English

Parabolic geometric Eisenstein series and constant term functors

Representation Theory 2025-07-30 v2 Algebraic Geometry

Abstract

We prove a compatibility between parabolic restriction of Whittaker sheaves and restriction of representations under the geometric Casselman-Shalika equivalence. To do this, we establish various Hecke structures on geometric Eisenstein series functors, generalizing results of Braverman-Gaitsgory in the case of a principal parabolic. Moreover, we relate compactified and non-compactified geometric Eisenstein series functors via Koszul duality. We sketch a proof that the spectral-to-automorphic geometric Langlands functor commutes with constant term functors.

Keywords

Cite

@article{arxiv.2507.13930,
  title  = {Parabolic geometric Eisenstein series and constant term functors},
  author = {Joakim Faergeman and Andreas Hayash},
  journal= {arXiv preprint arXiv:2507.13930},
  year   = {2025}
}

Comments

Minor edits to the introduction and acknowledgements section. Comments are very welcome!

R2 v1 2026-07-01T04:07:48.589Z