Pre-Big-Bang in String Cosmology

TL;DR

This paper explores the pre-big-bang phase in string cosmology, driven by duality symmetries, and discusses potential observational signatures like relic gravitons and CMB distortions.

Contribution

It introduces the concept of a pre-big-bang phase arising from string dualities and examines its possible observational evidence.

Findings

Pre-big-bang phase characterized by accelerated evolution.

Potential detection of relic gravitons as evidence.

Distortions in the cosmic microwave background may indicate pre-big-bang signatures.

Abstract

The duality-type symmetries of string cosmology naturally lead to a pre-big-bang phase of accelerated evolution as dual counterpart of the decelerated expansion of standard cosmology. We discuss several properties of this scenario, including the possibility that tracks of the pre-big-bang may be found either in the spectrum of relic gravitons or in the distortion they induce on the cosmic microwave background.