Algebra and Geometry Seminar

It has been known for many years now that representation theoretic information is encoded in the geometry of Schubert varieties (e.g. the Kazhdan-Lusztig conjectures). In this talk, we are interested in representation theory over a field of positive characteristic, and how the presence or absence of torsion in intersection cohomology affects this representation theory. I will talk about some examples of this phenomenon, as well as how to construct new examples which show how bad the geometry can be (constructing non-perverse parity sheaves).