arXiv subjects

J. R. S. Nascimento

Publications and source records attributed to J. R. S. Nascimento.

16 recordsLinked to original sources

arXiv2006

On the duality of three-dimensional superfield theories

Within the superfield approach, we consider the duality between the supersymmetric Maxwell-Chern-Simons and self-dual theories in three spacetime dimensions. Using a gauge embedding method, we construct the dual theory to the self-dual model interacting with a matter superfield, which turns out to be not the Maxwell-Chern-Simons theory coupled to matter, but a more complicated model, with a ``restricted'' gauge invariance. We stress the difficulties in dualizing the self-dual field coupled to matter into a theory with complete gauge invariance. After that, we show that the duality, achieved between these two models at the tree level, also holds up to the lowest order quantum corrections.

hep-th↗

arXiv2004

Issues of duality on non-commutative manifolds: the {\it non-equivalence} between self-dual and topologically massive models

We study issues of duality and dual equivalence in non-commutative manifolds. In particular the question of dual equivalence for the actions of the non-commutative extensions of the self-dual model (NC-SD) in 3D space-time and the Maxwell-Chern-Simons model (MCS-SD) is investigate. We show that former model {\it is not} dual equivalent the non-commutative extension of the Maxwell-Chern-Simons model, as widely believed, but a to deformed version of it that is disclosed here. Our results are not restrict to any finite order in the Seiberg-Witten expansion involving the non-commutative parameter $θ$.

hep-th↗

arXiv2003

Noncommutative massive Thirring model in three-dimensional spacetime

We evaluate the noncommutative Chern-Simons action induced by fermions interacting with an Abelian gauge field in a noncommutative massive Thirring model in (2+1)-dimensional spacetime. This calculation is performed in the Dirac and Majorana representations. We observe that in Majorana representation when $θ$ goes to zero we do not have induced Chern-Simons term in the dimensional regularization scheme.

hep-th↗

arXiv2003

On the dual equivalence of the self-dual and topologically massive p-form models

We study the duality symmetry in p-form models containing a generalized $B_q\wedge F_{p+1}$ term in spacetime manifolds of arbitrary dimensions. The equivalence between the $B_q\wedge F_{p+1}$ self-dual ($SD_{B\wedge F}$) and the $B_q\wedge F_{p+1}$ topologically massive ($TM_{B\wedge F}$) models is established using a gauge embedding procedure, including the minimal coupling to conserved charged matter current. The minimal coupling adopted for both tensor fields in the self-dual representation is transformed into a non minimal magnetic like coupling in the topologically massive representation but with the currents swapped. It is known that to establish this equivalence a current-current interaction term is needed to render the matter sector unchanged. We show that both terms arise naturally from the embedding adopted. Comparison with Higgs/Julia-Toulouse duality is established.

hep-th↗

arXiv2002

Duality in nonlinear B$\wedge$F models: equivalence between self-dual and topologically massive Born-Infeld B$\wedge$F models

We study the dual equivalence between the nonlinear generalization of the self-dual ($NSD_{B\wedge F}$) and the topologically massive $B\wedge F$ models with particular emphasis on the nonlinear electrodynamics proposed by Born and Infeld. This is done through a dynamical gauge embedding of the nonlinear self-dual model yielding to a gauge invariant and dynamically equivalent theory. We clearly show that nonpolinomial $NSD_{B\wedge F}$ models can be mapped, through a properly defined duality transformation, into $TM_{B\wedge F}$ actions. The general result obtained is then particularized for a number of examples, including the Born-Infeld-BF (BIBF) model that has experienced a revival in the recent literature.

hep-th↗

arXiv2002

On the dual equivalence of the self-dual and topologically massive $B\wedge F$ models coupled to dynamical fermionic matter

We study the equivalence between the $B\wedge F$ self-dual ($SD_{B\wedge F}$) and the $B\wedge F$ topologically massive ($TM_{B\wedge F}$) models including the coupling to dynamical, U(1) charged fermionic matter. This is done through an iterative procedure of gauge embedding that produces the dual mapping. In the interactive cases, the minimal coupling adopted for both vector and tensor fields in the self-dual representation is transformed into a non minimal magnetic like coupling in the topologically massive representation but with the currents swapped. It is known that to establish this equivalence a current-current interaction term is needed to render the matter sector unchanged. We show that both terms arise naturally from the embedding procedure.

hep-th↗

arXiv2001

On the dual equivalence of the Born-Infeld-Chern-Simons model coupled to dynamical U(1) charged matter

We study the equivalence between a nonlinear self-dual model (NSD) with the Born-Infeld-Chern-Simons (BICS) models using an iterative gauge embedding procedure that produces the duality mapping, including the case where the NSD model is minimally coupled to dynamical, U(1) charged fermionic matter. The duality mapping introduces a current-current interaction term while at the same time the minimal coupling of the original nonlinear self-dual model is replaced by a non-minimal magnetic like coupling in the BICS side.

