On third homologies of groups and of quandles via the Dijkgraaf-Witten invariant and Inoue-Kabaya map
arXiv:1210.6540
Abstract
We propose a simple method to produce quandle cocycles from group cocycles, as a modification of Inoue-Kabaya chain map. We further show that, in respect to "universal central extended quandles", the chain map induces an isomorphism between their third homologies. For example, all Mochizuki's quandle 3-cocycles are shown to be derived from group cocycles of some non-abelian group. As an application, we calculate some -equivariant parts of the Dijkgraaf-Witten invariants of some cyclic branched covering spaces, via some cocycle invariant of links.
27 pages, 6 figures. This paper is a generalization and modification of the previous paper arXiv:1103.3839 [math.GT]