Resolution of null fiber and conormal bundles on the Lagrangian Grassmannian

Abstract

We study the null fiber of a moment map related to dual pairs. We construct an equivariant resolution of singularities of the null fiber, and get conormal bundles of closed $ K_C $-orbits in the Lagrangian Grassmannian as the categorical quotient. The conormal bundles thus obtained turn out to be a resolution of singularities of the closure of nilpotent $ K_C $-orbits, which is a "quotient" of the resolution of the null fiber.