Gravitational power from cosmic string loops with many kinks

TL;DR

This paper analyzes how a large number of kinks on cosmic string loops influence gravitational wave emission, revealing that kink proliferation accelerates loop decay but does not enhance individual burst rates, affecting gravitational wave background predictions.

Contribution

It provides a detailed analysis of gravitational power radiated by loops with many kinks and revises decay times and burst predictions for loops with junctions.

Findings

Power radiated scales linearly with the number of kinks.

Loops with many kinks decay faster than previously thought.

Kink-kink bursts can dominate the stochastic gravitational wave background.

Abstract

We investigate the effect of a large number of kinks on the gravitational power radiated by cosmic string loops. We show that the total power radiated by a loop with N left-moving and right-moving kinks is proportional to N and increases with the typical kink angle. We then apply these results to loops containing junctions which give rise to a proliferation of the number of sharp kinks. We show that the time of gravitational decay of these loops is smaller than previously assumed. In light of this we revisit the gravitational wave burst predictions from a network containing such loops. We find there is no parameter regime in which the rate of individual kink bursts is enhanced with respect to standard networks. By contrast, there remains a region of parameter space for which the kink-kink bursts dominate the stochastic background. Finally, we discuss the order of magnitude of the typical number of sharp kinks resulting from kink proliferation on loops with junctions.