In mathematics, a braided Hopf algebra is a Hopf algebra in a braided monoidal category. The most common braided Hopf algebras are objects in a Yetter–Drinfeld category of a Hopf algebra H, particularly the Nichols algebra of a braided vectorspace in that category.
The notion should not be confused with quasitriangular Hopf algebra.
Let H be a Hopf algebra over a field k, and assume that the antipode of H is bijective. A Yetter–Drinfeld module R over H is called a braided bialgebra in the Yetter–Drinfeld category if
A braided bialgebra in is called a braided Hopf algebra, if there is a morphism of Yetter–Drinfeld modules such that