Spontaneous Breaking of Lepton Number and Cosmological Domain Wall Problem

TL;DR

The paper discusses how spontaneous lepton number breaking can cause cosmological domain walls and proposes solutions to avoid this problem within the Majoron neutrino mass model.

Contribution

It identifies the domain wall problem in spontaneous lepton number breaking and offers realistic models to prevent it.

Findings

Spontaneous lepton number breaking can lead to cosmological domain walls.

Certain models can avoid the domain wall problem.

The Majoron paradigm is central to the analysis.

Abstract

We show that if global lepton number symmetry is spontaneously broken in a post inflation epoch, then it can lead to the formation of cosmological domain walls. This happens in the well-known "Majoron paradigm" for neutrino mass generation. We propose some realistic examples which allow spontaneous lepton number breaking to be safe from such domain walls.