We give a geometric proof of a “parity-switching” phenomenon that occurs when applying the local Langlands and Jacquet–Langlands correspondence to a self-dual supercuspidal representation ofGL(n) over a nonarchimedean local field. This turns out to reflect a duality property on the self-dual part of the `-adic étale cohomology of the Lubin–Tate tower.

In these notes, based on my lectures at the FRG workshop on “Characters, Liftings, and Types” at American University in June 2012, I give an introduction to the conjectural Local Langlands Correspondence (LLC), for split semisimple groups over a nonarchimedean local field. This conjecture has been evolving over the past 45 years (with roots going back much further) to the point that today’s sta...

Representations of affine and graded Hecke algebras associated to Weyl groups play an important role in the Langlands correspondence for the admissible representations of a reductive p-adic group. We work in the general setting of a graded Hecke algebra associated to any real reflection group with arbitrary parameters. In this setting we provide a classification of all irreducible representatio...

Let T be a split torus over local or global function field. The theory of BrylinskiDeligne gives rise to the metaplectic central extensions of T by a finite cyclic group. The representation theory of these metaplectic tori has been developed to some extent in the works of M. Weissman, G. Savin, W. T. Gan, P. McNamara and others. In this paper we propose a geometrization of this theory in the fr...

In the context of the local Langlands philosopy for R, Adams, Barbasch and Vogan describe a bijection between the simple Harish-Chandra modules for a real reductive group G(R) and the space of “complete geometric parameters”—a space of equivariant local systems on a variety on which the Langlands-dual of G(R) acts. By a conjecture of Soergel, this bijection can be enhanced to an equivalence of ...

The main purpose of this paper is to produce a geometric realization for the tempered modules of the affine Hecke algebra of type C (1) n with arbitrary, non-root of unity, unequal parameters, using the exotic DeligneLanglands correspondence ([Ka08a]). Our classification has several applications to the Weyl group module structure of the tempered Hecke algebra modules. In particular, we provide ...

The local Langlands conjectures imply that to every generic supercuspidal irreducible representation of G2 over a p-adic field, one can associate a generic supercuspidal irreducible representation of either PGSp6 orPGL3. We prove this conjectural dichotomy, demonstrating a precise correspondence between certain representations of G2 and other representations of PGSp6 and PGL3 when p 6= 2. This ...

Abstract We study the Picard–Lefschetz formula for Siegel modular threefolds of paramodular level and prove weight-monodromy conjecture its middle degree inner cohomology. give some applications to Langlands programme: using Rapoport-Zink uniformisation supersingular locus special fiber, we construct a geometric Jacquet–Langlands correspondence between $${\text {GSp}}_4$$ <mml:math xmlns:mml="h...