Spontaneous Breaking of Lepton Number and Cosmological Domain Wall Problem

Understand

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.