Mackey formulas for smooth stacks
Abstract
We study parabolic induction and restriction functors on derived categories of constructible sheaves, D-modules, and other sheaf theories on smooth stacks with good or adequate moduli spaces. We prove a commutation rule between them in the form of a Mackey filtration, indexed by the set of relative positions of two elements in the component lattice, a combinatorial structure that characterizes inductions and restrictions on a given stack. This generalizes similar results for adjoint quotient stacks studied in generalized Springer theory and the theory of character sheaves, and for stacks of quiver representations appearing in Lusztig's categorification of quantum groups. We also apply our result to the stack of semistable principal bundles on a curve, as a first step towards Mackey formulas in geometric Langlands correspondences.
Related
- Base change and the Mackey formula in Deligne--Lusztig theory
- Constant spectral Mackey functors and the equivariant Steenrod algebra
- Igusa stacks and the cohomology of Shimura varieties
- On the variation of slopes over moduli stacks of Galois representations
- Fundamental groups of proper algebraic stacks are finitely presented
BibTeX
@misc{bu2026mackey,
title = {{Mackey formulas for smooth stacks}},
author = {Chenjing Bu and Lucien Hennecart},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.29970},
eprint = {2610.29970},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.29970},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Mackey formulas for smooth stacks
AU - Chenjing Bu
AU - Lucien Hennecart
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2610.29970
UR - https://arxiv.org/abs/2610.29970
AB - We study parabolic induction and restriction functors on derived categories of constructible sheaves, D-modules, and other sheaf theories on smooth stacks with good or adequate moduli spaces. We prove a commutation rule between them in the form of a Mackey filtration, indexed by the set of relative positions of two elements in the component lattice, a combinatorial structure that characterizes inductions and restrictions on a given stack. This generalizes similar results for adjoint quotient stacks studied in generalized Springer theory and the theory of character sheaves, and for stacks of quiver representations appearing in Lusztig's categorification of quantum groups. We also apply our result to the stack of semistable principal bundles on a curve, as a first step towards Mackey formulas in geometric Langlands correspondences.
ER -