Lorentz-violating effects in three-dimensional QEDQED

Inspired in discussions presented lately regarding Lorentz-violating interaction terms in \cite{13,6}, we propose here a slightly different version for the coupling term. We will consider a modified quantum electrodynamics with violation of Lorentz symmetry defined in a $\left( 2+1\right)$-dimensional spacetime. We define the Lagrangian density with a Lorentz-violating interaction, where the the spacetime dimensionality is explicitly taken into account in its definition. The work encompasses an analysis of this model at both zero and finite-temperature, where very interesting features are known to occur due to the spacetime dimensionality. With that in mind we expect that the spacetime dimensionality may provide new insights about the radiative generation of higher-derivative terms into the action, implying in a new Lorentz-violating electrodynamics, as well the nonminimal coupling may provide interesting implications on the thermodynamical quantities.Comment: 14 pages, to appear at Int. J. Mod. Phys.

Thermal effective Lagrangian of generalized electrodynamics in static gravitational fields

In this paper we compute the effective Lagrangian of static gravitational fields interacting with thermal fields of generalized electrodynamics at high temperature. We employ the usual Matsubara imaginary-time formalism to obtain a closed form expression to the thermal effective Lagrangian at one-loop and two-loop order, in an arbitrary $\omega$-dimensional spacetime, in which the equivalence between the static hard thermal loops and those with zero external energy-momentum is widely explored. Afterwards, the symmetries of the resulting expressions are discussed as well as the presence of the Tolman \emph{local} temperature.Comment: 15 pages. arXiv admin note: text overlap with arXiv:1311.2519 by other author

On the Bhabha scattering for z=2z=2 Lifshitz QED

In this paper we compute and discuss the differential cross section of the Bhabha scattering in the framework of the $z=2$ Lifshitz QED. We start by constructing the classical solutions for the fermionic fields, in particular the completeness relations, and also deriving the theory's propagators. Afterwards, we compute the photon exchange and pair annihilation contributions for the Bhabha's process, and upon the results we establish the magnitude of the theory's free parameter by looking for small deviations of the QED tree results.Comment: 10 page

Born-Infeld electrodynamics in very special relativity

In this work we discuss the properties of a modified Born-Infeld electrodynamics in the framework of very special relativity (VSR). This proposal allows us to study VSR mass effects in a gauge-invariant context of nonlinear electrodynamics. It is analyzed in detail the electrostatic solutions for two different cases, as well as the VSR dispersion relations are found to be of a \emph{massive} particle with nonlinear modifications. Afterwards, the field energy and static potential are computed, in the latter we find from the VSR contribution a novel long-range $1/L^3$ correction to the Coulomb potential, in contrast to the $1/L^5$ correction of the usual Born-Infeld theory.Comment: 14 pages; to appear in PL

Axion Mass Bound in Very Special Relativity

In this paper we propose a very special relativity (VSR)-inspired description of the axion electrodynamics. This proposal is based upon the construction of a proper study of the SIM$(2)$--VSR gauge-symmetry. It is shown that the VSR nonlocal effects give a health departure from the usual axion field theory. The axionic classical dynamics is analysed in full detail, first by a discussion of its solution in the presence of an external magnetic field. Next, we compute photon-axion transition in VSR scenario by means of Primakoff interaction, showing the change of a linearly polarized light to a circular one. Afterwards, duality symmetry is discussed in the VSR framework.Comment: 16 pages; to appear in PL

Higher-derivative non-Abelian gauge fields via the Faddeev-Jackiw formalism

In this paper we analyze two higher-derivative theories, the generalized electrodynamics and the Alekseev-Arbuzov-Baikov's effective Lagrangian from the point of view of Faddeev-Jackiw sympletic approach. It is shown that the full set of constraint is obtained directly from the zero-mode eigenvectors, and that they are in accordance with known results from Dirac's theory, a remnant and recurrent issue in the literature. The method shows to be rather economical in relation to the Dirac's one, obviating thus unnecessary classification and calculations. Afterwards, to conclude we construct the transition-amplitude of the non-Abelian theory following a constrained BRST-method.Comment: 17 page

Nonperturbative Aspects of the two-dimensional Massive Gauged Thirring Model

In this paper we present a study based on the use of functional techniques on the issue of insertions of massive fermionic fields in the two-dimensional massless Gauged Thirring Model. As it will be shown, the fermionic mass contributes to the Green's functions in a surprisingly simple way, leaving therefore the original nonperturbative nature of the massless results still intact in the massive theory. Also, by means of complementarity, we present a second discussion of the massive model, now at its bosonic representation.Comment: 18 pages, to appear at Int. J. Mod. Phys.

K\"all\'en-Lehmann representation of noncommutative quantum electrodynamics

Noncommutative (NC) quantum field theory is the subject of many analyses on formal and general aspects looking for deviations and, therefore, potential noncommutative spacetime effects. Within of this large class, we may now pay some attention to the quantization of NC field theory on lower dimensions and look closely at the issue of dynamical mass generation to the gauge field. This work encompasses the quantization of the two-dimensional massive quantum electrodynamics and three-dimensional topologically massive quantum electrodynamics. We begin by addressing the problem on a general dimensionality making use of the perturbative Seiberg-Witten map to, thus, construct a general action, to only then specify the problem to two and three dimensions. The quantization takes place through the K\"all\'en-Lehmann spectral representation and Yang-Feldman-K\"all\'en formulation, where we calculate the respective spectral density function to the gauge field. Furthermore, regarding the photon two-point function, we discuss how its infrared behavior is related to the term generated by quantum corrections in two dimensions, and, moreover, in three dimensions, we study the issue of nontrivial {\theta}-dependent corrections to the dynamical mass generation