We study a natural construction of Hopf algebra quotients canonically associated to an R-matrix in a finite dimensional Hopf algebra. We apply this construction to show that a quasitriangular Hopf algebra whose dimension is odd and square-free is necessarily cocommutative.
A family of algebra maps $H\to A_i$ whose common domain is a Hopf algebra is said to be jointly inner faithful if it does not factor simultaneously through a proper Hopf quotient of $H$. We show that tensor and free products of jointly inner faithful maps of Hopf algebras are again jointly inner faithful, generalizing a number of results in the literature on torus generation of compact quantum groups.
We build on our construction of Hopf algebroids from noncommutative calculi under the further assumption of surjectivity for the calculus. We also introduce the notions of Hopf ideals and isotopy quotients for arbitrary Hopf algebroids. Using these ingredients, we prove a Riemann-Hilbert correspondence for digraphs, by showing that the groupoid algebra of the fundamental groupoid of a digraph is isomorphic to the isotopy quotient of the Hopf algberoid corresponding to flat connections over the digraph.
We show that the matrix embeddings in Bratteli diagrams are iterated direct sums of Hopf-Galois extensions (quantum principle bundles) for certain abelian groups. The corresponding strong universal connections are computed. We show that $ M_{n}(\mathbb{C})$ is a trivial quantum principle bundle for the Hopf algebra $ \mathbb{C}[\mathbb{Z}_{n} \times \mathbb{Z}_{n}] $. We conclude with an application relating known calculi on groups to calculi on matrices.
本文引入了Hopf-Galois扩张的伽罗瓦论,证明了H-余代数的子代数与霍普夫代数H的广义余代数之间存在Galois联络。此外,我们还证明了定义Q-Galois扩张的这些行列式Q是我们的Galois联络的闭元。推广了M. Masuoka和H. J. Schneider的结果,证明了任意有限维霍普夫代数的右理想、余理想和右余理想子代数之间存在双射对应关系,并在一般(即无限维)情况下重新表述了这一尚未解决的问题.对于分裂扩张,我们将Galois联络的闭元作为Hopf-Galois扩张。我们描述了我们的结果与F. van Oystaeyen,Y. Zhang和P. Schauenburg关于双伽罗瓦扩张的结果。
We characterize braided commutative Yetter-Drinfeld $C^*$-algebras over weak Hopf $C^*$-algebras in categorical terms. Using this, we then study quotient type coideal subalgebras of a given weak Hopf $C^*$-algebra $\mathcal G$ and coideal subalgebras invariant with respect to the adjoint action of $\mathcal G$. Finally, as an example, we explicitly describe quotient type coideal subalgebras of the weak Hopf $C^*$-algebras associated with Tambara-Yamagami categories.
The coset $G$-space of a finite group and a subgroup is a fundamental module of study of Schur and others around 1930; for example, its endomorphism algebra is a Hecke algebra of double cosets. We study and review its generalization $Q$ to Hopf subalgebras, especially the tensor powers and similarity as modules over a Hopf algebra, or what's the same, Morita equivalence of the endomorphism algebras. We prove that $Q$ has a nonzero integral if and only if the modular function restricts to the modular function of the Hopf subalgebra. We also study and organize knowledge of $Q$ and its tensor pow…
We show that the Kac-Paljutkin Hopf algebra appears as a quotient of $C(SU_{-1}(2))$, which means that the corresponding quantum group $G_{KP}$ can be regarded as a quantum subgroup of $SU_{-1}(2)$. We combine the fact that corepresentation category of the Kac-Paljutkin Hopf algebra is a Tambara-Yamagami tensor category associated with the Krein 4-group and the method of graded twisting of Hopf algebras, to construct the Hopf *-homomorphism.
Finite Dimensional Pointed Hopf Algebras with Abelian Coradical and Cartan matrices
在以前的工作\cite{AS2}中,我们展示了如何附加到一个点的Hopf代数A与corradical $\kΓ$,一个严格分次的Hopf代数R的范畴$_Γ^Γ\Cal{YD}$的Yetter-Drinfeld模块$Γ$。本文考虑A的另一个不变量,即R的由本原元空间V生成的子代数R'。这类代数是已知的,因为开创性的工作尼科尔斯。结果表明,R'完全由编织物c决定:V \otimes V \to V \otimes V。我们表示R' = B(V)。我们进一步假设$Γ$是有限阿贝尔的。则c由矩阵(b_{ij})给出,其元素是单位根;我们还假设它们具有奇数阶。我们介绍这些编织的概念,“编织的Cartan型”,我们附加一个广义Cartan矩阵的Cartan型编织。证明了B(V)是有限维的,如果它对应的矩阵是有限Cartan型的,并给出了逆命题的充分条件.作为结果,我们得到了许多新的家庭的点霍普夫代数。当$Γ$是素数阶群的副本的直和时,条件成立且任何矩阵是Cartan型的。作为一个例子,我们对有限维余根分次的、一次生成的且余根为奇素维p的点霍普夫代数进行了分类,并刻画了一次生成的p^4阶余根分次点霍普夫代数.
We use a version of Haboush's theorem over complete local Noetherian rings to prove faithfulness of the lifting for semisimple cosemisimple Hopf algebras and separable (braided, symmetric) fusion categories from characteristic $p$ to characteristic zero (arXiv/math:0203060, Section 9), showing that, moreover, any isomorphism between such structures can be reduced modulo $p$. This fills a gap in arXiv/math:0203060, Subsection 9.3. We also show that lifting of semisimple cosemisimple Hopf algebras is a fully faithful functor, and prove that lifting induces an isomorphism on Picard and Brauer-Pic…
We determine convex PBW-type Lyndon bases for two-parameter quantum groups $U_{r,s}(F_4)$ with detailed commutation relations. We construct a finite-dimensional Hopf algebra $\mathfrak u_{r,s}(F_4)$, as a quotient of $U_{r,s}(F_4)$ by a Hopf ideal generated by certain central elements, which is pointed, and of a Drinfel'd double structure under a certain condition. All of Hopf isomorphisms of $\mathfrak u_{r,s}(F_4)$ are determined which are important for seeking the possible new pointed objects in low order with $(\ell, 210)\ne 1$. Finally, necessary and sufficient conditions for $\mathfrak u…
After a thorough treatment of all algebraic structures involved, we address two dimensional holonomy operators with values in crossed modules of Hopf algebras and in crossed modules of associative algebras (called here crossed modules of bare algebras.) In particular, we will consider two general formulations of the two-dimensional holonomy of a (fully primitive) Hopf 2-connection (exact and blur), the first being multiplicative the second being additive, proving that they coincide in a certain natural quotient (defining what we called the fuzzy holonomy of a fully primitive Hopf 2-connection)…