Gravitational Wave Mountains: current-carrying domain walls

TL;DR

This paper predicts a new gravitational wave signature from current-carrying domain walls with fermionic zero modes, characterized by mountain-like peaks in the spectrum, potentially detectable by future observatories.

Contribution

It introduces the concept of spherons, metastable topological remnants, causing distinctive peaks in GW spectra from current-carrying domain walls, a novel prediction in cosmological GW research.

Findings

GW spectrum features mountain-like peaks due to spherons

Detectability of signals by LISA and ET is enhanced

GW signals from DW networks could be stronger than previously thought

Abstract

Domain wall (DW) networks may have formed in the early universe following the spontaneous breaking of a discrete symmetry. Notably, several particle physics models predict the existence of current-carrying DWs, which can capture and store particles as zero modes on it. In this study, we demonstrate that gravitational waves (GWs) generated by current-carrying DWs with fermionic zeromodes exhibit a novel feature: an additional peak in the GW spectrum resembling mountains, arising from metastable topological remnants, which we term ``spherons.'' This distinct signature could be detectable in upcoming GW observatories such as LISA and ET. The results suggest that DW networks in beyond Standard Model scenarios could emit GW signals that are significantly stronger and with greater detectability than previously expected.