Abstract. The aim of this paper is to contribute more examples and classification results of finite pointed quasi-quantum groups within the quiver framework initiated in [5,6]. The focus is put on finite dimensional graded Majid algebras generated by group-like elements and two skew-primitive elements which are mutually skew-commutative. Such quasi-quantum groups are associated to quasi-quantum planes in the sense of nonassociative geomertry [14,15]. As an application, we obtain an explicit classification of graded pointed Majid algebras with abelian coradical of dimension p 3 and p 4 for any prime number p.
IntroductionThe classification problem of finite pointed tensor categories and the underlying quasi-quantum groups in accordance to the Tannaka-Krein duality has been an active research theme for quite some time. In [5,6], the quiver framework was proposed by the first author to tackle this problem and some interesting results have been obtained in this direction, see for example [7,8,12].The aim of this paper is to contribute more examples and classification results of finite pointed quasiquantum groups within the quiver framework. We focus on the class of finite dimensional graded pointed Majid algebras which are generated by group-like elements and two skew-primitive elements which are mutually skew-commutative. The reason is twofold. On the one hand, such Majid algebras are relatively easy and a complete classification may be attainable. On the other hand, this class of Majid algebras are interesting in nonassociative geometry, namely, they may be viewed as the "coordinate algebra" of nonassociative planes, see [14,15].The notion of Majid algebras adopted here stands for coquasi-Hopf algebras, or dual quasi-Hopf algebras used by some authors. We remark that the study of Majid algebras and their comodule categories is the main task of the classification problem of tensor categories and quasi-quantum groups, see for instance [5] for an explanation.Throughout we work over the field which is algebraically closed with characteristic 0. We aim to classify finite dimensional graded pointed Majid algebras M over satisfying (R1): M is generated by an abelian group G and two skew-primitive elements {X, Y }; and (R2): the skew-primitive elements are skew-commutative, i.e., XY = qY X for some q ∈ * .Here, by graded we mean M is coradically graded, that is, M admits a decomposition M = n≥0 M (n) and M n := 0≤i≤n M (i) is the n-th term of its coradical filtration. By the assumption, the coradical of M is M 0 = ( G, Φ), which is a Majid subalgebra of M and the associator Φ is in fact a normalized 3-cocycle on G. By Key words and phrases. quasi-quantum plane, quasi-quantum group, Hopf quiver.