Emergent scenario in mimetic gravity

TL;DR

This paper investigates the stability of Einstein static universes within mimetic gravity, demonstrating conditions under which a non-singular emergent universe can evolve into inflation, thus addressing the big bang singularity.

Contribution

It shows that stable Einstein static solutions exist in mimetic gravity under specific conditions, enabling a non-singular emergent universe scenario.

Findings

Stable Einstein static solutions exist under certain conditions.

The universe can exit the static state and enter inflation.

The emergent scenario can resolve the big bang singularity in mimetic gravity.

Abstract

The emergent scenario provides a possible way to avoid the big bang singularity by assuming that the universe originates from an Einstein static state. Therefore, an Einstein static universe stable under perturbations is crucial to a successful implementation of the emergent mechanism. In this paper, we analyze the stability of the Einstein static universe against the scalar perturbations in the mimetic theory and find that stable Einstein static solutions exist under certain conditions in this theory. In the original mimetic gravity, the Einstein static universe is unstable. Then, we find that the universe can naturally exit from the initial static state, evolve into an inflationary era and then exit from the inflationary era. Thus, the emergent scenario can be used to resolve the big bang singularity in the mimetic theory.