Platonic and alternatinc 2-groups
Category Theory
2018-02-15 v1 Algebraic Topology
Abstract
We recall Schur's work on universal central extensions and develop the analogous theory for categorical extensions of groups. We prove that the String 2-groups are universal in this sense and study in detail their restrictions to the finite subgroups of the Spin groups. Of particular interest are subgroups of the 3-sphere Spin(3), as well as the spin double covers of the alternating groups, whose categorical extensions turn out to be governed by the stable 3-stem.
Cite
@article{arxiv.1605.09192,
title = {Platonic and alternatinc 2-groups},
author = {Narthana Epa and Nora Ganter},
journal= {arXiv preprint arXiv:1605.09192},
year = {2018}
}
Comments
25 pages