Chen–Ruan cohomology of some moduli spaces

Abstract. Let X be a compact connected Riemann surface of genus at least two. Let r be a prime number and ξ − → X a holomorphic line bundle such that r is not a divisor of degree(ξ). LetMξ(r) denote the moduli space of stable vector bundles over X of rank r and determinant ξ. By Γ we will denote the group of line bundles L over X such that L⊗r is trivial. This group Γ acts onMξ(r) by the rule (E,L) 7− →