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Related papers: Weak mixing for locally compact quantum groups

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We define a new approximation property for tracial von Neumann algebras, called \textit{weakly mixing approximation property} which, for discrete groups and II$_1$ factors, is equivalent to the negation of Kazhdan's property (T).

Operator Algebras · Mathematics 2025-08-05 Paul Jolissaint

A non-unital generalization of weak bialgebra is proposed with a multiplier-valued comultiplication. Certain canonical subalgebras of the multiplier algebra (named the `base algebras') are shown to carry coseparable co-Frobenius coalgebra…

Quantum Algebra · Mathematics 2013-10-29 Gabriella Böhm , José Gómez-Torrecillas , Esperanza López-Centella

The description of the subgroup structure of a non-commutative division ring is the subject of the intensive study in the theory of division rings in particular, and of the theory of skew linear groups in general. This study is still so far…

Rings and Algebras · Mathematics 2020-11-04 Bui Xuan Hai , Huynh Viet Khanh

We note a generalization of Whyte's geometric solution to the von Neumann problem for locally compact groups in terms of Borel and clopen piecewise translations. This strengthens a result of Paterson on the existence of Borel paradoxical…

Group Theory · Mathematics 2019-05-21 Friedrich Martin Schneider

We study weak mixing of all orders for weakly mixing measure preserving dynamical systems, where the dynamics is given by the action of an abelian second countable topological group which has an invariant measure under the group operation.…

Dynamical Systems · Mathematics 2007-05-23 Conrad Beyers , Rocco Duvenhage , Anton Stroh

We transfer Knapp-Stein $R$-groups for unitary weakly unramified characters between a $p$-adic quasi-split group and its non-quasi-split inner forms, and provide the structure of those $R$-groups for a general connected reductive group over…

Number Theory · Mathematics 2022-10-06 Kwangho Choiy

We study weak amenability for locally compact quantum groups in the sense of Kustermans and Vaes. In particular, we focus on non-discrete examples. We prove that a coamenable quantum group is weakly amenable if there exists a net of…

Operator Algebras · Mathematics 2015-06-16 Martijn Caspers

In this article we will see some properties that guarantee that a product of an ergodic non-singular action and a probability preserving ergodic action is also an ergodic action. We will start by proving 'The multiplier theorem' for locally…

Dynamical Systems · Mathematics 2019-02-20 Adi Glücksam

We initiate a study of cohomological aspects of weakly almost periodic group representations on Banach spaces, in particular, isometric representations on reflexive Banach spaces. Using the Ryll-Nardzewski fixed point Theorem, we prove a…

Group Theory · Mathematics 2013-02-12 Uri Bader , Christian Rosendal , Roman Sauer

We present a generalization of Hirschman's entropic uncertainty principle for locally compact abelian groups to unimodular locally compact quantum groups. As a corollary, we strengthen a well-known uncertainty principle for compact groups,…

Mathematical Physics · Physics 2015-06-19 Jason Crann , Mehrdad Kalantar

A discrete group $G$ is called W*-superrigid if the group $G$ can be entirely recovered from the ambient group von Neumann algebra $L(G)$. We introduce an analogous notion for discrete quantum groups. We prove that this strengthened quantum…

Operator Algebras · Mathematics 2026-04-15 Milan Donvil , Stefaan Vaes

We prove the first rigidity and classification theorems for crossed product von Neumann algebras given by actions of non-discrete, locally compact groups. We prove that for arbitrary free probability measure preserving actions of connected…

Operator Algebras · Mathematics 2018-07-20 Arnaud Brothier , Tobe Deprez , Stefaan Vaes

In this article, we give a class of examples of compact quantum groups and unitary 2-cocycles on them, such that the twisted quantum groups are non-compact, but still locally compact quantum groups (in the sense of Kustermans and Vaes).…

Operator Algebras · Mathematics 2010-06-14 Kenny De Commer

Using methods coming from non-formal equivariant quantization, we construct in this short note a unitary dual 2-cocycle on a discrete family of quotient groups of subgroups of the affine group of a local field (which is not of…

Operator Algebras · Mathematics 2018-09-26 David Jondreville

The concept of weak Lie motion (weak Lie symmetry) is introduced through ${\cal{L}}_{\xi}{\cal{L}}_{\xi}g_{ab}=0,$ (${\cal{L}}_{\xi}{\cal{L}}_{\xi}f=0$). Applications are given which exhibit a reduction of the usual symmetry, e.g., in the…

Mathematical Physics · Physics 2015-06-12 Hubert F. M. Goenner

We show that a compact representation of a semisimple Lie group has an orthogonal decomposition into finite length representations. This generalises and simplifies a number of more special spectral theorems in the literature. We apply it to…

Number Theory · Mathematics 2024-01-30 Anton Deitmar

A set of bounded linear operators from a Banach space to a Banach lattice is collectively L-weakly compact whenever union of images of the unit ball is L-weakly compact. We extend the Meyer-Nieberg duality theorem to collectively L-weakly…

Functional Analysis · Mathematics 2024-10-29 Eduard Emelyanov

Local versions of measurability have been around for a long time. Roughly, one splits the notion of $\mu $-completeness into pieces, and asks for a uniform ultrafilter over $\mu $ satisfying just some piece of $\mu $-completeness. Analogue…

Logic · Mathematics 2014-04-08 Paolo Lipparini

We survey recent progress in the theory of weak containment of measure preserving group actions.

Dynamical Systems · Mathematics 2019-04-17 Peter Burton , Alexander S. Kechris

For different classes of measure preserving transformations, we investigate collections of sets that exhibit the property of lightly mixing. Lightly mixing is a stronger property than topological mixing, and requires that a lim inf is…

Dynamical Systems · Mathematics 2016-04-06 Terrence M. Adams