Schubert calculus on the grassmannian of hermitian lagrangian spaces

Abstract

The grassmannian of hermitian lagrangian spaces in ${\mathbb{C}}^n\oplus {\mathbb{C}}^n$ is a natural compactification of the space of hermitian $n\times n$ matrices. We describe a Schubert-like, Whitney regular stratification on this space which has a Morse theoretic origin. We prove that these strata define closed subanalytic currents à la R. Hardt, generating the integral homology of this space, we investigate their intersection theoretic properties, and we prove certain odd (in K-theoretic sense) Thom-Porteous type theorems.

52 pages, 1 figure. Fixed typos, added new references