naturally arise because the spurions are often surrounded by superspace projection operators. Our results are general apart from the restrictions that higher super covariant derivative terms and some finite effects due to non-commutativity of superfield dependent mass matrices are ignored. One of the soft potentials induces renormalization of the Kaehler potential. (author)

Effective-field theories for heavy quarkonium

International Nuclear Information System (INIS)

Brambilla, Nora; Pineda, Antonio; Soto, Joan; Vairo, Antonio

2005-01-01

This article reviews recent theoretical developments in heavy-quarkonium physics from the point of view of effective-field theories of QCD. We discuss nonrelativistic QCD and concentrate on potential nonrelativistic QCD. The main goal will be to derive Schroedinger equations based on QCD that govern heavy-quarkonium physics in the weak- and strong-coupling regimes. Finally, the review discusses a selected set of applications, which include spectroscopy, inclusive decays, and electromagnetic threshold production

Theory of critical phenomena in finite-size systems scaling and quantum effects

CERN Document Server

Brankov, Jordan G; Tonchev, Nicholai S

2000-01-01

The aim of this book is to familiarise the reader with the rich collection of ideas, methods and results available in the theory of critical phenomena in systems with confined geometry. The existence of universal features of the finite-size effects arising due to highly correlated classical or quantum fluctuations is explained by the finite-size scaling theory. This theory (1) offers an interpretation of experimental results on finite-size effects in real systems; (2) gives the most reliable tool for extrapolation to the thermodynamic limit of data obtained by computer simulations; (3) reveals

Low energy effective Lagrangians in open superstring theory

International Nuclear Information System (INIS)

Medina, Ricardo

2008-01-01

The low energy effective Lagrangian describes the interactions of the massless modes of String Theory. Present work is being done to obtain all alpha' 3 terms (bosonic and fermionic) by means of the known 5-point amplitudes and SUSY

DsixTools: the standard model effective field theory toolkit

Energy Technology Data Exchange (ETDEWEB)

Celis, Alejandro [Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Arnold Sommerfeld Center for Theoretical Physics, Munich (Germany); Fuentes-Martin, Javier; Vicente, Avelino [Universitat de Valencia-CSIC, Instituto de Fisica Corpuscular, Valencia (Spain); Virto, Javier [University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland)

2017-06-15

We present DsixTools, a Mathematica package for the handling of the dimension-six standard model effective field theory. Among other features, DsixTools allows the user to perform the full one-loop renormalization group evolution of the Wilson coefficients in the Warsaw basis. This is achieved thanks to the SMEFTrunner module, which implements the full one-loop anomalous dimension matrix previously derived in the literature. In addition, DsixTools also contains modules devoted to the matching to the ΔB = ΔS = 1, 2 and ΔB = ΔC = 1 operators of the Weak Effective Theory at the electroweak scale, and their QCD and QED Renormalization group evolution below the electroweak scale. (orig.)

Nuclear Lattice Simulations with Chiral Effective Field Theory

OpenAIRE

Lee, Dean

2008-01-01

We present recent results on lattice simulations using chiral effective field theory. In particular we discuss lattice simulations for dilute neutron matter at next-to-leading order and three-body forces in light nuclei at next-to-next-to-leading order.

Heavy quark effective theory and heavy baryon transitions

International Nuclear Information System (INIS)

Hussain, F.

1992-01-01

The heavy quark effective theory (HQET) is applied to study the weak decay of heavy mesons and heavy baryons and to predict the form factors for heavy to heavy and heavy to light transitions. 28 refs, 10 figs, 2 tabs

Effective theory of the D = 3 center vortex ensemble

Science.gov (United States)

Oxman, L. E.; Reinhardt, H.

2018-03-01

By means of lattice calculations, center vortices have been established as the infrared dominant gauge field configurations of Yang-Mills theory. In this work, we investigate an ensemble of center vortices in D = 3 Euclidean space-time dimension where they form closed flux loops. To account for the properties of center vortices detected on the lattice, they are equipped with tension, stiffness and a repulsive contact interaction. The ensemble of oriented center vortices is then mapped onto an effective theory of a complex scalar field with a U(1) symmetry. For a positive tension, small vortex loops are favoured and the Wilson loop displays a perimeter law while for a negative tension, large loops dominate the ensemble. In this case the U(1) symmetry of the effective scalar field theory is spontaneously broken and the Wilson loop shows an area law. To account for the large quantum fluctuations of the corresponding Goldstone modes, we use a lattice representation, which results in an XY model with frustration, for which we also study the Villain approximation.

THREE THEORIES OF COGNITIVE REPRESENTATION AND CRITERIA FOR EVALUATING TRAINING EFFECTS

NARCIS (Netherlands)

Tomic, W.; Kingma, J.

2008-01-01

The development of cognitive representation is the main theme of the three classic theories on how children learn new concepts (Piaget, Bruner, Vygotsky). However, these theories do not agree on evaluation standards for training effectiveness. According to Piaget, it is only when stringent criteria

An effective theory of massive gauge bosons

International Nuclear Information System (INIS)

Doria, R.M.; Helayel Neto, J.A.

1986-01-01

The coupling of a group-valued massive scalar field to a gauge field through a symmetric rank-2 field strenght is studied. By considering energies very small compared with the mass of the scalar and invoking the decoupling theorem, one is left with a low-energy effective theory describing a dynamics of massive vector fields. (Author) [pt

Cognitive Load Theory and the Effects of Transient Information on the Modality Effect

Science.gov (United States)

Leahy, Wayne; Sweller, John

2016-01-01

Based on cognitive load theory and the "transient information effect," this paper investigated the "modality effect" while interpreting a contour map. The length and complexity of auditory and visual text instructions were manipulated. Experiment 1 indicated that longer audio text information within a presentation was inferior…

The Effect of Religion on Ethnic Tolerance in Malaysia: The Application of Rational Choice Theory (RCT) and the Theory of Planned Behaviour (TPB)

Science.gov (United States)

Idris, Fazilah; Abdullah, Mohd Richard Neles; Ahmad, Abdul Razak; Mansor, Ahmad Zamri

2016-01-01

There has been little research done on explaining the ethnic tolerance behavior from the perspective of sociological theories. The authors chose rational choice theory and the theory of planned behavior as they are widely used in explaining the human social behaviour. In this article, the theories are used to explain the effects of religion on…

The Magnus Effect in Theory and in Reality

Science.gov (United States)

Ahlborn, F

1930-01-01

A discussion of the Flettner rotor is presented from a nautical and economic viewpoint, and although it was a failure, the experimental and theoretical inventions cannot be disregarded. The following critical and experimental investigation will show the relations and applicability of the theories and practical applications. The Magnus effect is described in detail and a discussion and critical review of the Magnus effect is included.

Effective theories of single field inflation when heavy fields matter

CERN Document Server

Achucarro, Ana; Hardeman, Sjoerd; Palma, Gonzalo A; Patil, Subodh P

2012-01-01

We compute the low energy effective field theory (EFT) expansion for single-field inflationary models that descend from a parent theory containing multiple other scalar fields. By assuming that all other degrees of freedom in the parent theory are sufficiently massive relative to the inflaton, it is possible to derive an EFT valid to arbitrary order in perturbations, provided certain generalized adiabaticity conditions are respected. These conditions permit a consistent low energy EFT description even when the inflaton deviates off its adiabatic minimum along its slowly rolling trajectory. By generalizing the formalism that identifies the adiabatic mode with the Goldstone boson of this spontaneously broken time translational symmetry prior to the integration of the heavy fields, we show that this invariance of the parent theory dictates the entire non-perturbative structure of the descendent EFT. The couplings of this theory can be written entirely in terms of the reduced speed of sound of adiabatic perturbat...

Effective theories in physics. From planetary orbits to elementary particle masses

International Nuclear Information System (INIS)

Wells, James D.

2012-01-01

There is significant interest in the Philosophy of Science community to understand the role that ''effective theories'' have in the work of forefront science. The ideas of effective theories have been implicit in science for a long time, but have only been articulated well in the last few decades. Since Wilson's renormalization group revolution in the early 1970's, the science community has come to more fully understand its power, and by the mid-1990's it had gained its apotheosis. It is still one of the most powerful concepts in science, which has direct impact in how one thinks about and formulates theories of nature. It is this power that this Brief sets out to emphasize through historical analysis and current examples.

Effective theories in physics from planetary orbits to elementary particle masses

CERN Document Server

Wells, James D

2012-01-01

There is significant interest in the Philosophy of Science community to understand the role that "effective theories" have in the work of forefront science. The ideas of effective theories have been implicit in science for a long time, but have only been articulated well in the last few decades. Since Wilson's renormalization group revolution in the early 1970's, the science community has come to more fully understand its power, and by the mid-1990's it had gained its apotheosis. It is still one of the most powerful concepts in science, which has direct impact in how one thinks about and formulates theories of nature. It is this power that this Brief sets out to emphasize through historical analysis and current examples.

The effective QCD theory at low energy; La theorie effective de QCD a basse energie

Energy Technology Data Exchange (ETDEWEB)

Knecht, M. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

1995-12-31

Quantum chromodynamics is studied here in the range of low energies. The Chiral perturbation theory is presented, this theory is based on a thorough study of QCD symmetry, of general field theory principles and of S-matrices. Ward identities are defined within the scope of current algebras and by using functional method. Their consequences on Chiral structure of QCD emptiness and on strong interaction at low energies are studied. The pion-pion diffusion at low energies is treated as an example. (A.C.) 70 refs.

Effective field theory and integrability in two-dimensional Mott transition

International Nuclear Information System (INIS)

Bottesi, Federico L.; Zemba, Guillermo R.

2011-01-01

Highlights: → Mott transition in 2d lattice fermion model. → 3D integrability out of 2D. → Effective field theory for Mott transition in 2d. → Double Chern-Simons. → d-Density waves. - Abstract: We study the Mott transition in a two-dimensional lattice spinless fermion model with nearest neighbors density-density interactions. By means of a two-dimensional Jordan-Wigner transformation, the model is mapped onto the lattice XXZ spin model, which is shown to possess a quantum group symmetry as a consequence of a recently found solution of the Zamolodchikov tetrahedron equation. A projection (from three to two space-time dimensions) property of the solution is used to identify the symmetry of the model at the Mott critical point as U q (sl(2)-circumflex)xU q (sl(2)-circumflex), with deformation parameter q = -1. Based on this result, the low-energy effective field theory for the model is obtained and shown to be a lattice double Chern-Simons theory with coupling constant k = 1 (with the standard normalization). By further employing the effective filed theory methods, we show that the Mott transition that arises is of topological nature, with vortices in an antiferromagnetic array and matter currents characterized by a d-density wave order parameter. We also analyze the behavior of the system upon weak coupling, and conclude that it undergoes a quantum gas-liquid transition which belongs to the Ising universality class.

Fluctuations effects in diblock copolymer fluids: Comparison of theories and experiment

International Nuclear Information System (INIS)

Guenza, M.; Schweizer, K.S.

1997-01-01

The analytic Polymer Reference Interaction Site Model (PRISM) theory of structurally and interaction symmetric Gaussian diblock copolymer fluids is reformulated, extended, and applied to make predictions for experimentally observable equilibrium properties of the disordered state. These include the temperature, degree of polymerization, copolymer composition, and polymer density or concentration dependences of the peak scattering intensity, effective chi-parameter, and heat capacity. The location of the order-disorder transition is empirically estimated based on the disordered, strongly fluctuating state scattering function. Detailed numerical applications of PRISM theory demonstrates it provides an excellent description of the data. An in depth comparison of the mathematical structure and predictions of PRISM theory with the highly coarse-grained, incompressible Brazovski endash Leibler endash Fredrickson endash Helfand (BLFH) fluctuation corrected field theory is also carried out. Under some conditions (nearly symmetric composition, high melt densities, moderate temperatures) there are striking mathematical similarities between the predictions of the physically very different theories, although quantitative differences always persist. However, for strongly asymmetric copolymer compositions, short chains, compressible copolymer solutions, and low temperatures many qualitative differences emerge. The possibility of multiple, self-consistent fluctuation feedback mechanisms within the most general PRISM approach are identified, their qualitative features discussed, and contrasted with alternative versions of the fluctuation-corrected incompressible field theories due to BLFH and Stepanow. The predictions of PRISM and BLFH theory for the composition, copolymer density, temperature, and molecular weight dependence of the effective chi-parameter are presented and qualitatively compared with recent experiments. copyright 1997 American Institute of Physics

Higgs effective field theories. Systematics and applications

Energy Technology Data Exchange (ETDEWEB)

Krause, Claudius G.

2016-07-28

Researchers of the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) announced on July 4th, 2012, the observation of a new particle. The properties of the particle agree, within the relatively large experimental uncertainties, with the properties of the long-sought Higgs boson. Particle physicists around the globe are now wondering, ''Is it the Standard Model Higgs that we observe; or is it another particle with similar properties?'' We employ effective field theories (EFTs) for a general, model-independent description of the particle. We use a few, minimal assumptions - Standard Model (SM) particle content and a separation of scales to the new physics - which are supported by current experimental results. By construction, effective field theories describe a physical system only at a certain energy scale, in our case at the electroweak-scale v. Effects of new physics from a higher energy-scale, Λ, are described by modified interactions of the light particles. In this thesis, ''Higgs Effective Field Theories - Systematics and Applications'', we discuss effective field theories for the Higgs particle, which is not necessarily the Higgs of the Standard Model. In particular, we focus on a systematic and consistent expansion of the EFT. The systematics depends on the dynamics of the new physics. We distinguish two different consistent expansions. EFTs that describe decoupling new-physics effects and EFTs that describe non-decoupling new-physics effects. We briefly discuss the first case, the SM-EFT. The focus of this thesis, however, is on the non-decoupling EFTs. We argue that the loop expansion is the consistent expansion in the second case. We introduce the concept of chiral dimensions, equivalent to the loop expansion. Using the chiral dimensions, we expand the electroweak chiral Lagrangian up to next-to-leading order, O(f{sup 2}/Λ{sup 2})=O(1/16π{sup 2}). Further, we discuss how different

Distinguishing f(R) theories from general relativity by gravitational lensing effect

Energy Technology Data Exchange (ETDEWEB)

Liu, Hongguang [Beijing Normal University, Department of Physics, Beijing (China); Aix Marseille Universite et Universite de Toulon, Centre de Physique Theorique (UMR 7332), Marseille (France); Wang, Xin; Li, Haida; Ma, Yongge [Beijing Normal University, Department of Physics, Beijing (China)

2017-11-15

The post-Newtonian formulation of a general class of f(R) theories is set up in a third-order approximation. It turns out that the information of a specific form of f(R) gravity is encoded in the Yukawa potential, which is contained in the perturbative expansion of the metric components. Although the Yukawa potential is canceled in the second-order expression of the effective refraction index of light, detailed analysis shows that the difference of the lensing effect between the f(R) gravity and general relativity does appear at the third order when √(f''(0)/f{sup '}(0)) is larger than the distance d{sub 0} to the gravitational source. However, the difference between these two kinds of theories will disappear in the axially symmetric spacetime region. Therefore only in very rare case the f(R) theories are distinguishable from general relativity by gravitational lensing effect in a third-order post-Newtonian approximation. (orig.)

Systematic improvement of parton showers with effective theory

International Nuclear Information System (INIS)

Baumgart, Matthew; Marcantonini, Claudio; Stewart, Iain W.

2011-01-01

We carry out a systematic classification and computation of next-to-leading order kinematic power corrections to the fully differential cross section in the parton shower. To do this we devise a map between ingredients in a parton shower and operators in a traditional effective field theory framework using a chain of soft-collinear effective theories. Our approach overcomes several difficulties including avoiding double counting and distinguishing approximations that are coordinate choices from true power corrections. Branching corrections can be classified as hard-scattering, that occur near the top of the shower, and jet-structure, that can occur at any point inside it. Hard-scattering corrections include matrix elements with additional hard partons, as well as power suppressed contributions to the branching for the leading jet. Jet-structure corrections require simultaneous consideration of potential 1→2 and 1→3 branchings. The interference structure induced by collinear terms with subleading powers remains localized in the shower.

The faster-X effect: integrating theory and data.

Science.gov (United States)

Meisel, Richard P; Connallon, Tim

2013-09-01

Population genetics theory predicts that X (or Z) chromosomes could play disproportionate roles in speciation and evolutionary divergence, and recent genome-wide analyses have identified situations in which X or Z-linked divergence exceeds that on the autosomes (the so-called 'faster-X effect'). Here, we summarize the current state of both the theory and data surrounding the study of faster-X evolution. Our survey indicates that the faster-X effect is pervasive across a taxonomically diverse array of evolutionary lineages. These patterns could be informative of the dominance or recessivity of beneficial mutations and the nature of genetic variation acted upon by natural selection. We also identify several aspects of disagreement between these empirical results and the population genetic models used to interpret them. However, there are clearly delineated aspects of the problem for which additional modeling and collection of genomic data will address these discrepancies and provide novel insights into the population genetics of adaptation. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Lamb shift in muonic hydrogen and the proton radius from effective field theories

Energy Technology Data Exchange (ETDEWEB)

Peset, Clara; Pineda, Antonio [Universitat Autonoma de Barcelona, Grup de Fisica Teorica, Dept. Fisica and IFAE, Bellaterra (Barcelona) (Spain)

2015-12-15

We comprehensively analyse the theoretical prediction for the Lamb shift in muonic hydrogen, and the associated determination of the proton radius. We use effective field theories. This allows us to relate the proton radius with well-defined objects in quantum field theory, eliminating unnecessary model dependence. The use of effective field theories also helps us to organize the computation so that we can clearly state the parametric accuracy of the result. In this paper we review all (and check several of) the contributions to the energy shift of order α{sup 5}, as well as those that scale like α{sup 6} x logarithms in the context of non-relativistic effective field theories of QED. (orig.)

Hyperon-nucleon interactions - a chiral effective field theory approach

NARCIS (Netherlands)

Polinder, H.; Haidenbauer, J.; Meissner, U.G.

2006-01-01

We construct the leading order hyperon–nucleon potential in chiral effective field theory. We show that a good description of the available data is possible and discuss briefly further improvements of this scheme

Analysis of General Power Counting Rules in Effective Field Theory

CERN Document Server

Gavela, B M; Manohar, A V; Merlo, L

2016-01-01

We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.

Extended Soliton Solutions in an Effective Action for SU(2 Yang-Mills Theory

Directory of Open Access Journals (Sweden)

Nobuyuki Sawado

2006-01-01

Full Text Available The Skyrme-Faddeev-Niemi (SFN model which is an O(3 σ model in three dimensional space up to fourth-order in the first derivative is regarded as a low-energy effective theory of SU(2 Yang-Mills theory. One can show from the Wilsonian renormalization group argument that the effective action of Yang-Mills theory recovers the SFN in the infrared region. However, the theory contains an additional fourth-order term which destabilizes the soliton solution. We apply the perturbative treatment to the second derivative term in order to exclude (or reduce the ill behavior of the original action and show that the SFN model with the second derivative term possesses soliton solutions.

EFFECTIVE ACTIONS FOR HETEROTIC STRING THEORY

NARCIS (Netherlands)

SUELMANN, H

Heterotic String Theory is an attempt to construct a description of nature that is more satisfying than the Standard Model. A major problem is that it is very difficult to do explicit calculations in string theory. Therefore, it is useful to construct a 'normal' field theory that approximates HST.

Theory of inelastic effects in resonant atom-surface scattering

International Nuclear Information System (INIS)

Evans, D.K.

1983-01-01

The progress of theoretical and experimental developments in atom-surface scattering is briefly reviewed. The formal theory of atom-surface resonant scattering is reviewed and expanded, with both S and T matrix approaches being explained. The two-potential formalism is shown to be useful for dealing with the problem in question. A detailed theory based on the S-matrix and the two-potential formalism is presented. This theory takes account of interactions between the incident atoms and the surface phonons, with resonant effects being displayed explicitly. The Debye-Waller attenuation is also studied. The case in which the atom-surface potential is divided into an attractive part V/sub a/ and a repulsive part V/sub r/ is considered at length. Several techniques are presented for handling the scattering due to V/sub r/, for the case in which V/sub r/ is taken to be the hard corrugated surface potential. The theory is used to calculate the scattered intensities for the system 4 He/LiF(001). A detailed comparison with experiment is made, with polar scans, azimuthal scans, and time-of-flight measurements being considered. The theory is seen to explain the location and signature of resonant features, and to provide reasonable overall agreement with the experimental results

Designing theoretically-informed implementation interventions: Fine in theory, but evidence of effectiveness in practice is needed

Directory of Open Access Journals (Sweden)

Reeves Scott

2006-02-01

Full Text Available Abstract The Improved Clinical Effectiveness through Behavioural Research Group (ICEBeRG authors assert that a key weakness in implementation research is the unknown applicability of a given intervention outside its original site and problem, and suggest that use of explicit theory offers an effective solution. This assertion is problematic for three primary reasons. First, the presence of an underlying theory does not necessarily ease the task of judging the applicability of a piece of empirical evidence. Second, it is not clear how to translate theory reliably into intervention design, which undoubtedly involves the diluting effect of "common sense." Thirdly, there are many theories, formal and informal, and it is not clear why any one should be given primacy. To determine whether explicitly theory-based interventions are, on average, more effective than those based on implicit theories, pragmatic trials are needed. Until empirical evidence is available showing the superiority of theory-based interventions, the use of theory should not be used as a basis for assessing the value of implementation studies by research funders, ethics committees, editors or policy decision makers.

Transmission Creep: Media Effects Theories and Journalism Studies in a Digital Era

OpenAIRE

Singer, J.

2016-01-01

The nature of digital media challenges the explanatory power of effects theories that rest on a transmission model of communication. As essentially linear conceptualizations reliant on identification and measurement of discrete message components, these twentieth-century theories are poorly suited to contemporary journalistic structures and forms. This article adds to the call for a more richly theorized concept of relationship effects suitable to an immersive, iterative, and interconnected e...

A note on the effective medium theory of random resistive-reactive medium

International Nuclear Information System (INIS)

Kumar, N.; Jayannavar, A.M.

1981-06-01

The effective medium theory for a system with randomly distributed point conductivity and polarizability is re-formulated, with attention to cross-terms involving the two disorder parameters. The treatment reveals a certain inconsistency of the conventional theory owing to the neglect of the Maxwell-Wagner effect. The results are significant for the critical resistivity and dielectric anomalies of a binary liquid mixture at the phase-separation point. (author)

Generalized string theory mapping relations between gravity and gauge theory

International Nuclear Information System (INIS)

Bjerrum-Bohr, N.E.J.

2003-01-01

A previous study of the Kawai, Lewellen and Tye (KLT) relations between gravity and gauge theories, imposed by the relationship of closed and open strings, are here extended in the light of general relativity and Yang-Mills theory as effective field theories. We discuss the possibility of generalizing the traditional KLT mapping in this effective setting. A generalized mapping between the effective Lagrangians of gravity and Yang-Mills theory is presented, and the corresponding operator relations between gauge and gravity theories at the tree level are further explored. From this generalized mapping remarkable diagrammatic relations are found, linking diagrams in gravity and Yang-Mills theory, as well as diagrams in pure effective Yang-Mills theory. Also the possibility of a gravitational coupling to an antisymmetric field in the gravity scattering amplitude is considered, and shown to allow for mixed open-closed string solutions, i.e., closed heterotic strings

Integrability in heavy quark effective theory

Science.gov (United States)

Braun, Vladimir M.; Ji, Yao; Manashov, Alexander N.

2018-06-01

It was found that renormalization group equations in the heavy-quark effective theory (HQET) for the operators involving one effective heavy quark and light degrees of freedom are completely integrable in some cases and are related to spin chain models with the Hamiltonian commuting with the nondiagonal entry C( u) of the monodromy matrix. In this work we provide a more complete mathematical treatment of such spin chains in the QISM framework. We also discuss the relation of integrable models that appear in the HQET context with the large-spin limit of integrable models in QCD with light quarks. We find that the conserved charges and the "ground state" wave functions in HQET models can be obtained from the light-quark counterparts in a certain scaling limit.

