4 papers
Non-abelian Hopf Cohomology of Radford products
P. Nuss, M. Wambst
We study the non-abelian Hopf cohomology theory of Radford products with coefficients in a comodule algebra. We show that these sets can be expressed in terms of the non-abelian Ho…
Non-Abelian Hopf Cohomology II -- the General Case --
Philippe Nuss, Marc Wambst
We introduce and study non-abelian cohomology sets of Hopf algebras with coefficients in Hopf comodule algebras. We prove that these sets generalize as well Serre's non-abelian gro…
Non-Abelian Hopf Cohomology
Philippe Nuss, Marc Wambst
We introduce non-abelian cohomology sets of Hopf algebras with coefficients in Hopf modules. We prove that these sets generalize Serre's non-abelian group cohomology theory. Using…
Galois-Azumaya Extensions and the Brauer-Galois Group of a Commutative Ring
Philippe Nuss
We attach to any commutative ring R a subgroup of the Brauer group of R, called the Brauer-Galois group of R. Its elements are the classes of the Azumaya R-algebras which can be re…