Realizing chiral fermions in the type IIB matrix model at finite N

Abstract

We discuss how chiral fermions can appear in the type IIB matrix model, which is considered to be a nonperturbative formulation of superstring theory. In particular, we are concerned with a constructive definition of the theory, in which we start with a finite-N configuration and take the large-N limit later on. We point out that there exists a certain necessary condition which the structure of the extra dimensions should satisfy. As an example, we consider a previous proposal using intersecting branes and show that chiral fermions can indeed be realized in four dimensions by introducing a matrix counterpart of warped space-time. This is remarkable in view of the well-known difficulty in realizing chiral fermions in lattice gauge theory.