English

On integral local Shimura varieties

Algebraic Geometry 2026-01-21 v4 Number Theory Representation Theory

Abstract

We give a construction of "integral local Shimura varieties" which are formal schemes that generalize the well-known integral models of the Drinfeld pp-adic upper half spaces. The construction applies to all classical groups, at least for odd pp. These formal schemes also generalize the formal schemes defined by Rapoport-Zink via moduli of pp-divisible groups, and are characterized purely in group-theoretic terms. More precisely, for a local pp-adic Shimura datum (G,b,μ)(G, b, \mu) and a quasi-parahoric group scheme G\mathcal G for GG, Scholze has defined a functor on perfectoid spaces which parametrizes pp-adic shtukas. He conjectured that this functor is representable by a normal formal scheme which is locally formally of finite type and flat over OE˘O_{\breve E}. Scholze-Weinstein proved this conjecture when (G,b,μ)(G, b, \mu) is of (P)EL type by using Rapoport-Zink formal schemes. We prove this conjecture for any (G,μ)(G, \mu) of abelian type when p2p\neq 2, and when p=2p=2 and GG is of type AA or CC. We also relate the generic fiber of this formal scheme to the local Shimura variety, a rigid-analytic space attached by Scholze to (G,b,μ,G)(G, b, \mu, {\mathcal G}).

Keywords

Cite

@article{arxiv.2204.02829,
  title  = {On integral local Shimura varieties},
  author = {Georgios Pappas and Michael Rapoport},
  journal= {arXiv preprint arXiv:2204.02829},
  year   = {2026}
}

Comments

61 pages, final version

R2 v1 2026-06-24T10:39:52.823Z