(3+1)-dimensional expanding universe from a Lorentzian matrix model for superstring theory in (9+1)-dimensions

TL;DR

This paper demonstrates that a Lorentzian matrix model for superstring theory dynamically produces a 3+1 dimensional expanding universe, with space and time emerging from fundamental matrices, resembling the birth of our universe.

Contribution

It provides a nonperturbative, Lorentzian matrix model that shows the emergence of a 3+1 dimensional expanding universe from superstring theory.

Findings

Space and time emerge dynamically from the matrices.

Three spatial directions start expanding at a critical time.

The model suggests a possible origin of our universe's expansion.

Abstract

We study the Lorentzian version of the type IIB matrix model as a nonperturbative formulation of superstring theory in (9+1)-dimensions. Monte Carlo results show that not only space but also time emerges dynamically in this model. Furthermore, the real-time dynamics extracted from the matrices turns out to be remarkable: 3 out of 9 spatial directions start to expand at some critical time. This can be interpreted as the birth of our Universe.