Brane Worlds, String Cosmology, and AdS/CFT

TL;DR

This paper explores the dynamics of brane worlds in de Sitter and anti-de Sitter spacetimes using the thin-shell formalism, highlighting phases of contraction and expansion, and discusses potential applications of AdS/CFT correspondence for non-perturbative string cosmology.

Contribution

It introduces a detailed analysis of brane motion in time-dependent AdS and dS bulks and proposes a novel approach to applying AdS/CFT for non-perturbative cosmological models.

Findings

Brane scale factor exhibits singular and non-singular phases.

Phases of contraction and expansion are related to quotients of AdS spacetime.

Potential for non-perturbative description via AdS/CFT correspondence.

Abstract

Using the thin-shell formalism we discuss the motion of domain walls in de Sitter and anti-de Sitter (AdS) time-dependent bulks. This motion results in a dynamics for the brane scale factor. We show that in the case of a clean brane the scale factor describes both singular and non-singular universes, with phases of contraction and expansion. These phases can be understood as quotients of AdS spacetime by a discrete symmetry group. We discuss this effect in some detail, and suggest how the AdS/CFT correspondence could be applied to obtain a non perturbative description of brane-world string cosmology.