Gravitational Wave Bursts from Cosmic Superstrings with Y-junctions

TL;DR

This paper investigates how Y-junctions in cosmic superstring loops influence gravitational wave signals, finding that while individual burst strengths are similar, junctions introduce additional contributions to the signals.

Contribution

It provides a detailed analysis of gravitational wave emissions from cosmic superstring loops with Y-junctions, highlighting new effects caused by junction dynamics.

Findings

Individual burst strengths remain largely unchanged.

Y-junctions add new contributions to gravitational wave signals.

Strings expanding at light speed at junctions affect wave emissions.

Abstract

Cosmic superstring loops generically contain strings of different tensions that meet at Y-junctions. These loops evolve non-periodically in time, and have cusps and kinks that interact with the junctions. We study the effect of junctions on the gravitational wave signal emanating from cosmic string cusps and kinks. We find that earlier results on the strength of individual bursts from cusps and kinks on strings without junctions remain largely unchanged, but junctions give rise to additional contributions to the gravitational wave signal coming from strings expanding at the speed of light at a junction and kinks passing through a junction.