Gravitational Quasinormal Modes of Regular Phantom Black Hole

TL;DR

This paper studies the gravitational quasinormal modes of regular phantom black holes across different spacetimes, revealing how perturbation decay and thermodynamics depend on the scalar field coupling parameter.

Contribution

It derives master equations for gravitational perturbations of regular phantom black holes and analyzes how their QNMs and thermodynamics vary with the coupling parameter in various spacetimes.

Findings

QNMs are similar for odd and even parities across spacetimes

Decay rates depend strongly on the coupling parameter $b$

Thermodynamics is also influenced by the scalar field coupling

Abstract

We investigate the gravitational quasi-normal modes (QNMs) for a type of regular black hole (BH) known as phantom BH, which is a static self-gravitating solution of a minimally coupled phantom scalar field with a potential. The studies are carried out for three different spacetimes: asymptotically flat, de Sitter (dS), and anti de Sitter (AdS). In order to consider the standard odd parity and even parity of gravitational perturbations, the corresponding master equations are derived. The QNMs are discussed by evaluating the temporal evolution of the perturbation field which, in turn, provides direct information on the stability of BH spacetime. It is found that in asymptotically flat, dS and AdS spacetimes, the gravitational perturbations have similar characteristics for both odd and even parities. The decay rate of perturbation is strongly dependent on the scale parameter $b$, which measures the coupling strength between phantom scalar field and the gravity. Furthermore, through the analysis of Hawking radiation, it is shown that the thermodynamics of such regular phantom BH is also influenced by $b$. The obtained results might shed some light on the quantum interpretation of QNM perturbation.