A NEW APPROACH TO STRING COSMOLOGY

We discuss quotients of Anti-de Sitter (AdS) spacetime by a discrete g roup in light of the AdS-CFT correspondence. Some quotients describe c losed universes which expand from zero volume to a maximum size and th en contract. Maldacena's conjecture suggests that they should be repre sented in string theory by suitable quotients of the boundary conforma l field theory. We discuss the required identifications, and construct the states associated with the linearized supergravity modes in the c osmological background.