The prismatic realization functor for Shimura varieties of abelian type
Naoki Imai, Hiroki Kato, Alex Youcis
TL;DR
The paper develops a comprehensive prismatic framework for Shimura varieties of abelian type by constructing a prismatic F-gauge realization of the universal $ ext{G}( ext{Z}_p)$-local system and embedding it into a syntomic context. It establishes integral canonical models as syntomic/prismatic objects characterized by a universal deformation space and a Serre--Tate–type deformation theorem, mirroring Drinfeld’s motivic perspective in the abelian-type setting. It then connects these prismatic realizations with existing étale, crystalline, and cohomological structures, proving compatibility with Lovering’s crystalline picture and deriving cohomological consequences such as crystalline lattices and syntomic refinements. The results yield a robust, motivic viewpoint on the $p$-adic geometry of Shimura varieties, provide a syntomic characterization of integral models, and illuminate extensions to G-zips and related moduli problems with potential Langlands-theoretic implications.
Abstract
For the integral canonical model $\mathscr{S}_{\mathsf{K}^p}$ of a Shimura variety $\mathrm{Sh}_{\mathsf{K}_0\mathsf{K}^p}(\mathbf{G},\mathbf{X})$ of abelian type at hyperspecial level $K_0=\mathcal{G}(\mathbb{Z}_p)$, we construct a prismatic $F$-gauge model for the `universal' $\mathcal{G}(\mathbb{Z}_p)$-local system on $\mathrm{Sh}_{\mathsf{K}_0\mathsf{K}^p}(\mathbf{G},\mathbf{X})$. We use this to obtain several new results about the $p$-adic geometry of Shimura varieties, notably an abelian-type analogue of the Serre--Tate deformation theorem (realizing an expectation of Drinfeld in the abelian-type case) and a prismatic characterization of these models at individual level.
