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J. A. Helayel-Neto

Publications and source records attributed to J. A. Helayel-Neto.

At least 37 records · Page 2Linked to original sources
arXiv2005

Lorentz-symmetry Violation and Electrically Charged Vortices in the Planar Regime

We start from a Lorentz non-invariant Abelian-Higgs model in 1+3 dimensions, and carry out its dimensional reduction to $D=1+2$. The planar model resulting thereof is composed by a Maxwell-Chern-Simons-Proca gauge sector, a massive scalar sector, and a mixing term (involving the fixed background, $v^μ$) that realizes Lorentz violation for the reduced model. Vortex-type solutions of the planar model are investigated,revealing charged vortex configurations that recover the usual Nielsen-Olesen configuration in the asymptotic regime. The Aharonov-Casher Effect in layered superconductors, that shows interference of neutral particles with a magnetic moment moving around a line charge, is also studied. Our charged vortex solutions exhibit a screened electric field that induces the same phase shift as the one caused by the charged wire.

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arXiv2005

Casimir Effect for Gauge Scalars: The Kalb-Ramond Case

In this work we calculate the functional generator of the Green's functions of the Kalb-Ramond field in 3+1 dimensions. We also calculate the functional generator, and corresponding Casimir energy, of the same field when it is submitted to boundary conditions on two parallel planes. The boundary conditions we consider can be interpreted as a kind of conducting planes for the field in compearing with the Maxwell case. We compare our result with the standard ones for the scalar and Maxwell fields.

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arXiv2005

On the Electric Charge Quantization from the Dirac-Aharonov-Bohm Potential

The purpose of this paper is to show that, under certain restrictions, we can take a Dirac-Aharonov-Bohm potential as a pure gauge field. We argue that a modified quantization condition comes out for the electric charge that may open up the way for the understanding of fractional charges. One does not need any longer to rely on the existence of a magnetic monopole to justify electric charge quantization.

quant-ph↗
arXiv2005

On the Integrability and Chaos of an N=2 Maxwell-Chern-Simons-Higgs Mechanical Model

We apply different integrability analysis procedures to a reduced (spatially homogeneous) mechanical system derived from an off-shell non-minimally coupled N=2 Maxwell-Chern-Simons-Higgs model that presents BPS topological vortex excitations, numerically obtained with an ansatz adopted in a special - critical coupling - parametric regime. As a counterpart of the regularity associated to the static soliton-like solution, we investigate the possibility of chaotic dynamics in the evolution of the spatially homogeneous reduced system, descendant from the full N=2 model under consideration. The originally rich content of symmetries and interactions, N=2 susy and non-minimal coupling, singles out the proposed model as an interesting framework for the investigation of the role played by (super-)symmetries and parametric domains in the triggering/control of chaotic behavior in gauge systems. After writing down effective Lagrangian and Hamiltonian functions, and establishing the corresponding canonical Hamilton equations, we apply global integrability Noether point symmetries and Painleveproperty criteria to both the general and the critical coupling regimes. As a non-integrable character is detected by the pair of analytical criteria applied, we perform suitable numerical simulations, as we seek for chaotic patterns in the system evolution. Finally, we present some Comments on the results and perspectives for further investigations and forthcoming communications.

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arXiv2005

Classical Solutions in a Lorentz-violating Scenario of Maxwell-Chern-Simons-Proca Electrodynamics

Taking as starting point the planar model arising from the dimensional reduction of the Abelian-Higgs Carroll-Field-Jackiw model, we write down and study the extended Maxwell equations and the corresponding 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 a 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.

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arXiv2005

Recent Results on N=2,4 Supersymmetry with Lorentz Symmetry Violating

In this work, we propose the N=2 and N=4 supersymmetric extensions of the Lorentz-breaking Abelian Chern-Simons term. We formulate the question of the Lorentz violation in 6 and 10 dimensions to obtain the bosonic sectors of $N=2-$ and $N=4-$ supersymmetries, respectively. From this, we carry out an analysis in N=1, D=4 superspace and, in terms of $N=1-$ superfields, we are able to write down the N=2 and N=4 supersymmetric extensions of the Lorentz-violating action term.

