Superradiant instability of fivedimensional rotating charged AdS black holes
Abstract
We study the instability of small AdS black holes with two independent rotation parameters in minimal fivedimensional gauged supergravity to massless scalar perturbations. We analytically solve the KleinGordon equation for lowfrequency perturbations in two regions of the spacetime of these black holes: namely, in the region close to the horizon and in the farregion. By matching the solutions in an intermediate region, we calculate the frequency spectrum of quasinormal modes. We show that in the regime of superradiance only the modes of even orbital quantum number undergo negative damping, resulting in exponential growth of the amplitude. That is, the black holes become unstable to these modes. Meanwhile, the modes of odd orbital quantum number do not undergo any damping, oscillating with frequencyshifts. This is in contrast with the case of fourdimensional small KerrAdS black holes which exhibit the instability to all modes of scalar perturbations in the regime of superradiance.
 Publication:

Physical Review D
 Pub Date:
 January 2009
 DOI:
 10.1103/PhysRevD.79.024013
 arXiv:
 arXiv:0808.0280
 Bibcode:
 2009PhRvD..79b4013A
 Keywords:

 04.20.Jb;
 04.70.s;
 Exact solutions;
 Physics of black holes;
 High Energy Physics  Theory;
 General Relativity and Quantum Cosmology
 EPrint:
 24 pages, REVTeX