LARGE-N UNIVERSALITY OF THE 2-DIMENSIONAL YANG-MILLS STRING

We exhibit the gauge-group independence (''universality'') of all norm alized non-intersecting Wilson loop expectation values in the large N limit of two-dimensional Yang-Mills theory. This universality is most easily understood via the string theory reformulation of these gauge t heories. By constructing an isomorphism between the string maps contri buting to normalized Wilson loop expectation values in the different t heories, we prove the large N universality of these observables on any surface, The string calculation of the Wilson loop expectation value on the sphere also leads to an indication of the large N phase transit ion separating strong- and weak-coupling phases.