English
Related papers

Related papers: Co-Amenability of compact quantum groups

200 papers

We introduce an appropriate notion of inner amenability for locally compact quantum groups, study its basic properties, related notions, and examples arising from the bicrossed product construction. We relate these notions to homological…

Operator Algebras · Mathematics 2018-05-24 Jason Crann

Noncommutative K\"ahler structures were recently introduced as an algebraic framework for studying noncommutative complex geometry on quantum homogeneous spaces. In this paper, we introduce the notion of a \emph{compact quantum homogeneous…

Quantum Algebra · Mathematics 2026-03-17 Biswarup Das , Réamonn Ó Buachalla , Petr Somberg

We provide a detailed study of actions of the integers on compact quantum metric spaces, which includes general criteria ensuring that the associated crossed product algebra is again a compact quantum metric space in a natural way. We…

Operator Algebras · Mathematics 2021-07-01 Jens Kaad , David Kyed

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

A version of group cohomology for locally compact groups and Polish modules has previously been developed using a bar resolution restricted to measurable cochains. That theory was shown to enjoy analogs of most of the standard algebraic…

Group Theory · Mathematics 2012-11-27 Tim Austin , Calvin C. Moore

We propose a definition of compact quantum groupoids in the setting of C*-algebras, associate to such a quantum groupoid a regular C*-pseudo-multiplicative unitary, and use this unitary to construct a dual Hopf C*-bimodule and to pass to a…

Operator Algebras · Mathematics 2013-07-02 Thomas Timmermann

We first show that co-amenability does not pass to subgroups, answering a question asked by Eymard in 1972. We then address co-amenability for von Neumann algebras, describing notably how it relates to the former.

Group Theory · Mathematics 2007-05-23 Nicolas Monod , Sorin Popa

Analytic properties of right topological groups have been extensively studied in the compact admissible case (i.e when the group has a dense topological center). This was inspired by the existence of a Haar measure on such groups. In this…

Functional Analysis · Mathematics 2019-11-27 Prachi Loliencar

Given a discrete quantum group A we construct a certain Hopf *-algebra AP which is a unital *-subalgebra of the multiplier algebra of A. The structure maps for AP are inherited from M(A) and thus the construction yields a compactification…

Quantum Algebra · Mathematics 2016-08-15 P. M. Sołtan

Compact-group representations on Banach spaces are known to be norm-continuous precisely when they have finite spectra. For a quantum group with continuous-function algebra $\mathcal{C}(\mathbb{G})$ norm continuity can be cast analogously…

Operator Algebras · Mathematics 2026-03-27 Alexandru Chirvasitu

We study stability properties of amenable locally compact quantum groups under the bicrossed product construction. We obtain as our main result an equivalence between amenability of the bicrossed product and amenability of the matched…

Quantum Algebra · Mathematics 2007-05-23 P. Desmedt , J. Quaegebeur , S. Vaes

We prove that a compact quantum group with faithful Haar state which has a faithful action on a compact space must be a Kac algebra, with bounded antipode and the square of the antipode being identity. The main tool in proving this is the…

Quantum Algebra · Mathematics 2010-07-20 Debashish Goswami

We introduce a non commutative analog of the Bohr compactification. Starting from a general quantum group G we define a compact quantum group bG which has a universal property such as the universal property of the classical Bohr…

Operator Algebras · Mathematics 2007-07-17 P. M. Sołtan

In this work we introduce and study a new notion of amenability for actions of locally compact groups on $C^*$-algebras. Our definition extends the definition of amenability for actions of discrete groups due to Claire…

Operator Algebras · Mathematics 2022-05-04 Alcides Buss , Siegfried Echterhoff , Rufus Willett

This is a survey of some aspects of the subject of approximation properties for locally compact quantum groups, based on lectures given at the {\it Topological Quantum Groups} Graduate School, 28 June - 11 July, 2015 in Bed\l{}ewo, Poland.…

Operator Algebras · Mathematics 2016-05-09 Michael Brannan

It is the goal of this article to extend the notion of quantization from the standard interpretation focused on non-commuting observables defined starting from classical analogues, to the topological equivalents defined in terms of…

General Physics · Physics 2014-11-18 Andrei T. Patrascu

The notion of compact quantum subgroup is revisited and an alternative definition is given. Induced representations are considered and a Frobenius reciprocity theorem is obtained. A relationship between ergodic actions of compact quantum…

Operator Algebras · Mathematics 2013-09-24 Claudia Pinzari

We investigate compact quantum group actions on unital $C^*$-algebras by analyzing invariant subsets and invariant states. In particular, we come up with the concept of compact quantum group orbits and use it to show that countable compact…

Operator Algebras · Mathematics 2015-11-17 Huichi Huang

Partial actions of groups on C*-algebras and the closely related actions and coactions of Hopf algebras received much attention over the last decades. They arise naturally as restrictions of their global counterparts to non-invariant…

Operator Algebras · Mathematics 2018-11-14 Franziska Kraken , Paula Quast , Thomas Timmermann

We propose a definition of a quantum homogeneous space of a locally compact quantum group. We show that classically it reduces to the notion of a homogeneous spaces. On the quantum level our definition goes beyond the quotient case. It…

Operator Algebras · Mathematics 2014-10-30 Pawel Kasprzak