Strings in Singular Time-Dependent Backgrounds

TL;DR

This paper reviews the construction and analysis of exact conformal field theory backgrounds with space-like singularities, discussing their algebraic and geometric properties, and introduces new results on a two-dimensional cosmology with gauge fields.

Contribution

It provides a comprehensive review of time-dependent string backgrounds with singularities and presents new exact CFT models involving two-dimensional cosmology with gauge fields.

Findings

Analysis of algebraic and geometric aspects of singular backgrounds

Discussion of physical issues and difficulties in such systems

Introduction of a new two-dimensional cosmology model with gauge fields

Abstract

We review the construction of time-dependent backgrounds with space-like singularities. We mainly consider exact CFT backgrounds. The algebraic and geometric aspects of these backgrounds are discussed. Physical issues, results and difficulties associated with such systems are reviewed. Finally, we present some new results: a two dimensional cosmology in the presence of an Abelian gauge field described within a family of (SL(2)xU(1))/(U(1)xZ) quotient CFTs.