String Cosmology: An Update

TL;DR

This paper reviews recent advances in string cosmology, focusing on the pre-big-bang scenario, including initial conditions, transition mechanisms, and perturbation generation, aiming for a singularity-free inflationary model.

Contribution

It provides an update on the progress in understanding key issues like initial conditions, graceful exit, and perturbations in string cosmology's pre-big-bang model.

Findings

Progress in understanding initial conditions and transition mechanisms.

Insights into the generation of inhomogeneity perturbations.

Advancements towards a singularity-free inflationary cosmology.

Abstract

A string cosmology scenario ("pre-big-bang") postulates that the evolution of the Universe starts from a state of very small curvature and coupling, undergoes a long phase of dilaton-driven kinetic inflation and at some later time joins smoothly standard radiation dominated cosmological evolution, thus giving rise to a singularity free inflationary cosmology. I report on recent progress in understanding some outstanding issues such as initial conditions, graceful exit transition and generation of inhomogeneity perturbations.