SearcharxivSearch

arXiv subjects

W. C. Santos

Publications and source records attributed to W. C. Santos.

4 recordsLinked to original sources

Spontaneous Lorentz symmetry violation and topological defects for the Chern-Simons matter vector field

The study of topological defects occurring in vector and tensor fields is an intriguing subject and little explored in the literature. In this article, we analyze the topological defects arising from the spontaneous violation of Lorentz symmetry for a vector matter field with Chern-Simons term in a Minkowski spacetime in $(1+2)D$. As a consequence, the resulting nonlinear equations include a topological mass via the Chern-Simons term, which leads to a vector version of a soliton state. We show that the topological defects arising from the vector field can be categorized as either vortices, with topology $S^{1}\times\mathbb{R}$, or domain-walls, with topology $S^{0} \times\mathbb{R}^2$. The vortex solutions were analyzed using a procedure similar to the Nielsen-Olesen one, though extended to the vector case to account for a spontaneous violation of Lorentz symmetry. We also analyze the influence of the topological mass and verify the stability of the model as well as the magnetic vortex in $(1+2)D$. We show that domain-wall solutions also emerge as an effect of the violation of the Lorentz symmetry expressed by the vacuum of the vector field. We obtain general equations for this new class of domain walls involving the Lorentz violation parameter and the topological mass. By means of the energy-momentum tensor, we verify the instability of the formation of these domain walls in $(1+2)D$.

hep-th

Bumblebee field in a Topological Framework

A vector field coming from spontaneous Lorentz violation mechanism, namely Bumblebee model is analysed in a topological framework in a $(1+2)D$ Minkowski space-time. Taking a $(1+2)D$ nonlinear Bumblebee vector matter field dynamics where we include topological like Chern-Simons type terms, a vector version of a soliton state, or vortex was found. The Nielsen-Olesen procedure was used in order to derive a Lorentz-violation vector parameter which characterizes, via Spontaneous Symmetry Breaking mechanism, the non-trivial vacuum. We verify the stability of the model as much as the magnetic vortex, and noticed that the soliton modes with polarized direction generated can be associated with local anisotropy of vacuum energy. The vortex equations of motion and the asymptotic behaviour is presented. We have obtained that the effect of the Lorentz symmetry violation expressed by the a time-like Bumblebee vector field vacuum could be shown as kind of pulse at a fixed point $r_0$ in a limitless universe, or as a barrier at $r_0$ which can represent a boundary in the universe, if the Bumblebee vector field vacuum has space-like characteristic. We also analyse the spectrum via propagators where we note that the topological mass contributes as well to the dynamical mass poles. We obtain that the Chern-Simons type terms, in fact, indicates the "speed" of the field to saturate the asymptotic limit and that the vortex core can not be dimension zero.

hep-th

Noncommutative geometry induced by spin effects

In this paper we study the nonlocal effects of noncommutative spacetime on simple physical systems. Our main point is the assumption that the noncommutative effects are consequences of a background field which generates a local spin structure. So, we reformulate some simple electrostatic models in the presence of a spin-deformation contribution to the geometry of the motion, and we obtain an interesting correlation amongst the deformed area vector, the 3D noncommutative effects and the usual spin vector given in quantum mechanics framework. Remarkably we can observe that a spin-orbit coupling term comes to light on the spatial sector of a potential wrote in terms of noncommutative coordinates what indicates that bound states are particular cases in this procedure. Concerning to confined or bounded particles in this noncommutative domain we verify that the kinetic energy is modified by a deformation factor. Finally, we discuss about perspectives.

hep-th

Charged Tensor Matter Fields and Lorentz Symmetry Violation via Spontaneous Symmetry Breaking

We consider a model with a charged vector field along with a Cremmer-Scherk-Kalb-Ramond (CSKR) matter field coupled to a U(1) gauge potential. We obtain a natural Lorentz symmetry violation due to the local U(1) spontaneous symmetry breaking mechanism triggered by the imaginary part of the vector matter. The choice of the unitary gauge leads to the decoupling of the gauge-KR sector from the Higgs-KR sector. The excitation spectrum is carefully analyzed and the physical modes are identified. We propose an identification of the neutral massive spin-1 Higgs-like field with the massive Z' boson of the so-called mirror matter models.

hep-th