The MSSM without gluinos; an effective field theory for the stop sector

Energy Technology Data Exchange (ETDEWEB)

Aebischer, Jason; Greub, Christoph [University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Crivellin, Andreas [Paul Scherrer Institut (PSI), Villigen (Switzerland); Yamada, Youichi [Tohoku University, Department of Physics, Sendai (Japan)

2017-11-15

In this article we study the MSSM with stops and Higgs scalars much lighter than gluinos and squarks of the first two generations. In this setup, one should use an effective field theory with partial supersymmetry in which the gluino and heavy squarks are integrated out in order to connect SUSY parameters (given at a high scale) to observables in the stop sector. In the construction of this effective theory, valid below the gluino mass scale, we take into account O(α{sub 3}) and O(Y{sub t,b}{sup 2}) effects and calculate the matching as well as the renormalization group evolution. As a result, the running of the parameters for the stop sector is modified with respect to the full MSSM and SUSY relations between parameters are broken. We show that for some couplings sizable numerical differences exist between the effective field theory approach and the naive calculation based on the MSSM running. (orig.)

Precision constraints on the top-quark effective field theory at future lepton colliders

Energy Technology Data Exchange (ETDEWEB)

Durieux, Gauthier

2017-08-15

We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the e{sup +}e{sup -}→bW{sup +} anti bW{sup -} process. Statistically optimal observables are exploited to constrain simultaneously and efficiently all relevant operators. Their constraining power is sufficient for quadratic effective-field-theory contributions to have negligible impact on limits which are therefore basis independent. This is contrasted with the measurements of cross sections and forward-backward asymmetries. An overall measure of constraints strength, the global determinant parameter, is used to determine which run parameters impose the strongest restriction on the multidimensional effective-field-theory parameter space.

Precision constraints on the top-quark effective field theory at future lepton colliders

International Nuclear Information System (INIS)

Durieux, Gauthier

2017-08-01

We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the e + e - →bW + anti bW - process. Statistically optimal observables are exploited to constrain simultaneously and efficiently all relevant operators. Their constraining power is sufficient for quadratic effective-field-theory contributions to have negligible impact on limits which are therefore basis independent. This is contrasted with the measurements of cross sections and forward-backward asymmetries. An overall measure of constraints strength, the global determinant parameter, is used to determine which run parameters impose the strongest restriction on the multidimensional effective-field-theory parameter space.

2PI effective action for the SYK model and tensor field theories

Science.gov (United States)

Benedetti, Dario; Gurau, Razvan

2018-05-01

We discuss the two-particle irreducible (2PI) effective action for the SYK model and for tensor field theories. For the SYK model the 2PI effective action reproduces the bilocal reformulation of the model without using replicas. In general tensor field theories the 2PI formalism is the only way to obtain a bilocal reformulation of the theory, and as such is a precious instrument for the identification of soft modes and for possible holographic interpretations. We compute the 2PI action for several models, and push it up to fourth order in the 1 /N expansion for the model proposed by Witten in [1], uncovering a one-loop structure in terms of an auxiliary bilocal action.

Theory of geomagnetic effects of cosmic rays: its past and presence

Energy Technology Data Exchange (ETDEWEB)

Gall, R [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Geofisica

1981-03-01

The interest expressed by Lemaitre and Vallarta in the nature of universal corpuscular radiation, remnant of the exploded primogenitive atom, culminated in 1932, in the development of their theory of the geomagnetic effects of cosmic rays, a tool since its publication, basic to cosmic radiation research and to the advancement of cosmic ray astronomy. Between 1940 and 1960 challenging experimental data from proliferating cosmic radiation stations and of direct detection techniques provided geomagnetic field models for greater theoretical precision. The discoveries since the advent of the space age of the Earth's cavity and geomagnetic tail, and of the nonrelativistic solar cosmic rays have resulted in a new branch of the theory dealing with magnetosphere effects in the propagation of low energy cosmic radiations. The theory's importance and application to cosmic bodies other than the Earth is discussed.

Hyperons in nuclear matter from SU(3) chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Petschauer, Stefan; Kaiser, Norbert [Technische Universitaet Muenchen (Germany); Haidenbauer, Johann [Forschungszentrum Juelich (Germany); Meissner, Ulf G. [Forschungszentrum Juelich (Germany); Universitaet Bonn (Germany); Weise, Wolfram [Technische Universitaet Muenchen (Germany); ECT, Trento (Italy)

2016-07-01

Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. The splittings among the Σ{sup +}, Σ{sup 0} and Σ{sup -} potentials have a non-linear dependence on the isospin asymmetry which goes beyond the usual parametrization in terms of an isovector Lane potential.

Theory of the spin Peltier effect

Science.gov (United States)

Ohnuma, Y.; Matsuo, M.; Maekawa, S.

2017-10-01

A microscopic theory of the spin Peltier effect in a bilayer structure comprising a paramagnetic metal (PM) and a ferromagnetic insulator (FI) based on the nonequilibrium Green's function method is presented. Spin current and heat current driven by temperature gradient and spin accumulation are formulated as functions of spin susceptibilities in the PM and the FI, and are summarized by Onsager's reciprocal relations. By using the current formulas, we estimate heat generation and absorption at the interface driven by the heat-current injection mediated by spins from PM into FI.

Naturalness in an Effective Field Theory for Neutron Star Matter

International Nuclear Information System (INIS)

Razeira, Moises; Vasconcellos, Cesar A.Z.; Bodmann, Bardo E.J.; Coelho, Helio T.; Dillig, Manfred

2004-01-01

High density hadronic matter is studied in a generalized relativistic multi-baryon lagrangian density. By comparing the predictions of our model with estimates obtained within a phenomenological naive dimensional analysis based on the naturalness of the coefficients of the theory, we show that naturalness plays a major role in effective field theory and, in combination with experiment, could represent a relevant criterium to select a model among others in the description of global static properties of neutron stars

Concreteness effects in semantic processing: ERP evidence supporting dual-coding theory.

Science.gov (United States)

Kounios, J; Holcomb, P J

1994-07-01

Dual-coding theory argues that processing advantages for concrete over abstract (verbal) stimuli result from the operation of 2 systems (i.e., imaginal and verbal) for concrete stimuli, rather than just 1 (for abstract stimuli). These verbal and imaginal systems have been linked with the left and right hemispheres of the brain, respectively. Context-availability theory argues that concreteness effects result from processing differences in a single system. The merits of these theories were investigated by examining the topographic distribution of event-related brain potentials in 2 experiments (lexical decision and concrete-abstract classification). The results were most consistent with dual-coding theory. In particular, different scalp distributions of an N400-like negativity were elicited by concrete and abstract words.

Effective spacetime understanding emergence in effective field theory and quantum gravity

CERN Document Server

Crowther, Karen

2016-01-01

This book discusses the notion that quantum gravity may represent the "breakdown" of spacetime at extremely high energy scales. If spacetime does not exist at the fundamental level, then it has to be considered "emergent", in other words an effective structure, valid at low energy scales. The author develops a conception of emergence appropriate to effective theories in physics, and shows how it applies (or could apply) in various approaches to quantum gravity, including condensed matter approaches, discrete approaches, and loop quantum gravity.

Superfield approach to calculation of effective potential in supersymmetric field theories

International Nuclear Information System (INIS)

Bukhbinder, I.L.; Kuzenko, S.M.; Yarevskaya, Zh.V.

1993-01-01

Superfield method of computing effective potential in supersymmetric field theories is suggested. The one-loop effective potential of the Wess-Zumino model is found. The prescription for obtaining multi-loop corrections is described

World-volume effective action of exotic five-brane in M-theory

International Nuclear Information System (INIS)

Kimura, Tetsuji; Sasaki, Shin; Yata, Masaya

2016-01-01

We study the world-volume effective action of an exotic five-brane, known as the M-theory 5"3-brane (M5"3-brane) in eleven dimensions. The supermultiplet of the world-volume theory is the N=(2,0) tensor multiplet in six dimensions. The world-volume action contains three Killing vectors k̂_I_̂"M (Î=1,2,3) associated with the U(1)"3 isometry. We find the effective T-duality rule for the eleven-dimensional backgrounds that transforms the M5-brane effective action to that of the M5"3-brane. We also show that our action provides the source term for the M5"3-brane geometry in eleven-dimensional supergravity.

Perturbation theory and nonperturbative effects: a happy marriage?

International Nuclear Information System (INIS)

Chyla, J.

1992-01-01

Perturbation expansions in renormalized quantum theories are reformulated in a way that permits a straightforward handling of situations when in the conventional approach, i.e. in fixed renormalization scheme, these expansions are factorially divergent and even of asymptotically constant sign. The result takes the form of convergent (under certain circumstances) expansions in a set of functions Z k (a,χ) of the couplant and the free parameter χ specifies the procedure involved. The value of χ is shown to be correlated to the basic properties of nonperturbative effects as embodied in power corrections. A close connection of this procedure to the Borel summation technique is demonstrated and its relation to conventional perturbation theory in fixed renormalization schemes elucidated. (author) 3 figs., 17 refs

Inclusion of Dispersion Effects in Density Functional Theory

DEFF Research Database (Denmark)

Møgelhøj, Andreas

on fitting to high-level ab initio and experimental results. The fitting scheme, based on Baysian theory, focuses on the three aspects: a) model space, b) datasets, and c) model selection. The model space consists of a flexible expansion of the exchange enhancement factor in the generalized gradient......In this thesis, applications and development will be presented within the field of van der Waals interactions in density functional theory. The thesis is based on the three projects: i) van der Waals interactions effect on the structure of liquid water at ambient conditions, ii) development......-range van der Waals interactions is essential to describe the adsorption/desorption process and commonly used generalized gradient approximation functionals are seen to be incapable of this....

Mass terms in effective theories of high density quark matter

Science.gov (United States)

Schäfer, T.

2002-04-01

We study the structure of mass terms in the effective theory for quasiparticles in QCD at high baryon density. To next-to-leading order in the 1/pF expansion we find two types of mass terms: chirality conserving two-fermion operators and chirality violating four-fermion operators. In the effective chiral theory for Goldstone modes in the color-flavor-locked (CFL) phase the former terms correspond to effective chemical potentials, while the latter lead to Lorentz invariant mass terms. We compute the masses of Goldstone bosons in the CFL phase, confirming earlier results by Son and Stephanov as well as Bedaque and Schäfer. We show that to leading order in the coupling constant g there is no antiparticle gap contribution to the mass of Goldstone modes, and that our results are independent of the choice of gauge.

An interface energy density-based theory considering the coherent interface effect in nanomaterials

Science.gov (United States)

Yao, Yin; Chen, Shaohua; Fang, Daining

2017-02-01

To characterize the coherent interface effect conveniently and feasibly in nanomaterials, a continuum theory is proposed that is based on the concept of the interface free energy density, which is a dominant factor affecting the mechanical properties of the coherent interface in materials of all scales. The effect of the residual strain caused by self-relaxation and the lattice misfit of nanomaterials, as well as that due to the interface deformation induced by an external load on the interface free energy density is considered. In contrast to the existing theories, the stress discontinuity at the interface is characterized by the interface free energy density through an interface-induced traction. As a result, the interface elastic constant introduced in previous theories, which is not easy to determine precisely, is avoided in the present theory. Only the surface energy density of the bulk materials forming the interface, the relaxation parameter induced by surface relaxation, and the mismatch parameter for forming a coherent interface between the two surfaces are involved. All the related parameters are far easier to determine than the interface elastic constants. The effective bulk and shear moduli of a nanoparticle-reinforced nanocomposite are predicted using the proposed theory. Closed-form solutions are achieved, demonstrating the feasibility and convenience of the proposed model for predicting the interface effect in nanomaterials.

Z3 - invariant effective theory of deconfining phase transition

International Nuclear Information System (INIS)

So, Hiroto

1986-01-01

A Z 3 -invariant scalar model is proposed as an effective theory of deconfining phase transition of QCD. Coupling constants in the potential are determined by Monte Carlo methods. The structure of renormalization trajectories for coupling constants is investigated. (author)

Minimal flavour violation an effective field theory approach

CERN Document Server

D'Ambrosio, G.; Isidori, G.; Strumia, A.

2002-01-01

We present a general analysis of extensions of the Standard Model which satisfy the criterion of Minimal Flavour Violation (MFV). We define this general framework by constructing a low-energy effective theory containing the Standard Model fields, with one or two Higgs doublets and, as the only source of SU(3)^5 flavour symmetry breaking, the background values of fields transforming under the flavour group as the ordinary Yukawa couplings. We analyse present bounds on the effective scale of dimension-six operators, which range between 1 and 10 TeV, with the most stringent constraints imposed by B -> X_s gamma. In this class of theories, it is possible to relate predictions for FCNC processes in B physics to those in K physics. We compare the sensitivity of various experimental searches in probing the hypothesis of MFV. Within the two-Higgs-doublet scenario, we develop a general procedure to obtain all tan(beta)-enhanced Higgs-mediated FCNC amplitudes, discussing in particular their impact in B -> l^+l^-, Delta...

Theory of the isotope effect in superconducting compounds

International Nuclear Information System (INIS)

Culetto, F.J.; Rainer, D.

1978-05-01

We present a theoretical analysis of the isotope effect on the superconducting transition temperature. Our method is to calculate via formal perturbation theory the response of the transition temperature to small changes of the masses of the various constituents of the compound. We discuss the relation between the isotope effect and various more fundamental parameters in strong coupling superconductors. As illustrative examples, we consider the systems Pd-H(D) alloys and the binary Chevrel phase superconductor Mo 6 Se 8 , and show that analysis of the isotope effect can yield useful information concerning interaction mechanisms in these compounds. (orig.)

The Effects of Racial Conflict on Organizational Performance: A Search for Theory

Science.gov (United States)

Byrd, Marilyn Y.

2007-01-01

This article addresses the effect of racial conflict on organizational performance as an issue that needs theoretical support in the foundational theories of human resource development (HRD). While the field of HRD recognizes theories from multiple disciplines, the field lacks a theoretical framework to inform leadership in managing racial…

Nuclear Forces from Effective Field Theory

International Nuclear Information System (INIS)

Krebs, H.

2011-01-01

Chiral effective field theory allows for a systematic and model-independent derivation of the forces between nucleons in harmony with the symmetries of the quantum chromodynamics. After a brief review on the current status in the development of the chiral nuclear forces I will focus on the role of the Δ-resonance contributions in the nuclear dynamics.We find improvement in the convergence of the chiral expansion of the nuclear forces if we explicitly take into account the Δ-resonance degrees of freedom. The overall results for two-nucleon forces with and without explicit Δ-resonance degrees of freedom are remarkably similar. We discussed the long- and shorter-range N 3 LO contributions to chiral three-nucleon forces. No additional free parameters appear at this order. There are five different topology classes which contribute to the forces. Three of them describe long-range contributions which constitute the first systematic corrections to the leading 2π exchange that appear at N 2 LO. Another two contributions are of a shorter range and include, additionally to an exchange of pions, also one short-range contact interaction and all corresponding 1/m corrections. The requirement of renormalizability leads to unique expressions for N 3 LO contributions to the three-nucleon force (except for 1/m-corrections). We presented the complete N 2 LO analysis of the nuclear forces with explicit Δ-isobar degrees of freedom. Although the overall results in the isospin-conserving case are very similar in the Δ-less and Δ-full theories, we found a much better convergence in all peripheral partial waves once Δ-resonance is explicitly taken into account. The leading CSB contributions to nuclear forces are proportional to nucleon- and Δ-mass splittings. There appear strong cancellations between the two contributions which at leading order yield weaker V III potentials. This effect is, however, entirely compensated at subleading order such that the results in the theories

Probing non-perturbative effects in M-theory

International Nuclear Information System (INIS)

Hatsuda, Yasuyuki; Okuyama, Kazumi

2014-07-01

The AdS/CFT correspondence enables us to probe M-theory on various backgrounds from the corresponding dual gauge theories. Here we investigate in detail a three-dimensional U(N) N=4 super Yang-Mills theory coupled to one adjoint hypermultiplet and N f fundamental hypermultiplets, which is large N dual to M-theory on AdS 4 x S 7 /Z N f . Using the localization and the Fermi-gas formulation, we explore non-perturbative corrections to the partition function. As in the ABJM theory, we find that there exists a non-trivial pole cancellation mechanism, which guarantees the theory to be well-defined, between worldsheet instantons and membrane instantons for all rational (in particular, physical or integral) values of N f .

World-volume effective action of exotic five-brane in M-theory

Energy Technology Data Exchange (ETDEWEB)

Kimura, Tetsuji [Research and Education Center for Natural Sciences, Keio University, Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521 (Japan); Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan); Sasaki, Shin [Department of Physics, Kitasato University,Sagamihara 252-0373 (Japan); Yata, Masaya [Department of Physics, National University of Singapore,2, Science Drive 3, Singapore 117542 (Singapore)

2016-02-25

We study the world-volume effective action of an exotic five-brane, known as the M-theory 5{sup 3}-brane (M5{sup 3}-brane) in eleven dimensions. The supermultiplet of the world-volume theory is the N=(2,0) tensor multiplet in six dimensions. The world-volume action contains three Killing vectors k̂{sub Î}{sup M} (Î=1,2,3) associated with the U(1){sup 3} isometry. We find the effective T-duality rule for the eleven-dimensional backgrounds that transforms the M5-brane effective action to that of the M5{sup 3}-brane. We also show that our action provides the source term for the M5{sup 3}-brane geometry in eleven-dimensional supergravity.

Quantum optical effective-medium theory for loss-compensated metamaterials

DEFF Research Database (Denmark)

Amooghorban, Ehsan; Mortensen, N. Asger; Wubs, Martijn

2013-01-01

A central aim in metamaterial research is to engineer subwavelength unit cells that give rise to desired effective-medium properties and parameters, such as a negative refractive index. Ideally one can disregard the details of the unit cell and employ the effective description instead. A popular...... effective parameters are insufficient to describe the propagation of quantum states of light. Furthermore, we propose a quantum optical effective-medium theory instead and show that it correctly predicts the properties of the light emerging from loss-compensated metamaterials. © 2013 American Physical...

Theory of Brownian motion with the Alder-Wainwright effect

International Nuclear Information System (INIS)

Okabe, Y.

1986-01-01

The Stokes-Boussinesq-Langevin equation, which describes the time evolution of Brownian motion with the Alder-Wainwright effect, can be treated in the framework of the theory of KMO-Langevin equations which describe the time evolution of a real, stationary Gaussian process with T-positivity (reflection positivity) originating in axiomatic quantum field theory. After proving the fluctuation-dissipation theorems for KMO-Langevin equations, the authors obtain an explicit formula for the deviation from the classical Einstein relation that occurs in the Stokes-Boussinesq-Langevin equation with a white noise as its random force. The authors interested in whether or not it can be measured experimentally

Status of effective field theory of NN scattering

International Nuclear Information System (INIS)

Beane, S.R.

1998-06-01

There exist many nucleon-nucleon potentials which reproduce phase shifts and nuclear properties with remarkable accuracy. Three fundamental features are shared by these potential models: (1) pions are important at long distances, (2) there is a source of intermediate-range attraction, and (3) there is a source of short-distance repulsion. However, in general, distinct physical mechanisms in these models account for the same feature of the nuclear force. Agreement with experiment is maintained in spite of these differences because of the large number of fit parameters. Systematic approaches to the scattering of strongly interacting particles, such as chiral perturbation theory, are based on the ideas of effective field theory (EFT). The author reviews recent progress in developing a systematic power counting scheme for scattering processes involving more than one nucleon

Complexity growth in massive gravity theories, the effects of chirality, and more

Science.gov (United States)

Ghodrati, Mahdis

2017-11-01

To study the effect of parity violation on the rate of complexity growth, by using "complexity=action " conjecture, we find the complexity growth rates in different solutions of the chiral theory of topologically massive gravity (TMG) and parity-preserving theory of new massive gravity (NMG). Using the results, one can see that decreasing the parameter μ , which increases the effect of the Chern-Simons term and increases chirality, would increase the rate of growth of complexity. Also one can observe a stronger correlation between complexity growth and temperature rather than complexity growth and entropy. At the end we comment on the possible meaning of the deforming term of chiral Liouville action for the rate of complexity growth of warped conformal field theories in the tensor network renormalization picture.

Effective field theory analysis of Higgs naturalness

Energy Technology Data Exchange (ETDEWEB)

Bar-Shalom, Shaouly [Technion-Israel Inst. of Tech., Haifa (Israel); Soni, Amarjit [Brookhaven National Lab. (BNL), Upton, NY (United States); Wudka, Jose [Univ. of California, Riverside, CA (United States)

2015-07-20

Assuming the presence of physics beyond the Standard Model ( SM) with a characteristic scale M ~ O (10) TeV, we investigate the naturalness of the Higgs sector at scales below M using an effective field theory (EFT) approach. We obtain the leading 1 -loop EFT contributions to the Higgs mass with a Wilsonian-like hard cutoff, and determine t he constraints on the corresponding operator coefficients for these effects to alleviate the little hierarchy problem up to the scale of the effective action Λ < M , a condition we denote by “EFT-naturalness”. We also determine the types of physics that can lead to EFT-naturalness and show that these types of new physics are best probed in vector-boson and multiple-Higgs production. The current experimental constraints on these coefficients are also discussed.

Effective average action for gauge theories and exact evolution equations

International Nuclear Information System (INIS)

Reuter, M.; Wetterich, C.

1993-11-01

We propose a new nonperturbative evolution equation for Yang-Mills theories. It describes the scale dependence of an effective action. The running of the nonabelian gauge coupling in arbitrary dimension is computed. (orig.)

Unified theory of dislocation motion including thermal activation and inertial effects

International Nuclear Information System (INIS)

Isaac, R.D.; Granato, A.V.

1979-01-01

Transition-state rate theory has generally been used to explain the temperature dependence of the flow stress of a crystal. However, the existence of a change in the flow stress during the superconducting transition indicates the presence of inertial effects in which dislocations overcome obstacles mechanically rather than thermally. It is shown here that the thermally activated and the inertial overcoming of obstacles are not unrelated but can both be derived from principles of stochastic motion. This leads to a theory of dislocation motion that includes both thermal activation and inertial effects. It is also shown that a distribution of activation energies must be considered to account for the experimental data

Heavy baryon transitions and the heavy quark effective theory

International Nuclear Information System (INIS)

Hussain, F.

1992-01-01

Heavy baryon decays are studied in the context of the Bethe-Salpeter approach to the heavy quark effective theory. A drastic reduction, in the number of independent form factors, is found. Results are presented both for heavy to heavy and heavy to light baryon decays. (orig.)

Effective field theory of dark matter from membrane inflationary paradigm

Science.gov (United States)

Choudhury, Sayantan; Dasgupta, Arnab

2016-09-01

In this article, we have studied the cosmological and particle physics constraints on dark matter relic abundance from effective field theory of inflation from tensor-to-scalar ratio (r), in case of Randall-Sundrum single membrane (RSII) paradigm. Using semi-analytical approach we establish a direct connection between the dark matter relic abundance (ΩDMh2) and primordial gravity waves (r), which establishes a precise connection between inflation and generation of dark matter within the framework of effective field theory in RSII membrane. Further assuming the UV completeness of the effective field theory perfectly holds good in the prescribed framework, we have explicitly shown that the membrane tension, σ ≤ O(10-9) Mp4 , bulk mass scale M5 ≤ O(0.04 - 0.05) Mp, and cosmological constant Λ˜5 ≥ - O(10-15) Mp5 , in RSII membrane plays the most significant role to establish the connection between dark matter and inflation, using which we have studied the features of various mediator mass scale suppressed effective field theory "relevant operators" induced from the localized s, t and u channel interactions in RSII membrane. Taking a completely model independent approach, we have studied an exhaustive list of tree-level Feynman diagrams for dark matter annihilation within the prescribed setup and to check the consistency of the obtained results, further we apply the constraints as obtained from recently observed Planck 2015 data and Planck + BICEP2 + Keck Array joint data sets. Using all of these derived results we have shown that to satisfy the bound on, ΩDMh2 = 0.1199 ± 0.0027, as from Planck 2015 data, it is possible to put further stringent constraint on r within, 0.01 ≤ r ≤ 0.12, for thermally averaged annihilation cross-section of dark matter, 〈 σv 〉 ≈ O(10-28 - 10-27) cm3 / s, which are very useful to constrain various membrane inflationary models.

