Sheared displays and $p$-divisible groups
Manuel Hoff, Eike Lau
TL;DR
This work develops a Dieudonné theory for $p$-divisible groups via sheared Witt vectors ${}^sW(R)$, proving an equivalence between all $p$-divisible groups and plain sheared displays and thereby extending classical displays to the full BT category. It builds a comprehensive framework of frames and windows in the sheared setting, constructs a Tate-module functor and a crystalline Dieudonné functor ${}^{s\!}D_R$, and establishes descent results across fpqc, syntomic, and $p^\infty$-root topologies. The approach yields a robust, mostly non-higher-categorical path to the Dieudonné theory in the sheared context, aligns with known results in the perfect-reduction case, and provides a platform to address Drinfeld’s conjectures and related prismatic perspectives, including $p=2$ considerations via crystalline techniques. Overall, the paper unifies displays and BT groups through sheared structures, enabling explicit constructions, deformation analyses, and dualities that underpin a full Dieudonné equivalence in broad generality.
Abstract
We develop a Dieudonné theory for $p$-divisible groups using sheared Witt vectors.
