Previous Special Year Seminar

Dec
02
2020

Geometric and Modular Representation Theory Seminar

Geometric Satake equivalence: a historical survey
3:00pm|Simonyi Hall 101 and Remote Access

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...

Dec
01
2020

SL2 Seminar

The ABG Equivalence
3:00pm|Remote Access

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...

Nov
17
2020

SL2 Seminar

No seminar: workshop
3:00pm|Remote Access
Nov
11
2020

Geometric and Modular Representation Theory Seminar

Iwahori-Whittaker category and geometric Casselman-Shalika
3:00pm|Simonyi Hall 101 and Remote Access

This talk will be an exposition of a recent paper of Bezrukavnikov-Gaitsgory-Mirkovic-Riche-Rider giving an Iwahori-Whittaker model for the Satake category. The main point is that their argument works for modular coefficients. I will give some...

Nov
10
2020

SL2 Seminar

Blocks and Defect Groups of SLn
3:00pm|Remote Access

The modular representation theory of a finite group naturally breaks into different pieces called blocks, and the defect of a block is a sort of measure of its complexity. I will recall some basic aspects of this theory, and then give the complete...

Nov
04
2020

Geometric and Modular Representation Theory Seminar

The Derived Geometric Satake Equivalence of Bezrukavnikov and Finkelberg
3:00pm|Simonyi Hall 101 and Remote Access

This is the last talk towards understanding Bezrukavnikov-Finkelberg's derived geometric Satake equivalence. With the preparations from previous talks, we will introduce two filtrations: a topological filtration on the equivariant cohomology and an...

Nov
03
2020

SL2 Seminar

Decomposition numbers in defining characteristic
4:00pm|Remote Access

The decomposition of the reduction of a Deligne--Lusztig character as a sum of Weyl modules is given by Jantzen's formula. In the case of $SL_2(F_q)$ the formula can be proved by a direct computation, and as a result we will see that the entries in...