Validity of Emparan-Horowitz-Myers argument in Hawking radiation into massless spin-2 fields

Abstract

The Hawking radiation for massless spin-2 fields is numerically studied when the spacetime background is (4+n)-dimensional Schwarzschild black hole phase. In order to check the validity of the Emparan-Horowitz-Myers argument, {\it black holes radiate mainly on the brane}, we assume that the radial equation for the massless spin-2 fields propagating on the brane obeys the master equation approximately. The transmission coefficient is computed explicitly by making use of the Hawking-Hartle theorem. It is shown that the total emission rates into the bulk are dominant compared to the rates on the visible brane when $n \geq 3$. However, the bulk-to-brane relative emissivities per degree of freedom always remain O(1) roughly. The experimental significance of these results in the production of mini black holes in future colliders is briefly discussed.