The geometric Langlands correspondence has been interpreted as the mirror symmetry of the Hitchin fibrations for two dual reductive groups. This mirror symmetry, in turn, reduces to T–duality on the generic Hitchin fibers, which are smooth tori. In this paper we study what happens when the Hitchin fibers on the B-model side develop orbifold singularities. These singularities correspond to local...

Let E/F be a finite and Galois extension of non-archimedean local fields. G connected reductive group defined over E let M:=RE/FG the F obtained by Weil restriction scalars. We investigate depth, enhanced Langlands correspondence, in transition from G(E) to M(F). obtain depth-comparison formula for Weil-restricted groups.

The geometric Langlands correspondence has been interpreted as the mirror symmetry of the Hitchin fibrations for two dual reductive groups. This mirror symmetry, in turn, reduces to T–duality on the generic Hitchin fibers, which are smooth tori. In this paper we study what happens when the Hitchin fibers on the B-model side develop orbifold singularities. These singularities correspond to local...

Let G = Sp(2n,C) be a complex symplectic group. We introduce a G× (C)-variety Nl, which we call the l-exotic nilpotent cone. Then, we realize the Hecke algebra H of type C (1) n with three parameters via equivariant algebraic K-theory in terms of the geometry of N2. This enables us to establish a Deligne-Langlands type classification of simple H-modules under a mild assumption on parameters. As...

The cohomology of the Lubin-Tate tower is known to realize the local Langlands correspondence for GL(n) over a nonarchimedean local field. In this article we make progress towards a purely local proof of this fact. To wit, we find a family of formal schemes V such that the generic fiber of V is isomorphic to an open subset of Lubin-Tate space at infinite level, and such that the middle cohomolo...

Let G be a unitary group over a totally real field, and X a Shimura variety associated to G. For certain primes p of good reduction for X, we construct cycles Xτ0,i on the characteristic p fiber of X. These cycles are defined as the loci on which the Verschiebung map has small rank on particular pieces of the Lie algebra of the universal abelian variety on X. The geometry of these cycles turns ...