GASC Seminar

 
Affine Weyl groups in K-theory and representation theory

 

Alexander Postnikov

MIT
 
 

Northeastern University

Monday, October 6, 2003


 

Talk at 1:30 p.m. in 509 Lake Hall


 

Abstract:   We present a simple model for characters of irreducible representations of semi-simple Lie groups and, more generally, for Demazure characters. This is a combinatorial counterpart of the Littelmann path model. We give an explicit combinatorial Chevalley-type formula for equivariant K-theory of generalized flag manifolds G/B. The construction is given in terms of alcove paths, which correspond to decompositions of affine Weyl group elements, and saturated chains in the Bruhat order on the usual Weyl group. A key ingredient is a certain R-matrix that satisfies the Yang-Baxter equation.

     This is joint work with Cristian Lenart.



Here are some directions to Northeastern University. Lake Hall can be best accessed from the entrance on the corner of Greenleaf Street and Leon Street.



GASC Seminar Home Page Posted: September 13, 2003.   Comments to:  a.suciu@neu.edu  
Web page:  Alexandru I. Suciu  URL: http://www.math.neu.edu/gasc/abs/postnikov03.html