Quasi-polynomials and the singular $[Q,R]=0$ theorem

Abstract

In this short note we revisit the `shift-desingularization' version of the $[Q,R]=0$ theorem for possibly singular symplectic quotients. We take as starting point an elegant proof due to Szenes-Vergne of the quasi-polynomial behavior of the multiplicity as a function of the tensor power of the prequantum line bundle. We use the Berline-Vergne index formula and the stationary phase expansion to compute the quasi-polynomial, adapting an early approach of Meinrenken.

References in corpus (1)

• Witten non abelian localization for equivariant K-theory, and the [Q,R]=0 theorem

Cited by in corpus (1)

• Coarse geometry and Callias quantisation