SMS scnews item created by Anthony Henderson at Fri 24 Aug 2007 1544
Type: Seminar
Distribution: World
Expiry: 31 Aug 2007
Calendar1: 31 Aug 2007 1205-1255
CalLoc1: Carslaw 373
CalTitle1: Algebra Seminar: Parkinson -- Path combinatorics in loop groups
Auth: anthonyh@asti.maths.usyd.edu.au

Algebra Seminar

Path combinatorics in loop groups

James Parkinson

31st August, 12:05-12:55pm, Carslaw 373


Abstract

In this talk we discuss some joint work with Arun Ram on the combinatorics of the loop group G=G(k((t))), where G(.) is a Kac-Moody-Tits group functor. The points of the affine flag variety G/I (with I an Iwahori subgroup) can be indexed by generalised labeled Littelmann paths, which control various double coset decompositions of G.

In the case when G(.) is of finite type this model can be made very explicit, since the loop group G=G(k((t))) is (essentially) the affine Kac-Moody group. In this case the combinatorics of labeled Littelmann paths is very closely related to retractions in the affine building.


After the seminar we will take the speaker to lunch.

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

Anthony Henderson anthonyh@maths.usyd.edu.au.