English

Generic representations, open parameters and ABV-packets for $p$-adic groups

Representation Theory 2024-04-12 v1 Algebraic Geometry Number Theory

Abstract

If π\pi is a representation of a pp-adic group G(F)G(F), and ϕ\phi is its Langlands parameter, can we use the moduli space of Langlands parameters to find a geometric property of ϕ\phi that will detect when π\pi is generic? In this paper we show that if GG is classical or if we assume the Kazhdan-Lusztig hypothesis for GG, then the answer is yes, and the property is that the orbit of ϕ\phi is open. We also propose an adaptation of Shahidi's enhanced genericity conjecture to ABV-packets: for every Langlands parameter ϕ\phi for a pp-adic group G(F)G(F), the ABV-packet ΠϕABV(G(F))\Pi^{\mathrm{ABV}}_\phi(G(F)) contains a generic representation if and only if the local adjoint L-function L(s,ϕ,Ad)L(s,\phi,\mathop{\text{Ad}}) is regular at s=1s=1, and show that this condition is equivalent to the "open parameter" condition above. We show that this genericity conjecture for ABV-packets follows from other standard conjectures and we verify its validity with the same conditions on GG. We show that, in this case, the ABV-packet for ϕ\phi coincides with its LL-packet. Finally, we prove Vogan's conjecture on AA-packets for tempered parameters.

Keywords

Cite

@article{arxiv.2404.07463,
  title  = {Generic representations, open parameters and ABV-packets for $p$-adic groups},
  author = {Clifton Cunningham and Sarah Dijols and Andrew Fiori and Qing Zhang},
  journal= {arXiv preprint arXiv:2404.07463},
  year   = {2024}
}
R2 v1 2026-06-28T15:50:41.384Z