MULTICRITICAL MULTI-CUT MATRIX MODELS

We study matrix model critical phenomena occurring when the endpoints of two or more eigenvalue cuts collide. We construct multicritical potentials for hermitian matrix models whose eigenvalue distribution has support on two or more cuts. In the double scaling limit the two-cut models are proven to be in the same universality class as the unitary matrix models. We show how the isomonodromic deformation formalism emerges naturally from the double scaling limit. Models with more cuts are obtained by an "orbifold procedure". We perform the double scaling limit for the simplest such model, which involves four cuts.