Sequences of divided powers in irreducible, cocommutative Hopf algebras
Sequences of divided powers in irreducible, cocommutative Hopf algebras
In Hopf algebras with one grouplike element, M. E. Sweedler showed that over perfect fields, sequences of divided powers in cocommutative, irreducible Hopf algebras can be extended if certain “coheight” conditions are met. Here, we show that with a suitable generalization of “coheight", Sweedler’s theorem is true over nonperfect fields. …