Commutator-central maps, brace blocks, and {H}opf-{G}alois structures on {G}alois extensions

Alan Koch

Let $G$ be a nonabelian group. We show how a collection of compatible endomorphisms ${\psi }_i:G\to G$ such that ${\psi }_i([G,G])\le Z(G)$ for all $i$ allows us to construct a family of bi-sk…