Unitary IIB Matrix Model and the Dynamical Generation of the Space Time

TL;DR

This paper introduces a unitary matrix model as a regularization of the IIB matrix model, incorporating fermions with overlap formalism, and explores the potential for dynamical four-dimensional space-time generation.

Contribution

It presents a new regularization of the IIB matrix model with manifest U(1)^10 symmetry and discusses mechanisms for spontaneous symmetry breaking leading to 4D space-time.

Findings

One-loop effective action computed around BPS configurations.

Manifest U(1)^10 symmetry preserved in the regularization.

Scenario proposed for 4D space-time emergence via symmetry breaking.

Abstract

We propose a unitary matrix model as a regularization of the IIB matrix model of Ishibashi-Kawai-Kitazawa-Tsuchiya (IKKT). The fermionic part is incorporated using the overlap formalism in order to avoid unwanted ``doublers'' while preserving the global gauge invariance. This regularization, unlike the one adopted by IKKT, has manifest U(1)^10 symmetry, which corresponds to the ten-dimensional translational invariance of the space time. We calculate one-loop effective action around some typical BPS-saturated configurations in the weak coupling limit. We also discuss a possible scenario for the dynamical generation of the four-dimensional space time through spontaneous breakdown of the U(1)^10 symmetry in the double scaling limit.