GAUGE DEFORMATIONS FOR HOPF ALGEBRAS WITH THE DUAL CHEVALLEY PROPERTY

Let A be a Hopf algebra over a field K of characteristic zero such that its coradical H is a finite-dimensional sub-Hopf algebra. Our main theorem shows that there is a gauge transformation zeta on A such that A(zeta) congruent to Q#H where A(zeta) is the dual quasi-bialgebra obtained from A by twisting its multiplication by zeta, Q is a connected dual quasi-bialgebra in (HYD)-Y-H and Q#H is a dual quasi-bialgebra called the bosonization of Q by H.