Idéaux différentiels
Integral differentials and Fermat congruences.
Integration of differential forms on schemes.
Irreducible Jacobian derivations in positive characteristic
We prove that an irreducible polynomial derivation in positive characteristic is a Jacobian derivation if and only if there exists an (n-1)-element p-basis of its ring of constants. In the case of two variables we characterize these derivations in terms of their divergence and some nontrivial constants.