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Related papers: Compact C*-quantum groupoids

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We discuss just infiniteness of C*-algebras associated to discrete quantum groups and relate it to the C*-uniqueness of the quantum groups in question, i.e. to the uniqueness of a C*-completion of the underlying Hopf *-algebra. It is shown…

Operator Algebras · Mathematics 2019-07-03 Martijn Caspers , Adam Skalski

In a recent article, we gave a definition of partition C*-algebras. These are universal C*-algebras based on algebraic relations which are induced from partitions of sets. In this follow up article, we show that often we can associate a…

Operator Algebras · Mathematics 2017-10-25 Moritz Weber

We introduce the analog of Bohr compactification for discrete quantum groups on C*-algebra level. The cases of unimodular and general C*-algebraic discrete quantum groups are treated separately. The passage from the former case to the…

Operator Algebras · Mathematics 2016-08-15 P. M. Sołtan

An algebraic quantum group is a multiplier Hopf algebra with integrals. In this paper we will develop a theory of algebraic quantum hypergroups. It is very similar to the theory of algebraic quantum groups, except that the comultiplication…

Rings and Algebras · Mathematics 2007-05-23 L. Delvaux , A. Van Daele

In two articles ([L2], [L3]), Franck Lesieur had introduced a notion of quantum groupoid, in the setting of von Neumann algebras, using intensively the notion of pseudo-multiplicative unitary, which had been introduced in a previous article…

Operator Algebras · Mathematics 2007-05-23 Michel Enock

We establish the equivalence of three versions of a finite dimensional quantum groupoid: a generalized Kac algebra introduced by T. Yamanouchi, a weak $C^*$-Hopf algebra introduced by G. Bohm, F. Nill and K. Szlachanyi (with an involutive…

Quantum Algebra · Mathematics 2007-05-23 D. Nikshych , L. Vainerman

Generalizing the notion of matched pair of groups, we define and study matched pairs of locally compact groupoids endowed with Haar systems, in order to give new examples of measured quantum groupoids.

Operator Algebras · Mathematics 2011-05-27 Jean-Michel Vallin

Let $G$ be a locally compact group. Consider the C$^*$-algebra $C_0(G)$ of continuous complex functions on $G$, tending to 0 at infinity. The product in $G$ gives rise to a coproduct $\Delta_G$ on the C$^*$-algebra $C_0(G)$. A locally…

Operator Algebras · Mathematics 2007-05-23 M. B. Landstad , A. Van Daele

In this work, we introduce a class of Timmermann's measured multiplier Hopf *-algebroids called algebraic quantum transformation groupoids of compact type. Each object in this class admits a Pontrjagin-like dual called an algebraic quantum…

Quantum Algebra · Mathematics 2023-07-03 Frank Taipe

We present a general theory of braided quantum groups in the C*-algebraic framework using the language of multiplicative unitaries. Starting with a manageable multiplicative unitary in the representation category of the quantum codouble of…

Operator Algebras · Mathematics 2024-06-25 Sutanu Roy

This paper introduces a canonical Polish groupoid associated to any separable unital C*-algebra, termed the unitary conjugation groupoid. It is defined as the semidirect product of the algebra's dual space by its unitary group, acting by…

Operator Algebras · Mathematics 2026-03-06 Shih-Yu Chang

Generalizing the notion of a multiplicative unitary (in the sense of Baaj-Skandalis), which plays a fundamental role in the theory of locally compact quantum groups, we develop in this paper the notion of a multiplicative partial isometry.…

Operator Algebras · Mathematics 2026-02-25 Byung-Jay Kahng

In this paper we introduce the notion of a Hopf C*-algebra and construct the counit and antipode. A Hopf C*-algebra is a C*-algebra with comultiplication satisfying some extra condition which makes possible the construction of the counit…

Operator Algebras · Mathematics 2007-05-23 Stefaan Vaes , Alfons Van Daele

We show how the C*-algebras of quantum complex projective spaces (standard or nonstandard) are related to groupoids.

Operator Algebras · Mathematics 2007-05-23 Albert Jeu-Liang Sheu

Van Daele and Wang developed a purely algebraic notion of weak multiplier Hopf algebras, which extends the notions of Hopf algebras, multiplier Hopf algebras, and weak Hopf algebras. With an additional requirement of an existence of left or…

Quantum Algebra · Mathematics 2023-06-27 Byung-Jay Kahng

In this article, we will define two canonical cohomology theories for Hopf $C^*$-algebras and for Hopf von Neumann algebras (with coefficients in their bicomodules). We will then study the situations when these cohomologies vanish. The…

Operator Algebras · Mathematics 2007-05-23 Chi-Keung Ng

Let $B$ and $C$ be non-degenerate idempotent algebras and assume that $E$ is a regular separability idempotent in $M(B\otimes C)$. Define $A=C\otimes B$ and $\Delta:A\to M(A\otimes A)$ by $\Delta(c\otimes b)=c\otimes E\otimes b$. The pair…

Rings and Algebras · Mathematics 2017-02-17 Alfons Van Daele

Taking a groupoid C*-algebra approach to the study of the quantum complex projective spaces $\mathbb{P}^{n}\left( \mathcal{T}\right) $ constructed from the multipullback quantum spheres introduced by Hajac and collaborators, we analyze the…

Operator Algebras · Mathematics 2018-02-13 Albert Jeu-Liang Sheu

By weakening the counit and antipode axioms of a C*-Hopf algebra and allowing for the coassociative coproduct to be non-unital we obtain a quantum group, that we call a weak C*-Hopf algebra, which is sufficiently general to describe the…

q-alg · Mathematics 2009-10-28 G. Bohm , K. Szlachanyi

This is the last part of a series of three papers on the subject. In the first part we have considered the duality of algebraic quantum groups. In that paper, we use the term algebraic quantum group for a regular multiplier Hopf algebra…

Quantum Algebra · Mathematics 2023-04-27 Alfons Van Daele