$p$-adic hyperbolicity for Shimura varieties and period images
Abstract
We prove that Shimura varieties and geometric period images satisfy a -adic extension property for large enough primes . More precisely, let denote the inclusion of the closed punctured unit disc in the closed unit disc. Let be either a Shimura variety or a geometric period image with torsion-free level structure. Let be a discretely valued -adic field containing the number field of definition of , where is a large enough prime. Then, any rigid-analytic map defined over whose image intersects the good reduction locus of (with respect to an integral canonical model) extends to a map . We note that this hypothesis is vacuous if is proper. We also deduce an application to algebraicity of rigid-analytic maps. Our methods also apply to the more general situation of the rigid generic fiber of formal schemes admitting Fontaine-Laffaile modules which satisfy certain positivity conditions.
Keywords
Cite
@article{arxiv.2509.25461,
title = {$p$-adic hyperbolicity for Shimura varieties and period images},
author = {Benjamin Bakker and Abhishek Oswal and Ananth N. Shankar and Zijian Yao},
journal= {arXiv preprint arXiv:2509.25461},
year = {2026}
}
Comments
We have now removed a good-reduction hypothesis for Shimura varieties