45,323 research outputs found
Magnetoelectric boundary simulated by a Chern-Simons-like model
No full textIn this work we study some physical phenomena that emerge in the vicinity of a magnetoelectric boundary. For simplicity, we restrict to the case of a planar boundary described by a coupling between the gauge field with a planar external Chern-Simons-like potential. The results are obtained exactly. We compute the correction undergone by the photon propagator due to the presence of the Chern-Simons coupling and we investigate the interaction between a stationary point-like charge and the magnetoelectric boundary. In the limit of a perfect mirror, where the coupling constant between the field and the potential diverges, we recover the image method. For a non perfect mirror, we show that we have an attenuated image charge and, in addition, an image magnetic monopole whose field strength does not exhibit the presence of the undesirable and artificial divergences introduced by Dirac strings. We also study the interaction between the plate and a quantum particle with spin. In this case we have a kind of charge-magnetic dipole interaction due to the magnetoelectric properties of the plate
Scattering Amplitudes of Massive N=2 Gauge Theories in Three Dimensions
No full textWe study the scattering amplitudes of mass-deformed Chern-Simons theories and Yang-Mills-Chern-Simons theories with N=2 supersymmetry in three dimensions. In particular, we derive the on-shell supersymmetry algebras which underlie the scattering matrices of these theories. We then compute various 3 and 4-point on-shell tree-level amplitudes in these theories. For the mass-deformed Chern-Simons theory, odd-point amplitudes vanish and we find that all of the 4-point amplitudes can be encoded elegantly in superamplitudes. For the Yang-Mills-Chern-Simons theory, we obtain all of the 4-point tree-level amplitudes using a combination of perturbative techniques and algebraic constraints and we comment on difficulties related to computing amplitudes with external gauge fields using Feynman diagrams. Finally, we propose a BCFW recursion relation for mass-deformed theories in three dimensions and discuss the applicability of this proposal to mass-deformed N=2 theories
Solitons in low-dimensional sigma models
No full textThe aim of this thesis is to study topological soliton solutions in classical field theories, called sigma models, on a three-dimensional space. In chapter 1 we review the general field-theoretical framework of classical soliton solutions and exemplify it on the main features of the 0(3) σ-model and the Abehan Higgs model in (2+1) dimensions. In chapter 2 a U(l)-gauged 0(3) σ-model is discussed, where the behaviour of the gauge field is determined by a Chern-Simons term in the action. We find numerical solutions for radially symmetric fields and discuss those of degree one and two. They carry a non-vanishing angular momentum and can be interpreted as classical anyons. A similar model is studied in chapter 3. Here the potential is of Higgs-type and chosen to produce a Bogomol'nyi model where the energy is bounded from below by a linear combination of the topological degree of the matter fields and the local U(l)-charge. Depending on internal parameters, the solutions are solitons or vortices. We study them numerically and prove for a certain range of the matter field's vacuum value that there cannot be a 1-soliton.In chapter 4 we discuss a modified 0(3) σ-model in (3+0) dimensions. The topological stability of the solitons is here imphed by the degree of the map S(^3) → S(^2), which provides a lower boundon the potential energy of the configuration. Numerical solutions are obtained for configurations of azimuthal symmetry and the spectrum of slowly rotating solitons is approximated. Chapter 5 deals with a theory where the fields are maps IR(^2+1) → CP(^2). The Lagrangian includes a potential and a fourth-order term in the field-gradient. We find a family of static analytic solutions of degree one and study the 2-soIiton configuration numerically by using a gradient-flow equation on the moduli space of solutions. We conclude this thesis with a brief summary and give an outlook to open questions
Einstein-Chern-Simons equations on the 3-brane world
No full textIn this article it is studied the 3-brane world in the context of
five-dimensional Einstein-Chern-Simons gravity. We started by considering
Israel's junction condition for AdS-Chern-Simons gravity. Using the S-expansion
procedure, we mapped the AdS-Chern-Simons junction conditions to
Einstein-Chern-Simons gravity, allowing us to derive effective four-dimensional
