Asymptotic black hole quasinormal frequencies

We give a new derivation of the quasinormal frequencies of Schwarzschild black holes in d 4 and Reissner-Nordstr m black holes in d = 4, in the limit of in nite damping. For Schwarzschild in d 4 w e nd that the asymptotic real part is T Hawking log (3) for scalar perturbations and for some gravitational perturbations this con rms a result previously obtained by other means in the case d = 4. For Reissner-Nordstr m in d = 4 w e nd a speci c generally aperiodic behavior for the quasinormal frequencies, both for scalar perturbations and for electromagneticgravitational perturbations. The formulae are obtained by studying the monodromy of the perturbation analytically continued to the complex plane the analysis depends essentially on the behavior of the potential in the " region near the black hole singularity.