Stability and Quasinormal Modes of Black Holes in Conformal Weyl Gravity

TL;DR

This paper studies the stability and quasinormal modes of black holes in conformal Weyl gravity, comparing them with Schwarzschild solutions, and explores how the theory's parameters affect their dynamical properties in different spacetimes.

Contribution

It provides a detailed analysis of black hole stability and quasinormal modes in conformal Weyl gravity, including new computations in dS and AdS backgrounds using advanced numerical methods.

Findings

Black holes in conformal Weyl gravity exhibit distinct quasinormal mode spectra from Schwarzschild black holes.

The presence of quasi-resonance modes is possible for Weyl black hole solutions.

The free parameter of the theory influences the quasinormal frequencies and their deviations from standard solutions.

Abstract

In this paper, we first investigate the thermal stability of black holes in conformal Weyl gravity with a comparison with the Schwarzschild black holes. Then, we consider a minimally coupled massive scalar perturbation and calculate the quasinormal modes in asymptotically dS spacetime by employing the sixth order WKB approximation and asymptotic iteration method. The deviations from those of the Schwarzschild-dS solutions are obtained and the possibility of the presence of quasi-resonance modes for Weyl black hole solutions is investigated. Finally, we consider a massless scalar perturbation in the background of asymptotically AdS solutions and calculate the quasinormal modes by using the pseudospectral method. The effects of the free parameter of the theory on the quasinormal modes are studied and deviations from those of the Schwarzschild-AdS black holes are investigated. The imaginary part of quasinormal frequencies in AdS spacetime is the time scale of a thermal state (in the conformal field theory) to approach thermal equilibrium.