Electroweak Vacuum Stabilized by Moduli during/after Inflation

TL;DR

This paper proposes that a moduli field with Planck-suppressed interactions can alter the Higgs quartic coupling in the early universe, stabilizing the electroweak vacuum during and after inflation.

Contribution

It introduces a simple mechanism involving moduli fields to modify the Higgs potential, ensuring vacuum stability throughout cosmic inflation and its aftermath.

Findings

Higgs quartic coupling can be effectively altered by moduli fields.

The modified coupling leads to a stable Higgs potential during inflation.

The approach provides a natural solution to vacuum metastability issues.

Abstract

It is known that the present electroweak vacuum is likely to be metastable and it may lead to a serious instability during/after inflation. We propose a simple solution to the problem of vacuum instability during/after inflation. If there is a moduli field which has Planck-suppressed interactions with the standard model fields, the Higgs quartic coupling in the early universe naturally takes a different value from the present one. A slight change of the quartic coupling in the early universe makes the Higgs potential absolutely stable and hence we are free from the vacuum instability during/after inflation.