Reading Seminar: More sheaf theory and Verma modules

The first part of this talk will be a continuation by TB of last week's talk, explaining how the Decomposition Theorem is used to prove the relation between stalks of intersection cohomology and Kazhdan-Lusztig polynomials for finite Weyl groups. With any remaining time OW will begin explaining the relation between KL polynomials and multiplicities in Verma modules for semisimple Lie algebras.