We write double-struck D for the crystalline Dieudonné module functor on p-divisible groups over a base S of characteristic p. The main results are: the full faithfulness of double-struck D over excellent local complete intersection schemes, and the full faithfulness of double-struck D up to isogeny when S is local excellent. We make use of the desingularization of D. Pospescu and the extension theorem of A.J. de Jong.
- Barsotti-Tate groups
- Crystalline Dieudonné module theory
- p-divisible groups