Quasinormal resonances of a charged scalar field in a charged Reissner-Nordstrom black-hole spacetime: A WKB analysis

The fundamental quasinormal resonances of charged Reissner-Nordstrom black holes due to charged scalar perturbations are derived analytically. In the WKB regime, qQ >> n, we obtain a simple expression for the fundamental quasinormal resonances: omega = qQ/r(+) - i2 pi T-BH(n + 1/2), where T-BH and Q are the temperature and electric charge of the black hole and q is the electric charge of the field. Remarkably. our results show that the relaxation dynamics of a perturbed Reissner-Nordstrom black hole may saturate the recently proposed universal relaxation bound. (C) 2012 Elsevier B.V. All rights reserved.