Geordie Williamson, Lecture IV - 26 January 2015
Channel: SNS Sciences
Date: 2015-02-06

Geordie Williamson (Max-Planck-Institute, Bonn) - Lecture IV
http://www.crm.sns.it/course/4033/

This mini-course will be an introduction to perverse sheaves, with emphasis on examples from representation theory. It will be a course full of pictures and examples, with the aim of trying to get some feeling for the fundamentals of perverse sheaves: t-structures and gluing, intersection cohomology complexes, the decomposition theorem, vanishing and nearby cycles. As a grand finale I hope to cover de Cataldo and Migliorini's proof of the decomposition theorem. Although the most important concepts will be recalled, I will assume a basic knowledge of sheaves and derived categories. (If you have never worked with sheaves, cohomology or derived categories before the learning curve will be steep.)