English

EKOR strata for Shimura varieties with parahoric level structure

Algebraic Geometry 2020-11-18 v2 Number Theory

Abstract

In this paper we study the geometry of reduction modulo pp of the Kisin-Pappas integral models for certain Shimura varieties of abelian type with parahoric level structure. We give some direct and geometric constructions for the EKOR strata on these Shimura varieties, using the theories of GG-zips and mixed characteristic local G\mathcal{G}-Shtukas. We establish several basic properties of these strata, including the smoothness, dimension formula, and closure relation. Moreover, we apply our results to the study of Newton strata and central leaves on these Shimura varieties.

Keywords

Cite

@article{arxiv.1910.07785,
  title  = {EKOR strata for Shimura varieties with parahoric level structure},
  author = {Xu Shen and Chia-Fu Yu and Chao Zhang},
  journal= {arXiv preprint arXiv:1910.07785},
  year   = {2020}
}

Comments

84 pages; minor revisons; to appear in Duke Math. J

R2 v1 2026-06-23T11:46:27.055Z