English

On parahoric $(\mathcal{G}, \mu)$-displays

Algebraic Geometry 2023-11-02 v1 Number Theory

Abstract

We develop tools to study spaces of pp-divisible groups and Abelian varieties with additional structure. More precisely, we extend the definition of parahoric (Dieudonn\'e) (G,μ)(\mathcal{G}, \mu)-displays given by Pappas to not necessarily pp-torsionfree base rings and also introduce the notion of an (m,n)(m, n)-truncated (G,μ)(\mathcal{G}, \mu)-display. Then we study the deformation theory of Dieudonn\'e (G,μ)(\mathcal{G}, \mu)-displays. As an application we realize the EKOR stratification of the special fiber of a Kisin-Pappas integral Shimura variety of Hodge type as the fibers of a smooth morphism into the algebraic stack of (2,1-rdt)(2, 1\text{-}\mathrm{rdt})-truncated (G,μ)(\mathcal{G}, \mu)-displays.

Keywords

Cite

@article{arxiv.2311.00127,
  title  = {On parahoric $(\mathcal{G}, \mu)$-displays},
  author = {Manuel Hoff},
  journal= {arXiv preprint arXiv:2311.00127},
  year   = {2023}
}

Comments

37 pages

R2 v1 2026-06-28T13:07:57.569Z