Central motives on parahoric flag varieties
Robert Cass
University of Michigan, Ann Arbor, USA; Claremont McKenna College, USAThibaud van den Hove
Max Planck Institute for Mathematics, Bonn, GermanyJakob Scholbach
Università degli Studi di Padova, Italy

Abstract
We construct a refinement of Gaitsgory’s central functor for integral motivic sheaves, and show it preserves stratified Tate motives. Towards this end, we develop a reformulation of unipotent motivic nearby cycles, which also works over higher-dimensional bases. We moreover introduce Wakimoto motives and use them to show that our motivic central functor is t-exact. A decategorification of these functors yields a new approach to generic Hecke algebras for general parahorics.
Cite this article
Robert Cass, Thibaud van den Hove, Jakob Scholbach, Central motives on parahoric flag varieties. J. Eur. Math. Soc. (2025), published online first
DOI 10.4171/JEMS/1748