Short distances, black holes, and TeV gravity

The Hawking effect can be rederived in terms of two-point functions and in such a way that it makes it possible to estimate, within the conventional semiclassical theory, the contribution of ultrashort distances at $I^+$ to the Planckian spectrum. Thermality is preserved for black holes with $\kappa l_P << 1$. However, deviations from the Planckian spectrum can be found for mini black holes in TeV gravity scenarios, even before reaching the Planck phase.