Black hole formation from collisions of cosmic fundamental strings

TL;DR

This paper develops a formalism for string interactions and demonstrates that certain cosmic string collisions can result in black hole formation when velocities are sufficiently low.

Contribution

It introduces a general framework for string joining and splitting, and applies it to show black hole formation from cosmic string collisions.

Findings

Black hole formation occurs in string collisions with low relative velocities.

Interconnection of strings with opposite angular momentum can lead to gravitational collapse.

The formalism applies to both open and closed cosmic strings.

Abstract

We develop the general formalism for joining, splitting and interconnection of closed and open strings. As an application, we study examples of fundamental cosmic string collisions leading to gravitational collapse. We find that the interconnection of two strings of equal and opposite maximal angular momentum and arbitrarily large mass generically leads to the formation of black holes, provided their relative velocity is small enough.