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Related papers: Around Property (T) for quantum groups

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We reformulate and extend the geometric method for proving Kazhdan property T developed by Dymara and Januszkiewicz and used by Ershov and Jaikin. The main result says that a group G, generated by finite subgroups G_i, has property T if the…

Group Theory · Mathematics 2009-12-01 M. Kassabov

A topological group G is defined to have property (OB) if any G-action by isometries on a metric space, which is separately continuous, has bounded orbits. We study this topological analogue of the socalled Bergman property in the context…

Logic · Mathematics 2007-05-23 Christian Rosendal

According to Bestvina-Bromberg-Fujiwara, a finitely generated group is said to have property (QT) if it acts isometrically on a finite product of quasi-trees so that orbital maps are quasi-isometric embeddings. We prove that the fundamental…

Geometric Topology · Mathematics 2025-03-12 Suzhen Han , Hoang Thanh Nguyen , Wenyuan Yang

We consider two random group models: the hexagonal model and the square model, defined as the quotient of a free group by a random set of reduced words of length four and six respectively. Our first main result is that in this model there…

Group Theory · Mathematics 2019-06-25 Tomasz Odrzygóźdź

We prove that amenability of a unitary co-representation $U$ of a locally compact quantum group passes to unitary co-representations that weakly contain $U$. This generalizes a result of Bekka, and answers affirmatively a question of…

Operator Algebras · Mathematics 2017-05-30 Chi-Keung Ng , Ami Viselter

The notion of strong 1-boundedness for finite von Neumann algebras was introduced by Jung in arXiv:math/0510576 . This framework provided a free probabilistic approach to study rigidity properties and classification of finite von Neumann…

Operator Algebras · Mathematics 2021-10-26 Ben Hayes , David Jekel , Srivatsav Kunnawalkam Elayavalli

Let $H$ be a proper subgroup of a discrete group $G$. We introduce a notion of relative inner amenability of $H$ in $G$, we prove some equivalent conditions and provide examples as well as counter-examples. We also discuss the corresponding…

Group Theory · Mathematics 2014-08-08 Paul Jolissaint

In this paper, we provide several instances in which interesting approximation and stability properties are inherited by quotients with respect to finitely generated normal subgroups or, more strongly, normal subgroups with Kazhdan's…

Group Theory · Mathematics 2025-12-18 Vadim Alekseev , Andreas Thom

We prove that every sofic approximation of a property (T) group is approximately isomorphic to one having geometric property (T), and more generally, a box space of graphs which has boundary geometric property (T) is approximately…

Group Theory · Mathematics 2025-11-21 Vadim Alekseev , Stefan Drigalla

We present a recent result of Ibarluc\'ia stating that every Roelcke precompact Polish group has Kazhdan's property (T). This striking theorem builds on the characterization of Roelcke precompact Polish groups as automorphism groups of…

Group Theory · Mathematics 2021-06-17 François Le Maître

We give a local characterization of the existence of Kazhdan projections for arbitary families of Banach space representations of a compactly generated locally compact group $G$. We also define and study a natural generalization of the Fell…

Functional Analysis · Mathematics 2021-03-25 Mikael de la Salle

In this paper we study of the BGG-categories $\mathcal O_q$ associated to quantum groups. We prove that many properties of the ordinary BGG-category $\mathcal O$ for a semisimple complex Lie algebra carry over to the quantum case. Of…

Representation Theory · Mathematics 2017-05-10 Henning Haahr Andersen , Volodymyr Mazorchuk

The $k$-gonal models of random groups are defined as the quotients of free groups on $n$ generators by cyclically reduced words of length $k$. As $k$ tends to infinity, this model approaches the Gromov density model. In this paper we show…

Group Theory · Mathematics 2021-04-14 MurphyKate Montee

Geometric property (T) was defined by Willett and Yu, first for sequences of graphs and later for more general discrete spaces. Increasing sequences of graphs with geometric property (T) are expanders, and they are examples of coarse spaces…

Functional Analysis · Mathematics 2021-05-27 Jeroen Winkel

We generalize the notion of weakly mixing unitary representations to locally compact quantum groups, introducing suitable extensions of all standard characterizations of weak mixing to this setting. These results are used to complement the…

Operator Algebras · Mathematics 2017-07-11 Ami Viselter

Let $\mathcal{G}$ be an algebraic quantum group. We introduce an equivariant algebraic $kk$-theory for $\mathcal{G}$-module algebras. We study an adjointness theorem related with smash product and trivial action. We also discuss a duality…

K-Theory and Homology · Mathematics 2019-04-19 Eugenia Ellis

Well defined quantum field theory (QFT) for the electroweak force including quantum electrodynamics (QED) and the weak force is obtained by considering natural unitary representations of a group $K\subset U(2,2)$, where $K$ is locally…

Mathematical Physics · Physics 2021-06-16 John Mashford

We study the Haagerup--Kraus approximation property for locally compact quantum groups, generalising and unifying previous work by Kraus--Ruan and Crann. Along the way we discuss how multipliers of quantum groups interact with the…

Operator Algebras · Mathematics 2024-01-05 Matthew Daws , Jacek Krajczok , Christian Voigt

We show that for any co-amenable compact quantum group A=C(G) there exists a unique compact Hausdorff topology on the set EA of isomorphism classes of ergodic actions of G such that the following holds: for any continuous field of ergodic…

Operator Algebras · Mathematics 2009-09-29 Hanfeng Li

In this paper we continue our study of property (RD) for Hecke pairs initiated in (V. Shirbisheh, Property (RD) for Hecke pairs. Mathematical Physics, Analysis and Geometry, vol. 15, no. 2, (2012), 173--192). We study the behavior of…

Group Theory · Mathematics 2012-12-13 Vahid Shirbisheh