Time domain analysis of superradiant instability for the charged stringy black hole–mirror system

Physics Letters B

Hongbao Zhang¹  Junkun Zhao²  Ran Li²  Yu Tian³ 

[1] Department of Physics, Beijing Normal University, Beijing 100875, China;Department of Physics, Henan Normal University, Xinxiang 453007, China;School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China;

关键词: Charged black holes in string theory;    Superradiant instability;    Time domain analysis;   

DOI  :  10.1016/j.physletb.2015.09.073

来源: DOAJ

【 摘 要 】

It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical methods. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington–Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge–Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. The existence of the rapid growth mode makes the charged stringy black hole a good test ground to study the nonlinear development of superradiant instability.

【 授权许可】

Unknown