Effects of one-loop corrections in the Weinberg-Salam theory

International Nuclear Information System (INIS)

Bardin, D.Y.; Fedorenko, O.M.; Christova, P.C.

1982-01-01

We have studied the one-loop effects in the Weinberg-Salam theory in the natural renormalization scheme which we have generalized to the case of an arbitrary unitary mixing of the fermion fields. We have discussed in detail the problems which are connected with carrying out the renormalization program in the Weinberg-Salam theory. We have calculated the masses of the W and Z bosons. We present a description of the finite renormalizations which relate to each other the three definitions of the Weinberg parameter sin 2 theta/sub W/

Theory of tunneling ionization of molecules: Weak-field asymptotics including dipole effects

DEFF Research Database (Denmark)

Tolstikhin, Oleg I.; Morishita, Toru; Madsen, Lars Bojer

2011-01-01

The formulation of the parabolic adiabatic expansion approach to the problem of ionization of atomic systems in a static electric field, originally developed for the axially symmetric case [ Phys. Rev. A 82 023416 (2010)], is generalized to arbitrary potentials. This approach is used to rederive...... the asymptotic theory of tunneling ionization in the weak-field limit. In the atomic case, the resulting formulas for the ionization rate coincide with previously known results. In addition, the present theory accounts for the possible existence of a permanent dipole moment of the unperturbed system and, hence......, applies to polar molecules. Accounting for dipole effects constitutes an important difference of the present theory from the so-called molecular Ammosov-Delone-Krainov theory. The theory is illustrated by comparing exact and asymptotic results for a set of model polar molecules and a realistic molecular...

Effective theory of black holes in the 1/D expansion

International Nuclear Information System (INIS)

Emparan, Roberto; Shiromizu, Tetsuya; Suzuki, Ryotaku; Tanabe, Kentaro; Tanaka, Takahiro

2015-01-01

The gravitational field of a black hole is strongly localized near its horizon when the number of dimensions D is very large. In this limit, we can effectively replace the black hole with a surface in a background geometry (e.g. Minkowski or Anti-deSitter space). The Einstein equations determine the effective equations that this ‘black hole surface’ (or membrane) must satisfy. We obtain them up to next-to-leading order in 1/D for static black holes of the Einstein-(A)dS theory. To leading order, and also to next order in Minkowski backgrounds, the equations of the effective theory are the same as soap-film equations, possibly up to a redshift factor. In particular, the Schwarzschild black hole is recovered as a spherical soap bubble. Less trivially, we find solutions for ‘black droplets’, i.e. black holes localized at the boundary of AdS, and for non-uniform black strings.

Symmetry behavior of the effective gauge theory

International Nuclear Information System (INIS)

Midorikawa, S.

1981-01-01

The restoration of spontaneously broken CP invariance is investigated by using the effective QED lagrangian obtained from the standard SU(2) x U(1) gauge theory with two Higgs doublets. It is shown that the large electromagnetic field may restore CP invariance by changing the relative phase angle of Higgs vacuum expectation values even before one of the vacuum expectation values of the two Higgs doublets disappears. Further large magnetic field may lead to the fine structure constant with discontinuous behavior. (orig.)

Neutrino Majorana masses from string theory instanton effects

International Nuclear Information System (INIS)

Ibanez, Luis E.; Uranga, Angel M.

2007-01-01

Finding a plausible origin for right-handed neutrino Majorana masses in semirealistic compactifications of string theory remains one of the most difficult problems in string phenomenology. We argue that right-handed neutrino Majorana masses are induced by non-perturbative instanton effects in certain classes of string compactifications in which the U(1) B-L gauge boson has a Stueckelberg mass. The induced operators are of the form e -U ν R ν R where U is a closed string modulus whose imaginary part transforms appropriately under B-L. This mass term may be quite large since this is not a gauge instanton and Re U is not directly related to SM gauge couplings. Thus the size of the induced right-handed neutrino masses could be a few orders of magnitude below the string scale, as phenomenologically required. It is also argued that this origin for neutrino masses would predict the existence of R-parity in SUSY versions of the SM. Finally we comment on other phenomenological applications of similar instanton effects, like the generation of a μ-term, or of Yukawa couplings forbidden in perturbation theory

Three-body interactions in many-body effective field theory

International Nuclear Information System (INIS)

Furnstahl, R.J.

2004-01-01

This contribution is an advertisement for applying effective field theory (EFT) to many-body problems, including nuclei and cold atomic gases. Examples involving three-body interactions are used to illustrate how EFT's quantify and systematically eliminate model dependence, and how they make many-body calculations simpler and more powerful

Orbital effect of the magnetic field in dynamical mean-field theory

Science.gov (United States)

Acheche, S.; Arsenault, L.-F.; Tremblay, A.-M. S.

2017-12-01

The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms calls for systematic studies of orbital effects of the magnetic field on the self-energy of interacting systems. Here we demonstrate theoretically that orbital effects of magnetic fields can be treated within single-site dynamical mean-field theory with a translationally invariant quantum impurity problem. As an example, we study the one-band Hubbard model on the square lattice using iterated perturbation theory as an impurity solver. We recover the expected quantum oscillations in the scattering rate, and we show that the magnetic fields allow the interaction-induced effective mass to be measured through the single-particle density of states accessible in tunneling experiments. The orbital effect of magnetic fields on scattering becomes particularly important in the Hofstadter butterfly regime.

Effective field theory for cold atoms

International Nuclear Information System (INIS)

Hammer, H.-W.

2005-01-01

Effective Field Theory (EFT) provides a powerful framework that exploits a separation of scales in physical systems to perform systematically improvable, model-independent calculations. Particularly interesting are few-body systems with short-range interactions and large two-body scattering length. Such systems display remarkable universal features. In systems with more than two particles, a three-body force with limit cycle behavior is required for consistent renormalization already at leading order. We will review this EFT and some of its applications in the physics of cold atoms. Recent extensions of this approach to the four-body system and N-boson droplets in two spatial dimensions will also be discussed

Extension of anisotropic effective medium theory to account for an arbitrary number of inclusion types

Science.gov (United States)

Myles, Timothy D.; Peracchio, Aldo A.; Chiu, Wilson K. S.

2015-01-01

The purpose of this work is to extend, to multi-components, a previously reported theory for calculating the effective conductivity of a two component mixture. The previously reported theory involved preferentially oriented spheroidal inclusions contained in a continuous matrix, with inclusions oriented relative to a principle axis. This approach was based on Bruggeman's unsymmetrical theory, and is extended to account for an arbitrary number of different inclusion types. The development begins from two well-known starting points; the Maxwell approach and the Maxwell-Garnett approach for dilute mixtures. It is shown that despite these two different starting points, the final Bruggeman type equation is the same. As a means of validating the developed expression, comparisons are made to several existing effective medium theories. It is shown that these existing theories coincide with the developed equations for the appropriate parameter set. Finally, a few example mixtures are considered to demonstrate the effect of multiple inclusions on the calculated effective property. Inclusion types of different conductivities, shapes, and orientations are considered and each of the aforementioned properties is shown to have a potentially significant impact on the calculated mixture property.

Framing anomaly in the effective theory of the fractional quantum Hall effect.

Science.gov (United States)

Gromov, Andrey; Cho, Gil Young; You, Yizhi; Abanov, Alexander G; Fradkin, Eduardo

2015-01-09

We consider the geometric part of the effective action for the fractional quantum Hall effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to obtain the correct gravitational linear response functions. In the lowest order in gradients, the linear response generating functional includes Chern-Simons, Wen-Zee, and gravitational Chern-Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states.

Reported Theory Use by Digital Interventions for Hazardous and Harmful Alcohol Consumption, and Association With Effectiveness: Meta-Regression

Science.gov (United States)

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%, Ptheory 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

Effective Higgs theories in supersymmetric grand unification

Energy Technology Data Exchange (ETDEWEB)

Zheng, Sibo [Chongqing University, Department of Physics, Chongqing (China)

2017-09-15

The effective Higgs theories at the TeV scale in supersymmetric SU(5) grand unification models are systematically derived. Restricted to extensions on 5{sub H} containing the Higgs sector we show that only two types of real (vector-like) models and one type of chiral model are found to be consistent with perturbative grand unification. While the chiral model has been excluded by the LHC data, the fate of perturbative unification will be uniquely determined by the two classes of vector-like models. (orig.)

Rosetta: an operator basis translator for standard model effective field theory

Energy Technology Data Exchange (ETDEWEB)

Falkowski, Adam [Laboratoire de Physique Théorique, Bat. 210, Université Paris-Sud, 91405, Orsay (France); Fuks, Benjamin [Département Recherches Subatomiques, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg/CNRS-IN2P3, 23 rue du Loess, 67037, Strasbourg (France); Mawatari, Kentarou [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Pleinlaan 2, 1050, Brussels (Belgium); Mimasu, Ken, E-mail: k.mimasu@sussex.ac.uk [Department of Physics and Astronomy, University of Sussex, BN1 9QH, Brighton (United Kingdom); Riva, Francesco [CERN, Theory Division, 1211, Geneva (Switzerland); Sanz, Verónica [Department of Physics and Astronomy, University of Sussex, BN1 9QH, Brighton (United Kingdom)

2015-12-10

We introduce Rosetta, a program allowing for the translation between different bases of effective field theory operators. We present the main functions of the program and provide an example of usage. One of the Lagrangians which Rosetta can translate into has been implemented into FeynRules, which allows Rosetta to be interfaced into various high-energy physics programs such as Monte Carlo event generators. In addition to popular bases choices, such as the Warsaw and Strongly Interacting Light Higgs bases already implemented in the program, we also detail how to add new operator bases into the Rosetta package. In this way, phenomenological studies using an effective field theory framework can be straightforwardly performed.

Rosetta: an operator basis translator for standard model effective field theory

Energy Technology Data Exchange (ETDEWEB)

Falkowski, Adam [Universite Paris-Sud, Laboratoire de Physique Theorique, Bat. 210, Orsay (France); Fuks, Benjamin [Universite de Strasbourg/CNRS-IN2P3, Departement Recherches Subatomiques, Institut Pluridisciplinaire Hubert Curien, Strasbourg (France); Mawatari, Kentarou [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Brussels (Belgium); Mimasu, Ken; Sanz, Veronica [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); Riva, Francesco [CERN, Theory Division, Geneva (Switzerland)

2015-12-15

We introduce Rosetta, a program allowing for the translation between different bases of effective field theory operators. We present the main functions of the program and provide an example of usage. One of the Lagrangians which Rosetta can translate into has been implemented into FeynRules, which allows Rosetta to be interfaced into various high-energy physics programs such as Monte Carlo event generators. In addition to popular bases choices, such as the Warsaw and Strongly Interacting Light Higgs bases already implemented in the program, we also detail how to add new operator bases into the Rosetta package. In this way, phenomenological studies using an effective field theory framework can be straightforwardly performed. (orig.)

Molecular Theory and the Effects of Solute Attractive Forces on Hydrophobic Interactions.

Science.gov (United States)

Chaudhari, Mangesh I; Rempe, Susan B; Asthagiri, D; Tan, L; Pratt, L R

2016-03-03

The role of solute attractive forces on hydrophobic interactions is studied by coordinated development of theory and simulation results for Ar atoms in water. We present a concise derivation of the local molecular field (LMF) theory for the effects of solute attractive forces on hydrophobic interactions, a derivation that clarifies the close relation of LMF theory to the EXP approximation applied to this problem long ago. The simulation results show that change from purely repulsive atomic solute interactions to include realistic attractive interactions diminishes the strength of hydrophobic bonds. For the Ar-Ar rdfs considered pointwise, the numerical results for the effects of solute attractive forces on hydrophobic interactions are opposite in sign and larger in magnitude than predicted by LMF theory. That comparison is discussed from the point of view of quasichemical theory, and it is suggested that the first reason for this difference is the incomplete evaluation within LMF theory of the hydration energy of the Ar pair. With a recent suggestion for the system-size extrapolation of the required correlation function integrals, the Ar-Ar rdfs permit evaluation of osmotic second virial coefficients B2. Those B2's also show that incorporation of attractive interactions leads to more positive (repulsive) values. With attractive interactions in play, B2 can change from positive to negative values with increasing temperatures. This is consistent with the puzzling suggestions of decades ago that B2 ≈ 0 for intermediate cases of temperature or solute size. In all cases here, B2 becomes more attractive with increasing temperature.

W-pair production near threshold in unstable particle effective theory

Energy Technology Data Exchange (ETDEWEB)

Falgari, Pietro

2008-11-07

In this thesis we present a dedicated study of the four-fermion production process e{sup +}e{sup -}{yields}{mu}{sup -} anti {nu}{sub {mu}}u anti dX near the W-pair production threshold, in view of its importance for a precise determination of the W-boson mass at the ILC. The calculation is performed in the framework of unstable-particle effective theory, which allows for a gauge-invariant inclusion of instability effects, and for a systematic approximation of the full cross section with an expansion in the coupling constants, the ratio {gamma}{sub W}/M{sub W}, and the non-relativistic velocity v of the W boson. The effective-theory result, computed to next-to-leading order in the expansion parameters {gamma}{sub W}/M{sub W}{proportional_to}{alpha}{sub ew}{proportional_to}v{sup 2}, is compared to the full numerical next-to-leading order calculation of the four-fermion production cross section, and agreement to better than 0.5% is found in the region of validity of the effective theory. Furthermore, we estimate the contributions of missing higher-order corrections to the four-fermion process, and how they translate into an error on the W-boson mass determination. We find that the dominant theoretical uncertainty on MW is currently due to an incomplete treatment of initial-state radiation, while the remaining combined uncertainty of the two NLO calculations translates into {delta}M{sub W}{approx} 5 MeV. The latter error is removed by an explicit computation of the dominant missing terms, which originate from the expansion in v of next-to-next-to-leading order Standard Model diagrams. The effect of resummation of logarithmically-enhanced terms is also investigated, but found to be negligible. (orig.)

Theory of the quantized Hall effect. Pt. 3

International Nuclear Information System (INIS)

Levine, H.; Pruisken, A.M.M.; Libby, S.B.

1984-01-01

In the previous paper, we have demonstrated the need for a phase transition as a function of theta in the non-liner sigma-model describing the quantized Hall effect. In this work, we present arguments for the occurrence of exactly such a transition. We make use of a dilute gas instanton approximation as well as present a more rigorous duality argument to show that the usual scaling of the conductivity to zero at large distances is altered whenever sigmasub(xy)sup((0)) approx.= 1/2ne 2 /h, n integer. This then completes our theory of the quantized Hall effect. (orig.)

Nonlocal modification and quantum optical generalization of effective-medium theory for metamaterials

DEFF Research Database (Denmark)

Wubs, Martijn; Yan, Wei; Amooghorban, Ehsan

2013-01-01

A well-known challenge for fabricating metamaterials is to make unit cells significantly smaller than the operating wavelength of light, so one can be sure that effective-medium theories apply. But do they apply? Here we show that nonlocal response in the metal constituents of the metamaterial...... leads to modified effective parameters for strongly subwavelength unit cells. For infinite hyperbolic metamaterials, nonlocal response gives a very large finite upper bound to the optical density of states that otherwise would diverge. Moreover, for finite hyperbolic metamaterials we show that nonlocal...... response affects their operation as superlenses, and interestingly that sometimes nonlocal theory predicts the better imaging. Finally, we discuss how to describe metamaterials effectively in quantum optics. Media with loss or gain have associated quantum noise, and the question is whether the effective...

Reformulation of the Hermitean 1-matrix model as an effective field theory

Energy Technology Data Exchange (ETDEWEB)

Klitz, Alexander

2009-07-15

The formal Hermitean 1-matrix model is shown to be equivalent to an effective field theory. The correlation functions and the free energy of the matrix model correspond directly to the correlation functions and the free energy of the effective field theory. The loop equation of the field theory coupling constants is stated. Despite its length, this loop equation is simpler than the loop equations in the matrix model formalism itself since it does not contain operator inversions in any sense, but consists instead only of derivative operators and simple projection operators. Therefore the solution of the loop equation could be given for an arbitrary number of cuts up to the fifth order in the topological expansion explicitly. Two different methods of obtaining the contributions to the free energy of the higher orders are given, one depending on an operator H and one not depending on it. (orig.)

Constraints on effective Lagrangian of D-branes from non-commutative gauge theory

International Nuclear Information System (INIS)

Okawa, Yuji; Terashima, Seiji

2000-01-01

It was argued that there are two different descriptions of the effective Lagrangian of gauge fields on D-branes by non-commutative gauge theory and by ordinary gauge theory in the presence of a constant B field background. In the case of bosonic string theory, however, it was found in the previous works that the two descriptions are incompatible under the field redefinition which relates the non-commutative gauge field to the ordinary one found by Seiberg and Witten. In this paper we resolve this puzzle to observe the necessity of gauge-invariant but B-dependent correction terms involving metric in the field redefinition which have not been considered before. With the problem resolved, we establish a systematic method under the α' expansion to derive the constraints on the effective Lagrangian imposed by the compatibility of the two descriptions where the form of the field redefinition is not assumed

Analysis of safety supervision effect on coal mine using game theory

Energy Technology Data Exchange (ETDEWEB)

Zhou Min; Xiao Zhong-hai [China University of Mining & Technology, Xuzhou (China). School of Management

2006-07-01

A two-phase game model was constructed based on economic game theory to improve the inefficient supervision conditions of coalmining enterprises' safety production. The inner mechanism of safety supervision system was carefully studied. The strategy set of the dynamic game-theory relations between colliery proprietor and safety supervision department and the strict competitive game-theory relations between safety supervision department and workers at the production line was analyzed. The conditions of achieving the dominant-strategy equilibrium were revealed. Upon this basis, the possible solution set of safety benefit distribution for the cooperative game-theory of triple party was obtained and the effective and cooperative fair solution was formed. Finally, conclusions are drawn as follows: the combination of necessary penalty to supervisors and operators with the fair distribution of safety benefits can realize the zero-defect of operational violation, so that the violation behavior can be completely avoided. 10 refs., 7 figs.

A review of the findings and theories on surface size effects on visual attention.

Science.gov (United States)

Peschel, Anne O; Orquin, Jacob L

2013-12-09

That surface size has an impact on attention has been well-known in advertising research for almost a century; however, theoretical accounts of this effect have been sparse. To address this issue, we review studies on surface size effects on eye movements in this paper. While most studies find that large objects are more likely to be fixated, receive more fixations, and are fixated faster than small objects, a comprehensive explanation of this effect is still lacking. To bridge the theoretical gap, we relate the findings from this review to three theories of surface size effects suggested in the literature: a linear model based on the assumption of random fixations (Lohse, 1997), a theory of surface size as visual saliency (Pieters etal., 2007), and a theory based on competition for attention (CA; Janiszewski, 1998). We furthermore suggest a fourth model - demand for attention - which we derive from the theory of CA by revising the underlying model assumptions. In order to test the models against each other, we reanalyze data from an eye tracking study investigating surface size and saliency effects on attention. The reanalysis revealed little support for the first three theories while the demand for attention model showed a much better alignment with the data. We conclude that surface size effects may best be explained as an increase in object signal strength which depends on object size, number of objects in the visual scene, and object distance to the center of the scene. Our findings suggest that advertisers should take into account how objects in the visual scene interact in order to optimize attention to, for instance, brands and logos.

Field theory of anyons and the fractional quantum Hall effect

International Nuclear Information System (INIS)

Viefers, S.F.

1997-11-01

The thesis is devoted to a theoretical study of anyons, i.e. particles with fractional statistics moving in two space dimensions, and the quantum Hall effect. The latter constitutes the only known experimental realization of anyons in that the quasiparticle excitations in the fractional quantum Hall system are believed to obey fractional statistics. First, the properties of ideal quantum gases in two dimensions and in particular the equation of state of the free anyons gas are discussed. Then, a field theory formulation of anyons in a strong magnetic field is presented and later extended to a system with several species of anyons. The relation of this model to fractional exclusion statistics, i.e. intermediate statistics introduced by a generalization of the Pauli principle, and to the low-energy excitations at the edge of the quantum Hall system is discussed. Finally, the Chern-Simons-Landau-Ginzburg theory of the fractional quantum Hall effect is studied, mainly focusing on edge effects; both the ground state and the low-energy edge excitations are examined in the simple one-component model and in an extended model which includes spin effects

Nucleon Polarisabilities and Effective Field Theories

Science.gov (United States)

Griesshammer, Harald W.

2017-09-01

Low-energy Compton scattering probes the nucleon's two-photon response to electric and magnetic fields at fixed photon frequency and multipolarity. It tests the symmetries and strengths of the interactions between constituents, and with photons. For convenience, this energy-dependent information is often compressed into the two scalar dipole polarisabilities αE 1 and βM 1 at zero photon energy. These are fundamental quantities, and important for the proton charge radius puzzle and the Lamb shift of muonic hydrogen. Combined with emerging lattice QCD computations, they provide stringent tests for our understanding of hadron structure. Extractions of the proton and neutron polarisabilities from all published elastic data below 300 MeV in Chiral Effective Field Theory with explicit Δ (1232) are now available. This talk emphasises χEFT as natural bridge between lattice QCD and ongoing or approved efforts at HI γS, MAMI and MAX-lab. Chiral lattice extrapolations from mπ > 200 MeV to the physical point compare well to lattice computations. Combining χEFT with high-intensity experiments with polarised targets and polarised beams will extract not only scalar polarisabilities, but in particular the four so-far poorly explored spin-polarisabilities. These parametrise the stiffness of the spin in external electro-magnetic fields (nucleonic bi-refringence/Faraday effect). New chiral predictions for proton, deuteron and 3He observables show intriguing sensitivities on spin and neutron polarisabilities. Data consistency and a model-independent quantification of residual theory uncertainties by Bayesian analysis are also discussed. Proton-neutron differences explore the interplay between chiral symmetry breaking and short-distance Physics. Finally, I address their impact on the neutron-proton mass difference, big-bang nucleosynthesis, and their relevance for anthropic arguments. Supported in part by DOE DE-SC0015393 and George Washington University.

Study on combat effectiveness of air defense missile weapon system based on queuing theory

Science.gov (United States)

Zhao, Z. Q.; Hao, J. X.; Li, L. J.

2017-01-01

Queuing Theory is a method to analyze the combat effectiveness of air defense missile weapon system. The model of service probability based on the queuing theory was constructed, and applied to analyzing the combat effectiveness of "Sidewinder" and "Tor-M1" air defense missile weapon system. Finally aimed at different targets densities, the combat effectiveness of different combat units of two types' defense missile weapon system is calculated. This method can be used to analyze the usefulness of air defense missile weapon system.

Conspiracy Theory

DEFF Research Database (Denmark)

Bjerg, Ole; Presskorn-Thygesen, Thomas

2017-01-01

The paper is a contribution to current debates about conspiracy theories within philosophy and cultural studies. Wittgenstein’s understanding of language is invoked to analyse the epistemological effects of designating particular questions and explanations as a ‘conspiracy theory......’. It is demonstrated how such a designation relegates these questions and explanations beyond the realm of meaningful discourse. In addition, Agamben’s concept of sovereignty is applied to explore the political effects of using the concept of conspiracy theory. The exceptional epistemological status assigned...... to alleged conspiracy theories within our prevalent paradigms of knowledge and truth is compared to the exceptional legal status assigned to individuals accused of terrorism under the War on Terror. The paper concludes by discussing the relation between conspiracy theory and ‘the paranoid style...

Dark energy and modified gravity in the Effective Field Theory of Large-Scale Structure

Science.gov (United States)

Cusin, Giulia; Lewandowski, Matthew; Vernizzi, Filippo

2018-04-01

We develop an approach to compute observables beyond the linear regime of dark matter perturbations for general dark energy and modified gravity models. We do so by combining the Effective Field Theory of Dark Energy and Effective Field Theory of Large-Scale Structure approaches. In particular, we parametrize the linear and nonlinear effects of dark energy on dark matter clustering in terms of the Lagrangian terms introduced in a companion paper [1], focusing on Horndeski theories and assuming the quasi-static approximation. The Euler equation for dark matter is sourced, via the Newtonian potential, by new nonlinear vertices due to modified gravity and, as in the pure dark matter case, by the effects of short-scale physics in the form of the divergence of an effective stress tensor. The effective fluid introduces a counterterm in the solution to the matter continuity and Euler equations, which allows a controlled expansion of clustering statistics on mildly nonlinear scales. We use this setup to compute the one-loop dark-matter power spectrum.

