The extensions of gravitational soliton solutions with real poles

TL;DR

This paper investigates vacuum gravitational soliton solutions with real poles, analyzing their singularities and possible extensions, revealing their nature as null matter sheets or coordinate artifacts in cosmological models.

Contribution

It provides a detailed analysis of the singularities in gravitational soliton solutions with real poles and explores methods to extend these solutions through such singularities.

Findings

Some singularities are null matter sheets, not true physical singularities.

Extensions through singularities can be achieved, revealing richer solution structures.

The analysis enhances understanding of soliton solutions in cosmological contexts.

Abstract

We analyse vacuum gravitational "soliton" solutions with real poles in the cosmological context. It is well known that these solutions contain singularities on certain null hypersurfaces. Using a Kasner seed solution, we demonstrate that these may contain thin sheets of null matter or may be simple coordinate singularities, and we describe a number of possible extensions through them.