×

Semisimple Hopf algebras of dimension \(6\), \(8\). (English) Zbl 0839.16036

The author determines the isomorphism classes of semisimple Hopf algebras \(A\) of dimension 6, 8 over an algebraically closed field \(k\) such that \((\dim A)1\neq 0\). As conclusions, he shows that such Hopf algebras of dimension 6 consist of 3 isomorphism classes represented by \(kC_6\), \(kS_3\), \(k^{S_3}\) where \(S_3\) denotes the symmetric group of degree 3 and \(C_6\) denotes the cyclic group of order 6; such Hopf algebras of dimension 8 consist of 8 isomorphism classes represented by \(k(C_2\times (C_2\times C_2))\), \(k(C_2\times C_4)\), \(kC_8\), \(kD\), \(k^D\), \(kQ\), \(k^Q\), \(A\), where \(D= C_4\rtimes C_2\) is the dihedral group, \(Q\) is the quaternion group. Among these, \(A\) is the unique one that is neither commutative nor cocommutative and is generated as a Hopf algebra by \(x\), \(y\), \(z\) with some relations. To show this, an important role is played by the biproduct and the bicrossed product.
The classification of semisimple Hopf algebras of various small dimensions is an important subject. The author and some other mathematicians have obtained many results. The author is planning to go on with this work and in particular to complete the classification of all semisimple Hopf algebras of dimensions up to 31.
Reviewer: Li Fang (Nanjing)

MSC:

16W30 Hopf algebras (associative rings and algebras) (MSC2000)
16P10 Finite rings and finite-dimensional associative algebras
Full Text: DOI

References:

[1] Doi, Y.; Takeuchi, M., Hopf-Galois extensions of algebras, the Miyashita-Ulbrich actions, and Azumaya algebras, Journal of Algebra, 121, 488-516 (1989) · Zbl 0675.16004 · doi:10.1016/0021-8693(89)90079-3
[2] [H1] I. Hofstetter,Erweiterungen von Hopf-Algebren und ihre kohomologische Beschreibung, Dissertation, Universität München, 1990.
[3] Hofstetter, I., Extensions of Hopf algebras and their cohomological description, Journal of Algebra, 164, 264-298 (1994) · Zbl 0819.16032 · doi:10.1006/jabr.1994.1063
[4] [LR] R. Larson and D. Radford,Semisimple Hopf algebras, Journal of Algebra, to appear. · Zbl 0822.16034
[5] Masuoka, A., Freeness of Hopf algebras over coideal subalgebras, Communications in Algebra, 20, 1353-1373 (1992) · Zbl 0804.16040 · doi:10.1080/00927879208824408
[6] Masuoka, A.; Doi, Y., Generalization of cleft comodule algebras, Communications in Algebra, 20, 3703-3721 (1992) · Zbl 0806.16041 · doi:10.1080/00927879208824536
[7] Nichols, W.; Zoeller, M., A Hopf algebra freeness theorem, American Journal of Mathematics, 111, 381-385 (1989) · Zbl 0672.16006 · doi:10.2307/2374514
[8] Passman, D., Infinite Crossed Products (1989), London: Academic Press, London · Zbl 0662.16001
[9] Radford, D., The structure of Hopf algebras with a projection, Journal of Algebra, 92, 322-347 (1985) · Zbl 0549.16003 · doi:10.1016/0021-8693(85)90124-3
[10] Schneider, H.-J., Normal basis and transitivity of crossed products for Hopf algebras, Journal of Algebra, 152, 289-312 (1992) · Zbl 0789.16026 · doi:10.1016/0021-8693(92)90034-J
[11] Singer, W., Extension theory for connected Hopf algebras, Journal of Algebra, 21, 1-16 (1972) · Zbl 0269.16011 · doi:10.1016/0021-8693(72)90031-2
[12] Sweedler, M., Hopf Algebras (1969), New York: Benjamin, New York · Zbl 0194.32901
[13] Takeuchi, M., Matched pairs of groups and bismash products of Hopf algebras, Communications in Algebra, 9, 841-882 (1981) · Zbl 0456.16011 · doi:10.1080/00927878108822621
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.