Mazzitelli, Francisco D.Russo, J. G. (Jorge Guillermo)2010-05-062010-05-0619930556-2821https://hdl.handle.net/2445/12478We consider a renormalizable two-dimensional model of dilaton gravity coupled to a set of conformal fields as a toy model for quantum cosmology. We discuss the cosmological solutions of the model and study the effect of including the back reaction due to quantum corrections. As a result, when the matter density is below some threshold new singularities form in a weak-coupling region, which suggests that they will not be removed in the full quantum theory. We also solve the Wheeler-DeWitt equation. Depending on the quantum state of the Universe, the singularities may appear in a quantum region where the wave function is not oscillatory, i.e., when there is not a well-defined notion of classical spacetime.8 p.application/pdfeng(c) The American Physical Society, 1993General relativity (Physics)GravitacióMatèria interstel·larCosmologiaRelativitat general (Física)GravitationInterstellar matterCosmologyinfo:eu-repo/semantics/article512127info:eu-repo/semantics/openAccess