Quasinormal modes of scalar and Dirac perturbations of Bardeen de Sitter black holes

Abstract

So far the study of black hole perturbations has been mostly focused upon the classical black holes with singularities at the origin and hidden by event horizon. Compared to that, the regular black holes are a completely new class of solutions arising out of modification of general theory of relativity by coupling gravity to an external form of matter. Therefore it is extremely important to study the behavior of such regular black holes under different types of perturbations. Recently a new regular Bardeen black hole solution with a de Sitter branch has been proposed by Fernando [ arXiv:1611.05337 [gr-qc]]. We compute the quasi-normal (QN) frequencies for the regular Bardeen de Sitter (BdS) black hole due to massless and massive scalar field perturbations as well as the massless Dirac perturbations. We analyze the behavior of both real and imaginary parts of QN frequencies by varying different parameters of the theory.