hep-th↗

arXiv2001

Dual equivalence between Self-Dual and Maxwell-Chern-Simons models coupled to dynamical U(1) charged matter

We study the equivalence between the self-dual and the Maxwell-Chern-Simons (MCS) models coupled to dynamical, U(1) charged matter, both fermionic and bosonic. This is done through an iterative procedure of gauge embedding that produces the dual mapping of the self-dual vector field theory into a Maxwell-Chern-Simons version. In both cases, to establish this equivalence a current-current interaction term is needed to render the matter sector unchanged. Moreover, the minimal coupling of the original self-dual model is replaced by a non-minimal magnetic like coupling in the MCS side. Unlike the fermionic instance however, in the bosonic example the dual mapping proposed here leads to a Maxwell-Chern-Simons theory immersed in a field dependent medium.

hep-th↗

arXiv2000

Radiatively Induced Lorentz and CPT Violation in QED at Finite Temperature

In this paper we evaluate the induced Lorentz and CPT violating Chern-Simons term in the QED action at finite temperature. We do this using the method of derivative expansion of fermion determinants. Also, we use the imaginary-time formalism to calculate the temperature dependence of the Chern-Simons term

hep-th↗

arXiv2000

Self-Dual Model Coupled to Bosons

In this paper we investigated the dynamics, at the quantum level, of the self-dual field minimally coupled to bosons. In this investigation we use the Dirac bracket quantization procedure to quantize the model. Also, the relativistic invariance is tested in connection with the elastic boson-boson scattering amplitudes.

hep-th↗

arXiv1999

Charged Vacuum Condensate Near a Superconducting Cosmic String

A charged superconductiong cosmic string produces an extremely large electric field in its vicinity. This leads to vacuum instability and to the formation of a charged vacuum condensate which screens the electric charge of the string. We analyze the structure of this condensate using the Thomas-Fermi method.

hep-th↗

arXiv1997

Soliton Stability in Systems of Two Real Scalar Fields

In this paper we consider a class of systems of two coupled real scalar fields in bidimensional spacetime, with the main motivation of studying classical or linear stability of soliton solutions. Firstly, we present the class of systems and comment on the topological profile of soliton solutions one can find from the first-order equations that solve the equations of motion. After doing that, we follow the standard approach to classical stability to introduce the main steps one needs to obtain the spectra of Schrödinger operators that appear in this class of systems. We consider a specific system, from which we illustrate the general calculations and present some analytical results. We also consider another system, more general, and we present another investigation, that introduces new results and offers a comparison with the former investigations.

hep-th↗

arXiv1996

Alternate route to soliton solutions in hydrogen-bonded chains

In this paper we offer an alternate route for investigating soliton solutions in hydrogen-bonded chains. This is done by examining a class of systems of two coupled real scalar fields. We show that this route allows investigating several models for hydrogen-bonded chains in a unified manner. We also show how to investigate interesting issues, in particular the one concerning classical or linear stability of solitonic solutions.

cond-mat↗

arXiv1996

Gauge Invariant Effective Potential for Abelian Maxwell-Chern-Simons Systems

We investigate the effective potential for Abelian Maxwell--Chern--Simons systems. The calculations follow an alternate approach, recently proposed as a gauge invariant formulation of the effective potential, constructed in terms of a gauge invariant order parameter. We compare the results with another investigation, obtained within a standard route of calculating the effective potential.

hep-th↗

arXiv1992

Electron--Electron Bound States in QED$_{3}$

This paper is dedicated to the study of the existence and the properties of electron-electron bound states in QED$_3$. A detailed analysis of the infrared structure of the perturbative series of the theory is presented. We start by analyzing the two-point Green's function, in the Bloch-Nordsieck approximation. The theory appears to be plagued by severe infrared divergencies, which nevertheless disappear when vacuum-polarization effects are non-perturbatively taken into account. The dynamical induction of a Chern-Simons term is at the root of this mechanism. {}From the inspection of the electron-electron non-relativistic potential it then follows that equally charged fermions may either repel or attract and, moreover, that bound states do in fact exist in the theory. We calculate numerically the binding energies and average radius of the bound states. We find an accidental quasi-degeneracy of the ground state of the system, between the lowest-energy $l=-3$ and $l=-5$ states, which could be related to a radio-frequency resonance in high-$T_c$ superconductors.

hep-th↗

arXiv1992

Attractive Forces Between Electrons in QED$_{3}$

Vacuum polarization effects are non-perturbatively incorporated into the photon propagator to eliminate the severe infrared problems characteristic of QED$_3$. The theory is thus rephrased in terms of a massive vector boson whose mass is $e^2/(8π)$. Subsequently, it is shown that electron-electron bound states are possible in QED$_3$.

hep-th↗