Condition for superradiance in higher-dimensional rotating black holes

摘要

It is shown that the superradiance modes always exist in the radiation by the (4 + n)-dimensional rotating black holes. Using a Bekenstein argument the condition for the superradiance modes is shown to be 0 < to < m Omega for the scalar, electromagnetic and gravitational waves when the spacetime background has a single angular momentum parameter about an axis on the brane, where Q is a rotational frequency of the black hole and m is an azimuthal quantum number of the radiated wave. (c) 2005 Elsevier B.V. All rights reserved.