Quasinormal modes of charged black holes in string theory

TL;DR

This paper investigates the quasinormal modes of scalar and Dirac fields in Garfinkle-Horowitz-Strominger black hole spacetime, revealing how dilaton and mass influence decay rates and comparing approximation methods.

Contribution

It provides a comparative analysis of WKB and P"{o}schl-Teller approximations for QNMs in charged black holes within string theory.

Findings

Higher dilatons lead to faster decay of scalar QNMs.

Higher mass results in slower decay of QNMs.

WKB and P"{o}schl-Teller methods agree well for small mode numbers.

Abstract

Both scalar and Dirac quasinormal modes in Garfinkle-Horowitz-Strominger black hole spacetime are studied by using the WKB approximation and the P\"{o}schl-Teller approximation. For scalar field, we find that the QNMs with higher dilatons decay more rapidly than that with lower ones. However, this is not the case for mass $m$. Fields with higher mass will decay more slowly. The similar behaviors appear in the case of Dirac field. We also find that QNM frequencies evaluated by using WKB approximation and P\"{o}schl-Teller approximation have a good agreement with each other when mode number $n$ is small.