A RENORMALIZATION-GROUP STUDY OF ASYMMETRICALLY COUPLED MINIMAL MODELS

We investigate the renormalization group flows and fixed point structu re of many coupled minimal models. The models are coupled two by two b y energy-energy couplings. We take the general approach where the bare couplings are all taken to be independent. New fixed points are found for N models (N greater than or equal to 3). At these fixed points, t he coupling constants all have the same magnitude, but some are positi ve while others are negative. By analogy with spin lattices, these can be interpeted as non-frustrated configurations with a maximal number of antiferromagnetic links. The stability of the different fixed point s is studied. We compute the critical exponents and spin-spin correlat ion functions between different models. Our classification is shown to be complete. (C) 1998 Elsevier Science B.V. All rights reserved.