Special Year 2020-21: Geometric and Modular Representation Theory

SL2 Seminar

January 19, 2021 | 3:00pm - 5:00pm

Let $G$ be an algebraic group defined over a finite field $F_q$. Through the lens of Tannakian formalism I will give a categorical description of the relationship between the representation theory of the algebraic group $G$ and the representation...

Smith theory is a type of equivariant localization with respect to a cyclic group of prime order $p$, with coefficients in a field of the same characteristic $p$. It has been the source of various recent advances in modular representation theory and...

The talk is about convolution in the setting of geometric representation theory. What are its formal properties? As a starting point, let $G$ be a group and let $D(G)$ be the derived category of constructible sheaves on it. Convolution turns $D(G)$...

SL2 Seminar

December 15, 2020 | 3:00pm - 5:00pm

We survey work over the last 50 years advancing our understandingof cohomology of groups. We begin with results of Daniel Quillen which have influenced all that follows. We mention stability results of Cline, Parshall, Scott, and van der Kallen...

Motivated by a formal similarity between the Hard Lefschetz theorem and the geometric Satake equivalence we study vector spaces that are graded by a weight lattice and are endowed with linear operators in simple root directions. We allow field...

Before the "geometric Satake equivalence" there was a decategorified version of it which however contained most of its essential features. In my talk I will talk about some of the ideas which have led to this theory. In particular I will explain the...

SL2 Seminar

December 01, 2020 | 3:00pm - 5:00pm

Broue's Conjecture for $SL_2(\mathbb{F}_q)$ in defining characteristic, predicts a derived equivalence between the principal block of this group and the principal block of a Borel. A structurally similar equivalence exist in the case of the...