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arXiv2005

Non-Minimal Coupling to a Lorentz-Violating Background and Topological Implications

The non-minimal coupling of fermions to a background responsible for the breaking of Lorentz symmetry is introduced in Dirac's equation; the non-relativistic regime is contemplated, and the Pauli's equation is used to show how an Aharonov-Casher phase may appear as a natural consequence of the Lorentz violation, once the particle is placed in a region where there is an electric field. Different ways of implementing the Lorentz breaking are presented and, in each case, we show how to relate the Aharonov-Casher phase to the particular components of the background vector or tensor that realises the violation of Lorentz symmetry.

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arXiv2005

A Remark on the Aharonov-Bohm Potential and a Discussion on the Electric Charge Quantization

The purpose of this work is to stress on a mathematical requirement of the Stokes' theorem that, naturally, yields a reassessment of the electric charge quantization condition, which is, here, explicitly carried out in the context of the Aharonov-Bohm set-up. We argue that, by virtue of an ambiguity in the definition of the circulation of the vector potential, a modified quantization condition comes out for the electric charge that opens the way for understanding fundamental fractional charges. One does not, any longer, need to rely on the existence of a magnetic monopole to justify electric charge quantization.

quant-ph↗
arXiv2005

Off-Shell Extended Supersymmetries and Lorentz-Violating Abelian Gauge Models

In this work, we propose the N=2 and N=4 supersymmetric extensions realized off-shell of the Abelian gauge model with Chern-Simons Lorentz-breaking term. We start with the theory in 6 and 10 dimensions and reduce à la Scherk the space-like coordinates to carry out the D=5 model in both cases. Then, we reduce the fifth space-like coordinate using the Legendre transformation technique for dimensional reduction. The last reduction method provides us with auxiliary fields that yield the superalgebra closed off-shell. Since the reduced bosonic Lagrangians from $6D$ and $10D$ are the same as the N=2 and N=4 SUSY-versions of the theory, respectively, we use the superspace-superfield formalism in N=1 to achieve the supersymmetric version of model.

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arXiv2005

Hyperbolic Space Forms and Orbifold Compactification in M-Theory

We analyze solutions of string theory and supergravity which involve real hyperbolic spaces. Examples of string compactifications are given in terms of hyperbolic coset spaces of finite volume $Γ\backslash {\mathbb H}^N$, where $Γ$ is a discrete group of isometries of ${\mathbb H}^N$. We describe finite flux and the tensor kernel associated with hyperbolic spaces. The case of arithmetic geometry of $Γ= SL(2, {\mathbb Z}+i{\mathbb Z})/\{\pm Id\}$, where $Id$ is the identity matrix, is analyzed. We discuss supersymmetry surviving for supergravity solutions involving real hyperbolic space factors, string-supergravity correspondence and holography principle for a class of conformal field theories.

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arXiv2005

Electron-Electron Bound States in Maxwell-Chern-Simons-Proca QED3

We start from a parity-breaking MCS QED$_{3}$ model with spontaneous breaking of the gauge symmetry as a framework for evaluation of the electron-electron interaction potential and for attainment of numerical values for the e-e bound state. Three expressions are obtained for the potential according to the polarization state of the scattered electrons. In an energy scale compatible with Condensed Matter electronic excitations, these three potentials become degenerated. The resulting potential is implemented in the Schrodinger equation and the variational method is applied to carry out the electronic binding energy. The resulting binding energies in the scale of 10-100 meV and a correlation length in the scale of 10-30 Angs. are possible indications that the MCS-QED$_{3}$ model adopted may be suitable to address an eventual case of e-e pairing in the presence of parity-symmetry breakdown. The data analyzed here suggest an energy scale of 10-100 meV to fix the breaking of the U(1)-symmetry. PACS numbers: 11.10.Kk 11.15.Ex 74.20.-z 74.72.-h ICEN-PS-01/17

