Manoel M. Ferreira Jr

Aharonov-Bohm-Casher Problem with a nonminimal Lorentz-violating coupling

The Aharonov-Bohm-Casher problem is examined for a charged particle describing a circular path in presence of a Lorentz-violating background nonminimally coupled to a spinor and a gauge field. It were evaluated the particle eigenenergies, showing that the LV background is able to lift the original degenerescence in the absence of magnetic field and even for a neutral particle. The Aharonov-Casher phase is used to impose an upper bound on the background magnitude. A similar analysis is accomplished in a space endowed with a topological defect, revealing that both the disclination parameter and the LV background are able to modify the particle eigenenergies. We also analyze the particular case where the particle interacts harmonically with the topological defect and the LV background, with similar results.

Classical solutions in a Lorentz violating scenario of Maxwell-Chern-Simons-Proca electrodynamics

Abstract.Taking as starting point the planar model that arises from the dimensional reduction of the Abelian-Higgs Carroll-Field-Jackiw model, we write down and study the extended Maxwell equations and the associated wave equations for the potentials. The solutions for these equations correspond to the usual ones for the MCS-Proca system, supplemented with background-dependent correction terms. In the case of a purely timelike background, exact algebraic solutions are presented which possess a similar behavior to the MCS-Proca counterparts near and far from the origin. On the other hand, for a purely spacelike background, only approximate solutions are feasible. They consist of non-trivial analytic expressions with manifest evidence of spatial anisotropy, which is consistent with the existence of a privileged direction in space. These solutions also behave similarly to the MCS-Proca ones near and far from the origin.

A comment on the topological phase for anti-particles in a Lorentz-violating environment

Abstract Recently, a scheme to analyse topological phases in quantum mechanics by means of the non-relativistic limit of fermions non-minimally coupled to a Lorentz-breaking background has been proposed. In this Letter, we show that the fixed background, responsible for the Lorentz-symmetry violation, may induce opposite Aharonov–Casher phases for a particle and its corresponding anti-particle. We then argue that such a difference may be used to investigate the asymmetry for particle/anti-particle as well as to propose bounds on the associated Lorentz-symmetry violating parameters.

Feynman propagator for the nonbirefringent CPT-even electrodynamics of the standard model extension

The CPT-even gauge sector of the standard model extension is composed of 19 components comprised in the tensor (K{sub F}){sub {mu}{nu}{rho}{sigma}}, of which nine do not yield birefringence. In this work, we examine the Maxwell electrodynamics supplemented by these nine nonbirefringent CPT-even components in aspects related to the Feynman propagator and full consistency (stability, causality, unitarity). We adopt a prescription that parametrizes the nonbirefringent components in terms of a symmetric and traceless tensor, K{sub {mu}{nu}}, and second parametrization that writes K{sub {mu}{nu}} in terms of two arbitrary four-vectors, U{sub {mu}} and V{sub {nu}}. We then explicitly evaluate the gauge propagator of this electrodynamics in a tensor closed way. In the sequel, we show that this propagator and involved dispersion relations can be specialized for the parity-odd and parity-even sectors of the tensor (K{sub F}){sub {mu}{nu}{rho}{sigma}}. In this way, we reassess some results of the literature and derive some new outcomes showing that the parity-even anisotropic sector engenders a stable, noncausal and unitary electrodynamics.

Gauge propagator and physical consistency of the CPT-even part of the Standard Model Extension

In this work, we explicitly evaluate the gauge propagator of the Maxwell theory supplemented by the CPT-even term of the standard model extension. First, we specialize our evaluation for the parity-odd sector of the tensor W{sub {mu}}{sub {nu}}{sub {rho}}{sub {sigma}}, using a parametrization that retains only the three nonbirefringent coefficients. From the poles of the propagator, it is shown that physical modes of this electrodynamics are stable, noncausal and unitary. In the sequel, we carry out the parity-even gauge propagator using a parametrization that allows to work with only the isotropic nonbirefringent element. In this case, we show that the physical modes of the parity-even sector of the tensor W are causal, stable and unitary for a limited range of the isotropic coefficient.

Classical solutions in a Lorentz violating Maxwell-Chern-Simons electrodynamics

We take as starting point the planar model arising from the dimensional reduction of the Maxwell Electrodynamics with the (Lorentz-violating) Carroll-Field-Jackiw term. We then write and study the extended Maxwell equations and the corresponding wave equations for the potentials. The solution to these equations show some interesting deviations from the usual MCS Electrodynamics, with background-dependent correction terms. In the case of a time-like background, the correction terms dominate over the MCS sector in the region far from the origin, and establish the behaviour of a massless Electrodynamics (in the electric sector). In the space-like case, the solutions indicate the clear manifestation of spatial anisotropy, which is consistent with the existence of a privileged direction is space.

Finite temperature behavior of the CPT-even and parity-even electrodynamics of the standard model extension

In this work, we examine the finite temperature properties of the

Classical solutions for the Lorentz-violating and CPT-even term of the Standard Model Extension

CPT

Lorentz-violating contributions of the Carroll-Field-Jackiw model to the CMB anisotropy

-even and Lorentz-invariance-violating (LIV) electrodynamics of the standard model extension, represented by the term

Dimensional reduction of the CPT-even electromagnetic sector of the Standard Model Extension

{W}_{\ensuremath{\alpha}\ensuremath{\nu}\ensuremath{\rho}\ensuremath{\varphi}}{F}^{\ensuremath{\alpha}\ensuremath{\nu}}{F}^{\ensuremath{\rho}\ensuremath{\varphi}}