**Title:** What is the Langlands program about?

**Abstract:** Rather than try to give a straight answer to this question, I will describe some of the mathematical problems that can be solved with the help of the Langlands program, or that fit under its umbrella. Most of these problems arise in number theory, but the applications as well as the methods involve geometry, representation theory, and harmonic analysis; there will even be a glimpse of quantum physics. I'll also give a sense of how the scope of the Langlands program is constantly expanding. If you leave the lecture with the impression that the Langlands program can be about anything at all, you won't be entirely mistaken.

**Bio:** Dr. Michael Harris is Professor of Mathematics at Columbia University and Emeritus Professor at Université Paris 7-Denis Diderot. He shared the Clay Research Award with Richard Taylor and received the Grand Prix Sophie Germain de l'Académie des Sciences, both in 2007. He was named to the Institut Universitaire de France in 2001 and directed the Automorphic Forms project of the Institut Mathématique de Jussieu from 2001-2007. He is a member of Academia Europea, a Fellow of the American Mathematical Society, a member of the American Academy of Arts and Sciences, and a member of the National Academy of Sciences. Harris's work has focused on the interplay between two approaches to number theory: the Langlands program, which reinterprets the Galois groups of number fields using methods borrowed from mathematical physics, and Grothendieck's theory of motives, which sees the same phenomena from the standpoint of topology.

### Location and Address

The Frick Fine Arts Building Room 125

### Speaker Information

Dr. Michael Harris