The Theory of the Reentrant Effect in Susceptibility of Cylindrical Mesoscopic Samples

International Nuclear Information System (INIS)

Gogadze, G.A.

2006-01-01

A theory has been developed to explain the anomalous behavior of the magnetic susceptibility of a normal metal-superconductor (NS) structure in weak magnetic fields at milli kelvin temperatures. The effect was discovered experimentally [A. C. Mota et al., Phys. Rev. Lett. 65, 1514 (1990)]. In cylindrical superconducting samples covered with a thin normal pure metal layer, the susceptibility exhibited a reentrant effect: it started to increase unexpectedly when the temperature was lowered below 100 mK. The effect was observed in mesoscopic NS structures when the N and S metals were in good electric contact. The theory proposed is essentially based on the properties of the Andreev levels in the normal metal. When the magnetic field (or temperature) changes, each of the Andreev levels coincides from time to time with the chemical potential of the metal. As a result, the state of the NS structure experiences strong degeneracy, and the quasiparticle density of states exhibits resonance spikes. This generates a large paramagnetic contribution to the susceptibility, which adds to the diamagnetic contribution, thus leading to the reentrant effect. The explanation proposed was obtained within the model of free electrons. The theory provides a good description of the experimental results

Effective theory analysis for vector-like quark model

Science.gov (United States)

Morozumi, Takuya; Shimizu, Yusuke; Takahashi, Shunya; Umeeda, Hiroyuki

2018-04-01

We study a model with a down-type SU(2) singlet vector-like quark (VLQ) as a minimal extension of the standard model (SM). In this model, flavor-changing neutral currents (FCNCs) arise at tree level and the unitarity of the 3× 3 Cabibbo-Kobayashi-Maskawa (CKM) matrix does not hold. In this paper, we constrain the FCNC coupling from b\\rArr s transitions, especially B_s\\rArr μ^+μ^- and \\bar{B}\\rArr X_sγ processes. In order to analyze these processes we derive an effective Lagrangian that is valid below the electroweak symmetry breaking scale. For this purpose, we first integrate out the VLQ field and derive an effective theory by matching Wilson coefficients up to one-loop level. Using the effective theory, we construct the effective Lagrangian for b\\rArr sγ^{(*)}. It includes the effects of the SM quarks and the violation of CKM unitarity. We show the constraints on the magnitude of the FCNC coupling and its phase by taking account of the current experimental data on Δ M_{B_s}, Br[B_s\\rArrμ^+μ^-], Br[\\bar{B}\\rArr X_sγ], and CKM matrix elements, as well as theoretical uncertainties. We find that the constraint from Br[B_s\\rArrμ^+μ^-] is more stringent than that from Br[\\bar{B}\\rArr X_sγ]. We also obtain a bound for the mass of the VLQ and the strength of the Yukawa couplings related to the FCNC coupling of the b\\rArr s transition. Using the CKM elements that satisfy the above constraints, we show how the unitarity is violated on the complex plane.

3D quantum gravity and effective noncommutative quantum field theory.

Science.gov (United States)

Freidel, Laurent; Livine, Etera R

2006-06-09

We show that the effective dynamics of matter fields coupled to 3D quantum gravity is described after integration over the gravitational degrees of freedom by a braided noncommutative quantum field theory symmetric under a kappa deformation of the Poincaré group.

Electromagnetic corrections to ππ scattering lengths: some lessons for the construction of effective hadronic field theories

International Nuclear Information System (INIS)

Maltman, K.

1998-01-01

Using the framework of effective chiral Lagrangians, we show that, in order to correctly implement electromagnetism (EM), as generated from the Standard Model, into effective hadronic theories (such as meson-exchange models) it is insufficient to consider only graphs in the low-energy effective theory containing explicit photon lines. The Standard Model requires the presence of contact interactions in the effective theory which are electromagnetic in origin, but which involve no photons in the effective theory. We illustrate the problems which can result from a ''standard'' EM subtraction: i.e., from assuming that removing all contributions in the effective theory generated by graphs with explicit photon lines fully removes EM effects, by considering the case of the s-wave ππ scattering lengths. In this case it is shown that such a subtraction procedure would lead to the incorrect conclusion that the strong interaction isospin-breaking contributions to these quantities were large when, in fact, they are known to vanish at leading order in m d -m u . The leading EM contact corrections for the channels employed in the extraction of the I=0,2 s-wave ππ scattering lengths from experiment are also evaluated. (orig.)

On the exotic Higgs decays in effective field theory

Energy Technology Data Exchange (ETDEWEB)

Belusca-Maito, Hermes; Falkowski, Adam [Universite Paris-Sud, Laboratoire de Physique Theorique, Orsay (France)

2016-09-15

We discuss exotic Higgs decays in an effective field theory where the Standard Model is extended by dimension-6 operators. We review and update the status of two-body lepton- and quark-flavor-violating decays involving the Higgs boson. We also comment on the possibility of observing three-body flavor-violating Higgs decays in this context. (orig.)

On the exotic Higgs decays in effective field theory.

Science.gov (United States)

Bélusca-Maïto, Hermès; Falkowski, Adam

2016-01-01

We discuss exotic Higgs decays in an effective field theory where the Standard Model is extended by dimension-6 operators. We review and update the status of two-body lepton- and quark-flavor-violating decays involving the Higgs boson. We also comment on the possibility of observing three-body flavor-violating Higgs decays in this context.

Gross theory of nuclear β-decay with shell effects

International Nuclear Information System (INIS)

Pabst, M.

1979-01-01

The present work tries to introduce shell effects selection rules into the gross theory systematically. Instead of an unbunched or bunched Fermigas spectrum a single-particle spectrum in the shell model with a Woods-Saxon potential is used. The knowledge of spin and parity of the levels allows us to introduce selection rules in an approximative way. (orig.)

Heavy baryons in the heavy quark effective theory

International Nuclear Information System (INIS)

Koerner, J.G.; Thompson, G.

1991-10-01

We give a mini-review of recent results on current-induced transitions between heavy baryons (and between heavy and light baryons) in the light of the new spin and flavour symmetries of the Heavy Quark Effective Theory (HQET). We discuss the structure of the 1/m corrections to the heavy mass limit and outline a diagrammatic proof that there are no 0(1/m) correction to the Voloshin-Shifman normalization condition at zero recoil. (orig.)

The behaviour of effective coupling constants in 'finite' grand unification theories in curved spacetime

International Nuclear Information System (INIS)

Buchbinder, I.L.; Odintsov, S.D.; Lichtzier, I.M.

1989-01-01

The question of the behaviour of effective coupling constants in one-loop 'finite' grand unification theories in curved spacetime is investigated. It is shown that in strong gravitational fields the effective coupling constant, corresponding to the parameter of non-minimal interaction of scalar and gravitational fields, tends to the conformal value or increases in an exponential fashion. The one-loop effective potential is obtained with accuracy to linear curvature terms. It is shown that, in external supergravity, supersymmetric finite theories admit asymptotic conformal invariance. (Author)

Power suppressed operators and gauge invariance in soft-collinear effective theory

International Nuclear Information System (INIS)

Bauer, Christian W.; Pirjol, Dan; Stewart, Iain W.

2003-01-01

The form of collinear gauge invariance for power suppressed operators in the soft-collinear effective theory (SCET) is discussed. Using a field redefinition we show that it is possible to make any power suppressed ultrasoft-collinear operators invariant under the original leading order gauge transformations. Our manipulations avoid gauge fixing. The Lagrangians to O(λ 2 ) are given in terms of these new fields. We then give a simple procedure for constructing power suppressed soft-collinear operators in SCET II by using an intermediate theory SCET I

Quantum effects from a purely geometrical relativity theory

International Nuclear Information System (INIS)

Ellis, Homer G

2005-01-01

A purely geometrical relativity theory results from a construction that produces from three-dimensional space a happy unification of Kaluza's five-dimensional theory and Weyl's conformal theory. The theory can provide geometrical explanations for the following observed phenomena, among others: (a) visibility lifetimes of elementary particles of lengths inversely proportional to their rest masses; (b) the equality of charge magnitude among all charged particles interacting at an event; (c) the propensity of electrons in atoms to be seen in discretely spaced orbits; and (d) 'quantum jumps' between those orbits. This suggests the possibility that the theory can provide a deterministic underpinning of quantum mechanics like that provided to thermodynamics by the molecular theory of gases

Reported Theory Use by Digital Interventions for Hazardous and Harmful Alcohol Consumption, and Association With Effectiveness: Meta-Regression.

Science.gov (United States)

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%, Ptheory 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.

The Gaussian streaming model and convolution Lagrangian effective field theory

Energy Technology Data Exchange (ETDEWEB)

Vlah, Zvonimir [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94306 (United States); Castorina, Emanuele; White, Martin, E-mail: zvlah@stanford.edu, E-mail: ecastorina@berkeley.edu, E-mail: mwhite@berkeley.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States)

2016-12-01

We update the ingredients of the Gaussian streaming model (GSM) for the redshift-space clustering of biased tracers using the techniques of Lagrangian perturbation theory, effective field theory (EFT) and a generalized Lagrangian bias expansion. After relating the GSM to the cumulant expansion, we present new results for the real-space correlation function, mean pairwise velocity and pairwise velocity dispersion including counter terms from EFT and bias terms through third order in the linear density, its leading derivatives and its shear up to second order. We discuss the connection to the Gaussian peaks formalism. We compare the ingredients of the GSM to a suite of large N-body simulations, and show the performance of the theory on the low order multipoles of the redshift-space correlation function and power spectrum. We highlight the importance of a general biasing scheme, which we find to be as important as higher-order corrections due to non-linear evolution for the halos we consider on the scales of interest to us.

Effective Medium Theory for Anisotropic Metamaterials

KAUST Repository

Zhang, Xiujuan

2017-11-12

This dissertation includes the study of effective medium theories (EMTs) and their applications in describing wave propagation in anisotropic metamaterials, which can guide the design of metamaterials. An EMT based on field averaging is proposed to describe a peculiar anisotropic dispersion relation that is linear along the symmetry line but quadratic in the perpendicular direction. This dispersion relation is associated with the topological transition of the iso-frequency contours (IFCs), suggesting interesting wave propagation behaviors from beam shaping to beam splitting. In the framework of coherent potential approximation, an analytical EMT is further developed, with the ability to build a direct connection between the microscopic structure and the macroscopic material properties, which overcomes the requirement of prior knowledge of the field distributions. The derived EMT is valid beyond the long-wavelength limit. Using the EMT, an anisotropic zero-index metamaterial is designed. Moreover, the derived EMT imposes a condition that no scattered wave is generated in the ambient medium, which suggests the input signal cannot detect any object that might exist, making it invisible. Such correspondence between the EMT and the invisibilityinspires us to explore the wave cloaking in the same framework of coherent potential approximation. To further broaden the application realm of EMT, an EMT using the parameter retrieval method is studied in the regimes where the previously-developed EMTs are no longer accurate. Based on this study, in conjunction with the EMT mentioned above, a general scheme to realize coherent perfect absorption (CPA) in anisotropic metamaterials is proposed. As an exciting area in metamaterials, the field of metasurfaces has drawn great attention recently. As an easily attainable device, a grating may be the simplest version of metasurfaces. Here, an analytical EMT for gratings made of cylinders is developed by using the multiple scattering

Theory of Nernst effect in layered superconductors

International Nuclear Information System (INIS)

Tinh, B D; Rosenstein, B

2009-01-01

We calculate, using the time-dependent Ginzburg-Landau (TDGL) equation with thermal noise, the transverse thermoelectric conductivity α xy , describing the Nernst effect, in type-II superconductor in the vortex-liquid regime. The method is an elaboration of the Hartree-Fock. An often made in analytical calculations additional assumption that only the lowest Landau level significantly contributes to α xy in the high field limit is lifted by including all the Landau levels. The resulting values in two dimensions (2D) are significantly lower than the numerical simulation data of the same model, but are in reasonably good quantitative agreement with experimental data on La 2 SrCuO 4 above the irreversibility line (below the irreversibility line at which α xy diverges and theory should be modified by including pinning effects).

Morphing the Shell Model into an Effective Theory

International Nuclear Information System (INIS)

Haxton, W. C.; Song, C.-L.

2000-01-01

We describe a strategy for attacking the canonical nuclear structure problem--bound-state properties of a system of point nucleons interacting via a two-body potential--which involves an expansion in the number of particles scattering at high momenta, but is otherwise exact. The required self-consistent solutions of the Bloch-Horowitz equation for effective interactions and operators are obtained by an efficient Green's function method based on the Lanczos algorithm. We carry out this program for the simplest nuclei, d and 3 He , in order to explore the consequences of reformulating the shell model as a controlled effective theory. (c) 2000 The American Physical Society

Localization of effective actions in open superstring field theory

Science.gov (United States)

Maccaferri, Carlo; Merlano, Alberto

2018-03-01

We consider the construction of the algebraic part of D-branes tree-level effective action from Berkovits open superstring field theory. Applying this construction to the quartic potential of massless fields carrying a specific worldsheet charge, we show that the full contribution to the potential localizes at the boundary of moduli space, reducing to elementary two-point functions. As examples of this general mechanism, we show how the Yang-Mills quartic potential and the instanton effective action of a Dp/D( p - 4) system are reproduced.

Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

International Nuclear Information System (INIS)

Hirano, Shin'ichi; Nishi, Sakine; Kobayashi, Tsutomu

2017-01-01

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

Energy Technology Data Exchange (ETDEWEB)

Hirano, Shin' ichi; Nishi, Sakine; Kobayashi, Tsutomu, E-mail: s.hirano@rikkyo.ac.jp, E-mail: sakine@rikkyo.ac.jp, E-mail: tsutomu@rikkyo.ac.jp [Department of Physics, Rikkyo University, Toshima, Tokyo 171-8501 (Japan)

2017-07-01

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

Dynamical symmetry breaking of λφ4 theory in the two loop effective potential

International Nuclear Information System (INIS)

Yang Jifeng; Ruan Jianhong

2002-01-01

The two loop effective potential of massless λφ 4 theory is presented in several regularization and renormalization prescriptions and the dynamical symmetry breaking solution is obtained in the strong-coupling situation in several prescriptions except the Coleman-Weinberg prescription. The beta function in the broken phase becomes negative and the UV fixed point turns out to be a strong-coupling one, and its numeric value varies with the renormalization prescriptions, a detail which is different from the asymptotic-free solution in the one loop case. The symmetry-breaking phase is shown to be an entirely strong-coupling phase. The reason for the relevance of the renormalization prescriptions is shown to be due to the nonperturbative nature of the effective potential. We also reanalyze the two loop effective potential by adopting a differential equation approach based on the understanding that all the quantum field theories are ill-defined formulations of the 'low-energy' effective theories of a complete underlying theory. The relevance of the prescriptions of fixing the local ambiguities to physical properties such as symmetry breaking is further emphasized. We also tentatively propose a rescaling insensitivity argument for fixing the quadratic ambiguities. Some detailed properties of the strongly coupled broken phase and related issues are discussed

Fusion-relevant basic radiation effects: theory and experiment

International Nuclear Information System (INIS)

Mansur, L.K.; Coghlan, W.A.; Farrell, K.; Horton, L.L.; Lee, E.H.; Lewis, M.B.; Packan, N.H.

1983-01-01

A summary is given of results of the basic radiation effects program at Oak Ridge National Laboratory, which are relevant to fusion reactor materials applications. The basic radiation effects program at ORNL is a large effort with the dual objectives of understanding the atomic and microstructural defect mechanisms underlying radiation effects and of determining principles for the design of radiation resistant materials. A strength of this effort is the parallel and integrated experimental and theoretical approaches in each major research area. The experimental effort is active in electron microscopy, ion irradiations and ion-beam techniques, neutron irradiations, surface analysis and in other areas. The theoretical effort is active in developing the theory of radiation effects for a broad range of phenomena and in applying it to the design and interpretation of experiments and to alloy design

Van der Waals Forces and Photon-Less Effective Field Theory

International Nuclear Information System (INIS)

Arriola, E.R.

2011-01-01

In the ultra-cold regime Van der Waals forces between neutral atoms can be represented by short range effective interactions. We show that universal low energy scaling features of the underlying vdW long range force stemming from two photon exchange impose restrictions on an Effective Field Theory without explicit photons. The role of naively redundant operators, relevant to the definition of three body forces, is also analyzed. (author)

Theory of the superconducting proximity effect below the transition temperature

International Nuclear Information System (INIS)

Silvert, W.

1975-01-01

The form of the low-temperature theory of the superconducting proximity effect depends on whether the non-linear terms are assumed to depend only on the local value of the gap or on its average value over some finite range. The local assumption leads to smaller values of the gap and to unphysical results at low temperatures. The effect of non-locality is significant even in the Ginsburg-Landau regime. (author)

Descriptive set theory

CERN Document Server

Moschovakis, YN

1987-01-01

Now available in paperback, this monograph is a self-contained exposition of the main results and methods of descriptive set theory. It develops all the necessary background material from logic and recursion theory, and treats both classical descriptive set theory and the effective theory developed by logicians.

Chern-Simons gauge theories for the fractional-quantum-Hall-effect hierarchy and anyon superconductivity

International Nuclear Information System (INIS)

Ezawa, Z.F.; Iwazaki, A.

1991-01-01

It is shown that Chern-Simons gauge theories describe both the fractional-quantum-Hall-effect (FQHE) hierarchy and anyon superconductivity, simply by field-theoretically extracting the effects of vortex excitations. Vortices correspond to Laughlin's quasiparticles or bound states of anyons. Both of these phenomena are explained by the condensations of these vortices. We clarify why the anyon systems become incompressible (FQHE) or compressible (anyon superconductivity) depending on the statistics. It is to be emphasized that we can derive an effective Lagrangian describing fully the FQHE hierarchy from a basic Chern-Simons gauge theory

Effective gravitational wave stress-energy tensor in alternative theories of gravity

International Nuclear Information System (INIS)

Stein, Leo C.; Yunes, Nicolas

2011-01-01

The inspiral of binary systems in vacuum is controlled by the stress-energy of gravitational radiation and any other propagating degrees of freedom. For gravitational waves, the dominant contribution is characterized by an effective stress-energy tensor at future null infinity. We employ perturbation theory and the short-wavelength approximation to compute this stress-energy tensor in a wide class of alternative theories. We find that this tensor is generally a modification of that first computed by Isaacson, where the corrections can dominate over the general relativistic term. In a wide class of theories, however, these corrections identically vanish at asymptotically flat, future, null infinity, reducing the stress-energy tensor to Isaacson's. We exemplify this phenomenon by first considering dynamical Chern-Simons modified gravity, which corrects the action via a scalar field and the contraction of the Riemann tensor and its dual. We then consider a wide class of theories with dynamical scalar fields coupled to higher-order curvature invariants and show that the gravitational wave stress-energy tensor still reduces to Isaacson's. The calculations presented in this paper are crucial to perform systematic tests of such modified gravity theories through the orbital decay of binary pulsars or through gravitational wave observations.

A Thermodynamical Theory with Internal Variables Describing Thermal Effects in Viscous Fluids

Science.gov (United States)

Ciancio, Vincenzo; Palumbo, Annunziata

2018-04-01

In this paper the heat conduction in viscous fluids is described by using the theory of classical irreversible thermodynamics with internal variables. In this theory, the deviation from the local equilibrium is characterized by vectorial internal variables and a generalized entropy current density expressed in terms of so-called current multipliers. Cross effects between heat conduction and viscosity are also considered and some phenomenological generalizations of Fourier's and Newton's laws are obtained.

On the Renormalization of the Effective Field Theory of Large Scale Structures

OpenAIRE

Pajer, Enrico; Zaldarriaga, Matias

2013-01-01

Standard perturbation theory (SPT) for large-scale matter inhomogeneities is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small on all scales; it does not fully account for deviations at large scales from a perfect pressureless fluid induced by short-scale non-linearities; for generic initial conditions, loop corrections are UV-divergent, making predictions cutoff dependent and hence unphysical. The Effective Field Theory o...

Phase space and jet definitions in soft-collinear effective theory

International Nuclear Information System (INIS)

Cheung, William Man-Yin; Luke, Michael; Zuberi, Saba

2009-01-01

We discuss consistent power counting for integrating soft and collinear degrees of freedom over arbitrary regions of phase space in the soft-collinear effective theory, and illustrate our results at one-loop with several jet algorithms: JADE, Sterman-Weinberg and k perpendicular . Consistently applying soft-collinear effective theory power counting in phase space, along with nontrivial zero-bin subtractions, prevents double counting of final states. The resulting phase space integrals over soft and collinear regions are individually ultraviolet divergent, but the phase space ultraviolet divergences cancel in the sum. Whether the soft and collinear contributions are individually infrared safe depends on the jet definition. We show that while this is true at one-loop for JADE and Sterman-Weinberg, the k perpendicular algorithm does not factorize into individually infrared safe soft and collinear pieces in dimensional regularization. We point out that this statement depends on the ultraviolet regulator, and that in a cutoff scheme the soft functions are infrared safe.

Framing effects are robust to linguistic disambiguation: A critical test of contemporary theory.

Science.gov (United States)

Chick, Christina F; Reyna, Valerie F; Corbin, Jonathan C

2016-02-01

Theoretical accounts of risky choice framing effects assume that decision makers interpret framing options as extensionally equivalent, such that if 600 lives are at stake, saving 200 implies that 400 die. However, many scholars have argued that framing effects are caused, instead, by filling in pragmatically implied information. This linguistic ambiguity hypothesis is grounded in neo-Gricean pragmatics, information leakage, and schema theory. In 2 experiments, we conducted critical tests of the linguistic ambiguity hypothesis and its relation to framing. We controlled for this crucial implied information by disambiguating it using instructions and detailed examples, followed by multiple quizzes. After disambiguating missing information, we presented standard framing problems plus truncated versions, varying types of missing information. Truncations were also critical tests of prospect theory and fuzzy trace theory. Participants were not only college students, but also middle-age adults (who showed similar results). Contrary to the ambiguity hypothesis, participants who interpreted missing information as complementary to stated information nonetheless showed robust framing effects. Although adding words like "at least" can change interpretations of framing information, this form of linguistic ambiguity is not necessary to observe risky choice framing effects. (c) 2016 APA, all rights reserved).

A Geometrical View of Higgs Effective Theory

CERN Multimedia

CERN. Geneva

2016-01-01

A geometric formulation of Higgs Effective Field Theory (HEFT) is presented. Experimental observables are given in terms of geometric invariants of the scalar sigma model sector such as the curvature of the scalar field manifold M. We show how the curvature can be measured experimentally via Higgs cross-sections, W_L scattering, and the S parameter. The one-loop action of HEFT is given in terms of geometric invariants of M. The distinction between the Standard Model (SM) and HEFT is whether M is flat or curved, with the curvature a signal of the scale of new physics.

Effective Lagrangians for SUSY QCD with properties seen in perturbation theory

International Nuclear Information System (INIS)

Sharatchandra, H.S.

1984-06-01

We construct effective Lagrangians for supersymmetric QCD which properly incorporate the relevant Ward identities and possess features encountered in perturbation theory. This shows that the unusual scenarios, proposed for SUSY QCD, are not necessary. (author)

Heavy quark effective theory and study of heavy hadron spectra

International Nuclear Information System (INIS)

Dong Yubing

1995-01-01

By employing the heavy quark effective theory, the spectra of heavy hadrons, such as heavy mesons (Q-barq), heavy baryons (QQq and Qqq) and heavy multiquark systems (Q-barQ-barqq) are studied systemically. The results are compared with the predictions for Q-barQ-barqq in potential model

Zero-range effective field theory for resonant wino dark matter. Part III. Annihilation effects

OpenAIRE

Braaten, Eric; Johnson, Evan; Zhang, Hong

2018-01-01

Near a critical value of the wino mass where there is a zero-energy S-wave resonance at the neutral-wino-pair threshold, low-energy winos can be described by a zero-range effective field theory (ZREFT) in which the winos interact nonperturbatively through a contact interaction and through Coulomb interactions. The effects of wino-pair annihilation into electroweak gauge bosons are taken into account through the analytic continuation of the real parameters for the contact interaction to comple...

