arXiv subjects

E. M. C. Abreu

Publications and source records attributed to E. M. C. Abreu.

26 records · Page 2Linked to original sources

arXiv2007

The dual embedding method in D=3

Improving the beginning steps of a previous work, we settle the dual embedding method (DEM) as an alternative and efficient method for obtaining dual equivalent actions also in D=3. We show that we can obtain dual equivalent actions which were previously obtained in the literature using the gauging iterative Noether dualization method (NDM). We believe that, with the arbitrariness property of the zero mode, the DEM is more profound since it can reveal a whole family of dual equivalent actions. After a review of our previous work, we obtain the dual equivalent theory of the self-dual model minimally coupled to U(1) charged bosonic matter. The result confirms the one obtained previously which is important since it has the same structure that appears in the Abelian Higgs model with an anomalous magnetic interaction.

hep-th↗

arXiv2006

Generalizing the Soldering procedure

We start this work by revisiting the problem of the soldering of two chiral Schwinger models of opposite chiralities. We verify that, in contrast with what one can conclude from the soldering literature, the usual sum of these models is, in fact, gauge invariant and corresponds to a composite model, where the component models are the vector and axial Schwinger models. As a consequence, we reinterpret this formalism as a kind of degree of freedom reduction mechanism. This result has led us to discover a second soldering possibility giving rise to the axial Schwinger model. This new result is seemingly rather general. We explore it here in the soldering of two Maxwell-Chern-Simons theories with different masses.

hep-th↗

arXiv2005

Electromagnetic waves, gravitational coupling and duality analysis

In this letter we introduce a particular solution for parallel electric and magnetic fields, in a gravitational background, which satisfy free-wave equations and the phenomenology suggested by astrophysical plasma physics. These free-wave equations are computed such that the electric field does not induce the magnetic field and vice-versa. In a gravitational field, we analyze the Maxwell equations and the corresponding electromagnetic waves. A continuity equation is presented. A commutative and noncommutative analysis of the electromagnetic duality is described.

hep-th↗

arXiv2005

On the Lorentz symmetry of the noncommutative chiral bosons

We study issues of Lorentz violation symmetry in the context of the recently proposed theory of noncommutative fields \cite{CCGM}, using the soldering formalism. To this end a noncommutative chiral-boson with a deformed algebra \cite{DGMJ}, used to study these notions in D=2, is properly generalized. We verify, also for this larger group of theories that, although the structure of the Lorentz group is preserved, the velocity of light is scaled by a function of the deformation parameter, as recently claimed. However, we found a sub-set of models where the velocity of propagation is maintained in spite of the presence of the deformed algebra. Effects of a preferred-frame of reference manifest by the presence of birefringence were also studied in the chiral boson framework leading to the scalar sector of the extended Standard Model recently proposed.

hep-th↗

arXiv2002

Dirac-like Monopoles in Three Dimensions and Their Possible Influences on the Dynamics of Particles

Dirac-like monopoles are studied in three-dimensional Abelian Maxwell and Maxwell-Chern-Simons models. Their scalar nature is highlighted and discussed through a dimensional reduction of four-dimensional electrodynamics with electric and magnetic sources. Some general properties and similarities of them when are considered in Minkowski or Euclidian space are mentioned. However, by virtue of the structure of the space-time in which they are considered a number of differences among them take place. Furthermore, we pay attention to some consequences of these objects when acting upon usual particles. Among other subjects, special attention is given to the study of a Lorentz-violating non-minimal coupling between neutral fermions and the field generated by a monopole alone. In addition, an analogue of the Aharonov-Casher effect is discussed in this framework.

hep-th↗

arXiv2002

Effective Action for QED with Fermion Self-Interaction in D=2 and D=3 Dimensions

In this work we discuss the effect of the quartic fermion self-interaction of Thirring type in QED in D=2 and D=3 dimensions. This is done through the computation of the effective action up to quadratic terms in the photon field. We analyze the corresponding nonlocal photon propagators nonperturbatively in % \frac{k}{m}, where k is the photon momentum and m the fermion mass. The poles of the propagators were determined numerically by using the Mathematica software. In D=2 there is always a massless pole whereas for strong enough Thirring coupling a massive pole may appear . For D=3 there are three regions in parameters space. We may have one or two massive poles or even no pole at all. The inter-quark static potential is computed analytically in D=2. We notice that the Thirring interaction contributes with a screening term to the confining linear potential of massive QED_{2}. In D=3 the static potential must be calculated numerically. The screening nature of the massive QED$_{3}$ prevails at any distance, indicating that this is a universal feature of % D=3 electromagnetic interaction. Our results become exact for an infinite number of fermion flavors.

hep-th↗

arXiv2001

The Jacobi identity for Dirac-like brackets

For redundant second-class constraints the Dirac brackets cannot be defined and new brackets must be introduced. We prove here that the Jacobi identity for the new brackets must hold on the surface of the second-class constraints. In order to illustrate our proof we work out explicitly the cases of a fractional spin particle in 2+1 dimensions and the original Brink-Schwarz massless superparticle in D=10 dimensions in a Lorentz covariant constraints separation.

hep-th↗

arXiv2000

Non-Abelian BFFT embedding, Schrödinger quantization and the anomaly of the O(N) nonlinear sigma model

We embed the O(N) nonlinear sigma model in a non-Abelian gauge theory. As a first class system, it is quantized using two different approaches: the functional Schrödinger method and the non-local field-antifield procedure. Firstly, the quantization is performed with the functional Schrödinger method, for N=2, obtaining the wave functionals for the ground and excited states. In the second place, using the BV formalism we compute the one-loop anomaly. This important result shows that the classical gauge symmetries, appearing due to the conversion via BFFT method, are broken at the quantum level.

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