Graviton emission in the bulk from a higher-dimensional Schwarzschild black hole

We consider the evaporation of (4+n)$(4+n)$-dimensional non-rotating black holes into gravitons. We calculate the energy emission rate for gravitons in the bulk obtaining analytical solutions of the master equation satisfied by all three types (S, V, T) of gravitational perturbations. Our results, valid in the low-energy regime, show a vector radiation dominance for every value of n. The calculated low-energy emission rate, for all types of degrees of freedom, is found to decrease with the number of extra dimensions n, as in the previously studied case of a bulk scalar field. By comparing the emission rates in the bulk for scalars and gravitons, we find that the one for gravitons remains well below that for a scalar field in the low-energy regime.