Deformation of Dirac operators along orbits and quantization of non-compact Hamiltonian torus manifolds

Abstract

We give a formulation of a deformation of Dirac operator along orbits of a group action on a possibly non-compact manifold to get an equivariant index and a K-homology cycle representing the index. We apply this framework to non-compact Hamiltonian torus manifolds to define geometric quantization from the view point of index theory. We give two applications. The first one is a proof of a [Q,R]=0 type theorem, which can be regarded as a proof of the Vergne conjecture for Abelian case. The other is a Danilov-type formula for toric case in the non-compact setting, which shows that this geometric quantization is independent of the choice of polarization. The proofs are based on the localization of index to lattice points.

27pages. Due to referee's comments several expositions are rewritten, and typos are corrected. Especially descriptions for non-abelian case are withdrawn. References uploaded. To appear in Canadian Journal of Mathematics