Gravitational Wave Gastronomy

TL;DR

This paper analyzes gravitational wave signals produced by the decay of hybrid topological defects formed during early Universe symmetry breaking, providing a way to identify specific symmetry breaking chains and scales.

Contribution

It introduces the concept of gravitational wave gastronomy, detailing how the decay of hybrid defects generates unique gravitational wave spectra that can inform grand unified theories.

Findings

Unique gravitational wave spectra from defect decay processes.

Potential to narrow down SO(10) symmetry breaking pathways.

Systems likely resolve monopole and domain wall problems.

Abstract

The symmetry breaking of grand unified gauge groups in the early Universe often leaves behind relic topological defects such as cosmic strings, domain walls, or monopoles. For some symmetry breaking chains, hybrid defects can form where cosmic strings attach to domain walls or monopoles attach to strings. In general, such hybrid defects are unstable, with one defect "eating" the other via the conversion of its rest mass into the other's kinetic energy and subsequently decaying via gravitational waves. In this work, we determine the gravitational wave spectrum from 1) the destruction of a cosmic string network by the nucleation of monopoles which cut up and "eat" the strings, 2) the collapse and decay of a monopole-string network by strings that "eat" the monopoles, 3) the destruction of a domain wall network by the nucleation of string-bounded holes on the wall that expand and "eat" the wall, and 4) the collapse and decay of a string-bounded wall network by walls that "eat" the strings. We call the gravitational wave signals produced from the "eating" of one topological defect by another gravitational wave gastronomy. We find that the four gravitational wave gastronomy signals considered yield unique spectra that can be used to narrow down the SO(10) symmetry breaking chain to the Standard Model and the scales of symmetry breaking associated with the consumed topological defects. Moreover, the systems we consider are unlikely to have a residual monopole or domain wall problem.