The differential effects of tangible rewards and praise on intrinsic motivation: A comparison of cognitive evaluation theory and operant theory.

Science.gov (United States)

Carton, J S

1996-01-01

Substantial research indicates that tangible rewards, such as money, prizes, and tokens, decrease response rates by undermining intrinsic motivation. In contrast, praise appears to increase response rates by enhancing intrinsic motivation. Based on their interpretation of available evidence, many social-cognitive researchers warn not to use tangible rewards in applied settings and to use praise instead. Furthermore, they suggest that the differential effects of the two types of rewards on intrinsic motivation cannot be explained using principles of operant psychology. Cognitive evaluation theory provides one of the most recent and widely cited social-cognitive explanations for the different effects of the two types of rewards on intrinsic motivation (Deci & Ryan, 1985). However, a review of existing research found little support for the explanations based on this theory and revealed three potential confounding effects: (a) temporal contiguity, (b) the number of reward administrations, and (c) discriminative stimuli associated with reward availability. These three confounding factors provide explanations for the effects of tangible rewards and praise on intrinsic motivation that are consistent with principles of operant psychology.

Effective leadership in salient groups: revisiting leader-member exchange theory from the perspective of the social identity theory of leadership.

Science.gov (United States)

Hogg, Michael A; Martin, Robin; Epitropaki, Olga; Mankad, Aditi; Svensson, Alicia; Weeden, Karen

2005-07-01

Two studies compared leader-member exchange (LMX) theory and the social identity theory of leadership. Study 1 surveyed 439 employees of organizations in Wales, measuring work group salience, leader-member relations, and perceived leadership effectiveness. Study 2 surveyed 128 members of organizations in India, measuring identification not salience and also individualism/collectivism. Both studies provided good support for social identity predictions. Depersonalized leader-member relations were associated with greater leadership effectiveness among high-than low-salient groups (Study 1) and among high than low identifiers (Study 2). Personalized leadership effectiveness was less affected by salience (Study 1) and unaffected by identification (Study 2). Low-salience groups preferred personalized leadership more than did high-salience groups (Study 1). Low identifiers showed no preference but high identifiers preferred depersonalized leadership (Study 2). In Study 2, collectivists did not prefer depersonalized as opposed to personalized leadership, whereas individualists did, probably because collectivists focus more on the relational self.

Mechanism of Strain Rate Effect Based on Dislocation Theory

International Nuclear Information System (INIS)

Kun, Qin; Shi-Sheng, Hu; Li-Ming, Yang

2009-01-01

Based on dislocation theory, we investigate the mechanism of strain rate effect. Strain rate effect and dislocation motion are bridged by Orowan's relationship, and the stress dependence of dislocation velocity is considered as the dynamics relationship of dislocation motion. The mechanism of strain rate effect is then investigated qualitatively by using these two relationships although the kinematics relationship of dislocation motion is absent due to complicated styles of dislocation motion. The process of strain rate effect is interpreted and some details of strain rate effect are adequately discussed. The present analyses agree with the existing experimental results. Based on the analyses, we propose that strain rate criteria rather than stress criteria should be satisfied when a metal is fully yielded at a given strain rate. (condensed matter: structure, mechanical and thermal properties)

Non-perturbative heavy quark effective theory. Introduction and status

International Nuclear Information System (INIS)

Sommer, Rainer; Humboldt-Universitaet, Berlin

2015-01-01

We give an introduction to Heavy Quark Effective Theory (HQET). Our emphasis is on its formulation non-perturbative in the strong coupling, including the non-perturbative determination of the parameters in the HQET Lagrangian. In a second part we review the present status of HQET on the lattice, largely based on work of the ALPHA collaboration in the last few years. We finally discuss opportunities and challenges.

Testing the Effectiveness of Online Assignments in Theory of Finance

Science.gov (United States)

Batu, Michael; Bower, Nancy; Lun, Esmond; Sadanand, Asha

2018-01-01

The authors investigated the effectiveness of online versus paper assignments using final examination scores in three cohorts of theory of finance. In particular, two cohorts were exposed to online assignments while another cohort was exposed to traditional assignments. The central result is that exposure to online assignments robustly leads to…

Degenerate Perturbation Theory for Electronic g Tensors: Leading-Order Relativistic Effects.

Science.gov (United States)

Rinkevicius, Zilvinas; de Almeida, Katia Julia; Oprea, Cornel I; Vahtras, Olav; Ågren, Hans; Ruud, Kenneth

2008-11-11

A new approach for the evaluation of the leading-order relativistic corrections to the electronic g tensors of molecules with a doublet ground state is presented. The methodology is based on degenerate perturbation theory and includes all relevant contributions to the g tensor shift up to order O(α(4)) originating from the one-electron part of the Breit-Pauli Hamiltonian-that is, it allows for the treatment of scalar relativistic, spin-orbit, and mixed corrections to the spin and orbital Zeeman effects. This approach has been implemented in the framework of spin-restricted density functional theory and is in the present paper, as a first illustration of the theory, applied to study relativistic effects on electronic g tensors of dihalogen anion radicals X2(-) (X = F, Cl, Br, I). The results indicate that the spin-orbit interaction is responsible for the large parallel component of the g tensor shift of Br2(-) and I2(-), and furthermore that both the leading-order scalar relativistic and spin-orbit corrections are of minor importance for the perpendicular component of the g tensor in these molecules since they effectively cancel each other. In addition to investigating the g tensors of dihalogen anion radicals, we also critically examine the importance of various relativistic corrections to the electronic g tensor of linear molecules with Σ-type ground states and present a two-state model suitable for an approximate estimation of the g tensor in such molecules.

Supergravity theories

International Nuclear Information System (INIS)

Uehara, S.

1985-01-01

Of all supergravity theories, the maximal, i.e., N = 8 in 4-dimension or N = 1 in 11-dimension, theory should perform the unification since it owns the highest degree of symmetry. As to the N = 1 in d = 11 theory, it has been investigated how to compactify to the d = 4 theories. From the phenomenological point of view, local SUSY GUTs, i.e., N = 1 SUSY GUTs with soft breaking terms, have been studied from various angles. The structures of extended supergravity theories are less understood than those of N = 1 supergravity theories, and matter couplings in N = 2 extended supergravity theories are under investigation. The harmonic superspace was recently proposed which may be useful to investigate the quantum effects of extended supersymmetry and supergravity theories. As to the so-called Kaluza-Klein supergravity, there is another possibility. (Mori, K.)

Finite-size effect of the dyonic giant magnons in N=6 super Chern-Simons theory

International Nuclear Information System (INIS)

Ahn, Changrim; Bozhilov, P.

2009-01-01

We consider finite-size effects for the dyonic giant magnon of the type IIA string theory on AdS 4 xCP 3 by applying the Luescher μ-term formula which is derived from a recently proposed S matrix for the N=6 super Chern-Simons theory. We compute explicitly the effect for the case of a symmetric configuration where the two external bound states, each of A and B particles, have the same momentum p and spin J 2 . We compare this with the classical string theory result which we computed by reducing it to the Neumann-Rosochatius system. The two results match perfectly.

A proposal for an effective interacting field theory of open and closed strings

International Nuclear Information System (INIS)

Baulieu, L.; Grossman, B.

1987-01-01

We propose the use of the reggeon-pomeron vertex to obtain an effective field theory for open and closed strings. We suggest that closed string fields are necessary in order to go off-shell in an open string field theory. We then find that the closed string fields satisfy the Virasoro constraints (including equal number of left and right movers) in an appropriate choice of gauge. (orig.)

Setting limits on Effective Field Theories: the case of Dark Matter

Science.gov (United States)

Pobbe, Federico; Wulzer, Andrea; Zanetti, Marco

2017-08-01

The usage of Effective Field Theories (EFT) for LHC new physics searches is receiving increasing attention. It is thus important to clarify all the aspects related with the applicability of the EFT formalism in the LHC environment, where the large available energy can produce reactions that overcome the maximal range of validity, i.e. the cutoff, of the theory. We show that this does not forbid to set rigorous limits on the EFT parameter space through a modified version of the ordinary binned likelihood hypothesis test, which we design and validate. Our limit-setting strategy can be carried on in its full-fledged form by the LHC experimental collaborations, or performed externally to the collaborations, through the Simplified Likelihood approach, by relying on certain approximations. We apply it to the recent CMS mono-jet analysis and derive limits on a Dark Matter (DM) EFT model. DM is selected as a case study because the limited reach on the DM production EFT Wilson coefficient and the structure of the theory suggests that the cutoff might be dangerously low, well within the LHC reach. However our strategy can also be applied, if needed, to EFT's parametrising the indirect effects of heavy new physics in the Electroweak and Higgs sectors.

Anomaly cancelation in field theory and F-theory on a circle

International Nuclear Information System (INIS)

Grimm, Thomas W.; Kapfer, Andreas

2016-01-01

We study the manifestation of local gauge anomalies of four- and six-dimensional field theories in the lower-dimensional Kaluza-Klein theory obtained after circle compactification. We identify a convenient set of transformations acting on the whole tower of massless and massive states and investigate their action on the low-energy effective theories in the Coulomb branch. The maps employ higher-dimensional large gauge transformations and precisely yield the anomaly cancelation conditions when acting on the one-loop induced Chern-Simons terms in the three- and five-dimensional effective theory. The arising symmetries are argued to play a key role in the study of the M-theory to F-theory limit on Calabi-Yau manifolds. For example, using the fact that all fully resolved F-theory geometries inducing multiple Abelian gauge groups or non-Abelian groups admit a certain set of symmetries, we are able to generally show the cancelation of pure Abelian or pure non-Abelian anomalies in these models.

Stakeholder Theory As an Ethical Approach to Effective Management: applying the theory to multiple contexts

Directory of Open Access Journals (Sweden)

Jeffrey S. Harrison

2015-09-01

Full Text Available Objective – This article provides a brief overview of stakeholder theory, clears up some widely held misconceptions, explains the importance of examining stakeholder theory from a variety of international perspectives and how this type of research will advance management theory, and introduces the other articles in the special issue. Design/methodology/approach – Some of the foundational ideas of stakeholder theory are discussed, leading to arguments about the importance of the theory to management research, especially in an international context. Findings – Stakeholder theory is found to be a particularly useful perspective for addressing some of the important issues in business from an international perspective. It offers an opportunity to reinterpret a variety of concepts, models and phenomena across may different disciplines. Practical implications – The concepts explored in this article may be applied in many contexts, domestically and internationally, and across business disciplines as diverse as economics, public administration, finance, philosophy, marketing, law, and management. Originality/value – Research on stakeholder theory in an international context is both lacking and sorely needed. This article and the others in this special issue aim to help fill that void.

The Effective Field Theory of nonsingular cosmology

Energy Technology Data Exchange (ETDEWEB)

Cai, Yong [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); Wan, Youping [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy,University of Science and Technology of China, Chinese Academy of Sciences,Hefei, Anhui 230026 (China); Li, Hai-Guang [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); Qiu, Taotao [Institute of Astrophysics, Central China Normal University,Wuhan 430079 (China); Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University,Wuhan 430079 (China); Piao, Yun-Song [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); Institute of Theoretical Physics, Chinese Academy of Sciences,P.O. Box 2735, Beijing 100190 (China)

2017-01-20

In this paper, we explore the nonsingular cosmology within the framework of the Effective Field Theory (EFT) of cosmological perturbations. Due to the recently proved no-go theorem, any nonsingular cosmological models based on the cubic Galileon suffer from pathologies. We show how the EFT could help us clarify the origin of the no-go theorem, and offer us solutions to break the no-go. Particularly, we point out that the gradient instability can be removed by using some spatial derivative operators in EFT. Based on the EFT description, we obtain a realistic healthy nonsingular cosmological model, and show the perturbation spectrum can be consistent with the observations.

The Effective Field Theory of nonsingular cosmology

International Nuclear Information System (INIS)

Cai, Yong; Wan, Youping; Li, Hai-Guang; Qiu, Taotao; Piao, Yun-Song

2017-01-01

In this paper, we explore the nonsingular cosmology within the framework of the Effective Field Theory (EFT) of cosmological perturbations. Due to the recently proved no-go theorem, any nonsingular cosmological models based on the cubic Galileon suffer from pathologies. We show how the EFT could help us clarify the origin of the no-go theorem, and offer us solutions to break the no-go. Particularly, we point out that the gradient instability can be removed by using some spatial derivative operators in EFT. Based on the EFT description, we obtain a realistic healthy nonsingular cosmological model, and show the perturbation spectrum can be consistent with the observations.

Renormalons and the heavy quark effective theory

CERN Document Server

Martinelli, G; Martinelli, G; Sachrajda, C T

1995-01-01

We propose a non-perturbative method for defining the higher dimensional operators which appear in the Heavy Quark Effective Theory (HQET), such that their matrix elements are free of renormalon singularities, and diverge at most logarithmically with the ultra-violet cut-off. Matrix elements of these operators can be computed numerically in lattice simulations of the HQET. We illustrate our procedures by presenting physical definitions of the binding energy (\\lb) and of the kinetic energy (-\\lambda_1/2m_Q) of the heavy quark in a hadron. This allows us to define a ``subtracted pole mass", whose inverse can be used as the expansion parameter in applications of the HQET.

Modeling of surface stress effects on bending behavior of nanowires: Incremental deformation theory

International Nuclear Information System (INIS)

Song, F.; Huang, G.L.

2009-01-01

The surface stress effects on bending behavior of nanowires have recently attracted a lot of attention. In this letter, the incremental deformation theory is first applied to study the surface stress effects upon the bending behavior of the nanowires. Different from other linear continuum approaches, the local geometrical nonlinearity of the Lagrangian strain is considered, therefore, the contribution of the surface stresses is naturally derived by applying the Hamilton's principle, and influence of the surface stresses along all surfaces of the nanowires is captured. It is first shown that the surface stresses along all surfaces have contribution not only on the effective Young's modulus of the nanowires but also on the loading term in the governing equation. The predictions of the effective Young's modulus and the resonance shift of the nanowires from the current method are compared with those from the experimental measurement and other existing approaches. The difference with other models is discussed. Finally, based on the current theory, the resonant shift predictions by using both the modified Euler-Bernoulli beam and the modified Timoshenko beam theories of the nanowires are investigated and compared. It is noticed that the higher vibration modes are less sensitive to the surface stresses than the lower vibration modes.

Effective field theory of an anomalous Hall metal from interband quantum fluctuations

Science.gov (United States)

Chua, Victor; Assawasunthonnet, Wathid; Fradkin, Eduardo

2017-07-01

We construct an effective field theory, a two-dimensional two-component metallic system described by a model with two Fermi surfaces ("pockets"). This model describes a translationally invariant metallic system with two types of fermions, each with its own Fermi surface, with forward scattering interactions. This model, in addition to the O (2 ) rotational invariance, has a U (1 )×U (1 ) symmetry of separate charge conservation for each Fermi surface. For sufficiently attractive interactions in the d -wave (quadrupolar) channel, this model has an interesting phase diagram that includes a spontaneously generated anomalous Hall metal phase. We derive the Landau-Ginzburg effective action of quadrupolar order parameter fields which enjoys an O (2 )×U (1 ) global symmetry associated to spatial isotropy and the internal U (1 ) relative phase symmetries, respectively. We show that the order parameter theory is dynamically local with a dynamical scaling of z =2 and perform a one-loop renormalization group analysis of the Landau-Ginzburg theory. The electronic liquid crystal phases that result from spontaneous symmetry breaking are studied and we show the presence of Landau damped Nambu-Goldstone modes at low momenta that is a signature of non-Fermi-liquid behavior. Electromagnetic linear response is also analyzed in both the normal and symmetry broken phases from the point of view of the order parameter theory. The nature of the coupling of electromagnetism to the order parameter fields in the normal phase is non-minimal and decidedly contains a precursor to the anomalous Hall response in the form of a order-parameter-dependent Chern-Simons term in the effective action.

Multimedia instructions and cognitive load theory: effects of modality and cueing.

Science.gov (United States)

Tabbers, Huib K; Martens, Rob L; van Merriënboer, Jeroen J G

2004-03-01

Recent research on the influence of presentation format on the effectiveness of multimedia instructions has yielded some interesting results. According to cognitive load theory (Sweller, Van Merriënboer, & Paas, 1998) and Mayer's theory of multimedia learning (Mayer, 2001), replacing visual text with spoken text (the modality effect) and adding visual cues relating elements of a picture to the text (the cueing effect) both increase the effectiveness of multimedia instructions in terms of better learning results or less mental effort spent. The aim of this study was to test the generalisability of the modality and cueing effect in a classroom setting. The participants were 111 second-year students from the Department of Education at the University of Gent in Belgium (age between 19 and 25 years). The participants studied a web-based multimedia lesson on instructional design for about one hour. Afterwards they completed a retention and a transfer test. During both the instruction and the tests, self-report measures of mental effort were administered. Adding visual cues to the pictures resulted in higher retention scores, while replacing visual text with spoken text resulted in lower retention and transfer scores. Only a weak cueing effect and even a reverse modality effect have been found, indicating that both effects do not easily generalise to non-laboratory settings. A possible explanation for the reversed modality effect is that the multimedia instructions in this study were learner-paced, as opposed to the system-paced instructions used in earlier research.

Effective field theory of thermal Casimir interactions between anisotropic particles.

Science.gov (United States)

Haussman, Robert C; Deserno, Markus

2014-06-01

We employ an effective field theory (EFT) approach to study thermal Casimir interactions between objects bound to a fluctuating fluid surface or interface dominated by surface tension, with a focus on the effects of particle anisotropy. The EFT prescription disentangles the constraints imposed by the particles' boundaries from the calculation of the interaction free energy by constructing an equivalent point particle description. The finite-size information is captured in a derivative expansion that encodes the particles' response to external fields. The coefficients of the expansion terms correspond to generalized tensorial polarizabilities and are found by matching the results of a linear response boundary value problem computed in both the full and effective theories. We demonstrate the versatility of the EFT approach by constructing the general effective Hamiltonian for a collection of particles of arbitrary shapes. Taking advantage of the conformal symmetry of the Hamiltonian, we discuss a straightforward conformal mapping procedure to systematically determine the polarizabilities and derive a complete description for elliptical particles. We compute the pairwise interaction energies to several orders for nonidentical ellipses as well as their leading-order triplet interactions and discuss the resulting preferred pair and multibody configurations. Furthermore, we elaborate on the complications that arise with pinned particle boundary conditions and show that the powerlike corrections expected from dimensional analysis are exponentially suppressed by the leading-order interaction energies.

Possible unifying effect of the dynamic theory

International Nuclear Information System (INIS)

Williams, P.E.

1983-05-01

This report presents the tentative results of recent research during which a neocoulombic electrostatic force of the form (k/r 2 )(1-lambda/r) exp(-lambda/r) was derived. This neocoulombic force offers a possible alternative explanation of nuclear phenomena without the necessity for postulating the existence of nuclear forces, and it allows the prediction of nuclear masses. The result is a view of physics in a five-dimensional manifold of space, time, and mass density in which the gauge field includes gravitational and electromagnetic components coupled by a single system of eight differential equations, quantum effects occur as the result of a restrictive assumption, and nuclear phenomena result from the new form for the electrostatic force. Also, the geometrical effect on the unit of action in quantum mechanics is presented, the self-energy of charged particles is calculated, and experimental tests of the theory are suggested

Baryonic forces and hyperons in nuclear matter from SU(3) chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Petschauer, Stefan Karl

2016-02-12

In this work the baryon-baryon interaction is studied at next-to-leading order in SU(3) chiral effective field theory and applied to hyperon-nucleon scattering. The properties of hyperons in isospin-symmetric as well as asymmetric nuclear matter are calculated within the Bruecker-Hartree-Fock formalism. Moreover, the leading three-baryon interaction is derived and its low-energy constants are estimated from decuplet intermediate states. We conclude, that chiral effective field theory is a well-suited tool to describe the baryonic forces.

A note on nonperturbative renormalization of effective field theory

Energy Technology Data Exchange (ETDEWEB)

Yang Jifeng [Department of Physics, East China Normal University, Shanghai 200062 (China)

2009-08-28

Within the realm of contact potentials, the key structures intrinsic of nonperturbative renormalization of T-matrices are unraveled using rigorous solutions and an inverse form of the algebraic Lippmann-Schwinger equation. The intrinsic mismatches between effective field theory power counting and nonperturbative divergence structures are shown for the first time to preclude the conventional counterterm algorithm from working in the renormalization of EFT for NN scattering in nonperturbative regimes.

A note on nonperturbative renormalization of effective field theory

International Nuclear Information System (INIS)

Yang Jifeng

2009-01-01

Within the realm of contact potentials, the key structures intrinsic of nonperturbative renormalization of T-matrices are unraveled using rigorous solutions and an inverse form of the algebraic Lippmann-Schwinger equation. The intrinsic mismatches between effective field theory power counting and nonperturbative divergence structures are shown for the first time to preclude the conventional counterterm algorithm from working in the renormalization of EFT for NN scattering in nonperturbative regimes.

Chiral perturbation theory

International Nuclear Information System (INIS)

Ecker, G.

1996-06-01

After a general introduction to the structure of effective field theories, the main ingredients of chiral perturbation theory are reviewed. Applications include the light quark mass ratios and pion-pion scattering to two-loop accuracy. In the pion-nucleon system, the linear σ model is contrasted with chiral perturbation theory. The heavy-nucleon expansion is used to construct the effective pion-nucleon Lagrangian to third order in the low-energy expansion, with applications to nucleon Compton scattering. (author)

Chiral effective field theory on the lattice at next-to-leading order

International Nuclear Information System (INIS)

Borasoy, B.; Epelbaum, E.; Krebs, H.; Meissner, U.G.; Lee, D.

2008-01-01

We study nucleon-nucleon scattering on the lattice at next-to-leading order in chiral effective field theory. We determine phase shifts and mixing angles from the properties of two-nucleon standing waves induced by a hard spherical wall in the center-of-mass frame. At fixed lattice spacing we test model independence of the low-energy effective theory by computing next-to-leading-order corrections for two different leading-order lattice actions. The first leading-order action includes instantaneous one-pion exchange and same-site contact interactions. The second leading-order action includes instantaneous one-pion exchange and Gaussian-smeared interactions. We find that in each case the results at next-to-leading order are accurate up to corrections expected at higher order. (orig.)

ΔΔ intermediate state in 1S0NN scattering from effective field theory

International Nuclear Information System (INIS)

Savage, M.J.

1997-01-01

We examine the role of the ΔΔ intermediate state in NN scattering in the 1 S 0 channel. The computation is performed at lowest order in an effective-field theory involving local four-fermion operators and one-pion exchange using dimensional regularization with minimal subtraction (MS). As first discussed by Weinberg, in the theory with only nucleons, the large-scattering length in this channel requires a small scale for the local N 4 operators. When Δ close-quote s are included (but without pions) a large-scattering length can be obtained from operators with a scale √(2M N (M Δ -M N )), but fine-tuning is required. The coefficients of the contact terms involving the Δ fields are not uniquely determined but for reasonable values one finds that, in general, NN scattering computed in the theory with Δ close-quote s looks like that computed in the theory without Δ close-quote s. The leading effect of the Δ close-quote s is to change the coefficients of the four-nucleon contact terms between the theories with and without Δ close-quote s. Further, the decoupling of the Δ close-quote s in the limit of large mass and strong coupling is clearly demonstrated. When pions are included, the typical scale for the contact terms is ∼100MeV, both with and without Δ close-quote s and is not set by √(2M N (M Δ -M N )). For reasonable values of contact terms that reproduce the scattering length and effective range (at lowest order) the phase shift is not well reproduced over a larger momentum range as is found in the theory without Δ close-quote s at lowest order. copyright 1997 The American Physical Society

On low rank classical groups in string theory, gauge theory and matrix models

International Nuclear Information System (INIS)

Intriligator, Ken; Kraus, Per; Ryzhov, Anton V.; Shigemori, Masaki; Vafa, Cumrun

2004-01-01

We consider N=1 supersymmetric U(N), SO(N), and Sp(N) gauge theories, with two-index tensor matter and added tree-level superpotential, for general breaking patterns of the gauge group. By considering the string theory realization and geometric transitions, we clarify when glueball superfields should be included and extremized, or rather set to zero; this issue arises for unbroken group factors of low rank. The string theory results, which are equivalent to those of the matrix model, refer to a particular UV completion of the gauge theory, which could differ from conventional gauge theory results by residual instanton effects. Often, however, these effects exhibit miraculous cancellations, and the string theory or matrix model results end up agreeing with standard gauge theory. In particular, these string theory considerations explain and remove some apparent discrepancies between gauge theories and matrix models in the literature

A multipole-expanded effective field theory for vortex ring-sound interactions

Science.gov (United States)

Garcia-Saenz, Sebastian; Mitsou, Ermis; Nicolis, Alberto

2018-02-01

The low-energy dynamics of a zero temperature superfluid or of the compressional modes of an ordinary fluid can be described by a simple effective theory for a scalar field — the superfluid `phase'. However, when vortex lines are present, to describe all interactions in a local fashion one has to switch to a magnetic-type dual two-form description, which comes with six degrees of freedom (in place of one) and an associated gauge redundancy, and is thus considerably more complicated. Here we show that, in the case of vortex rings and for bulk modes that are much longer than the typical ring size, one can perform a systematic multipole expansion of the effective action and recast it into the simpler scalar field language. In a sense, in the presence of vortex rings the non-single valuedness of the scalar can be hidden inside the rings, and thus out of the reach of the multipole expansion. As an application of our techniques, we compute by standard effective field theory methods the sound emitted by an oscillating vortex ring.

