The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform

F. A. Barone - One of the best experts on this subject based on the ideXlab platform.

  • New Effects in the Vicinity of a Perfectly Conducting Plate in a Non-minimal Lorentz Violation Scenario
    Brazilian Journal of Physics, 2020
    Co-Authors: L. H. C. Borges, F. A. Barone
    Abstract:

    In this paper we consider some physical phenomena in the vicinity of a Conducting Plate in a non-minimal Lorentz-violating scenario in 3 + 1 dimensions. We consider a model where the dynamics of the abelian gauge field is given by the standard Maxwell Lagrangian added by a Lorentz symmetry breaking term with the presence of higher order derivatives in the gauge field. The Lorentz symmetry breaking is due to the presence of a single background vector d ^ λ and we perform the calculations perturbatively up to first order in d ^ λ . We obtain the propagator for the gauge field in the presence of a mirror and the interaction force between the mirror and a point-like electric charge, as well as the interaction force between the mirror and an electric dipole. We show that, on the contrary to what happens in a minimal Lorentz-violating scenario with one single background field (L.H.C. Borges, F.A. Barone, Eur. Phys. J. C 693 , 77, 2017 ), the image method is not valid in the model that we consider in this paper. As a consequence, the symmetry of spatial reflection on the mirror is broken. We also investigate the emergence of a torque in a system composed by a mirror and a point-like electric charge, placed at a fixed distance apart each other. The results obtained in this work have no counterpart in the Maxwell electrodynamics and were not verified in any Lorentz-violating scenario previously.

  • New point-like sources and a Conducting surface in Maxwell–Chern–Simons electrodynamics
    The European Physical Journal C, 2020
    Co-Authors: L. H. C. Borges, F. E. Barone, C. C. H. Ribeiro, H. L. Oliveira, R. L. Fernandez, F. A. Barone
    Abstract:

    We investigate some aspects of the Maxwell–Chern–Simons electrodynamics focusing on physical effects produced by the presence of stationary sources and a perfectly Conducting Plate (mirror). Specifically, in addition to point charges, we propose two new types of point-like sources called topological source and Dirac point, and we also consider physical effects in various configurations that involve them. We show that the Dirac point is the source of the vortex field configurations. The propagator of the gauge field due to the presence of a Conducting Plate and the interaction forces between the Plate and point-like sources are computed. It is shown that the image method is valid for the point-like charges as well as for Dirac points. For the topological source we show that the image method is not valid and the symmetry of spatial refection on the mirror is broken. In all setups considered, it is shown that the topological source leads to the emergence of torques.

Bo Zhang - One of the best experts on this subject based on the ideXlab platform.

  • an inverse electromagnetic scattering problem for a bi periodic inhomogeneous layer on a perfectly Conducting Plate
    Applicable Analysis, 2011
    Co-Authors: Jiaqing Yang, Bo Zhang
    Abstract:

    This article is concerned with uniqueness for reconstructing a periodic inhomogeneous medium sitting on a perfectly Conducting Plate. We deal with the problem in the framework of time-harmonic Maxwell systems without TE or TM polarization. An orthogonal relation is obtained for two refractive indices and then used to prove that the refractive index can be uniquely identified from a knowledge of the incident fields and the total tangential electric field on a plane above the inhomogeneous medium, utilizing the eigenvalues and eigenfunctions of a quasi-periodic Sturm–Liouville eigenvalue problem.

  • an inverse electromagnetic scattering problem for a bi periodic inhomogeneous layer on a perfectly Conducting Plate
    arXiv: Analysis of PDEs, 2010
    Co-Authors: Jiaqing Yang, Bo Zhang
    Abstract:

    This paper is concerned with uniqueness for reconstructing a periodic inhomogeneous medium covered on a perfectly Conducting Plate. We deal with the problem in the frame of time-harmonic Maxwell systems without TE or TM polarization. An orthogonal relation for two refractive indices is obtained, and then inspired by Kirsch's idea, the refractive index can be identified by utilizing the eigenvalues and eigenfunctions of a quasi-periodic Sturm-Liouville eigenvalue problem.

  • electromagnetic scattering by an inhomogeneous Conducting or dielectric layer on a perfectly Conducting Plate
    Proceedings of The Royal Society A: Mathematical Physical and Engineering Sciences, 1998
    Co-Authors: Simon N Chandlerwilde, Bo Zhang
    Abstract:

    We consider a two-dimensional problem of scattering of a time harmonic electromagnetic plane wave by an inhomogeneous Conducting or dielectric layer on a perfectly Conducting Plate. The magnetic permeability is assumed to be a fixed positive constant in the media. The material properties of the media are characterized completely by an index of refraction, which is a bounded measurable function in the layer and a positive constant above the layer corresponding to a homogeneous dielectric medium. In this paper, we only examine the TM (transverse magnetic) polarization case. A radiation condition is introduced and equivalence with a second kind, Lippmann-Schwinger-type integral equation is shown. With additional assumptions on the index of refraction in the layer, uniqueness of solution is proved. Existence of solution is then established by employing a form of Fredholm alternative using a general result on the solvability of integral equations on unbounded domains published earlier by Chandler-Wilde and Zhang. An approximate analytic solution for the case of a thin inhomogeneous layer is obtained from the integral equation formulation and is used to show that, if the index of refraction is appropriately chosen, the scattered field can grow with distance from the Plate.

H A Nersisyan - One of the best experts on this subject based on the ideXlab platform.

