The master field for 2D QCD on the sphere

We continue our analysis of the field strength correlation functions of two-dimensional QCD on Riemann surfaces by studying the large N limit of these correlation functions on the sphere for the gauge group U(N). Our results allow us to exhibit an explicit master field for the field strength Fμν in a “topological gauge”, given by a single master matrix in the Lie algebra of the maximal torus of the gauge group. Field correlators are obtained from the traces of the products of the master field. We also obtain a master field for the gauge potential Aμ on the sphere, consistent with the master field for the field strength.