Phases and triple (multiple) point: Critical phenomena around the AD singularity

Abstract

Continuing with our previous series of work, we present a case study of the critical phenomena around Argyres-Douglas singularity of N=2 susy made at (A1,A4k−1),k=1,2 realized by one-unitary matrix model. We determine the phase diagram, which is recast into LEEA of N=2, 4d gauge theory by the 0d-4d connection. There are three distinct phases, each corresponding to an eigenvalue distribution with 0, 1, and 2 gaps. These form an entire phase diagram with a triple point. Examining the behavior of the planar free energy, we show, among other things, that the transition line between 1- and 2-gap phases ending at the triple point is the k=2 multicritical one.