Electroweak Symmetry Restoration in Extended Higgs Sectors via Domain Walls

TL;DR

This paper explores how domain walls in extended Higgs models like N2HDM can lead to electroweak symmetry restoration in the early universe, affecting cosmological processes such as baryogenesis.

Contribution

It demonstrates the possibility of electroweak symmetry restoration near domain walls in extended Higgs sectors, a novel insight into early universe cosmology.

Findings

Domain walls can induce electroweak symmetry restoration.

Sphaleron rates are unsuppressed inside the domain wall.

Implications for early universe baryogenesis.

Abstract

Domain walls are a type of topological defects that can arise in the early universe after the spontaneous breaking of a discrete symmetry. This occurs in several beyond Standard Model theories with an extended Higgs sector such as the Next-to-Two-Higgs-Doublet model (N2HDM). In this talk, I will discuss the domain wall solution related to the singlet scalar of the N2HDM and demonstrate the possibility of electroweak symmetry restoration (EWSR) in the vicinity of the domain wall. Such symmetry restoration can have profound implications on the early universe cosmology as the sphaleron rate inside the domain wall would, in principle, be unsuppressed compared with the rate outside the wall.