Heterotic M(atrix) strings and their interactions

Abstract

Following a recent proposal of Dijkgraaf, Verlinde and Verlinde, we show that the M(atrix) theory compactified on S 1 Z 2 provides us with a non-perturbative description of the second-quantized light-cone heterotic string. This so-called heterotic M(atrix) string theory is defined by a two-dimensional (8,0) supersymmetric chiral gauge theory with gauge group SO(2 N) in the large N limit. We argue that at the strong coupling fixed point the chiral gauge theory flows to a (8,0) superconformal field theory defined via the SN symmetric product space orbifold. We show that the leading order correction to the strong coupling expansion corresponds to a unique irrelevant operator of scaling dimension three and describes the joining and splitting cubic interactions of the light-cone heterotic string. We also speculate on a M(atrix) description of bosonic strings via dimensional reduction of d = 26 Yang-Mills theory.