The collision and snapping of cosmic strings generating spherical impulsive gravitational waves

TL;DR

This paper explores the Penrose method for creating spherical impulsive gravitational waves, focusing on cosmic string collisions and snapping phenomena, and provides explicit solutions within Einstein's equations.

Contribution

It introduces new exact solutions for cosmic string collisions and snapping events, extending the Penrose method with alternative spatial sections and cosmological constants.

Findings

Explicit solution for colliding cosmic strings in Minkowski space

Demonstration of spherical impulsive waves from snapping cosmic strings

Extension of Penrose method to include cosmological constant

Abstract

The Penrose method for constructing spherical impulsive gravitational waves is investigated in detail, including alternative spatial sections and an arbitrary cosmological constant. The resulting waves include those that are generated by a snapping cosmic string. The method is used to construct an explicit exact solution of Einstein's equations describing the collision of two nonaligned cosmic strings in a Minkowski background which snap at their point of collision.