Russo, J. G. (Jorge Guillermo)2010-05-062010-05-0619940556-2821https://hdl.handle.net/2445/12475A common belief is that further quantum corrections near the singularity of a large black hole should not substantially modify the semiclassical picture of black hole evaporation; in particular, the outgoing spectrum of radiation should be very close to the thermal spectrum predicted by Hawking. In this paper we explore a possible counterexample: in the context of dilaton gravity, we find that nonperturbative quantum corrections which are important in strong-coupling regions may completely alter the semiclassical picture, to the extent that the presumptive spacelike boundary becomes timelike, changing in this way the causal structure of the semiclassical geometry. As a result, only a small fraction of the total energy is radiated outside the fake event horizon; most of the energy comes in fact at later retarded times and there is no problem of information loss. This may constitute a general characteristic of quantum black holes, that is, quantum gravity might be such as to prevent the formation of global event horizons.17 p.application/pdfeng(c) The American Physical Society, 1994Relativitat general (Física)GravitacióGeneral relativity (Physics)Gravitationinfo:eu-repo/semantics/article512122info:eu-repo/semantics/openAccess