Scattering from charged black holes and supergravity

The scattering cross sections of the unpolarized electromagnetic and gravitational waves are shown to be equal for the extreme Reissner-Nordstr"om black hole using $N=2$ supergravity. The conversion cross sections between the unpolarized electromagnetic and gravitational waves are also shown to coincide. The gravitational and electromagnetic scattering cross sections are computed numerically for Reissner-Nordstr"om black holes for several charge-to-mass ratios and the coincidence between the two scattering cross sections for the extremal case is confirmed.