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arXiv2004

The N = 2 and N = 4 Supersymmetric Extensions of the Lorentz- and CPT-Violating Term in Abelian Gauge Theories

In this work, we propose the N=2 and N=4 supersymmetric extensions of the Lorentz-breaking Abelian Chern-Simons term. We formulate the question of the Lorentz violation in 6 and 10 dimensions to obtain the bosonic sectors of N=2, and N=4, supersymmetries, respectively. From this, we carry out an analysis in N=1, D=4 superspace and, in terms of N=1, superfields, we are able to write down the N=2 and N=4 supersymmetric versions of the Lorentz-violating action term.

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arXiv2004

Dimensional Reduction of the Abelian-Higgs Carroll-Field-Jackiw Model

Taking as a starting point a Lorentz non-invariant Abelian-Higgs model defined in 1+3 dimensions, we carry out its dimensional reduction to D=1+2, obtaining a new planar model composed by a Maxwell-Chern-Simons-Proca gauge sector, a massive scalar sector, and a mixing term (involving the fixed background (v^μ) that imposes the Lorentz violation to the reduced model. The propagators of the scalar and massive gauge field are evaluated and the corresponding dispersion relations determined. Based on the poles of the propagators, a causality and unitarity analysis is carried out at tree-level. One then shows that the model is totally causal and unitary.

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arXiv2004

Lorentz-breaking effects in scalar-tensor theories of gravity

In this work, we study the effects of breaking Lorentz symmetry in scalar-tensor theories of gravity taking torsion into account. We show that a space-time with torsion interacting with a Maxwell field by means of a Chern-Simons-like term is able to explain the optical activity in syncrotron radiation emitted by cosmological distant radio sources. Without specifying the source of the dilaton-gravity, we study the dilaton-solution. We analyse the physical implications of this result in the Jordan-Fierz frame. We also analyse the effects of the Lorentz breaking in the cosmic string formation process. We obtain the solution corresponding to a cosmic string in the presence of torsion by keeping track of the effects of the Chern-Simons coupling and calculate the charge induced on this cosmic string in this framework. We also show that the resulting charged cosmic string gives us important effects concerning the background radiation.The optical activity in this case is also worked out and discussed.

hep-th↗
arXiv2004

A Discussion on Supersymmetric Cosmic Strings with Gauge-Field Mixing

In this paper, following a stream of investigation on supersymmetric gauge theories with cosmic string solutions, we contemplate the possibility of building up a D-and-F term cosmic string by means of a gauge-field mixing in connection with a U(1) x U(1)'-symmetry. The spontaneous break of both gauge symmetry and supersymmetry are thoroughly analysed and the fermion zero-modes are worked out. The role of the gauge-field mixing parameter is elucidated in connection with the string configuration that comes out. As an application of the model presented here, we propose the possibility that the supersimetric cosmic string yield production of fermionic charge carriers that may eject, at their late stages, particles that subsequently decay to produce cosmic rays of ultra-high energy. In our work, it turns out that massive supersymmetric fermionic partners may be produced for a susy breaking scale in the range 10^{11} to 10^{13} GeV, which is compatible with the phenomenology of a gravitino mass at the TeV scale. We also determine the range of the gauge-field mixing parameter, α, in connection with the mass scales of the present model.

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arXiv2003

Anti-symmetric rank-2 Matter Field on Superspace for N_{T}=2

In this work, we discuss the interaction between anti-symmetric rank-two tensor matter and topological Yang-Mills fields. The matter field considered here is the rank-2 Avdeev-Chizhov tensor matter field in a suitably extended $N_{T}=2$ SUSY. We start off from the $N_{T}=2$, D=4 superspace formulation and we go over to Riemannian manifolds. The matter field is coupled to the topological Yang-Mills field. We show that both actions are obtained as $Q-$exact forms, which allows us to write the energy-momentum tensor as $Q-$exact observables.

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