Numerical study of superradiant instability for charged stringy black hole-mirror system

TL;DR

This paper numerically investigates the superradiant instability of a charged scalar field around a charged stringy black hole with a mirror boundary, analyzing how parameters like charge and mirror radius influence the instability growth.

Contribution

It provides a numerical analysis of superradiant instability in a charged stringy black hole-mirror system, comparing results with previous analytical predictions.

Findings

Imaginary part of BQN frequencies increases rapidly with scalar field charge q.

Superradiant instability depends on black hole charge Q, scalar charge q, and mirror radius r_m.

Numerical results align with analytical predictions for certain parameter ranges.

Abstract

We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various parameters of black hole charge $Q$, scalar field charge $q$, and mirror radius $r_m$. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge $q$ rapidly.