A New Approach to String Cosmology

TL;DR

This paper explores how certain quotients of Anti-de Sitter spacetime relate to cosmological models and their representation in string theory via the AdS-CFT correspondence, focusing on boundary conformal field theories and supergravity modes.

Contribution

It introduces a new approach to modeling cosmological universes within the AdS-CFT framework through specific spacetime quotients and boundary state constructions.

Findings

Certain AdS quotients describe expanding and contracting closed universes.

Boundary conformal field theory quotients can represent these cosmological models.

Constructed states correspond to linearized supergravity modes in the cosmological background.

Abstract

We discuss quotients of Anti-de Sitter (AdS) spacetime by a discrete group in light of the AdS-CFT correspondence. Some quotients describe closed universes which expand from zero volume to a maximum size and then contract. Maldacena's conjecture suggests that they should be represented in string theory by suitable quotients of the boundary conformal field theory. We discuss the required identifications, and construct the states associated with the linearized supergravity modes in the cosmological background.