Prospect theory or construal level theory? Diminishing sensitivity vs. psychological distance in risky decisions.

Science.gov (United States)

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.

The gamma N ---> Delta transition in chiral effective-field theory.

Energy Technology Data Exchange (ETDEWEB)

Vladimir Pascalutsa; Marc Vanderhaeghen

2006-04-27

We describe the pion electroproduction processes in the {Delta}(1232)-resonance region within the framework of chiral effective-field theory. By studying the observables of pion electroproduction in a next-to-leading order calculation we are able to make predictions and draw conclusions on the properties of the N {yields} {Delta} electromagnetic form factors.

The last gasp of Dark Matter effective theory

International Nuclear Information System (INIS)

Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

2016-07-01

We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.

The last gasp of Dark Matter effective theory

Energy Technology Data Exchange (ETDEWEB)

Bruggisser, Sebastian [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Riva, Francesco; Urbano, Alfredo [CERN, Geneva (Switzerland). Theoretical Physics Dept.

2016-07-15

We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.

The Last Gasp of Dark Matter Effective Theory

CERN Document Server

Bruggisser, Sebastian; Urbano, Alfredo

2016-11-10

We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.

Feynman rules for the Standard Model Effective Field Theory in R ξ -gauges

Science.gov (United States)

Dedes, A.; Materkowska, W.; Paraskevas, M.; Rosiek, J.; Suxho, K.

2017-06-01

We assume that New Physics effects are parametrized within the Standard Model Effective Field Theory (SMEFT) written in a complete basis of gauge invariant operators up to dimension 6, commonly referred to as "Warsaw basis". We discuss all steps necessary to obtain a consistent transition to the spontaneously broken theory and several other important aspects, including the BRST-invariance of the SMEFT action for linear R ξ -gauges. The final theory is expressed in a basis characterized by SM-like propagators for all physical and unphysical fields. The effect of the non-renormalizable operators appears explicitly in triple or higher multiplicity vertices. In this mass basis we derive the complete set of Feynman rules, without resorting to any simplifying assumptions such as baryon-, lepton-number or CP conservation. As it turns out, for most SMEFT vertices the expressions are reasonably short, with a noticeable exception of those involving 4, 5 and 6 gluons. We have also supplemented our set of Feynman rules, given in an appendix here, with a publicly available Mathematica code working with the FeynRules package and producing output which can be integrated with other symbolic algebra or numerical codes for automatic SMEFT amplitude calculations.

Effect of accretion on primordial black holes in Brans-Dicke theory

International Nuclear Information System (INIS)

Nayak, B.; Singh, L. P.; Majumdar, A. S.

2009-01-01

We consider the effect of accretion of radiation in the early Universe on primordial black holes in Brans-Dicke theory. The rate of growth of a primordial black hole due to accretion of radiation in Brans-Dicke theory is considerably smaller than the rate of growth of the cosmological horizon, thus making available sufficient radiation density for the black hole to accrete causally. We show that accretion of radiation by Brans-Dicke black holes overrides the effect of Hawking evaporation during the radiation dominated era. The subsequent evaporation of the black holes in later eras is further modified due to the variable gravitational 'constant', and they could survive up to longer times compared to the case of standard cosmology. We estimate the impact of accretion on modification of the constraint on their initial mass fraction obtained from the γ-ray background limit from presently evaporating primordial black holes.

New Constraints on Dark Matter Effective Theories from Standard Model Loops

CERN Document Server

Crivellin, Andreas; Procura, Massimiliano

2014-01-01

We consider an effective field theory for a gauge singlet Dirac dark matter (DM) particle interacting with the Standard Model (SM) fields via effective operators suppressed by the scale $\\Lambda \\gtrsim 1$ TeV. We perform a systematic analysis of the leading loop contributions to spin-independent (SI) DM--nucleon scattering using renormalization group evolution between $\\Lambda$ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity-suppressed and spin-dependent can actually contribute to SI scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are comparable to LHC bounds, and will significantly improve in the near future. Interestingly, the loop contribution we find is maximally isospin violating even if the underlying theory is isospin conserving.

The matter power spectrum in redshift space using effective field theory

Science.gov (United States)

Fonseca de la Bella, Lucía; Regan, Donough; Seery, David; Hotchkiss, Shaun

2017-11-01

The use of Eulerian 'standard perturbation theory' to describe mass assembly in the early universe has traditionally been limited to modes with k lesssim 0.1 h/Mpc at z=0. At larger k the SPT power spectrum deviates from measurements made using N-body simulations. Recently, there has been progress in extending the reach of perturbation theory to larger k using ideas borrowed from effective field theory. We revisit the computation of the redshift-space matter power spectrum within this framework, including for the first time the full one-loop time dependence. We use a resummation scheme proposed by Vlah et al. to account for damping of baryonic acoustic oscillations due to large-scale random motions and show that this has a significant effect on the multipole power spectra. We renormalize by comparison to a suite of custom N-body simulations matching the MultiDark MDR1 cosmology. At z=0 and for scales k lesssim 0.4 h/Mpc we find that the EFT furnishes a description of the real-space power spectrum up to ~ 2%, for the l = 0 mode up to ~ 5%, and for the l = 2, 4 modes up to ~ 25%. We argue that, in the MDR1 cosmology, positivity of the l=0 mode gives a firm upper limit of k ≈ 0.74 h/Mpc for the validity of the one-loop EFT prediction in redshift space using only the lowest-order counterterm. We show that replacing the one-loop growth factors by their Einstein-de Sitter counterparts is a good approximation for the l=0 mode, but can induce deviations as large as 2% for the l=2, 4 modes. An accompanying software bundle, distributed under open source licenses, includes Mathematica notebooks describing the calculation, together with parallel pipelines capable of computing both the necessary one-loop SPT integrals and the effective field theory counterterms.

Analysis of the Effect of Water Activity on Ice Formation Using a New Theory of Nucleation

Science.gov (United States)

Barahona, Donifan

2013-01-01

In this work a new theory of nucleation is developed and used to investigate the effect of water activity on the formation of ice within super-cooled droplets. The new theory is based on a novel concept where the interface is assumed to be made of liquid molecules trapped by the solid matrix. Using this concept new expressions are developed for the critical ice germ size and the nucleation work, with explicit dependencies on temperature and water activity. However unlike previous approaches, the new theory does not depend on the interfacial tension between liquid and ice. Comparison against experimental results shows that the new theory is able to reproduce the observed effect of water activity on nucleation rate and freezing temperature. It allows for the first time a theoretical derivation of the constant shift in water activity between melting and nucleation. The new theory offers a consistent thermodynamic view of ice nucleation, simple enough to be applied in atmospheric models of cloud formation.

Effective Einsteinian gravity from Poincare gauge field theory

International Nuclear Information System (INIS)

Baekler, P.; Mielke, E.W.

1985-10-01

The Poincare gauge theory of gravity should apply in the microphysical domain. Here we investigate its implications for macrophysics. Weakly self double dual Riemann-Cartan curvature is assumed throughout. It is shown that the metrical background is then determined by Einstein's field equations with the Belinfante-Rosenfeld symmetrized energy-momentum current amended by spin squared terms. Moreover, the effective cosmological constant can be reconciled with the empirical data by absorbing the corresponding constant curvature part into the dynamical torsion of recently found exact solutions. Macroscopically this extra torsion remains undetectable. (author)

Mass corrections in string theory and lattice field theory

International Nuclear Information System (INIS)

Del Debbio, Luigi; Kerrane, Eoin; Russo, Rodolfo

2009-01-01

Kaluza-Klein (KK) compactifications of higher-dimensional Yang-Mills theories contain a number of 4-dimensional scalars corresponding to the internal components of the gauge field. While at tree level the scalar zero modes are massless, it is well known that quantum corrections make them massive. We compute these radiative corrections at 1 loop in an effective field theory framework, using the background field method and proper Schwinger-time regularization. In order to clarify the proper treatment of the sum over KK modes in the effective field theory approach, we consider the same problem in two different UV completions of Yang-Mills: string theory and lattice field theory. In both cases, when the compactification radius R is much bigger than the scale of the UV completion (R>>√(α ' ), a), we recover a mass renormalization that is independent of the UV scale and agrees with the one derived in the effective field theory approach. These results support the idea that the value of the mass corrections is, in this regime, universal for any UV completion that respects locality and gauge invariance. The string analysis suggests that this property holds also at higher loops. The lattice analysis suggests that the mass of the adjoint scalars appearing in N=2, 4 super Yang-Mills is highly suppressed, even if the lattice regularization breaks all supersymmetries explicitly. This is due to an interplay between the higher-dimensional gauge invariance and the degeneracy of bosonic and fermionic degrees of freedom.

Theory of Electric-Field Effects on Electron-Spin-Resonance Hyperfine Couplings

International Nuclear Information System (INIS)

Karna, S.P.

1997-01-01

A quantum mechanical theory of the effects of a uniform electric field on electron-spin-resonance hyperfine couplings is presented. The electric-field effects are described in terms of perturbation coefficients which can be used to probe the local symmetry as well as the strength of the electric field at paramagnetic sites in a solid. Results are presented for the first-order perturbation coefficients describing the Bloembergen effect (linear electric-field effect on hyperfine coupling tensor) for the O atom and the OH radical. copyright 1997 The American Physical Society

The Microeconomic Theory of the Rebound Effect and Its Welfare Implications

OpenAIRE

Nathan W. Chan; Kenneth Gillingham

2015-01-01

Economists have long noted that improving energy efficiency could lead to a rebound effect, reducing or possibly even eliminating the energy savings from the efficiency improvement. This paper develops a generalized model to highlight features of the theory of the microeconomic rebound effect that are particularly relevant to empirical economists. We demonstrate when common elasticity identities used for empirical estimation are biased and how gross complement and substitute relationships gov...

Waltz's Theory of Theory

DEFF Research Database (Denmark)

Wæver, Ole

2009-01-01

-empiricism and anti-positivism of his position. Followers and critics alike have treated Waltzian neorealism as if it was at bottom a formal proposition about cause-effect relations. The extreme case of Waltz being so victorious in the discipline, and yet being consistently mis-interpreted on the question of theory......, shows the power of a dominant philosophy of science in US IR, and thus the challenge facing any ambitious theorising. The article suggests a possible movement of fronts away from the ‘fourth debate' between rationalism and reflectivism towards one of theory against empiricism. To help this new agenda...

The effective action of warped M-theory reductions with higher derivative terms — part I

Energy Technology Data Exchange (ETDEWEB)

Grimm, Thomas W.; Pugh, Tom G.; Weissenbacher, Matthias [Max Planck Institute for Physics,Föhringer Ring 6, 80805 Munich (Germany)

2016-01-25

M-theory accessed via eleven-dimensional supergravity admits globally consistent warped solutions with eight-dimensional compact spaces if background fluxes and higher derivative terms are considered. The internal background is conformally Kähler with vanishing first Chern class. We perturb these solutions including a finite number of Kähler deformations of the metric and vector deformations of the M-theory three-form. Special emphasis is given to the field-dependence of the warp-factor and the higher-derivative terms. We show that the three-dimensional two-derivative effective action takes a surprisingly simple form in terms of a single higher-curvature building block due to numerous non-trivial cancellations. Both the ansatz and the effective action admit a moduli dependent scaling symmetry of the internal metric. Furthermore, we find that the required departure from Ricci-flatness and harmonicity of the zero-mode eigenforms does not alter the effective theory.

The low-energy effective theory of QCD at small quark masses in a finite volume

Energy Technology Data Exchange (ETDEWEB)

Lehner, Christoph

2010-01-15

At low energies the theory of quantum chromodynamics (QCD) can be described effectively in terms of the lightest particles of the theory, the pions. This approximation is valid for temperatures well below the mass difference of the pions to the next heavier particles. We study the low-energy effective theory at very small quark masses in a finite volume V. The corresponding perturbative expansion in 1/{radical}(V) is called {epsilon} expansion. At each order of this expansion a finite number of low-energy constants completely determine the effective theory. These low-energy constants are of great phenomenological importance. In the leading order of the {epsilon} expansion, called {epsilon} regime, the theory becomes zero-dimensional and is therefore described by random matrix theory (RMT). The dimensionless quantities of RMT are mapped to dimensionful quantities of the low-energy effective theory using the leading-order lowenergy constants {sigma} and F. In this way {sigma} and F can be obtained from lattice QCD simulations in the '' regime by a fit to RMT predictions. For typical volumes of state-of-the-art lattice QCD simulations, finite-volume corrections to the RMT prediction cannot be neglected. These corrections can be calculated in higher orders of the {epsilon} expansion. We calculate the finite-volume corrections to {sigma} and F at next-to-next-to-leading order in the {epsilon} expansion. We also discuss non-universal modifications of the theory due to the finite volume. These results are then applied to lattice QCD simulations, and we extract {sigma} and F from eigenvalue correlation functions of the Dirac operator. As a side result, we provide a proof of equivalence between the parametrization of the partially quenched low-energy effective theory without singlet particle and that of the super-Riemannian manifold used earlier in the literature. Furthermore, we calculate a special version of the massless sunset diagram at finite volume without

Asymmetric Invisibility Cloaking Theory Based on the Concept of Effective Electromagnetic Fields for Photons

Science.gov (United States)

Amemiya, Tomo; Taki, Masato; Kanazawa, Toru; Arai, Shigehisa

2014-03-01

The asymmetric invisibility cloak is a special cloak with unidirectional transparency; that is, a person in the cloak should not be seen from the outside but should be able to see the outside. Existing theories of designing invisibility cloaks cannot be used for asymmetric cloaking because they are based on the transformation optics that uses Riemannian metric tensor independent of direction. To overcome this problem, we propose introducing directionality into invisibility cloaking. Our theory is based on ``the theory of effective magnetic field for photons'' proposed by Stanford University.[2] To realize asymmetric cloaking, we have extended the Stanford's theory to add the concept of ``effective electric field for photons.'' The effective electric and the magnetic field can be generated using a photonc resonator lattice, which is a kind of metamaterial. The Hamiltonian for photons in these fields has a similar form to that of the Hamiltonian for a charged particle in an electromagnetic field. An incident photon therefore experiences a ``Lorentz-like'' and a ``Coulomb-like'' force and shows asymmetric movement depending of its travelling direction.We show the procedure of designing actual invisibility cloaks using the photonc resonator lattice and confirm their operation with the aid of computer simulation. This work was supported in part by the MEXT; JSPS KAKENHI Grant Numbers #24246061, #24656046, #25420321, #25420322.

Doublet channel neutron-deuteron scattering in leading order effective field theory

OpenAIRE

B. BlankleiderFlinders U.; J. Gegelia(INFN)

2015-01-01

The doublet channel neutron-deuteron scattering amplitude is calculated in leading order effective field theory (EFT). It is shown that this amplitude does not depend on a constant contact interaction three-body force. Satisfactory agreement with available data is obtained when only two-body forces are included.

Strangeness S = -2 baryon-baryon interactions using chiral effective field theory

NARCIS (Netherlands)

Polinder, H.; Haidenbauer, J.; Meissner, U.G.

2007-01-01

We derive the leading order strangeness S =−2 baryon–baryon interactions in chiral effective field theory. The potential consists of contact terms without derivatives and of one-pseudoscalar-meson exchanges. The contact terms and the couplings of the pseudoscalar mesons to the baryons are related

Limitations of effective medium theory in multilayer graphite/hBN heterostructures

DEFF Research Database (Denmark)

Petersen, René; Pedersen, Thomas Garm; Gjerding, Morten Niklas

2016-01-01

We apply effective medium theory (EMT) to metamaterials consisting of a varying number of consecutive sheets of graphene and hexagonal boron nitride, and compare this with a full calculation of the permittivity and the reflection based on the tight binding method and the transfer matrix method...

Causality violations in Lovelock theories

Science.gov (United States)

Brustein, Ram; Sherf, Yotam

2018-04-01

Higher-derivative gravity theories, such as Lovelock theories, generalize Einstein's general relativity (GR). Modifications to GR are expected when curvatures are near Planckian and appear in string theory or supergravity. But can such theories describe gravity on length scales much larger than the Planck cutoff length scale? Here we find causality constraints on Lovelock theories that arise from the requirement that the equations of motion (EOM) of perturbations be hyperbolic. We find a general expression for the "effective metric" in field space when Lovelock theories are perturbed around some symmetric background solution. In particular, we calculate explicitly the effective metric for a general Lovelock theory perturbed around cosmological Friedman-Robertson-Walker backgrounds and for some specific cases when perturbed around Schwarzschild-like solutions. For the EOM to be hyperbolic, the effective metric needs to be Lorentzian. We find that, unlike for GR, the effective metric is generically not Lorentzian when the Lovelock modifications are significant. So, we conclude that Lovelock theories can only be considered as perturbative extensions of GR and not as truly modified theories of gravity. We compare our results to those in the literature and find that they agree with and reproduce the results of previous studies.

Asthma management simulation for children: translating theory, methods, and strategies to effect behavior change.

Science.gov (United States)

Shegog, Ross; Bartholomew, L Kay; Gold, Robert S; Pierrel, Elaine; Parcel, Guy S; Sockrider, Marianna M; Czyzewski, Danita I; Fernandez, Maria E; Berlin, Nina J; Abramson, Stuart

2006-01-01

Translating behavioral theories, models, and strategies to guide the development and structure of computer-based health applications is well recognized, although a continued challenge for program developers. A stepped approach to translate behavioral theory in the design of simulations to teach chronic disease management to children is described. This includes the translation steps to: 1) define target behaviors and their determinants, 2) identify theoretical methods to optimize behavioral change, and 3) choose educational strategies to effectively apply these methods and combine these into a cohesive computer-based simulation for health education. Asthma is used to exemplify a chronic health management problem and a computer-based asthma management simulation (Watch, Discover, Think and Act) that has been evaluated and shown to effect asthma self-management in children is used to exemplify the application of theory to practice. Impact and outcome evaluation studies have indicated the effectiveness of these steps in providing increased rigor and accountability, suggesting their utility for educators and developers seeking to apply simulations to enhance self-management behaviors in patients.

Modelling the rebound effect with network theory: An insight into the European freight transport sector

International Nuclear Information System (INIS)

Ruzzenenti, Franco; Basosi, Riccardo

2017-01-01

This paper presents a two pronged approach to the study of the rebound effect, with the aim of assessing the magnitude of the effect in the European freight transport sector and proposing a new modelling framework based on network theory. The (direct) rebound effect is assessed with: 1) an econometric regression; 2) a model based on network theory and statistical mechanics. According to the econometric model the European road freight transport sector undergone a negative rebound between of −74% between 1998 and 2007 and −146% between 1998 and 2011. The network analysis delivers an estimation of network rebound ranging between −29.37% and −7.25. Overall, these results indicate that energy efficiency in Europe, between 1998 and 2011, succeed in reducing the energy consumptions amid an increasing demand for transports. Results on rebound estimation depend on the decision of using GDP as an exogenous variable, an assumption that leaves questions open about the causality chain between growth and transports. Furthermore, the network analysis highlights a structural change –a migration of production factors offshore, that might partially explain this negative effect. In this view, rebound effect analysis on a local or regional scale is becoming more and more uncertain in a globally interconnected economic context. - Highlights: • An evaluation of direct rebound effect in the freight transports with an econometric model is performed. • A new concept of rebound effect based on network theory is presented and implemented. • A comparative analysis of the two different approaches is developed. • Both models indicate that the there was a negative rebound effect in European freight transports. • Network theory proved to be a promising approach to energy systems and rebound effect modelling.

Information loss in effective field theory: Entanglement and thermal entropies

Science.gov (United States)

Boyanovsky, Daniel

2018-03-01

Integrating out high energy degrees of freedom to yield a low energy effective field theory leads to a loss of information with a concomitant increase in entropy. We obtain the effective field theory of a light scalar field interacting with heavy fields after tracing out the heavy degrees of freedom from the time evolved density matrix. The initial density matrix describes the light field in its ground state and the heavy fields in equilibrium at a common temperature T . For T =0 , we obtain the reduced density matrix in a perturbative expansion; it reveals an emergent mixed state as a consequence of the entanglement between light and heavy fields. We obtain the effective action that determines the time evolution of the reduced density matrix for the light field in a nonperturbative Dyson resummation of one-loop correlations of the heavy fields. The Von-Neumann entanglement entropy associated with the reduced density matrix is obtained for the nonresonant and resonant cases in the asymptotic long time limit. In the nonresonant case the reduced density matrix displays an incipient thermalization albeit with a wave-vector, time and coupling dependent effective temperature as a consequence of memory of initial conditions. The entanglement entropy is time independent and is the thermal entropy for this effective, nonequilibrium temperature. In the resonant case the light field fully thermalizes with the heavy fields, the reduced density matrix loses memory of the initial conditions and the entanglement entropy becomes the thermal entropy of the light field. We discuss the relation between the entanglement entropy ultraviolet divergences and renormalization.

Toward a general theory of momentum-like effects.

Science.gov (United States)

Hubbard, Timothy L

2017-08-01

The future actions, behaviors, and outcomes of objects, individuals, and processes can often be anticipated, and some of these anticipations have been hypothesized to result from momentum-like effects. Five types of momentum-like effects (representational momentum, operational momentum, attentional momentum, behavioral momentum, psychological momentum) are briefly described. Potential similarities involving properties of momentum-like effects (continuation, coherence, role of chance or guessing, role of sensory processing, imperviousness to practice or error feedback, shifts in memory for position, effects of changes in velocity, rapid occurrence, effects of retention interval, attachment to an object rather than an abstract frame of reference, nonrigid transformation) are described, and potential constraints on a future theory of momentum-like effects (dynamic representation, nature of extrapolation, sensitivity to environmental contingencies, bridging gaps between stimulus and response, increasing adaptiveness to the environment, serving as a heuristic for perception and action, insensitivity to stimulus format, importance of subjective consequences, role of knowledge and belief, automaticity of occurrence, properties of functional architecture) are discussed. The similarity and ubiquity of momentum-like effects suggests such effects might result from a single or small number of mechanisms that operate over different dimensions, modalities, and time-scales and provide a fundamental adaptation for perception and action. Copyright © 2017. Published by Elsevier B.V.

Investigations in gauge theories, topological solitons and string theories

International Nuclear Information System (INIS)

1993-01-01

This is the Final Report on a supported research project on theoretical particle physics entitled ''Investigations in Gauge Theories, Topological Solitons and String Theories.'' The major theme of particle theory pursued has been within the rubric of the standard model, particularly on the interplay between symmetries and dynamics. Thus, the research has been carried out primarily in the context of gauge with or without chiral fermions and in effective chiral lagrangian field theories. The topics studied include the physical implications of abelian and non-abelian anomalies on the spectrum and possible dynamical symmetry breaking in a wide range of theories. A wide range of techniques of group theory, differential geometry and function theory have been applied to probe topological and conformal properties of quantum field theories in two and higher dimensions, the breaking of global chiral symmetries by vector-like gauge theories such as QCD,the phenomenology of a possibly strongly interacting Higgs sector within the minimal standard model, and the relevance of solitonic ideas to non-perturbative phenomena at SSC energies

A dual memory theory of the testing effect.

