Higher nearby cycles and central sheaves on affine flag varieties

Pramod N. Achar and Simon Riche

Journal of Singularities
volume 27 (2024), 1-30

Received: 19 May 2023. In revised form: 31 January 2024

DOI: 10.5427/jsing.2024.27a


Abstract:

In this paper we generalize and study a notion of (unipotent) nearby cycles over a higher dimensional base based on Beilinson's description of unipotent nearby cycles, following an idea of Gaitsgory. This generalization, in the setting of affine Grassmannians, is required in recent work of Bezrukavnikov-Braverman-Finkelberg-Kazhdan.


Author(s) information:

Pramod N. Achar
Department of Mathematics
Louisiana State University
Baton Rouge, LA 70803 U.S.A.
email: pramod.achar@math.lsu.edu

Simon Riche
Université Clermont Auvergne
CNRS, LMBP
F-63000 Clermont-Ferrand, France
email: simon.riche@uca.fr