Quasinormal modes of regular black holes

TL;DR

This paper investigates the quasinormal modes of regular black holes, which are non-singular solutions, by computing frequencies for scalar perturbations to understand their relaxation behavior.

Contribution

It provides the first detailed analysis of quasinormal frequencies for regular black holes, including both neutral and charged scalar field perturbations.

Findings

Regular black holes exhibit distinct quasinormal mode spectra from singular ones.

Charged scalar perturbations show different damping times compared to neutral cases.

Results suggest potential observational differences in gravitational wave signals.

Abstract

Black hole quasinormal frequencies are complex numbers that encode information on how a black hole relaxes after it has been perturbed and depend on the features of the geometry and on the type of perturbations. On the one hand, the examples studied so far in the literature focused on the case of black hole geometries with singularities in their interior. On the other hand, it is expected that quantum or classical modifications of general relativity may correct the pathological singular behavior of classical black hole solutions. Despite the fact that we do not have at hand a complete theory of quantum gravity, regular black hole solutions can be constructed by coupling gravity to an external form of matter, sometimes modeled by one form or another of nonlinear electrodynamics. It is therefore relevant to compute quasinormal frequencies for these regular solutions and see how differently, from the ordinary ones, regular black holes ring. In this paper, we take a step in this direction and, by computing the quasinormal frequencies, study the quasinormal modes of neutral and charged scalar field perturbations on regular black hole backgrounds in a variety of models.