Gravitational waves from domain walls in the next-to-minimal supersymmetric standard model

TL;DR

This paper investigates gravitational waves generated by unstable domain walls in the next-to-minimal supersymmetric standard model, highlighting their potential detectability via future pulsar timing experiments.

Contribution

It estimates the gravitational wave signatures from domain walls in NMSSM and explores their dependence on model parameters, especially in the decoupling limit.

Findings

Gravitational wave amplitude is large in the decoupling limit.

Predicted gravitational wave frequencies are within future pulsar timing sensitivity.

Domain wall collapse occurs before big bang nucleosynthesis, avoiding cosmological issues.

Abstract

The next-to-minimal supersymmetric standard model predicts the formation of domain walls due to the spontaneous breaking of the discrete $Z_3$-symmetry at the electroweak phase transition, and they collapse before the epoch of big bang nucleosynthesis if there exists a small bias term in the potential which explicitly breaks the discrete symmetry. Signatures of gravitational waves produced from these unstable domain walls are estimated and their parameter dependence is investigated. It is shown that the amplitude of gravitational waves becomes generically large in the decoupling limit, and that their frequency is low enough to be probed in future pulsar timing observations.