## JOINT MATHEMATICS COLLOQUIUM

 The fundamental lemma and its applications

# David Kazhdan

Hebrew University, Jerusalem

### MIT

#### Tea from 4:00 - 4:30 p.m. in Room 2-290 Refreshments afterwards, in Room 2-290

 Abstract:   One of difficulties in the theory of harmonic analysis on reductive groups $G$ over local and global fields $F$ is the existence of elements $g',g'' \in G(F)$ which are conjugate over the algebraic closure $\bar F$ of $F$ but are not conjugate over $F$. The fundamental lemma shows that this failure can be corrected if one takes into account the existence of endoscopic groups. The fundamental lemma was recently proved by Ngo. I'll discuss the precise formulation and some applications of this result.

 Web page:  Alexandru I. Suciu Comments to:  alexsuciu@neu.edu Posted: September 2, 2008 URL: http://www.math.neu.edu/bhmn/kazhdan08.html