Déformations des p-groupes finis à un schéma formel sans p-torsion

Abstract

Let S be a scheme over a perfect field k of characteristic p > 0 and let W (k) be the ring of Witt vectors. Let T be a p-torsion free formal W (k)-scheme (for the p-adic topology). Let S → T be a closed W (k)-immersion defined by an ideal equipped with divided powers. This Note presents a classification of the liftings to T, of commutative and locally free S-group-schemes with rank a power of p, called finite p-groups.