Zipping and Unzipping of Cosmic String Loops in Collision

TL;DR

This paper investigates the collision of cosmic string loops, revealing how junctions form and subsequently unzip, leading to disentanglement, which impacts the evolution of cosmic string networks, especially in cosmic superstring scenarios.

Contribution

It provides a theoretical explanation for the unzipping effect observed in simulations of cosmic string networks with multiple string types.

Findings

Junctions form upon loop collision and then unzip.

Unzipping leads to loop disentanglement.

Impacts evolution of cosmic string networks with junctions.

Abstract

In this paper the collision of two cosmic string loops is studied. After collision junctions are formed and the loops are entangled. We show that after their formation the junctions start to unzip and the loops disentangle. This analysis provides a theoretical understanding of the unzipping effect observed in numerical simulations of a network of cosmic strings with more than one type of cosmic strings. The unzipping phenomena have important effects in the evolution of cosmic string networks when junctions are formed upon collision, such as in a network of cosmic superstrings.