Singularities of N=1 supersymmetric gauge theory and matrix models -: art. no. 025

In N = 1 supersymmetric U(N) gauge theory with adjoint matter Phi, and polynomial tree-level superpotential W(Phi), the massless fluctuations about each quantum vacuum are generically described by U(1)(n) gauge theory for some n. However, by tuning the parameters of W(Phi) to non-generic values, we can reach singular vacua where additional fields become massless. Using both the matrix model prescription and the strong-coupling approach, we study in detail three examples of such singularities: the singularities of the n = 1 branch, intersections of n = 1 and n = 2 branches, and a class of N = 1 Argyres-Douglas points. In all three examples, we find that the matrix model description of the low-energy physics breaks down in some way at the singularity.