A new phase in the Lorentzian type IIB matrix model and the emergence of continuous space-time

TL;DR

This paper demonstrates the emergence of continuous 3+1-dimensional space-time in the Lorentzian type IIB matrix model using the complex Langevin method, overcoming previous approximation limitations and revealing a new phase.

Contribution

It introduces a new phase in the Lorentzian type IIB matrix model and employs the complex Langevin method to accurately study space-time emergence without approximation.

Findings

Emergence of continuous space-time in a new phase

Overcoming the sign problem with the complex Langevin method

Confirmation of spontaneous symmetry breaking leading to 3+1 dimensions

Abstract

The Lorentzian type IIB matrix model is a promising candidate for a non-perturbative formulation of superstring theory. In previous studies, Monte Carlo calculations provided interesting results indicating the spontaneous breaking of SO(9) to SO(3) and the emergence of (3+1)-dimensional space-time. However, an approximation was used to avoid the sign problem, which seemed to make the space-time structure singular. In this talk, we report our results obtained by using the complex Langevin method to overcome the sign problem instead of using this approximation. In particular, we discuss the emergence of continuous space-time in a new phase, which we discovered recently.