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Related papers: C*-pseudo-multiplicative unitaries

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Let $A$ and $B$ be arbitrary $C^*$-algebras, we prove that the existence of a Hilbert $A$-$B$-bimodule of finite index ensures that the WEP, QWEP, and LLP along with other finite-dimensional approximation properties such as CBAP and (S)OAP…

Operator Algebras · Mathematics 2017-05-25 Marzieh Forough , Massoud Amini

In this paper we complete in several aspects the picture of locally compact quantum groups. First of all we give a definition of a locally compact quantum group in the von Neumann algebraic setting and show how to deduce from it a…

Operator Algebras · Mathematics 2007-05-23 Johan Kustermans , Stefaan Vaes

Any $C^*$-algebra can be regarded as a generalization of locally compact, Hausdorff topological space $\mathcal X$. From the commutative commutative Gelfand-Na\u{\i}mark theorem it follows that the spectrum of any commutative $C^*$-algebra…

Operator Algebras · Mathematics 2026-03-17 Petr Ivankov

In this paper, motivated by the Berger, Coburn and Lebow and Bercovici, Douglas and Foias theory for tuples of commuting isometries, we study analytic representations and joint invariant subspaces of a class of commuting $n$-isometries and…

Functional Analysis · Mathematics 2019-08-28 B. Krishna Das , Ramlal Debnath , Jaydeb Sarkar

We extend the spectral theory of commutative C*-categories to the non full-case, introducing a suitable notion of spectral spaceoid provinding a duality between a category of "non-trivial" *-functors of non-full commutative C*-categories…

Operator Algebras · Mathematics 2025-11-04 Paolo Bertozzini , Roberto Conti , Wicharn Lewkeeratiyutkul , Kasemsun Rutamorn

We study representations of Hilbert bimodules on pairs of Hilbert spaces. If $A$ is a C*-algebra and $\mathsf{X}$ is a right Hilbert $A$-module, we use such representations to faithfully represent the C*-algebras $\mathcal{K}_A(\mathsf{X})$…

Operator Algebras · Mathematics 2024-10-18 Alonso Delfín

For a locally compact group $G$ we look at the group algebras $C_0(G)$ and $C_r^*(G)$, and we let $f\in C_0(G)$ act on $L^2(G)$ by the multiplication operator $M(f)$. We show among other things that the following properties are equivalent:…

Operator Algebras · Mathematics 2007-10-02 Magnus B. Landstad , A. Van Daele

We study the notions of nuclearity and exactness for module maps on $C^{*}$-algebras which are $C^*$-module over another $C^*$-algebra with compatible actions and examine finite approximation properties of such $C^*$-modules. We prove…

Operator Algebras · Mathematics 2022-06-15 Massoud Amini

We consider a class of C*-algebras associated to one parameter continuous tensor product systems of Hilbert modules, which can be viewed as continuous counterparts of Pimsner's Toeplitz algebras. By exhibiting a homotopy of…

Operator Algebras · Mathematics 2007-05-23 Ilan Hirshberg

We discuss basic topological properties of unitary dual spaces of nilpotent Lie groups, using some ideas from operator algebras and their noncommutative dimension theory. The general results are illustrated by many examples.

Operator Algebras · Mathematics 2017-07-19 Ingrid Beltita , Daniel Beltita

C*-algebras form rather general and rich mathematical structures that can be studied with different morphisms (preserving multiplication, or not), and with different properties (commutative, or not). These various options can be used to…

Category Theory · Mathematics 2017-01-11 Robert W. J. Furber , Bart P. F. Jacobs

C*-quantum groups with projection are the noncommutative analogues of semidirect products of groups. Radford's Theorem about Hopf algebras with projection suggests that any C*quantum group with projection decomposes uniquely into an…

Operator Algebras · Mathematics 2024-06-25 Ralf Meyer , Sutanu Roy , Stanisław Lech Woronowicz

We study coactions of concrete Hopf $C^{*}$-bimodules in the framework of (weak) $C^{*}$-pseudo-Kac systems, define reduced crossed products and dual coactions, and prove an analogue of Baaj-Skandalis duality.

Operator Algebras · Mathematics 2007-10-01 Thomas Timmermann

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

Quasi-multipliers for a Hilbert C*-bimodule V were introduced by Brown, Mingo and Shen 1994 as a certain subset of the Banach bidual module V**. We give another (equivalent) definition of quasi-multipliers for Hilbert C*-bimodules using the…

Operator Algebras · Mathematics 2018-09-25 Alexander Pavlov , Ulrich Pennig , Thomas Schick

The category of locally compact quantum groups can be described as either Hopf $*$-homomorphisms between universal quantum groups, or as bicharacters on reduced quantum groups. We show how So{\l}tan's quantum Bohr compactification can be…

Functional Analysis · Mathematics 2021-09-15 Matthew Daws

We introduce and study some new uniform structures for Hilbert $C^*$-modules over an algebra $A$. In particular, we prove that in some cases they have the same totally bounded sets. To define one of them, we introduce a new class of…

Operator Algebras · Mathematics 2024-02-29 Denis Fufaev , Evgenij Troitsky

This is Part II in our multi-part series of papers developing the theory of a subclass of locally compact quantum groupoids ("quantum groupoids of separable type"), based on the purely algebraic notion of weak multiplier Hopf algebras. The…

Operator Algebras · Mathematics 2019-08-21 Byung-Jay Kahng , Alfons Van Daele

We propose a definition of a "$C^*$-Eberlein" algebra, which is a weak form of a $C^*$-bialgebra with a sort of "unitary generator". Our definition is motivated to ensure that commutative examples arise exactly from semigroups of…

Functional Analysis · Mathematics 2021-09-15 Biswarup Das , Matthew Daws

We give a new Banach module characterization of $W^*$-modules, also known as selfdual Hilbert $C^*$-modules over a von Neumann algebra. This leads to a generalization of the notion, and the theory, of W*-modules, to the setting where the…

Operator Algebras · Mathematics 2009-08-28 David P. Blecher , Upasana Kashyap