Gravitational radiation from monopoles connected by strings

TL;DR

This paper investigates the gravitational wave background produced by monopole-antimonopole pairs connected by strings, analyzing their spectrum through analytical and numerical methods, focusing on oscillating pairs with straight strings.

Contribution

It provides the first detailed analytical and numerical analysis of gravitational radiation from monopole-string systems in cosmology.

Findings

Gravitational wave spectrum from monopole-string systems is characterized.

Oscillating monopole pairs produce a detectable gravitational wave background.

Analytical and numerical results are consistent for simple configurations.

Abstract

Monopole-antimonopole pairs connected by strings can be formed as topological defects in a sequence of cosmological phase transitions. Such hybrid defects typically decay early in the history of the universe but can still generate an observable background of gravitational waves. We study the spectrum of gravitational radiation from these objects both analytically and numerically, concentrating on the simplest case of an oscillating pair connected by a straight string.