Vacuum Stability in the Early Universe and the Backreaction of Classical Gravity

TL;DR

This paper explores how the early universe's high curvature impacts the stability of the electroweak vacuum, highlighting the importance of non-minimal coupling and curvature effects on vacuum decay and dark matter production.

Contribution

It introduces the role of spacetime curvature and non-minimal coupling in vacuum stability during the early universe, providing new bounds and mechanisms.

Findings

Curvature significantly modifies vacuum stability predictions.

Non-minimal coupling bounds are tightly constrained.

A new dark matter generation mechanism is proposed.

Abstract

In the case of a metastable electroweak vacuum the quantum corrected effective potential plays a crucial role in the potential instability of the Standard Model. In the Early Universe, in particular during inflation and reheating, this instability can be triggered leading to catastrophic vacuum decay. We discuss how the large spacetime curvature of the Early Universe can be incorporated in the calculation and in many cases significantly modify the flat space prediction. The two key new elements are the unavoidable generation of the non-minimal coupling between the Higgs field and the scalar curvature of gravity and a curvature induced contribution to the running of the constants. For the minimal set up of the Standard Model and a decoupled inflation sector we show how a metastable vacuum can lead to very tight bounds for the non-minimal coupling. We also discuss a novel and very much related dark matter generation mechanism.