FIELD-STRENGTH CORRELATORS FOR 2-DIMENSIONAL YANG-MILLS THEORIES OVERRIEMANN SURFACES

The path integral computation of field strength correlation functions for two-dimensional Yang-Mills theories over Riemann surfaces is studi ed. The calculation is carried out by Abelianization, which leads to c orrelators that are topological. They are nontrivial as a result of th e topological obstructions to the Abelianization. It is shown in the l arge N limit on the sphere that the correlators undergo second order p hase transitions at the critical point. Our results are applied to a c omputation of contractible Wilson loops.