William Fulton : Character formulas

Posted by , part of the Departmental Colloquium.

At

Oct. 16, 2009, 3 p.m.

In

Lecture Center D4

Abstract

In this expository talk, we show how a Riemann-Roch formalism leads to a simple proof of a general formula for restrictions of equivariant line bundles to fixed points. On homogeneous varieties it gives Weyl's character formula, and on toric varieties it gives Brion's formula for lattice points in polytopes. This is based on ideas of George Quart in the 1970's and recent conversations with Bill Graham.