Cosmological solutions with dilaton and maximally symmetric space in string theory

TL;DR

This paper explores time-dependent solutions in string theory with a dilaton and curved maximally symmetric spaces, identifying regular solutions with specific backgrounds and discussing their potential as exact conformal theories.

Contribution

It presents new regular solutions in string effective equations involving non-trivial backgrounds and negative curvature, expanding understanding of cosmological models in string theory.

Findings

Found regular solutions with antisymmetric tensor and vector backgrounds

Identified solutions in various dimensions with negative spatial curvature

Discussed the potential for these solutions to be exact conformal theories

Abstract

We discuss time - dependent solutions of the leading order string effective equations for a non-zero central charge deficit and curved maximally symmetric space. Some regular solutions are found for the case of non-trivial antisymmetric tensor and vector backgrounds (in various dimensions) and negative spatial curvature. It remains an open question which conformal theories are exact generalisations of these solutions.