Brane world from IIB matrices

TL;DR

This paper proposes a dynamical mechanism within type IIB matrix theory that naturally results in a four-dimensional brane universe, supported by simplified model demonstrations and implications for brane world model building.

Contribution

It introduces a novel dynamical mechanism for brane formation in type IIB superstring theory using the phase of the chiral fermion integral in the IKKT matrix model.

Findings

A lower-dimensional brane appears dynamically in the simplified model.

The phase of the chiral fermion integral plays a crucial role in brane formation.

Implications for constructing brane world models are discussed.

Abstract

We have recently proposed a dynamical mechanism that may realize a flat four-dimensional space time as a brane in type IIB superstring theory. A crucial role is played by the phase of the chiral fermion integral associated with the IKKT Matrix Theory, which is conjectured to be a nonperturbative definition of type IIB superstring theory. We demonstrate our mechanism by studying a simplified model, in which we find that a lower-dimensional brane indeed appears dynamically. We also comment on some implications of our mechanism on model building of the brane world.