Quasinormal modes of gravitational perturbation around some well-known regular black holes

TL;DR

This paper investigates the quasinormal modes of gravitational perturbations around various well-known regular black holes using numerical methods, revealing different behaviors of mode damping related to black hole parameters and confirming stability.

Contribution

It provides new numerical and analytical insights into gravitational QNMs of regular black holes, including asymptotic expressions in the eikonal limit and parameter-dependent behaviors.

Findings

Imaginary parts of QNMs vary with charge parameters across different black holes.

Gravitational perturbations are stable in all studied spacetimes.

Asymptotic QNM expressions are derived for large angular momentum.

Abstract

In this paper, the quasinormal modes of gravitational perturbation around some well-known regular black holes were evaluated by using the WKB approximation as well as the asymptotic iteration method. Through numerical calculation, we make a detailed analysis of the gravitational QNM frequencies by varying the characteristic parameters of the gravitational perturbation and the spacetime charge parameters of the regular black holes. It is found that the imaginary part of quasinormal modes as a function of the charge parameter has different monotonic behaviors for different black hole spacetimes. Moreover, the asymptotic expressions of gravitational QNMs for $l \gg 1$ are obtained by using the eikonal limit method. We demonstrate that the gravitational perturbation is stable in all these spacetimes.