Nonuniversality in random criticality

Abstract

We consider $N$ two-dimensional Ising models coupled in presence of quenched disorder and use scale invariant scattering theory to exactly show the presence of a line of renormalization group fixed points for any fixed value of $N$ other than 1. We show how this result relates to perturbative studies and sheds light on numerical simulations. We also observe that the limit $N\to 1$ may be of interest for the Ising spin glass, and point out potential relevance for nonuniversality in other contexts of random criticality.