Hawking radiation in D = 4 is regarded as a well-understood quantum theoretical feature of black holes (BH) or of other geometric backgrounds with an event horizon. On the other hand, the dilaton theory emerging after spherical reduction from Einstein gravity (SRG) and generalizations of those theories, only during the last years have been investigated in this connection. If the consideration o...

EN): In this thesis, we study several features of Hawking radiation in the presence of ultraviolet Lorentz violations. These violations are implemented by a modified dispersion relation that becomes nonlinear at short wavelengths. The motivations of this work arise on the one hand from the developing field of analog gravity, where we aim at measuring the Hawking effect in fluid flows that mimic...

The brick-wall model seeks to explain the Bekenstein-Hawking entropy as a wall-contribution to the thermal energy of ambient quantum fields raised to the Hawking temperature. Reservations have been expressed concerning the self-consistency of this model. For example, it predicts large thermal energy densities near the wall, producing a substantial mass-correction and, presumably , a large gravi...

Quantum back reaction due to N massless fields may be worked out to a considerable detail in a variant of integrable dilaton gravity model in two dimensions. It is shown that there exists a critical mass of collapsing object of order ¯ hN× (cosmo-logical constant) 1/2 , above which the end point of Hawking evaporation is two disconnected remnants of infinite extent, each separated by a mouth fr...

When a black hole is put in an empty space (zero temperature space) on which there is no matter except the matter of the Hawking radiation (Hawking field), then an outgoing energy flow from the black hole into the empty space exists. By the way, an equilibrium between two arbitrary systems can not allow the existence of an energy (heat) flow from one system to another. Consequently, in the case...