SMS scnews item created by Anthony Henderson at Sun 24 Aug 2008 1505
Type: Seminar
Distribution: World
Expiry: 29 Aug 2008
Calendar1: 29 Aug 2008 1205-1255
CalLoc1: Carslaw 159
CalTitle1: Algebra Seminar: Henderson -- Enhancing the nilpotent cone
Auth: anthonyh@asti.maths.usyd.edu.au

Algebra Seminar

Enhancing the nilpotent cone

Anthony Henderson

29th August, 12:05-12:55pm, Carslaw 159


Abstract

Many features of an algebraic group are controlled by the geometry of its nilpotent cone, which in the case of GLn(C) is merely the variety N of n×n nilpotent matrices. The study of the orbits of the group in its nilpotent cone leads to combinatorial data relating to the representations of the Weyl group, via the famous Springer correspondence.

As I announced in an Algebra Seminar last year, Pramod Achar and I have shown that studying the orbits of GLn(C) in the enhanced nilpotent cone Cn×N leads to exotic combinatorial data of type B/C (previously defined by Shoji under the name of "limit symbols"). This is closely related to Syu Kato's exotic Springer correspondence for the symplectic group.

In the current Seminar, I will review this story and bring it up to date.