Compatibility of $F$-isocrystals on adjoint Shimura varieties

Abstract

In this article, we extend past results of the last two authors to include compatibility of canonical $\ell$-adic local systems and canonical $F$-isocrystals on adjoint Shimura varieties in the superrigid regime. Our method relies on the crystallinity of canonical $p$-adic local systems due to Esnault--Groechenig as well as Margulis superrigidity and the crystalline-to-étale companion construction of Drinfeld, Abe--Esnault, and Kedlaya.

arXiv comment28 pages. The main argument is slightly simplified, and the exposition now contains a detailed explanation of Esnault--Groechenig's crystallinity argument in our setting. Numerous other minor changes. Comments welcome!