Finitely generated algebras defined by homogeneous quadratic monomial relations and their underlying monoids
Finitely generated algebras defined by homogeneous quadratic monomial relations and their underlying monoids
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由齐次二次单项式关系及其底层幺半群定义的有限生成代数
DOI:
10.1016/j.jalgebra.2015.05.017
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发表时间:
2015
影响因子:
0.9
通讯作者:
M. V. Campenhout
中科院分区:
文献类型:
--
作者:
E. Jespers;J. Okniński;M. V. Campenhout
We consider algebras over a field K with generators x 1, x 2,…, x n subject to (n 2) quadratic relations of the form x i x j= x k x l with (i, j)≠(k, l) and, moreover, every monomial x i x j appears at most once in one of the defining relations. If these relations are non-degenerate then it is shown that the algebra is left and right Noetherian, satisfies a polynomial identity and has Gelfand–Kirillov dimension at most n. In case the defining relations are square-free this was already established by Gateva-Ivanova, Jespers and Okniński. To prove these results we investigate the structure of the underlying monoid S, defined by the same presentation. It is called a quadratic monoid. We show that there is a strong link with the divisibility monoids and monoids of I-type (also referred to as YB-monoids). Monoids of I-type are examples of non-degenerate quadratic monoids. They are a monoid interpretation of non-degenerate involutive set-theoretic solutions of the Yang–Baxter equation and have been studied quite intensively in recent years, by Gateva-Ivanova and Van den Bergh, Etingof, Schedler and Soloviev, Jespers and Okniński. Divisibility monoids have been introduced by Kuske. These are cancellative monoids that include the class of monoids of I-type. We show that they have a presentation with at most (n 2) relations and if they have precisely (n 2) defining relations then they are monoids of I-type.