String creation in cosmologies with a varying dilaton

TL;DR

This paper investigates string creation in cosmological models derived from string theory with a varying dilaton, identifying an exponential divergence near singularities and proposing a potential resolution involving back-reaction effects leading to early-time de Sitter space.

Contribution

It analyzes string creation in FRW solutions with a dynamic dilaton and suggests a mechanism to resolve initial singularities through back-reaction effects.

Findings

Exponential divergence in string creation near space-like singularity.

Potential removal of singularity via back-reaction effects.

Early universe may resemble de Sitter space due to these effects.

Abstract

FRW solutions of the string theory low-energy effective actions are described, yielding a dilaton which first decreases and then increases. We study string creation in these backgrounds and find an exponential divergence due to an initial space-like singularity. We conjecture that this singularity may be removed by the effects of back-reaction, leading to a solution which at early times is de Sitter space.