4 papers
The Brauer group of modified supergroup algebras
Giovanna Carnovale
The computation of the Brauer group BM of modified supergroup algebras is perfomed, yielding, in particular, the computation of the Brauer group of all finite-dimensional triangula…
Lazy cohomology: an analogue of the Schur multiplier for arbitrary Hopf algebras
Julien Bichon, Giovanna Carnovale
We propose a detailed systematic study of a group H^2_L(A) associated, by elementary means of lazy 2-cocycles, to any Hopf algebra A. This group was introduced by Schauenburg (with…
When is a cleft extension Azumaya?
Giovanna Carnovale
We show which -cleft extensions $k#_σH^{op}$ of the base field for a dual quasitriangular Hopf algebra are -Azumaya. The result is given in terms of bijecti…
Cocycle twisting of E(n)-module algebras and applications to the Brauer group
G. Carnovale, J. Cuadra
We classify the orbits of coquasi-triangular structures for the Hopf algebra E(n) under the action of lazy cocycles and the Hopf automorphism group. This is applied to detect subgr…