Numerical calculation of the quasinormal frequencies for the Dirac field in a Lifshitz black brane

In the zero momentum limit we numerically calculate the quasinormal frequencies of the massive Dirac field propagating in a Lifshitz black brane. We focus on the non-exactly solvable cases for the fermionic perturbations, so that our results are an extension of the examples already reported for the massive Klein–Gordon and Dirac fields in the zero momentum limit. Based on our numerical results, we propose an analytical approximation of the obtained quasinormal frequencies of the Dirac field and compare their behavior with those of the Klein–Gordon field. We extend the results on the Klein–Gordon quasinormal frequencies already published. Furthermore, by imposing the Dirichlet boundary condition at the asymptotic region, we are able to find more general results for the fermionic exactly solvable case previously studied.

Effects of a Landau-Type Quantization Induced by the Lorentz Symmetry Violation on a Dirac Field

Inspired by the extension of the Standard Model, we analyzed the effects of the spacetime anisotropies on a massive Dirac field through a nonminimal CPT-odd coupling in the Dirac equation, where we proposed a possible scenario that characterizes the breaking of the Lorentz symmetry which is governed by a background vector field and induces a Landau-type quantization. Then, in order to generalize our system, we introduce a hard-wall potential and, for a particular case, we determine the energy levels in this background. In addition, at the nonrelativistic limit of the system, we investigate the effects of the Lorentz symmetry violation on thermodynamic aspects of the system.

On the nature of the neutrino

Assuming that one neutrino type with definite mass is described by a massive Dirac field operator, it is shown that the physical one-particle states for particles and antiparticles can be rotated to each other, irrespective of their helicity. This result is used to prove that the neutrino must necessarily be a Majorana particle.

New modes for massive Dirac field in higher-dimensional black holes

In this paper, we derive new modes for massive Dirac field in the background of a higher-dimensional Schwarzschild black hole. We use in our approach the Cartesian gauge defined in local frames. We work in the context of Arkani-Hamed, Dimopoulos and Dvali (ADD)-like theories, assuming that the Standard Model fields (fermions and bosons) live only on a (3+1)-dimensional brane and the extra dimensions of space can be large in size.

CASIMIR ENERGY FOR A MASSIVE DIRAC FIELD IN ONE SPATIAL DIMENSION: A DIRECT APPROACH

In this paper, we calculate the Casimir energy for a massive fermionic field confined between two points in one spatial dimension, with the MIT bag model boundary condition. We compute the Casimir energy directly by summing over the allowed modes. The method that we use is based on the Boyer's method, and there will be no need to resort to any analytic continuation techniques. We explicitly show the graph of the Casimir energy as a function of the distance between the points and the mass of the fermionic field. We also present a rigorous derivation of the MIT bag model boundary condition.

QUASINORMAL MODES AND STABILITY OF A FIVE-DIMENSIONAL DILATONIC BLACK HOLE

We exactly calculate the quasinormal frequencies of the electromagnetic and Klein–Gordon perturbations propagating in a five-dimensional dilatonic black hole. Furthermore, we exactly find the quasinormal frequencies of the massive Dirac field. Using these results we study the linear stability of this black hole. We compare our results for the quasinormal frequencies and for the linear stability of the five-dimensional black hole with those already published.