Science.gov (United States)

Rickard, Timothy C; Pan, Steven C

2017-06-05

A new theoretical framework for the testing effect-the finding that retrieval practice is usually more effective for learning than are other strategies-is proposed, the empirically supported tenet of which is that separate memories form as a consequence of study and test events. A simplest case quantitative model is derived from that framework for the case of cued recall. With no free parameters, that model predicts both proportion correct in the test condition and the magnitude of the testing effect across 10 experiments conducted in our laboratory, experiments that varied with respect to material type, retention interval, and performance in the restudy condition. The model also provides the first quantitative accounts of (a) the testing effect as a function of performance in the restudy condition, (b) the upper bound magnitude of the testing effect, (c) the effect of correct answer feedback, (d) the testing effect as a function of retention interval for the cases of feedback and no feedback, and (e) the effect of prior learning method on subsequent learning through testing. Candidate accounts of several other core phenomena in the literature, including test-potentiated learning, recognition versus cued recall training effects, cued versus free recall final test effects, and other select transfer effects, are also proposed. Future prospects and relations to other theories are discussed.

Heavy quark effective theory, interpolating fields and Bethe-Salpeter amplitudes

International Nuclear Information System (INIS)

Hussain, F.; Thomspon, G.

1994-07-01

We use the LSZ reduction theorem and interpolating fields, along with the heavy quark effective theory, to investigate the structure of the Bethe-Salpeter amplitude for heavy hadrons. We show how a simple form of this amplitude, used extensively in heavy hadron decay calculations, follows naturally up to O(1/M) from these field theoretic considerations. (author). 13 refs, 1 tab

Magnetic moment calculation for p+d→ 3 He+γ process in Big=bang nucleosynthesis with effective field theory

International Nuclear Information System (INIS)

Bayegan, S.; Sadeghi, H.

2004-01-01

In big-bang nucleosynthesis, processes relevant ti increasing of nucleon density are more important. One of the theories that its solutions more accurately explain the experimental works is Effective Field Theory in this paper. Magnetic moment (χM1) for radiative capture of protons by deuterons p + d → 3 He+γ process is calculated using Effective Field Theory. The calculation includes coulomb interaction up to next-to -next-leading order (N 2 LO)

Bending of marble with intrinsic length scales: a gradient theory with surface energy and size effects

International Nuclear Information System (INIS)

Vardoulakis, I.; Kourkoulis, S.K.; Exadaktylos, G.

1998-01-01

A gradient bending theory is developed based on a strain energy function that includes the classical Bernoulli-Euler term, the shape correction term (microstructural length scale) introduced by Timoshenko, and a term associated with surface energy (micromaterial length scale) accounting for the bending moment gradient effect. It is shown that the last term is capable to interpret the size effect in three-point bending (3PB), namely the decrease of the failure load with decreasing beam length for the same aspect ratio. This theory is used to describe the mechanical behaviour of Dionysos-Pentelikon marble in 3PB. Series of tests with prismatic marble beams of the same aperture but with different lengths were conducted and it was concluded that the present theory predicts well the size effect. (orig.)

Experimental verification of the statistical theories of scaling factor effect in fatigue fracture of steel

International Nuclear Information System (INIS)

Svistun, R.P.; Babej, Yu.I.; Tkachenko, N.N.

1976-01-01

Statistical theories of the scale effect in the fatigue failure of 40KH18N9T, 10 and 20 steels have been verified. The theories are shown to be not invariably suitable for a satisfactory exlanation of the fatigue strength of the samples with respect to their dimensions. One of the main reasons for displaying the scale effect in the process of steel fatigue is the sample self-heating, i.e. a temperature factor which in many cases overlaps a statistical one

Experimental verification of the statistical theories of scaling factor effect in fatigue fracture of steel

Energy Technology Data Exchange (ETDEWEB)

Svistun, R P; Babei, Yu I; Tkachenko, N N [AN Ukrainskoj SSR, Lvov. Fiziko-Mekhanicheskij Inst.; L' vovskij Lesotekhnicheskij Inst. (Ukrainian SSR))

1976-01-01

Statistical theories of the scale effect in the fatigue failure of 40KH18N9T, 10 and 20 steels have been verified. The theories are shown to be not invariably suitable for a satisfactory exlanation of the fatigue strength of the samples with respect to their dimensions. One of the main reasons for displaying the scale effect in the process of steel fatigue is the sample self-heating, i.e. a temperature factor which in many cases overlaps a statistical one.

Approximate design theory for a simple block design with random block effects

OpenAIRE

Christof, Karin

1985-01-01

Approximate design theory for a simple block design with random block effects / K. Christof ; F. Pukelsheim. - In: Linear statistical inference / ed. by T. Calinski ... - Berlin u. a. : Springer, 1985. - S. 20-28. - (Lecture notes in statistics ; 35)

String-theoretic breakdown of effective field theory near black hole horizons

Science.gov (United States)

Dodelson, Matthew; Silverstein, Eva

2017-09-01

We investigate the validity of the equivalence principle near horizons in string theory, analyzing the breakdown of effective field theory caused by longitudinal string spreading effects. An experiment is set up where a detector is thrown into a black hole a long time after an early infalling string. Light cone gauge calculations, taken at face value, indicate a detectable level of root-mean-square longitudinal spreading of the initial string as measured by the late infaller. This results from the large relative boost between the string and detector in the near-horizon region, which develops automatically despite their modest initial energies outside the black hole and the weak curvature in the geometry. We subject this scenario to basic consistency checks, using these to obtain a relatively conservative criterion for its detectability. In a companion paper, we exhibit longitudinal nonlocality in well-defined gauge-invariant S-matrix calculations, obtaining results consistent with the predicted spreading albeit not in a direct analog of the black hole process. We discuss applications of this effect to the firewall paradox, and estimate the time and distance scales it predicts for new physics near black hole and cosmological horizons.

Nonthermal fusion reactor concept based on Hall-effect magnetohydrodynamics plasma theory

International Nuclear Information System (INIS)

Witalis, E.A.

1988-01-01

The failure of magnetic confinement controlled thermonuclear fusion research to achieve its goal is attributed to its foundation on the incomplete MHD plasma description instead of the more general HMHD (Hall-effect magnetohydrodynamics) theory. The latter allows for a certain magnetic plasma self-confinement under described stringent conditions. A reactor concept based on the formation, acceleration, and forced disintegration of magnetized whirl structures, plasmoids, is proposed. The four conventional MHD theory objections, i.e., absence of dynamo action, fast decay caused by resistivity, non-existence of magnetic self-confinement, and negligible non-thermal fusion yield, are shown not to apply. Support for the scheme from dense plasma focus research is pointed out. (orig.) [de

I can do that: the impact of implicit theories on leadership role model effectiveness.

Science.gov (United States)

Hoyt, Crystal L; Burnette, Jeni L; Innella, Audrey N

2012-02-01

This research investigates the role of implicit theories in influencing the effectiveness of successful role models in the leadership domain. Across two studies, the authors test the prediction that incremental theorists ("leaders are made") compared to entity theorists ("leaders are born") will respond more positively to being presented with a role model before undertaking a leadership task. In Study 1, measuring people's naturally occurring implicit theories of leadership, the authors showed that after being primed with a role model, incremental theorists reported greater leadership confidence and less anxious-depressed affect than entity theorists following the leadership task. In Study 2, the authors demonstrated the causal role of implicit theories by manipulating participants' theory of leadership ability. They replicated the findings from Study 1 and demonstrated that identification with the role model mediated the relationship between implicit theories and both confidence and affect. In addition, incremental theorists outperformed entity theorists on the leadership task.

Field theory

CERN Multimedia

1999-11-08

In these lectures I will build up the concept of field theory using the language of Feynman diagrams. As a starting point, field theory in zero spacetime dimensions is used as a vehicle to develop all the necessary techniques: path integral, Feynman diagrams, Schwinger-Dyson equations, asymptotic series, effective action, renormalization etc. The theory is then extended to more dimensions, with emphasis on the combinatorial aspects of the diagrams rather than their particular mathematical structure. The concept of unitarity is used to, finally, arrive at the various Feynman rules in an actual, four-dimensional theory. The concept of gauge-invariance is developed, and the structure of a non-abelian gauge theory is discussed, again on the level of Feynman diagrams and Feynman rules.

Effects of Rotation and Gravity Field on Surface Waves in Fibre-Reinforced Thermoelastic Media under Four Theories

Directory of Open Access Journals (Sweden)

A. M. Abd-Alla

2013-01-01

Full Text Available Estimation is done to investigate the gravitational and rotational parameters effects on surface waves in fibre-reinforced thermoelastic media. The theory of generalized surface waves has been firstly developed and then it has been employed to investigate particular cases of waves, namely, Stoneley waves, Rayleigh waves, and Love waves. The analytical expressions for surface waves velocity and attenuation coefficient are obtained in the physical domain by using the harmonic vibrations and four thermoelastic theories. The wave velocity equations have been obtained in different cases. The numerical results are given for equation of coupled thermoelastic theory (C-T, Lord-Shulman theory (L-S, Green-Lindsay theory (G-L, and the linearized (G-N theory of type II. Comparison was made with the results obtained in the presence and absence of gravity, rotation, and parameters for fibre-reinforced of the material media. The results obtained are displayed by graphs to clear the phenomena physical meaning. The results indicate that the effect of gravity, rotation, relaxation times, and parameters of fibre-reinforced of the material medium is very pronounced.

Why are predictions of general relativity theory for gravitational effects non-unique?

International Nuclear Information System (INIS)

Loskutov, Yu.M.

1990-01-01

Reasons of non-uniqueness of predictions of the general relativity theory (GRT) for gravitational effects are analyzed in detail. To authors' opinion, the absence of comparison mechanism of curved and plane metrics is the reason of non-uniqueness

The effective supergravity of little string theory

Science.gov (United States)

Antoniadis, Ignatios; Delgado, Antonio; Markou, Chrysoula; Pokorski, Stefan

2018-02-01

In this work we present the minimal supersymmetric extension of the five-dimensional dilaton-gravity theory that captures the main properties of the holographic dual of little string theory. It is described by a particular gauging of N=2 supergravity coupled with one vector multiplet associated with the string dilaton, along the U(1) subgroup of SU(2) R-symmetry. The linear dilaton in the fifth coordinate solution of the equations of motion (with flat string frame metric) breaks half of the supersymmetries to N=1 in four dimensions. Interest in the linear dilaton model has lately been revived in the context of the clockwork mechanism, which has recently been proposed as a new source of exponential scale separation in field theory.

The effective supergravity of little string theory

Energy Technology Data Exchange (ETDEWEB)

Antoniadis, Ignatios [Sorbonne Universite, CNRS, Laboratoire de Physique Theorique et Hautes Energies, LPTHE, Paris (France); University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Delgado, Antonio [University of Notre Dame, Department of Physics, Notre Dame, IN (United States); Markou, Chrysoula [Sorbonne Universite, CNRS, Laboratoire de Physique Theorique et Hautes Energies, LPTHE, Paris (France); Pokorski, Stefan [University of Warsaw, Faculty of Physics, Institute of Theoretical Physics, Warsaw (Poland)

2018-02-15

In this work we present the minimal supersymmetric extension of the five-dimensional dilaton-gravity theory that captures the main properties of the holographic dual of little string theory. It is described by a particular gauging of N = 2 supergravity coupled with one vector multiplet associated with the string dilaton, along the U(1) subgroup of SU(2) R-symmetry. The linear dilaton in the fifth coordinate solution of the equations of motion (with flat string frame metric) breaks half of the supersymmetries to N = 1 in four dimensions. Interest in the linear dilaton model has lately been revived in the context of the clockwork mechanism, which has recently been proposed as a new source of exponential scale separation in field theory. (orig.)

P-odd effects in the e-d scattering in the vector-like theories

International Nuclear Information System (INIS)

Gakh, G.I.

1979-01-01

P-odd effects in elastic electron-deuteron scattering, due to the weak neutral currents, are analyzed in the framework of the vector-like theories. Considered is the case of the most general form of the P-invariance breaking in the elastic e - d scattering amplitude in both the leptonic and hadronic vertices. It is found that in the vector-like theories the parity violation in the electro-deuteron elastic scattering is confined in the hadronic vertex, while in the Weinberg-Salam model it is confined in the leptonic vertex. In the vector-like theories the asymmetry in the scattering of longitudinally polarized electrons by nonpolarized deuterons depends on the electromagnetic and weak form factors of a deuteron, whereas in the Weinberg-Salam model it does not depend on the structure of the deuteron. In the Weinberg-Salam model the asymmetry is independent on the T-violating form factors of the deuteron, whereas such a dependence is present in the vector-like theories

An Analysis of the Substitution Effect and of Revenue Effect in the Case of the Consumer’s Theory Provided with a CES Utility Function

Directory of Open Access Journals (Sweden)

Catalin Angelo Ioan

2012-02-01

Full Text Available In the consumer’s theory, a crucial problem is to determine the substitution effect and therevenue effect in the case of one good price’s modifing. There exists two theories due to John RichardHicks and Eugen Slutsky which allocates differentsshares of the total change of the consumption tothese effects. The paper makes an analysis betweenthe two effects, considering the general case of aCES utility function and introduces three indicators which will characterize these shares.

Usefulness of effective field theory for boosted Higgs production

Energy Technology Data Exchange (ETDEWEB)

Dawson, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Lewis, I. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Zeng, Mao [Stony Brook Univ., Stony Brook, NY (United States)

2015-04-07

The Higgs + jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high _pT. We examine the production process using an effective field theory (EFT) language and discussing the possibility of determining the nature of the underlying high-scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension-5 and dimension-7 are included in the EFT. As a byproduct of our study, we examine the region of validity of the EFT. Dimension-7 contributions in realistic new physics models give effects in the high _pT tail of the Higgs signal which are so tiny that they are likely to be unobservable.

Berry Fermi liquid theory

Energy Technology Data Exchange (ETDEWEB)

Chen, Jing-Yuan, E-mail: chjy@uchicago.edu [Kadanoff Center for Theoretical Physics, University of Chicago, Chicago, IL 60637 (United States); Stanford Institute for Theoretical Physics, Stanford University, CA 94305 (United States); Son, Dam Thanh, E-mail: dtson@uchicago.edu [Kadanoff Center for Theoretical Physics, University of Chicago, Chicago, IL 60637 (United States)

2017-02-15

We develop an extension of the Landau Fermi liquid theory to systems of interacting fermions with non-trivial Berry curvature. We propose a kinetic equation and a constitutive relation for the electromagnetic current that together encode the linear response of such systems to external electromagnetic perturbations, to leading and next-to-leading orders in the expansion over the frequency and wave number of the perturbations. We analyze the Feynman diagrams in a large class of interacting quantum field theories and show that, after summing up all orders in perturbation theory, the current–current correlator exactly matches with the result obtained from the kinetic theory. - Highlights: • We extend Landau’s kinetic theory of Fermi liquid to incorporate Berry phase. • Berry phase effects in Fermi liquid take exactly the same form as in Fermi gas. • There is a new “emergent electric dipole” contribution to the anomalous Hall effect. • Our kinetic theory is matched to field theory to all orders in Feynman diagrams.

Flexoelectric Effect on Vibration of Piezoelectric Microbeams Based on a Modified Couple Stress Theory

Directory of Open Access Journals (Sweden)

Xingjia Li

2017-01-01

Full Text Available A novel electric Gibbs function was proposed for the piezoelectric microbeams (PMBs by employing a modified couple stress theory. Based on the new Gibbs function and the Euler-Bernoulli beam theory, the governing equations which incorporate the effects of couple stress, flexoelectricity, and piezoelectricity were derived for the mechanics of PMBs. The analysis of the effective bending rigidity shows the effects of size and flexoelectricity can greaten the stiffness of PMBs so that the natural frequency increases significantly compared with the Euler-Bernoulli beam, and then the mechanical and electrical properties of PMBs are enhanced compared to the classical beam. This study can guide the design of microscale piezoelectric/flexoelectric structures which may find potential applications in the microelectromechanical systems (MEMS.

Effects of turbulence on the geometric collision rate of sedimenting droplets. Part 2. Theory and parameterization

International Nuclear Information System (INIS)

Ayala, Orlando; Rosa, Bogdan; Wang Lianping

2008-01-01

The effect of air turbulence on the geometric collision kernel of cloud droplets can be predicted if the effects of air turbulence on two kinematic pair statistics can be modeled. The first is the average radial relative velocity and the second is the radial distribution function (RDF). A survey of the literature shows that no theory is available for predicting the radial relative velocity of finite-inertia sedimenting droplets in a turbulent flow. In this paper, a theory for the radial relative velocity is developed, using a statistical approach assuming that gravitational sedimentation dominates the relative motion of droplets before collision. In the weak-inertia limit, the theory reveals a new term making a positive contribution to the radial relative velocity resulting from a coupling between sedimentation and air turbulence on the motion of finite-inertia droplets. The theory is compared to the direct numerical simulations (DNS) results in part 1, showing a reasonable agreement with the DNS data for bidisperse cloud droplets. For droplets larger than 30 μm in radius, a nonlinear drag (NLD) can also be included in the theory in terms of an effective inertial response time and an effective terminal velocity. In addition, an empirical model is developed to quantify the RDF. This, together with the theory for radial relative velocity, provides a parameterization for the turbulent geometric collision kernel. Using this integrated model, we find that turbulence could triple the geometric collision kernel, relative to the stagnant air case, for a droplet pair of 10 and 20 μm sedimenting through a cumulus cloud at R λ =2x10 4 and ε=600 cm 2 s -3 . For the self-collisions of 20 μm droplets, the collision kernel depends sensitively on the flow dissipation rate

Situated learning theory: adding rate and complexity effects via Kauffman's NK model.

Science.gov (United States)

Yuan, Yu; McKelvey, Bill

2004-01-01

For many firms, producing information, knowledge, and enhancing learning capability have become the primary basis of competitive advantage. A review of organizational learning theory identifies two approaches: (1) those that treat symbolic information processing as fundamental to learning, and (2) those that view the situated nature of cognition as fundamental. After noting that the former is inadequate because it focuses primarily on behavioral and cognitive aspects of individual learning, this paper argues the importance of studying learning as interactions among people in the context of their environment. It contributes to organizational learning in three ways. First, it argues that situated learning theory is to be preferred over traditional behavioral and cognitive learning theories, because it treats organizations as complex adaptive systems rather than mere information processors. Second, it adds rate and nonlinear learning effects. Third, following model-centered epistemology, it uses an agent-based computational model, in particular a "humanized" version of Kauffman's NK model, to study the situated nature of learning. Using simulation results, we test eight hypotheses extending situated learning theory in new directions. The paper ends with a discussion of possible extensions of the current study to better address key issues in situated learning.

Supersymmetric gauge theories from string theory; Theorie de jauge supersymetrique de la theorie des cordes

Energy Technology Data Exchange (ETDEWEB)

Metzger, St

2005-12-15

This thesis presents various ways to construct four-dimensional quantum field theories from string theory. In a first part we study the generation of a supersymmetric Yang-Mills theory, coupled to an adjoint chiral superfield, from type IIB string theory on non-compact Calabi-Yau manifolds, with D-branes wrapping certain sub-cycles. Properties of the gauge theory are then mapped to the geometric structure of the Calabi-Yau space. Even if the Calabi-Yau geometry is too complicated to evaluate the geometric integrals explicitly, one can then always use matrix model perturbation theory to calculate the effective superpotential. The second part of this work covers the generation of four-dimensional super-symmetric gauge theories, carrying several important characteristic features of the standard model, from compactifications of eleven-dimensional supergravity on G{sub 2}-manifolds. If the latter contain conical singularities, chiral fermions are present in the four-dimensional gauge theory, which potentially lead to anomalies. We show that, locally at each singularity, these anomalies are cancelled by the non-invariance of the classical action through a mechanism called 'anomaly inflow'. Unfortunately, no explicit metric of a compact G{sub 2}-manifold is known. Here we construct families of metrics on compact weak G{sub 2}-manifolds, which contain two conical singularities. Weak G{sub 2}-manifolds have properties that are similar to the ones of proper G{sub 2}-manifolds, and hence the explicit examples might be useful to better understand the generic situation. Finally, we reconsider the relation between eleven-dimensional supergravity and the E{sub 8} x E{sub 8}-heterotic string. This is done by carefully studying the anomalies that appear if the supergravity theory is formulated on a ten-manifold times the interval. Again we find that the anomalies cancel locally at the boundaries of the interval through anomaly inflow, provided one suitably modifies the

The renormalization group in effective chiral theories

International Nuclear Information System (INIS)

Varin, T.

2007-09-01

The dilepton production within the heavy ions collisions (CERN/SPS, SIS/HADES, RHIC) and the behaviour of vector mesons (in particular the rho meson) are among the main topics of quantum chromodynamics (QCD) in hadronic matter. One of the main goals is the study of partial or total restoration of chiral symmetry SU(2) x SU(2), for which effective theories need to be used. One of the important difficulties is to build a theory which allows to obtain predictions when approaching the phase transition by taking into account the phenomenological constraints at low temperature and/or density. The model used here (developed by M. Urban) is based on the gauged (rho and al mesons) linear sigma model adjusted (in practice the local symmetry is only approximate) to reproduce the phenomenology very well. The first part of this thesis consists in presenting a new cut-off based regularization scheme preserving symmetry requirements. The motivation of such a method is a correct accounting of quadratic and logarithmic divergences in view of their intensive use for the renormalisation group equations. For illustrative purposes we have applied it to QED in 4 and 5 dimensions. The second part of this work is devoted to the derivation of the RGE and their resolution. In particular, we show that both restorations (traditional and vector manifestation) can be obtained from our equations, but the most likely remains the 'traditional' Ginzburg-Landau scenario. (author)

Theory of Kondo effect in superconductors, 2

International Nuclear Information System (INIS)

Ichinose, Shin-ichi

1977-01-01

Thermodynamic properties of superconducting alloys near the transition temperature are studied within the interpolation approximation which is constructed so as to coincide with theories in limiting cases. By the use of this approximation, the specific heat jump at the transition temperature is calculated in the case of the magnitude of the impurity spin being 1/2. The result shows a continuous change of the specific heat jump with T sub(K)/T sub(c0) from the Abrikosov-Gorkov value to essentially BCS-like behavior in contrast to the Mueller-Hartmann-Zittartz theory. One has an example of a cross over between a weak coupling situation at T sub(K)/T sub(c0) > 1. The Hartree-Fock theory is also discussed in connection with the present calculation. (auth.)

Avoiding the approach trap: a response bias theory of the emotional Stroop effect.

Science.gov (United States)

Chajut, Eran; Mama, Yaniv; Levy, Leora; Algom, Daniel

2010-11-01

In the laboratory, people classify the color of emotion-laden words slower than they do that of neutral words, the emotional Stroop effect. Outside the laboratory, people react to features of emotion-laden stimuli or threatening stimuli faster than they do to those of neutral stimuli. A possible resolution to the conundrum implicates the counternatural response demands imposed in the laboratory that do not, as a rule, provide for avoidance in the face of threat. In 2 experiments we show that when such an option is provided in the laboratory, the response latencies follow those observed in real life. These results challenge the dominant attention theory offered for the emotional Stroop effect because this theory is indifferent to the vital approach-avoidance distinction.

Operator approach to effective medium theory to overcome a breakdown of Maxwell Garnett approximation

DEFF Research Database (Denmark)

Popov, Vladislav; Lavrinenko, Andrei; Novitsky, Andrey

2016-01-01

that the zeroth-, first-, and second-order approximations of the operator effective medium theory correspond to electric dipoles, chirality, and magnetic dipoles plus electric quadrupoles, respectively. We discover that the spatially dispersive bianisotropic effective medium obtained in the second...

Supersymmetric gauge theories from string theory

International Nuclear Information System (INIS)

Metzger, St.

