Graceful exit via polymerization of pre-big bang cosmology

TL;DR

This paper proposes a modified pre-big bang cosmology model incorporating Loop Quantum Cosmology techniques, successfully resolving the graceful exit problem by ensuring finite curvature and dilaton energy throughout cosmic evolution.

Contribution

It introduces a novel approach combining pre-big bang scenarios with Loop Quantum Cosmology to address the graceful exit issue.

Findings

Curvature and dilaton energy remain finite at all times.

Dilaton tends to a constant after the bounce.

The model resolves the graceful exit problem.

Abstract

We consider a phenomenological modification of the Pre Big Bang scenario using ideas from the resolution of curvature singularities in Loop Quantum Cosmology. We show that non-perturbative Loop modifications to the dynamics, arising from the underlying polymer representation, can resolve the graceful exit problem. The curvature and the dilaton energy stay finite at all times, in both the string and Einstein frames. In the string frame, the dilaton tends to a constant value at late times after the bounce.