## Examples of Self-Dual Hopf Algebras

J. Math. Sci. Univ. Tokyo
Vol. 6 (1999), No. 1, Page 181--215.

Andruskiewitsch, NicolÃ¡s ; Natale, Sonia
Examples of Self-Dual Hopf Algebras
We present a construction of non-trivial self-dual Hopf algebras over a field $\k$ obtained by a double extension process. The construction is not symmetric: it involves a 2-cocycle which, under a certain coboundary condition, disappears in the dual structure. We present several explicit examples in low dimensions; we recover families of examples introduced by S. Gelaki and R. Williams.