English

Airy sheaves for reductive groups

Algebraic Geometry 2024-02-06 v1 Number Theory Representation Theory

Abstract

We construct a class of \ell-adic local systems on A1\mathbb{A}^1 that generalizes the Airy sheaves defined by N. Katz to reductive groups. These sheaves are finite field analogues of generalizations of the classical Airy equation y(z)=zy(z)y''(z)=zy(z). We employ the geometric Langlands correspondence to construct the sought-after local systems as eigenvalues of certain rigid Hecke eigensheaves, following the methods developed by Heinloth, Ng\^o and Yun. The construction is motivated by a special case of Adler and Yu's construction of tame supercuspidal representations. The representations that we consider can be viewed as deeper analogues of simple supercuspidals. For GLn\mathrm{GL}_n, we compute the Frobenius trace of the local systems in question and show that they agree with Katz's Airy sheaves. We make precise conjectures about the ramification behaviour of the local systems at \infty. These conjectures in particular imply cohomological rigidity of Airy sheaves.

Keywords

Cite

@article{arxiv.2111.02256,
  title  = {Airy sheaves for reductive groups},
  author = {Konstantin Jakob and Masoud Kamgarpour and Lingfei Yi},
  journal= {arXiv preprint arXiv:2111.02256},
  year   = {2024}
}

Comments

30 pages

R2 v1 2026-06-24T07:24:31.507Z