Superradiance and black hole bomb in five-dimensional minimal ungauged supergravity

Understand

We examine the black hole bomb model which consists of a rotating black hole of five-dimenensional minimal ungauged supergravity and a reflecting mirror around it.

• For low-frequency scalar perturbations, we find solutions to the Klein-Gordon equation in the near-horizon and far regions of the black hole spacetime.
• To avoid solutions with logarithmic terms, we assume that the orbital quantum number $ l $ takes on nearly, but not exactly, integer values and perform the matching of these solutions in an intermediate region.
• This allows us to calculate analytically the frequency spectrum of quasinormal modes, taking the limits as $ l $ approaches even or odd integers separately.