Mathematics – Category Theory
Scientific paper
2011-06-03
Mathematics
Category Theory
13 pages
Scientific paper
We classify extensions of a group $G$ by a braided 2-group $\mathcal{B}$ as defined by Drinfeld, Gelaki, Nikshych, and Ostrik. We describe such extensions as homotopy classes of maps from the classifying space of $G$ to the classifying space of the 3-group of braided $\mathcal{B}$-bitorsors. The Postnikov system of the latter space contains a generalization of the classical Pontryagin square to the setting of local coefficients, which has been previously discussed by Baues and more recently, in a setting close to ours, by Etingof, Nikshych, and Ostrik. We give an explicit cochain-level description of this Pontryagin square for group cohomology.
No associations
LandOfFree
Extensions of groups by braided 2-groups does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Extensions of groups by braided 2-groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extensions of groups by braided 2-groups will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-6993