Light-like Big Bang singularities in string and matrix theories

TL;DR

This paper reviews the current understanding of light-like Big Bang singularities in string and matrix theories, highlighting both solved problems and open questions in modeling cosmological singularities.

Contribution

It provides a comprehensive status report on light-like Big Bang models in string and matrix theories, emphasizing their tractability and unresolved issues.

Findings

Light-like singularities are more tractable in string and matrix theories.

Current models include both solved and open problems.

The paper summarizes progress and challenges in understanding these singularities.

Abstract

Important open questions in cosmology require a better understanding of the Big Bang singularity. In string and matrix theories, light-like analogues of cosmological singularities (singular plane wave backgrounds) turn out to be particularly tractable. We give a status report on the current understanding of such light-like Big Bang models, presenting both solved and open problems.