2 papers
math.QA2007
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…
math.RA2005
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…