It is often claimed that a consistent theory of quantum gravity should avoid the singularities prediced by classical general relativity. While a general answer is not yet known, the fate of singularities can be investigated within simple models. In my talk, I shall discuss the quantum avoidance of classical singularities in quantum cosmology. I shall, in particular, address models where classically a singularity develops for large scale factors, such as a Big Rip or a Big Brake, and for which a quantum version without singularities exists. The discussion is performed within quantum geometrodynamics, that is, the Wheeler-DeWitt equation, but remarks are also made concerning the corresponding situation in loop quantum cosmology.

Place: Physics Dept. Meeting Room, 2th floor, IST