Seminars Sorted by Series

Most metals and ceramics are composed of many individual crystals fused together. Foams are composed of many individual bubbles. In both cases, as time passes, the picture evolves and coarsens. The average size of a crystal or a bubble increases....

I will review Hitchin's construction of the spectral curves and discuss the relation with endoscopy.

I will describe the construction the symmetries of the Hitchin fibration and the way in which the endoscopic groups appear in the variation of these symmetry groups.

I will formulate the geometric interpretation of the stabilization of (a part) of the geometric side of the trace formula for Lie algebra. The SL(2) case will be discussed in some details.

The first half of this talk will be devoted to describing Arthur's variant of the fundamental lemma for weighted orbital integrals. The second half will discuss a proof of the weighted fundamental lemma for Sp(4).

We give a geometric analog of the Weil representation of the metaplectic group, placing it in the framework of the geometric Langlands program. For a smooth projective curve X we introduce an algebraic stack \tilde\Bun_G of metaplectic bundles on X...

I will attempt to summarize the results in the following two papers, jointly written with R. Kottwitz and R. MacPherson: "Equivariant cohomology, Koszul duality, and the localization theorem" (Inv. Math., 1998) and "Homology of affine Springer...

I will continue the talk on October 20th. I will formulate the geometric interpretation of the stabilization of (a part) of the geometric side of the trace formula for Lie algebra. The SL(2) case will be discussed in some details.

In a recent article, Waldspurger proved that the fundamental lemma for Lie algebras doesn't depend on the characteristic of the base field (among other things...). In this talk, I would like to explain some ideas of the proof of that result.

In a series of lectures, I will discuss the proof of Langlands-Shelstad's fundamental lemma for Lie algebra. An overview will be given in the first lecture. In the following lectures, I will focuse on certain aspects of the geometry of the Hitchin...

The cohomology of arithmetic groups (with real coefficients) is usually understood in terms of automorphic forms. Such methods, however, fail (at least naively) to capture information about torsion classes in integral cohomology. We discuss a...

The cohomology of arithmetic groups (with real coefficients) is usually understood in terms of automorphic forms. Such methods, however, fail (at least naively) to capture information about torsion classes in integral cohomology. We discuss a...

I will outline the proof of various cases of the local-global compatibility statement alluded to in the title, and also explain its applications to the Fontaine—Mazur conjecture, and to a conjecture of Kisin.

I will outline the proof of various cases of the local-global compatibility statement alluded to in the title, and also explain its applications to the Fontaine--Mazur conjecture, and to a conjecture of Kisin.

Let $\overline K$ be an algebraic closure of a $p$-adic field $K$. We construct a separated noetherian regular scheme $X$ (nonalgebraic) equipped with an action of $G_K=\mathrm{Gal}(\overline{K}/K)$. We have $H^0(X, O_X) = Q_p$ and $H_1(X, O_X) = 0$...

Let p be an odd prime number and let F be a totally real field. Let F_cyc be the cyclotomic extension of F generated by the roots of unity of order a power of p . From the maximal abelian extension of F_cyc which is unramified (resp. unramified...

Let p and l be two distinct prime numbers, and fix a positive integer d . I will explain how the F_l-cohomology complex of the Lubin-Tate tower of height d of a p-adic field K realizes mod l versions of both the semi-simple Langlands correspondence...

The usual Katz-Mazur model for the modular curve X(p^n) has horribly singular reduction. For large n there isn't any model of X(p^n) which has good reduction, but after extending the base one can at least find a semistable model, which means that...

We will discuss a generalisation of Serre's conjecture on the possible weights of modular mod p Galois representations for a broad class of reductive groups. In good cases (essentially when the Galois representation is tamely ramified at p) the...

Let F be a locally compact non-Archimedean field, p its residue characteristic and G a connected reductive algebraic group over F . The classical Satake isomorphism describes the Hecke algebra (over the field of complex numbers) of double classes in...

Some automorphic forms, despite the fact they are algebraic, do not have any interpretation as cohomology classes on a Shimura variety: therefore nothing is known at present on their expected arithmetic properties. I shall explain how such forms...

Picard moduli spaces parametrize principally polarized abelian varieties with complex multiplication by the ring of integers in an imaginary-quadratic field. The loci where the abelian varieties split off an elliptic curve in a controlled way are...

We give a new local characterization of the Local Langlands Correspondence, using deformation spaces of p-divisible groups, and show its existence by a comparison with the cohomology of some Shimura varieties. This reproves results of Harris-Taylor...

I will describe a joint work with Barnet-Lamb, Gee and Taylor where we establish a potential automorphy result for compatible systems of Galois representations over totally real and CM fields. This is deduced from a potential automorphy result for...