Braided Hopf algebras arising from matched pairs of groups

Abstract

Let k be a field. Let also (F, G) be a matched pair of groups. We give necessary and sufficient conditions on a pair (σ, τ) of 2-cocycles in order that the crossed product algebra and the crossed coproduct coalgebra k^G{}^τ#_σ kF combine into a braided Hopf algebra. We also discuss diagonal realizations of such braided Hopf algebras in the category of Yetter-Drinfeld modules over a finite group.

25 pages, to appear in J. of Pure and Applied Algebra, appendix added at the end of the paper by suggestion of the referee