The local Langlands correspondence matches irreducible representations of a reductive p-adic group G(F ) with enhanced L-parameters. It is conjectured by Hellmann and Zhu that it can be categorified. Then it should become a fully faithful functor from a derived category of representations to a derived category of equivariant sheaves on some variety of L-parameters.We approach this conjecture in the case of finite length G(F )-representations. Then it runs via graded Hecke algebras associated to Bernstein components or to enhanced L-parameters. Here we work with graded Hecke algebras H on the Galois side, those can be constructed entirely in terms of a complex reductive group, endowed with data from L-parameters.We fix an arbitrary central character (σ, r) of H (which encodes the image of Frobenius by an L-parameter). That leads to a variety g σ,rN of nilpotent elements in the Lie algebra of G (possibilities for the monodromy operator from an Lparameter) and to a complex of equivariant constructible sheaves KN,σ,r on g σ,r N . We relate the (derived) endomorphism algebra of (g σ,r N , KN,σ,r) to a localization of H, which yields an equivalence between the appropriate categories of finite length modules of these algebras. From there we construct a fully faithful functor between:• the bounded derived category of finite length H-modules specified by the central character (σ, r), • the equivariant bounded derived category of constructible sheaves on g σ,rN . Also, we explicitly determine the images of standard modules under this functor. We expect that these results pave the way for more general instances of the aforementioned conjectural extension of the local Langlands correspondence.
ContentsGRADED HECKE ALGEBRAS AND EQUIVARIANT CONSTRUCTIBLE SHEAVES 6. Structure of the localized complexes K N,σ,r 31 7. A functor from sheaves to Hecke algebra modules 34 8. A functor from Hecke algebra modules to sheaves 39 9. Twisted graded Hecke algebras with a fixed r 42 Appendix A. Compatibility with parabolic induction 45 Appendix B. Localization in equivariant cohomology 52 References