PreprintCC BY 4.0arXiv
Parahoric motivic Hecke categories in equal and mixed characteristic
Abstract
We study constructible ℤ[1/p]-linear étale motives on parahoric Hecke stacks associated with quasi-split tamely ramified reductive groups. We prove a canonical equivalence between their equal-characteristic and Witt-vector incarnations that is monoidal with respect to convolution. This extends Bando's comparison, which concerns split reductive groups and constructible étale sheaves. The proof combines the study of a family of affine Grassmannians for Pappas--Zhu group schemes with the use of the motivic nearby cycles functor.
Related
BibTeX
@misc{bartling2026parahoric,
title = {{Parahoric motivic Hecke categories in equal and mixed characteristic}},
author = {Sebastian Bartling and Rızacan Çiloğlu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.05123},
eprint = {2609.05123},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.05123},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Parahoric motivic Hecke categories in equal and mixed characteristic
AU - Sebastian Bartling
AU - Rızacan Çiloğlu
PY - 2026
DA - 2026/09/04
PB - arXiv
DO - 10.48550/arxiv.2609.05123
UR - https://arxiv.org/abs/2609.05123
AB - We study constructible ℤ[1/p]-linear étale motives on parahoric Hecke stacks associated with quasi-split tamely ramified reductive groups. We prove a canonical equivalence between their equal-characteristic and Witt-vector incarnations that is monoidal with respect to convolution. This extends Bando's comparison, which concerns split reductive groups and constructible étale sheaves. The proof combines the study of a family of affine Grassmannians for Pappas--Zhu group schemes with the use of the motivic nearby cycles functor.
ER -