On Cores in Yetter-Drinfel'd Hopf Algebras
arXiv:1908.07620
Abstract
By constructing explicit examples, we show that the core of a group-like element in a cocommutative cosemisimple Yetter-Drinfel'd Hopf algebra over the group ring of a finite abelian group is not always completely trivial.
arXiv comment37 pages. See also https://www.math.mun.ca/~sommerh/