2005-12-01

This thesis presents various ways to construct four-dimensional quantum field theories from string theory. In a first part we study the generation of a supersymmetric Yang-Mills theory, coupled to an adjoint chiral superfield, from type IIB string theory on non-compact Calabi-Yau manifolds, with D-branes wrapping certain sub-cycles. Properties of the gauge theory are then mapped to the geometric structure of the Calabi-Yau space. Even if the Calabi-Yau geometry is too complicated to evaluate the geometric integrals explicitly, one can then always use matrix model perturbation theory to calculate the effective superpotential. The second part of this work covers the generation of four-dimensional super-symmetric gauge theories, carrying several important characteristic features of the standard model, from compactifications of eleven-dimensional supergravity on G 2 -manifolds. If the latter contain conical singularities, chiral fermions are present in the four-dimensional gauge theory, which potentially lead to anomalies. We show that, locally at each singularity, these anomalies are cancelled by the non-invariance of the classical action through a mechanism called 'anomaly inflow'. Unfortunately, no explicit metric of a compact G 2 -manifold is known. Here we construct families of metrics on compact weak G 2 -manifolds, which contain two conical singularities. Weak G 2 -manifolds have properties that are similar to the ones of proper G 2 -manifolds, and hence the explicit examples might be useful to better understand the generic situation. Finally, we reconsider the relation between eleven-dimensional supergravity and the E 8 x E 8 -heterotic string. This is done by carefully studying the anomalies that appear if the supergravity theory is formulated on a ten-manifold times the interval. Again we find that the anomalies cancel locally at the boundaries of the interval through anomaly inflow, provided one suitably modifies the classical action. (author)

The utility of quantum field theory

International Nuclear Information System (INIS)

Dine, Michael

2001-01-01

This talk surveys a broad range of applications of quantum field theory, as well as some recent developments. The stress is on the notion of effective field theories. Topics include implications of neutrino mass and a possible small value of sin(2β), supersymmetric extensions of the standard model, the use of field theory to understand fundamental issues in string theory (the problem of multiple ground states and the question: does string theory predict low energy supersymmetry), and the use of string theory to solve problems in field theory. Also considered are a new type of field theory, and indications from black hole physics and the cosmological constant problem that effective field theories may not completely describe theories of gravity. (author)

Use of Theory in Behavior Change Interventions.

Science.gov (United States)

Bluethmann, Shirley M; Bartholomew, L Kay; Murphy, Caitlin C; Vernon, Sally W

2017-04-01

Theory use may enhance effectiveness of behavioral interventions, yet critics question whether theory-based interventions have been sufficiently scrutinized. This study applied a framework to evaluate theory use in physical activity interventions for breast cancer survivors. The aims were to (1) evaluate theory application intensity and (2) assess the association between extensiveness of theory use and intervention effectiveness. Studies were previously identified through a systematic search, including only randomized controlled trials published from 2005 to 2013, that addressed physical activity behavior change and studied survivors who were theory items from Michie and Prestwich's coding framework were selected to calculate theory intensity scores. Studies were classified into three subgroups based on extensiveness of theory use (Level 1 = sparse; Level 2 = moderate; and Level 3 = extensive). Fourteen randomized controlled trials met search criteria. Most trials used the transtheoretical model ( n = 5) or social cognitive theory ( n = 3). For extensiveness of theory use, 5 studies were classified as Level 1, 4 as Level 2, and 5 as Level 3. Studies in the extensive group (Level 3) had the largest overall effect size ( g = 0.76). Effects were more modest in Level 1 and 2 groups with overall effect sizes of g = 0.28 and g = 0.36, respectively. Theory use is often viewed as essential to behavior change, but theory application varies widely. In this study, there was some evidence to suggest that extensiveness of theory use enhanced intervention effectiveness. However, there is more to learn about how theory can improve interventions for breast cancer survivors.

A general theory of effect size, and its consequences for defining the benchmark response (BMR) for continuous endpoints.

Science.gov (United States)

Slob, Wout

2017-04-01

A general theory on effect size for continuous data predicts a relationship between maximum response and within-group variation of biological parameters, which is empirically confirmed by results from dose-response analyses of 27 different biological parameters. The theory shows how effect sizes observed in distinct biological parameters can be compared and provides a basis for a generic definition of small, intermediate and large effects. While the theory is useful for experimental science in general, it has specific consequences for risk assessment: it solves the current debate on the appropriate metric for the Benchmark response in continuous data. The theory shows that scaling the BMR expressed as a percent change in means to the maximum response (in the way specified) automatically takes "natural variability" into account. Thus, the theory supports the underlying rationale of the BMR 1 SD. For various reasons, it is, however, recommended to use a BMR in terms of a percent change that is scaled to maximum response and/or within group variation (averaged over studies), as a single harmonized approach.

The Hawking effect in abelian gauge theories

International Nuclear Information System (INIS)

Stephens, C.R.

1989-01-01

In an effort to compare and contrast gravity with other field theories an investigation is made into whether the Hawking effect is a peculiarly gravitational phenomenon. It is found that the effect exists for a particular background abelian gauge field configuration, as well as certain background gravitational field configurations. Specifically, pair production in a uniform electric field is shown to admit a thermal interpretation. In an effort to find out just what is singular about gravity it is found that the Hawking temperature characteristic of a particular gravitational field configuration is independent of the properties of the quantum fields propagating theorem, in direct contrast to the gauge field case. This implies that if the one loop approximation is to be valid the electric field must be ''cold'' relative to the energy scales set by the quantum fields. In gravity, however, because of the existence of a fundamental scale, the Planck length, the gravitational field can be ''hot'' or ''cold'' and a one loop approximation still remain valid. copyright 1989 Academic Press, Inc

Politics, Security, Theory

DEFF Research Database (Denmark)

Wæver, Ole

2011-01-01

theory is found to ‘act politically’ through three structural features that systematically shape the political effects of using the theory. The article further discusses – on the basis of the preceding articles in the special issue – three emerging debates around securitization theory: ethics......This article outlines three ways of analysing the ‘politics of securitization’, emphasizing an often-overlooked form of politics practised through theory design. The structure and nature of a theory can have systematic political implications. Analysis of this ‘politics of securitization......’ is distinct from both the study of political practices of securitization and explorations of competing concepts of politics among security theories. It means tracking what kinds of analysis the theory can produce and whether such analysis systematically impacts real-life political struggles. Securitization...

Effective actions for gauge theories with Chern-Simons terms - I

International Nuclear Information System (INIS)

Bambah, B.A.; Mukku, C.

1989-01-01

The effective Lagrangian for a three-dimensional gauge theory with a Chern-Simons term is evaluated upto one-loop effects. It is shown to be completely finite. It also does not exhibit any imaginary part. The calculation is carried out in a background field analogue of the Feynman gauge and gauge invariance is maintained throughout the calculation. In an appendix an argument is presented as to why this Feynman gauge may be a 'good' gauge for our results to be applied to high temperature QCD and in particular to the quark-gluon plasma. (author). 12 refs

Being smart or getting smarter: Implicit theory of intelligence moderates stereotype threat and stereotype lift effects.

Science.gov (United States)

Froehlich, Laura; Martiny, Sarah E; Deaux, Kay; Goetz, Thomas; Mok, Sog Yee

2016-09-01

This research explores implicit theory of intelligence (TOI) as a moderator of stereotype activation effects on test performance for members of negatively stereotyped and of favourably stereotyped groups. In Germany, Turkish-origin migrants are stereotyped as low in verbal ability. We predicted that on a test diagnostic of verbal intelligence, endorsement of an entity TOI predicts stereotype threat effects for Turkish-origin students and stereotype lift effects for German students. This effect could account for some of the performance gap between immigrants and host society members after stereotype activation. Study 1 (N = 107) established structural equivalence of implicit theories across the ethnic groups. In two experimental studies (Study 2: N = 182, Study 3: N = 190), we tested the moderating effect of TOI in a 2 (stereotype activation: diagnostic vs. non-diagnostic test) × 2 (ethnicity: German vs. Turkish migration background) experimental design. The results showed that when the test was described as diagnostic of verbal intelligence, higher entity theory endorsement predicted stereotype threat effects for Turkish-origin students (Study 2 and Study 3) and stereotype lift effects for German students (Study 3). The results are discussed in terms of practical implications for educational settings and theoretical implications for processes underlying stereotype activation effects. © 2016 The British Psychological Society.

The $\\gamma N\\to \\De$ transition in chiral effective-field theory

Energy Technology Data Exchange (ETDEWEB)

Vladimir Pascalutsa; Marc Vanderhaeghen

2006-04-27

We describe the pion electroproduction processes in the {Delta}(1232)-resonance region within the framework of chiral effective-field theory. By studying the observables of pion electroproduction in a next-to-leading order calculation we are able to make predictions and draw conclusions on the properties of the N {yields} {Delta} electromagnetic form factors.

The effect of theory-based interventions on physical activity participation among overweight/obese individuals: a systematic review.

Science.gov (United States)

Bélanger-Gravel, A; Godin, G; Vézina-Im, L-A; Amireault, S; Poirier, P

2011-06-01

Little attention has been paid to the evaluation of the long-term impact of theory-based interventions on physical activity participation among overweight/obese individuals after the interventions have ended. The primary aim of this systematic review was to investigate the long-term effectiveness of theory-based interventions increasing physical activity and identify the most effective techniques for behaviour change among overweight/obese individuals. The secondary aim was to investigate the effect of these interventions on theoretical variables. Eighteen studies were reviewed. Among these studies, three reported significant short-term and two long-term effects of interventions on physical activity participation. Most of the studies observed a significant short- or long-term effect of time on this behaviour. Theoretical frameworks most often applied included the Behavioural Model and the Social Learning/Cognitive Theory. However, few of the studies reported any impact on theoretical variables. The most prevalent techniques consisted of providing opportunities for social comparison and instruction as well as self-monitoring. Leading techniques differentiating the experimental group from the control group included prompting practice and intentions formation and barriers identification. Although the combination of these three techniques appears successful, the long-term impact of theory-based interventions remains ambiguous. © 2010 The Authors. obesity reviews © 2010 International Association for the Study of Obesity.

Appealing to fear: A Meta-Analysis of Fear Appeal Effectiveness and Theories

Science.gov (United States)

Tannenbaum, Melanie B.; Hepler, Justin; Zimmerman, Rick S.; Saul, Lindsey; Jacobs, Samantha; Wilson, Kristina; Albarracin, Dolores

2018-01-01

Fear appeals are a polarizing issue, with proponents confident in their efficacy and opponents confident that they backfire. We present the results of a comprehensive meta-analysis investigating fear appeals’ effectiveness for influencing attitudes, intentions, and behaviors. We tested predictions from a large number of theories, the majority of which have never been tested meta-analytically until now. Studies were included if they contained a treatment group exposed to a fear appeal, a valid comparison group, a manipulation of depicted fear, a measure of attitudes, intentions, or behaviors concerning the targeted risk or recommended solution, and adequate statistics to calculate effect sizes. The meta-analysis included 127 papers (9% unpublished) yielding 248 independent samples (NTotal = 27,372) collected from diverse populations. Results showed a positive effect of fear appeals on attitudes, intentions, and behaviors, with the average effect on a composite index being random-effects d¯ = 0.29. Moderation analyses based on prominent fear appeal theories showed that the effectiveness of fear appeals increased when the message included efficacy statements, depicted high susceptibility and severity, recommended one-time only (vs. repeated) behaviors, and targeted audiences that included a larger percentage of female message recipients. Overall, we conclude that (a) fear appeals are effective at positively influencing attitude, intentions, and behaviors, (b) there are very few circumstances under which they are not effective, and (c) there are no identified circumstances under which they backfire and lead to undesirable outcomes. PMID:26501228

Heavy quark fragmentation functions in the heavy quark effective theory

International Nuclear Information System (INIS)

Martynenko, A.P.; Saleev, V.A.

1996-01-01

The fragmentation of b-bar-antiquark into polarized B c * -mesons and b-quark into P-wave (c-bar b) states in the Heavy Quark Effective Theory. The heavy quark fragmentation functions in longitudinally and transversely polarized S-wave b-bar c-states and P-wave mesons containing b-, c-quarks also, with the exact account of corrections of first order in 1/m b . 20 refs., 2 figs

On the calculation of finite-temperature effects in field theories

International Nuclear Information System (INIS)

Brandt, F.T.; Frenkel, J.; Taylor, J.C.

1991-03-01

We discuss an alternative method for computing finite-temperature effects in field theories, within the framework of the imaginary-time formalism. Our approach allows for a systematic calculation of the high temperature expansion in terms of Riemann Zeta functions. The imaginary-time result is analytically continued to the complex plane. We are able to obtain the real-time limit of the real and the imaginary parts of the Green functions. (author)

Quantum decision theory as quantum theory of measurement

International Nuclear Information System (INIS)

Yukalov, V.I.; Sornette, D.

2008-01-01

We present a general theory of quantum information processing devices, that can be applied to human decision makers, to atomic multimode registers, or to molecular high-spin registers. Our quantum decision theory is a generalization of the quantum theory of measurement, endowed with an action ring, a prospect lattice and a probability operator measure. The algebra of probability operators plays the role of the algebra of local observables. Because of the composite nature of prospects and of the entangling properties of the probability operators, quantum interference terms appear, which make actions noncommutative and the prospect probabilities nonadditive. The theory provides the basis for explaining a variety of paradoxes typical of the application of classical utility theory to real human decision making. The principal advantage of our approach is that it is formulated as a self-consistent mathematical theory, which allows us to explain not just one effect but actually all known paradoxes in human decision making. Being general, the approach can serve as a tool for characterizing quantum information processing by means of atomic, molecular, and condensed-matter systems

Comparison of potential models through heavy quark effective theory

International Nuclear Information System (INIS)

Amundson, J.F.

1995-01-01

I calculate heavy-light decay constants in a nonrelativistic potential model. The resulting estimate of heavy quark symmetry breaking conflicts with similar estimates from lattice QCD. I show that a semirelativistic potential model eliminates the conflict. Using the results of heavy quark effective theory allows me to identify and compensate for shortcomings in the model calculations in addition to isolating the source of the differences in the two models. The results lead to a rule as to where the nonrelativistic quark model gives misleading predictions

Prospects for direct detection of dark matter in an effective theory approach

International Nuclear Information System (INIS)

Catena, Riccardo

2014-01-01

We perform the first comprehensive analysis of the prospects for direct detection of dark matter with future ton-scale detectors in the general 11-dimensional effective theory of isoscalar dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle. The theory includes 8 momentum and velocity dependent dark matter-nucleon interaction operators, besides the familiar spin-independent and spin-dependent operators. From a variegated sample of 27 benchmark points selected in the parameter space of the theory, we simulate independent sets of synthetic data for ton-scale Germanium and Xenon detectors. From the synthetic data, we then extract the marginal posterior probability density functions and the profile likelihoods of the model parameters. The associated Bayesian credible regions and frequentist confidence intervals allow us to assess the prospects for direct detection of dark matter at the 27 benchmark points. First, we analyze the data assuming the knowledge of the correct dark matter nucleon-interaction type, as it is commonly done for the familiar spin-independent and spin-dependent interactions. Then, we analyze the simulations extracting the dark matter-nucleon interaction type from the data directly, in contrast to standard analyses. This second approach requires an extensive exploration of the full 11-dimensional parameter space of the dark matter-nucleon effective theory. Interestingly, we identify 5 scenarios where the dark matter mass and the dark matter-nucleon interaction type can be reconstructed from the data simultaneously. We stress the importance of extracting the dark matter nucleon-interaction type from the data directly, discussing the main challenges found addressing this complex 11-dimensional problem

The renormalization group study of the effective theory of lattice QED

International Nuclear Information System (INIS)

Sugiyama, Y.

1988-01-01

The compact U(1) lattice gauge theory with massless fermions (Lattice QED) is studied through the effective model analytically, using the renormalization group method. The obtained effective model is the local boson field system with non-local interactions. The authors study the existence of non-trivial fixed point and its scaling behavior. This fixed point seems to be tri-critical. Such fixed point is interpreted in terms of the original Lattice QED model, and the results are consistent with the Monte Calro study

Soil C and N availability determine the priming effect: microbial N mining and stoichiometric decomposition theories

Science.gov (United States)

Chen, Ruirui; Senbayram, Mehmet; Blagodatsky, Sergey; Dittert, Klaus; Lin, Xiangui; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2014-05-01

The increasing input of anthropogenically derived nitrogen (N) to ecosystems raises a crucial question: how does available N modify the decomposer community and thus affects the mineralization of soil organic matter (SOM). Moreover, N input modifies the priming effect (PE), that is, the effect of fresh organics on the microbial decomposition of SOM. We studied the interactive effects of C and N on SOM mineralization (by natural 13C labelling adding C4-sucrose or C4-maize straw to C3-soil) in relation to microbial growth kinetics and to the activities of five hydrolytic enzymes. This encompasses the groups of parameters governing two mechanisms of priming effects - microbial N mining and stoichiometric decomposition theories. In sole C treatments, positive PE was accompanied by a decrease in specific microbial growth rates, confirming a greater contribution of K-strategists to the decomposition of native SOM. Sucrose addition with N significantly accelerated mineralization of native SOM, whereas mineral N added with plant residues accelerated decomposition of plant residues. This supports the microbial mining theory in terms of N limitation. Sucrose addition with N was accompanied by accelerated microbial growth, increased activities of β-glucosidase and cellobiohydrolase, and decreased activities of xylanase and leucine amino peptidase. This indicated an increased contribution of r-strategists to the PE and to decomposition of cellulose but the decreased hemicellulolytic and proteolytic activities. Thus, the acceleration of the C cycle was primed by exogenous organic C and was controlled by N. This confirms the stoichiometric decomposition theory. Both K- and r-strategists were beneficial for priming effects, with an increasing contribution of K-selected species under N limitation. Thus, the priming phenomenon described in 'microbial N mining' theory can be ascribed to K-strategists. In contrast, 'stoichiometric decomposition' theory, that is, accelerated OM

The effective field theory of nonsingular cosmology: II

Energy Technology Data Exchange (ETDEWEB)

Cai, Yong; Li, Hai-Guang [University of Chinese Academy of Sciences, School of Physics, Beijing (China); Qiu, Taotao [Central China Normal University, Institute of Astrophysics, Wuhan (China); Piao, Yun-Song [University of Chinese Academy of Sciences, School of Physics, Beijing (China); Chinese Academy of Sciences, Institute of Theoretical Physics, P.O. Box 2735, Beijing (China)

2017-06-15

Based on the effective field theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT operators that are capable to avoid instabilities in nonsingular cosmologies, we construct a nonsingular model dubbed the Genesis-inflation model, in which a slowly expanding phase (namely, Genesis) with increasing energy density is followed by slow-roll inflation. The spectrum of the primordial perturbation may be simulated numerically, which shows itself a large-scale cutoff, as the large-scale anomalies in CMB might be a hint for. (orig.)

Probing scalar effective field theories with the soft limits of scattering amplitudes

Energy Technology Data Exchange (ETDEWEB)

Padilla, Antonio [School of Physics and Astronomy, University of Nottingham,University Park, Nottingham, NG7 2RD United Kingdom (United Kingdom); Stefanyszyn, David [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, Groningen, 9747 AG The (Netherlands); Wilson, Toby [School of Physics and Astronomy, University of Nottingham,University Park, Nottingham, NG7 2RD United Kingdom (United Kingdom)

2017-04-04

We investigate the soft behaviour of scalar effective field theories (EFTs) when there is a number of distinct derivative power counting parameters, ρ{sub 1}<ρ{sub 2}<…<ρ{sub Q}. We clarify the notion of an enhanced soft limit and use these to extend the scope of on-shell recursion techniques for scalar EFTs. As an example, we perform a detailed study of theories with two power counting parameters, ρ{sub 1}=1 and ρ{sub 2}=2, that include the shift symmetric generalised galileons. We demonstrate that the minimally enhanced soft limit uniquely picks out the Dirac-Born-Infeld (DBI) symmetry, including DBI galileons. For the exceptional soft limit we uniquely pick out the special galileon within the class of theories under investigation. We study the DBI galileon amplitudes more closely, verifying the validity of the recursion techniques in generating the six point amplitude, and explicitly demonstrating the invariance of all amplitudes under DBI galileon duality.

Effective theory for heavy quark QCD at finite temperature and density with stochastic quantization

Energy Technology Data Exchange (ETDEWEB)

Neuman, Mathias

2015-07-01

In this thesis we presented the derivation as well as the numerical and analytical treatment of an effective theory for lattice Quantum Chromodynamics (LQCD). We derived the effective theory directly from LQCD, which allows us to systematically introduce further improvements. The derivation was performed by means of an expansion around the limit of infinite quark masses and infinite gauge coupling. Using this theory we were able to derive results in the region of large densities. This region is, due to the sign problem, inaccessible to standard LQCD approaches. Although LQCD simulations at large densities have been performed recently by applying stochastic quantization, those are still limited to lattice with low numbers of timeslices and therefor can not reach the low temperature region. Furthermore, they can not be crosschecked with Monte-Carlo simulations. Since the equivalence between stochastic quantization and Monte-Carlo is unproven for the case of finite density systems, new approaches to access the cold dense region of the QCD phase diagram are desirable. The effective theory presented in this thesis provides such an approach. We introduced continuum QCD in chapter 2. In chapter 3 we presented how LQCD, i.e. QCD in a discretized space-time, can be formulated and used as a tool to explore the non-perturbative regions of the QCD phase diagram. Special emphasis was placed on simulations at finite baryon densities and the numerical problems that arise in this region. These problems are caused by the complexification of the action and are known as the sign problem. We gave a detailed presentation of the derivation of our effective theory in chapter 4. For this we performed expansions around the limit of strong coupling and static quarks, κ=β=0, introducing corrections order by order in the expansion parameters κ and β. Truncating the theory at different orders allowed us to determine the parameter region where the convergence to full LQCD is good. The gauge

Diffraction and angular momentum effects in semiclassical atomic scattering theory

International Nuclear Information System (INIS)

Russek, A.

1979-01-01

The semiclassical scattering theory of Mott and Massey and Ford and Wheeler is here extended to multichannel scattering as occurs at a crossing or pseudocrossing of the transient molecule formed by the colliding atoms. The generalized theory incorporates both interference and diffraction phenomena, but the emphasis in this work is on diffraction. For small-angle scattering, diffraction effects become broader, not narrower, as the collision energy increases: ΔbΔtau > or = h[E/sub inc//(2m)]/sup 1/2/ relates the uncertainties in impact parameter b and reduced scattering angle tau = E/sub inc/theta, and determines the range in b required to resolve a structure in the deflection function of height Δtau. In the kilovolt range of collision energies, the effects of local maxima and minima in the deflection function are washed out, and the Airy-function approximation of Ford and Wheeler is inappropriate to describe the differential cross section. More generally, it is shown that at keV collision energies the stationary-phase approximation, heretofore essential in the reduction to the semiclassical limit, breaks down in the vicinity of a level crossing. An approximate theorem is proposed which remains valid in this region and elsewhere reduces to the standard stationary-phase approximation. Several illustrative examples are considered. A separate development treats the effect on the differential scattering cross section of a change in electronic angular momentum when electronic excitation occurs

Item Response Theory Models for Wording Effects in Mixed-Format Scales

Science.gov (United States)

Wang, Wen-Chung; Chen, Hui-Fang; Jin, Kuan-Yu

2015-01-01

Many scales contain both positively and negatively worded items. Reverse recoding of negatively worded items might not be enough for them to function as positively worded items do. In this study, we commented on the drawbacks of existing approaches to wording effect in mixed-format scales and used bi-factor item response theory (IRT) models to…

Applications of Balance Theory to Faculty Effectiveness: An Assessment

Science.gov (United States)

Peterson, Robin T.; Limbu, Yam B.; Xu, Bing; Fischbach, Sarah

2012-01-01

This paper provides a critical examination of the potential role of balance theory and student liking (affect) of instructors as tools for marketing professors in assisting student learning. The nature of balance theory and evidence of the learning impact of affect toward instructors are discussed. An empirical test of the theory is provided, and…

Linking Adverse Childhood Effects and Attachment: A Theory of Etiology for Sexual Offending.

Science.gov (United States)

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.

Standard model effective field theory: Integrating out neutralinos and charginos in the MSSM