English

Grothendieck group of the stack of G-Zips

Algebraic Geometry 2024-10-03 v1

Abstract

Given a connected reductive group G over the finite field of order p and a cocharacter of G over the algebraic closure of the finite field, we can define G-Zips. The collection of these G-Zips form an algebraic stack which is a stack quotient of G. In this paper we study the K-theory rings of this quotient stack, focusing on the Grothendieck group. Under the additional assumption that the derived group is simply connected, the Grothendieck group is described as a quotient of the representation ring of the Levi subgroup centralising the cocharacter.

Keywords

Cite

@article{arxiv.2410.01547,
  title  = {Grothendieck group of the stack of G-Zips},
  author = {Simon Cooper},
  journal= {arXiv preprint arXiv:2410.01547},
  year   = {2024}
}