Supersymmetric harmonic oscillators on singular geometries

Abstract

Equivariant localization expresses global invariants in terms of local invariants, and many of them appearing in equivariant index theory, (holomorphic) Morse theory, geometric quantization and supersymmetric localization can be characterized as renormalized supertraces over cohomology groups of Hilbert complexes associated to local model geometries. This paper extends such local invariants, introducing and studying twisted de Rham and Dolbeault complexes (including Witten deformed versions) on singular spaces equipped with generalized radial (K\"ahler Hamiltonian) Morse functions and singular metrics arising naturally in algebraic geometry and moduli problems. We use the $\mathcal{N}=2$ supersymmetry and nilpotency properties of these complexes to extend an ansatz of Cheeger for the eigensections of the associated Laplace/Schr\"odinger type operators, reducing the problem to the study of Sturm-Liouville operators and one dimensional Schr\"odinger operators corresponding to different choices of domains, including those with del-bar Neumann boundary conditions for Dolbeault complexes. We define renormalized Lefschetz numbers and Morse polynomials generalizing those established in the smooth and conic settings where they have been used to compute many invariants of interest in physics and mathematics. We study structures on links of topological cones with singular K\"ahler metrics, which we use to describe associated analytic invariants including local cohomology groups. The techniques and results collected here are broadly applicable in the study of global analysis on singular spaces, including proofs of localization theorems with numerous applications.