Cosmic bounce and phantom-like equation of state from tunnelling

TL;DR

This paper proposes a quantum tunneling mechanism in scalar fields on a flat FLRW background that induces a cosmic bounce and phantom-like behavior without exotic matter or modified gravity, leading to a de Sitter phase.

Contribution

It introduces a novel quantum tunneling process in scalar fields that results in a bounce and phantom-like equation of state in cosmology, without needing exotic matter.

Findings

Quantum tunneling induces a bounce in flat FLRW cosmology.

The resulting state exhibits phantom-like behavior.

The mechanism naturally leads to a de Sitter phase.

Abstract

We allow a scalar field on a flat FLRW background metric to tunnel between two degenerate vacua. The resulting true vacuum state then violates the Null Energy Condition, and the corresponding homogeneous fluid induces a bounce, after which it has a phantom-like equation of state and asymptotically leads to a de Sitter phase. The mechanism presented here requires no exotic matter or modified gravity, it is purely generated by quantum fluctuations and is valid for a generic double well potential.