Verlinde formulas for nonsimply connected groups

Abstract

In 1999, Fuchs and Schweigert proposed formulas of Verlinde type for moduli spaces of surface group representations in compact nonsimply connected Lie groups. In this paper, we will prove a symplectic version of their conjecture for surfaces with at most one boundary component. A key tool in our computations is Kostant's notion of a maximal torus in apposition.