Galileon Bouncing Inflation after BICEP2

TL;DR

This paper proposes a nonsingular bouncing inflation model where the universe transitions from contraction to expansion, generating primordial perturbations and aligning with recent tensor-to-scalar ratio data, thus avoiding the Big Bang singularity.

Contribution

It introduces a Galileon-based bouncing inflation scenario that successfully integrates a bounce with inflation, addressing the singularity problem and matching observational data.

Findings

The model produces a tensor-to-scalar ratio consistent with BICEP2 data.

The bounce prevents the initial singularity in the early universe.

Primordial perturbations are generated during the inflationary phase.

Abstract

We present a nonsingular scenario in which an inflation era goes after a bounce from a contracting scenario in the early universe. The contracting of the universe is supposed to be slow, such that the initial anisotropies will not grow too fast to become dominant and destroy the bounce. After the bounce, the universe enters into an inflationary region and reheating phase, where primordial perturbations are generated. The tensor-to-scalar ratio of the perturbations are expected to be consistent with the newly released data, $r=0.2^{+0.07}_{-0.05}$. The addition of the bounce process is aimed at getting rid of the annoying Big-Bang Singularity, which generally exist in pure inflation models.