What does the Letelier-Gal'tsov metric describe?

TL;DR

This paper clarifies the structure of the Letelier-Gal'tsov spacetime, showing it describes parallel cosmic strings and addressing previous controversies about its definition.

Contribution

It demonstrates that the Letelier-Gal'tsov metric is well-defined only on a dense subset and clarifies its physical interpretation as parallel cosmic strings.

Findings

The metric is defined only on a dense subset of the manifold.

When extended by continuity, it describes parallel cosmic strings at rest.

Addresses controversy over the spacetime's structure.

Abstract

Recently the structure of the Letelier-Gal'tsov spacetime has become a matter of some controversy. I show that the metric proposed in \cite{letgal} is defined only on a dense subset of the whole manifold. In the case when it can be defined on the remainder by continuity, the resulting spacetime corresponds to a system of parallel cosmic strings at rest w.r.t. each other.