  • Casimir densities for a Conducting Plate in de Sitter spacetime
    Journal of Physics: Conference Series, 2014
    Co-Authors: A. S. Kotanjyan, Aram A. Saharian, H A Nersisyan
    Abstract:

    Two-point functions for the electromagnetic field in background of (D + 1)-dimensional dS spacetime are evaluated assuming that the field is prepared in the Bunch-Davies vacuum state. By using these functions, the vacuum expectation values (VEVs) of the field squared and the energy-momentum tensor are investigated in the geometry of a Conducting Plate. The VEVs are explicitly decomposed into the boundary-free and Plate-induced parts. For points outside of the Plate the renormalization is needed for the first parts only. Because of the maximal symmetry of the background spacetime and of the Bunch-Davies vacuum state, the boundary-free parts do not depend on spacetime coordinates, whereas the Plate-induced parts are functions of the proper distance of the observation point from the Plate. The Plate-induced part in the VEV of the energy-momentum tensor vanishes for D = 3 which is a direct consequence of a conformal invariance of the electromagnetic field for this spatial dimension. For D > 3, in addition to the diagonal components, the vacuum energy-momentum tensor has nonzero off-diagonal component which describes energy flux along the direction normal to the Plate.

  • Electromagnetic two-point functions and Casimir densities for a Conducting Plate in de Sitter spacetime
    Physics Letters B, 2014
    Co-Authors: Aram A. Saharian, A. S. Kotanjyan, H A Nersisyan
    Abstract:

    Abstract We evaluate the two-point function for the electromagnetic field tensor in ( D + 1 ) -dimensional de Sitter spacetime assuming that the field is prepared in Bunch–Davies vacuum state. This two-point function is used for the investigation of the vacuum expectation values (VEVs) of the field squared and the energy–momentum tensor in the presence of a Conducting Plate. The VEVs are decomposed into the boundary-free and Plate-induced parts. For the latter, closed form analytical expressions are given in terms of the hypergeometric function. For 3 ≤ D ≤ 8 the Plate-induced part in the VEV of the electric field squared is positive everywhere, whereas for D ≥ 9 it is positive near the Plate and negative at large distances. The VEV of the energy–momentum tensor, in addition to the diagonal components, contains an off-diagonal component which corresponds to the energy flux along the direction normal to the Plate. Simple asymptotic expressions are provided at small and large distances from the Plate compared with the de Sitter curvature scale. For D ≥ 4 , all the diagonal components of the Plate-induced vacuum energy–momentum tensor are negative and the energy flux is directed from the Plate.

Bradley J. Roth - One of the best experts on this subject based on the ideXlab platform.

  • Thermal fluctuations of the magnetic field over a thin Conducting Plate
    Journal of Applied Physics, 1998
    Co-Authors: Bradley J. Roth
    Abstract:

    The thermal fluctuations of the magnetic field over a thin Conducting Plate are calculated. The Plate is represented as a superposition of circuits, where each circuit consists of an array of current loops characterized by a particular spatial frequency. The thermally induced current in each loop is determined from the magnetic energy associated with the circuit and the equipartition theorem. This method gives results that are nearly identical to a previously published analysis of this problem by Varpula and Poutanen [J. Appl. Phys. 55, 4015 (1984)], in the limit when the Plate is thin.

L. H. C. Borges - One of the best experts on this subject based on the ideXlab platform.

  • New Effects in the Vicinity of a Perfectly Conducting Plate in a Non-minimal Lorentz Violation Scenario
    Brazilian Journal of Physics, 2020
    Co-Authors: L. H. C. Borges, F. A. Barone
    Abstract:

    In this paper we consider some physical phenomena in the vicinity of a Conducting Plate in a non-minimal Lorentz-violating scenario in 3 + 1 dimensions. We consider a model where the dynamics of the abelian gauge field is given by the standard Maxwell Lagrangian added by a Lorentz symmetry breaking term with the presence of higher order derivatives in the gauge field. The Lorentz symmetry breaking is due to the presence of a single background vector d ^ λ and we perform the calculations perturbatively up to first order in d ^ λ . We obtain the propagator for the gauge field in the presence of a mirror and the interaction force between the mirror and a point-like electric charge, as well as the interaction force between the mirror and an electric dipole. We show that, on the contrary to what happens in a minimal Lorentz-violating scenario with one single background field (L.H.C. Borges, F.A. Barone, Eur. Phys. J. C 693 , 77, 2017 ), the image method is not valid in the model that we consider in this paper. As a consequence, the symmetry of spatial reflection on the mirror is broken. We also investigate the emergence of a torque in a system composed by a mirror and a point-like electric charge, placed at a fixed distance apart each other. The results obtained in this work have no counterpart in the Maxwell electrodynamics and were not verified in any Lorentz-violating scenario previously.

  • New point-like sources and a Conducting surface in Maxwell–Chern–Simons electrodynamics
    The European Physical Journal C, 2020
    Co-Authors: L. H. C. Borges, F. E. Barone, C. C. H. Ribeiro, H. L. Oliveira, R. L. Fernandez, F. A. Barone
    Abstract:

    We investigate some aspects of the Maxwell–Chern–Simons electrodynamics focusing on physical effects produced by the presence of stationary sources and a perfectly Conducting Plate (mirror). Specifically, in addition to point charges, we propose two new types of point-like sources called topological source and Dirac point, and we also consider physical effects in various configurations that involve them. We show that the Dirac point is the source of the vortex field configurations. The propagator of the gauge field due to the presence of a Conducting Plate and the interaction forces between the Plate and point-like sources are computed. It is shown that the image method is valid for the point-like charges as well as for Dirac points. For the topological source we show that the image method is not valid and the symmetry of spatial refection on the mirror is broken. In all setups considered, it is shown that the topological source leads to the emergence of torques.