**SMS scnews item created by Anne Thomas at Mon 19 Mar 2012 1146**

Type: Seminar

Distribution: World

Expiry: 23 Mar 2012

**Calendar1: 23 Mar 2012 1205-1255**

**CalLoc1: Carslaw 175**

Auth: athomas(.pmstaff;2039.2002)@p615.pc.maths.usyd.edu.au

### Algebra Seminar

# Quiver Schur algebras and decomposition numbers

### Mathas

#### Friday March 23, 12:05--12:55pm, Carslaw 175

###### Speaker:

Andrew Mathas

###### Title:

Quiver Schur algebras and decomposition numbers

###### Abstract:

Brundan and Kleshchev have shown that the degenerate and non-degenerate Hecke algebras of type \(G(r,1,n)\) are \(\mathbf{Z}\)-graded. This puts a very rigid structure on the module categories of these algebras which is hard to work with but also provides a wealth of new information. I will describe how to extend the KLR grading on the Hecke algebras to the cyclotomic Schur algebras and also how to use these gradings to compute decomposition numbers of certain blocks, both in characteristic zero and in positive characteristic. This is joint work with Jun Hu.

---------------------------------------------------------------------------------------

After the seminar we will take the speaker to lunch.

See the Algebra Seminar web page for information about other seminars in the series.

John Enyang John.Enyang@sydney.edu.au