Entropy production by domain wall decay in the NMSSM

TL;DR

This paper investigates how the decay of domain walls in the NMSSM, caused by explicit symmetry breaking, leads to entropy production that can dilute unwanted relics like moduli and axions, impacting cosmological models.

Contribution

It introduces a detailed analysis of domain wall decay in the NMSSM and its cosmological consequences, focusing on entropy production and relic dilution.

Findings

Decay of domain walls produces significant late-time entropy.

Entropy production can dilute unwanted relics such as moduli and axions.

Implications for cosmological models and relic abundance constraints.

Abstract

We consider domain walls in the $Z_3$ symmetric NMSSM. The spontaneous $Z_3$ discrete symmetry breaking produces domain walls, and the stable domain walls are problematic. Thus, we assume the $Z_3$ symmetry is slightly but explicitly broken and the domain walls decay. Such a decay causes a large late-time entropy production. We study its cosmological implications on unwanted relics such as moduli, gravitino, LSP and axion.