Can the Big Bang Singularity be avoided by a single scalar field?

TL;DR

This paper explores whether a single scalar field with non-minimal coupling to gravity can prevent the Big Bang singularity, finding that non-linear couplings generally allow for singularity avoidance.

Contribution

It demonstrates that non-linear non-minimal couplings of a scalar field to gravity can generically avoid the Big Bang singularity, unlike linear couplings which require strict potential conditions.

Findings

Non-linear couplings can prevent the singularity.

Linear couplings require specific potential conditions.

Singularity avoidance is more generic with non-linear coupling.

Abstract

In this note, we investigate the possibility of avoiding the Big Bang singularity with a single scalar field which couples non-minimally to gravity. We show that in the case that gravity couples linearly to the field, some severe conditions on the field's potential have to be imposed. However, in non-linear case, it is quite generic to avoid the singularity with single scalar field.