Gravitational decoupling and regular hairy black holes: Geodesic stability, quasinormal modes, and thermodynamic properties

TL;DR

This paper investigates the stability of geodesic orbits, quasinormal modes, and thermodynamic properties of regular hairy black holes within a gravitational decoupling framework, highlighting the influence of hair parameters on observable phenomena.

Contribution

It introduces a comprehensive analysis of geodesic stability, quasinormal modes, and thermodynamics for regular hairy black holes, incorporating gravitational decoupling and exploring deviations from Schwarzschild solutions.

Findings

Hair parameter significantly affects orbit stability.

Deviations influence quasinormal mode spectra.

Thermodynamic properties are characterized by Rènyi and Bekenstein-Hawking entropies.

Abstract

The stability of geodesic orbits around a regular hairy black hole, in the gravitational decoupling setup, is investigated by employing Lyapunov exponents, which quantify the divergence rate of nearby trajectories in dynamical systems. Both timelike and null geodesics are addressed, probing the effect of the hair parameter on orbital stability. Deviations from the Schwarzschild solution have a significant influence on orbit stability, potentially providing observational signatures. Quasinormal modes of regular hairy black holes are calculated, and their thermodynamic properties are discussed. Both the R\'enyi and the Bekenstein-Hawking entropies are reported, deepening our understanding of gravitational dynamics in the strong-field regime, contributing to ongoing approaches to modified gravity.