A numerical simulation of pre-big bang cosmology

TL;DR

This paper uses numerical simulations to study the onset of pre-big bang inflation in an inhomogeneous universe, showing that certain regions can undergo inflation and become flat, with results aligning with analytic solutions.

Contribution

It provides the first detailed numerical analysis of pre-big bang inflation onset in an inhomogeneous setting, validating analytic asymptotic solutions.

Findings

Regions undergo dilaton-driven inflation

Spatial flatness ($\,\Omega \to 1$) achieved

Results agree with previous analytic models

Abstract

We analyse numerically the onset of pre-big bang inflation in an inhomogeneous, spherically symmetric Universe. Adding a small dilatonic perturbation to a trivial (Milne) background, we find that suitable regions of space undergo dilaton-driven inflation and quickly become spatially flat ($\Omega \to 1$). Numerical calculations are pushed close enough to the big bang singularity to allow cross checks against previously proposed analytic asymptotic solutions.