Superradiant instability of the charged scalar field in stringy black hole mirror system

Understand

It has been shown that the mass of the scalar field in the charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes.

• This is to say that the charged stringy black hole is stable against the massive charged scalar perturbation.
• In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition.
• The analytical expression of the unstable superradiant modes is derived by using the asymptotic matching method.