Hawking Radiation of the Brane-Localized Graviton from a $(4+n)$-dimensional Black Hole

Abstract

Following the Regge-Wheeler algorithm, we derive a radial equation for the brane-localized graviton absorbed/emitted by the $(4+n)$-dimensional Schwarzschild black hole. Making use of this equation the absorption and emission spectra of the brane-localized graviton are computed numerically. Existence of the extra dimensions generally suppresses the absorption rate and enhances the emission rate as other spin cases. The appearance of the potential well, however, when $n > \sqrt{\ell (\ell + 1) -2} - 1$ in the effective potential makes the decreasing behavior of the total absorption with increasing $n$ in the low-energy regime. The high-energy limit of the total absorption cross section seems to coincide with that of the brane-localized scalar cross section. The increasing rate of the graviton emission is very large compared to those of other brane-localized fields. This fact indicates that the graviton emission can be dominant one in the Hawking radiation of the higher-dimensional black holes when $n$ is large.