Factorisation structures of algebras and coalgebras
arXiv:math/9809063
Abstract
We consider the factorisation problem for bialgebras: when a bialgebra factorises as , where and are algebras and coalgebras (but not necessarly bialgebras). Given two maps $R: H\ot L\to L\ot H$ and $W:L\ot H\to H\ot L$, we introduce a product and give necessary and sufficient conditions for to be a bialgebra. It turns out that factorises as if and only if for some maps and . As examples of this product we recover constructions introduced by Majid and Radford. Also, some of the pointed Hopf algebras that were recently constructed bu Beattie, D\u asc\u alescu and Grünenfelder appear as special cases.
22 pages