Quasinormal modes of a black hole surrounded by quintessence

TL;DR

This paper investigates how quintessence surrounding a black hole affects the quasinormal modes of scalar field perturbations, revealing that quintessence influences decay rates and frequencies of these oscillations.

Contribution

It provides the first detailed analysis of quasinormal frequencies of black holes with quintessence using third-order WKB approximation, highlighting the role of the state parameter.

Findings

Quintessence causes scalar fields to damp more rapidly.

Increasing the state parameter $psilon$ raises the real part of frequencies.

Larger $psilon$ results in slower decay of scalar fields.

Abstract

Using the third-order WKB approximation, we evaluate the quasinormal frequencies of massless scalar field perturbation around the black hole which is surrounded by the static and spherically symmetric quintessence. Our result shows that due to the presence of quintessence, the scalar field damps more rapidly. Moreover, we also note that the quintessential state parameter $\epsilon$ (the ratio of pressure $p_q$ to the energy density $\rho_q$) play an important role for the quasinormal frequencies. As the state parameter $\epsilon$ increases the real part increases and the absolute value of the imaginary part decreases. This means that the scalar field decays more slowly in the larger $\epsilon$ quintessence case.