20 Pages

The Coquasitriangular Hopf Algebra Associated to a Rigid Yang–Baxter Coalgebra

WithMitsuhiro Takeuchi

By means of braiding systems, it is shown that for a Yang‐Baxter coalgebra (C, σ) there is a coalgebra map of C into a Hopf algebra H such that σ extends to a coquasitriangular structure on H if and only if σ is skew‐invertible.