Complex saddle points in the Gross-Witten-Wadia matrix model

Gabriel Álvarez, Luis Martínez Alonso, Elena Medina
2016 Physical Review D  
We give an exhaustive characterization of the complex saddle point configurations of the Gross-Witten-Wadia matrix model in the large-N limit. In particular, we characterize the cases in which the saddles accumulate in one, two, or three arcs, in terms of the values of the coupling constant and of the fraction of the total unit density that is supported in one of the arcs, and derive an explicit condition for gap closing associated to nonvacuum saddles. By applying the idea of large-N instanton
more » ... we also give direct analytic derivations of the weak-coupling and strong-coupling instanton actions.
doi:10.1103/physrevd.94.105010 fatcat:5adglprvgrg2zkqbv5667jfma4