Partially harmonic forms and models of H-series

Abstract

Let G be a real reductive Lie group, let H=TA be the identity component of a Cartan subgroup, and let h be the corresponding Cartan subalgebra. This leads to a parabolic subgroup of G whose identity component is MAN. The unitary G-representations induced by MAN are known as the H-series. We study symplectic geometry of G×h and apply geometric quantization to construct unitary G-representations by partially harmonic forms. They are direct integrals of the H-series, indexed by the image of the moment map. We also perform symplectic reduction and symplectic induction, and consider their analogues in representation theory via geometric quantization.