Einstein-Chern-Simons field equations
UNUSUAL NEGATIVE MOLECULAR IONS AND DIANIONS AND CHEMICAL BONDS INVOLVING RYDBERG ORBITALS
No full text1. Maciej Gutowski, Piotr Skurski, Kenneth D. Jordan, Jack Simons; Int J. Quant. Chem.; 64, 183 (1997). 2. P. Skurski, M. Gutowski and J. Simons, Int J. Quant Chem. 76. 197 (2000). 3. Alexander I. Boldyrev, Maciej Gutowski, and Jack Simons; Acc. Chem. Res.; 29, 497 (1996). 4. Jack Simons and Maciej Gutowski, Chem. Rev. 91, 669 (1991). 5. A. I. Boldyrev and J. Simons; J. Phys. Chem. 96, 8840 (1992); A. I. Boldyrev and J. Simons. J. Phys. Chem., 103, 3575 (1999).Author Institution: Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of UtahIn this presentation, our work and that of several other groups on the species listed in the title will be discussed. Particular emphasis will be given to: (a) dipole bound (which have also been the subject of numerous experimental studies), (b) dipole bound (which remain theoretical speculation), (c) resonance states of anions that can be made stable via ``solvation'', (d) dianions such as that have extremely high second electron binding (which occur in the solid state and in solution), (e) anions in which the ``extra'' electron occupies a Rydberg-like molecular (which have been seen experimentally), and (f) chemical bonds that arise when a Rydberg-like orbital is
A note on amplitudes in N=6 superconformal Chern-Simons theory
No full textThis is the accepted version of an article subsequently published in Journal of High Energy Physics July 2012, 2012:160. The original publication is available at www.springerlink.com http://link.springer.com/article/10.1007%2FJHEP07%282012%29160This version deposited to arXiv 30-07-12 arXiv:1205.6705v3 [hep-th
TERMO DE CHERN-SIMONS MISTO E A ESTATÍSTICA FRACIONÁRIA
No full textNeste trabalho estudamos um modelo que é descrito por uma Lagrangiana que carrega o termo de Chern-Simons Misto acoplado com o campo de matéria em uma teoria em que há quebra de simetria de Lorentz e analisamos a influência do termo de Chern-Simons para a estatística fracionária do sistema
Existence of solutions to Chern-Simons-Higgs equations on graphs
No full textLet be a finite graph. We consider the existence of solutions to a
generalized Chern-Simons-Higgs equation on , where
is a positive constant; is the inverse function of
on ; is a positive
integer; are distinct vertices of and
is the Dirac delta mass at . We prove that there is
critical value such that the generalized Chern-Simons-Higgs
equation has a solution if and only if . We also prove
the existence of solutions to the Chern-Simons-Higgs equation
on when takes the critical value and this completes
the results of An Huang, Yong Lin and Shing-Tung Yau (Commun. Math. Phys. 377,
613-621 (2020)).Comment: 13 page
Tachyon-dependent Chern-Simons terms and the V-QCD Baryon
No full textThe structure of the five-dimensional Tachyon-Chern-Simons action and its relevance to single-baryon states in the context of the V-QCD models for holographic QCD with backreacting flavor are analyzed. The most general form of the Tachyon-Chern-Simons 5-form, compatible with symmetries and flavor anomalies is determined. It is the sum of a non-trivial gauge-invariant 5-dimensional form and a non-invariant closed 5-form that reproduces the flavor anomalies. Single-baryon solutions of the gravity theory, arising from the DBI plus Tachyon-Chern-Simons actions are considered. The baryon is realised as a bulk axial instanton. The baryon ansatz and the field equations are derived and the boundary conditions are determined, which ensure that the solution has finite boundary energy and unit baryon charge. The boundary baryon number, which is computed from the universal (closed) part of the Tachyon-Chern-Simons action, is shown to coincide with the bulk axial instanton number
Higher dimensional abelian Chern-Simons theories and their link invariants
No full text40 pagesInternational audienceThe role played by Deligne-Beilinson cohomology in establishing the relation between Chern-Simons theory and link invariants in dimensions higher than three is investigated. Deligne-Beilinson cohomology classes provide a natural abelian Chern-Simons action, non trivial only in dimensions , whose parameter is quantized. The generalized Wilson -loops are observables of the theory and their charges are quantized. The Chern-Simons action is then used to compute invariants for links of -loops, first on closed -manifolds through a novel geometric computation, then on through an unconventional field theoretic computation
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