Classical Corrections in String Cosmology

TL;DR

This paper investigates classical corrections in string cosmology, exploring their role in preventing curvature growth during a deSitter-like phase, and examines the implications of symmetries and conformal field theory on fixed point behavior.

Contribution

It provides evidence that classical corrections can produce a saturation of curvature growth and discusses the fixed point structure using symmetry considerations and conformal perturbation theory.

Findings

Classical corrections may saturate curvature growth in string cosmology.

Imposing scale factor duality conflicts with fixed point behavior at all orders.

A new fixed point structure is identified through conformal perturbation analysis.

Abstract

An important element in a model of non-singular string cosmology is a phase in which classical corrections saturate the growth of curvature in a deSitter-like phase with a linearly growing dilaton (an `algebraic fixed point'). As the form of the classical corrections is not well known, here we look for evidence, based on a suggested symmetry of the action, scale factor duality and on conformal field theory considerations, that they can produce this saturation. It has previously been observed that imposing scale factor duality on the $O(\alpha')$ corrections is not compatible with fixed point behavior. Here we present arguments that these problems persist to all orders in $\alpha'$. We also present evidence for the form of a solution to the equations of motion using conformal perturbation theory, examine its implications for the form of the effective action and find novel fixed point structure.