English
Related papers

Related papers: On co-amenability for groups and von Neumann algeb…

200 papers

In his study of amenable unitary representations, M. E. B. Bekka asked if there is an analogue for such representations of the remarkable fixed-point property for amenable groups. In this paper, we prove such a fixed-point theorem in the…

Operator Algebras · Mathematics 2007-05-23 Anthony T. Lau , Alan L. T. Paterson

We introduce and study a new notion of amenability called symmetric pseudo-amenability. We obtain some properties of symmetrically pseudo-amenable Banach algebras and with examples, we compare this type of amenability with some other types…

Functional Analysis · Mathematics 2024-05-09 Hoger Ghahramani , Parvin Zamani

We prove non-amenability of the product replacement graphs \Gamma_n(G) for uniformly non-amenable groups. We also prove it for Z-large groups, when n is sufficiently large. It follows that \Gamma_n(G) is non-amenable when n is sufficiently…

Group Theory · Mathematics 2013-05-13 Anton Malyshev

We show that there is a one-to-one correspondence between compact quantum subgroups of a co-amenable locally compact quantum group $\mathbb{G}$ and certain left invariant C*-subalgebras of $C_0(\mathbb{G})$. We also prove that every compact…

Operator Algebras · Mathematics 2012-01-25 Pekka Salmi

From the mid-1970s, Eberhard Kirchberg undertook a remarkable extensive study of $C^*$-algebras exactness whose applications spread out to many branches of analysis. In this review we focus on the case of groupoid $C^*$-algebras for which…

Operator Algebras · Mathematics 2023-08-10 Claire Anantharaman-Delaroche

We investigate the notions of amenability and its related homological notions for a class of $I\times I$-upper triangular matrix algebra, say $UP(I,A)$, where $A$ is a Banach algebra equipped with a non-zero character. We show that…

Functional Analysis · Mathematics 2017-02-10 Amir Sahami

We introduce the notion of amenability for affine algebras. We characterize amenability by Folner-sequences, paradoxicality and the existence of finitely invariant dimension-measures. Then we extend the results of Rowen on ranks, from…

Rings and Algebras · Mathematics 2007-05-23 Gabor Elek

Motivated by a result of Ky Fan in 1965, we establish a characterization of a left amenable F-algebra (which includes the group algebra and the Fourier algebra of a locally compact group and quantum group algebras, or more generally the…

Functional Analysis · Mathematics 2014-04-15 Anthony T. -M. Lau , Yong Zhang

The Hochschild homology and cohomology group can be described in terms of the homology and cohomology of the classifying space of the groupoid of the adjoint action of the group under the suitable assumption of the finiteness of the…

Representation Theory · Mathematics 2019-01-30 A. S. Mishchenko

Based on the vanishing of the second Hochschild cohomology group of the enveloping algebra of the Heisenberg algebra it is shown that differential algebras coming from quantum groups do not provide a non-trivial deformation of quantum…

q-alg · Mathematics 2009-10-28 Mathias Pillin

We study qualitative properties of the group von Neumann algebra of a Baumslag-Solitar group. Namely, we prove that, in the non-amenable and {ICC} case, the associated ${\rm II}_1$ factor is prime, not solid, and does not have any Cartan…

Operator Algebras · Mathematics 2010-11-16 Pierre Fima

We generalize some basic C*-algebra and von Neumann algebra theory on hereditary C*-subalgebras and projections. In particular, we extend Murray-von Neumann equivalence from projections to *-annihilators and show that several of its…

Rings and Algebras · Mathematics 2017-02-10 Tristan Bice

We describe conditions that characterize amenability for groups in terms of positive definite functions valued in a von Neumann algebra.

Operator Algebras · Mathematics 2022-02-02 Mikaël Pichot , Erik Séguin

Beyond the locally compact case, equivalent notions of amenability diverge, and some properties no longer hold, for instance amenability is not inherited by topological subgroups. This investigation is guided by some amenability-type…

Group Theory · Mathematics 2025-03-05 Vladimir G. Pestov , Friedrich Martin Schneider

In this paper we describe the structure of all sequential isomorphisms between the sets of von Neumann algebra effects. It turns out that if the underlying algebras have no commutative direct summands, then every sequential isomorphism…

Operator Algebras · Mathematics 2007-05-23 Lajos Molnar

Using the Foelner condition for coamenable quantum groups we derive information about the ring theoretical structure of the Hopf algebras arising from such quantum groups, as well as an approximation result concerning the Murray von Neumann…

Operator Algebras · Mathematics 2011-05-11 David Kyed , Andreas Thom

In this paper, we introduce the concept of biamenability of Banach algebras and we show that despite the apparent similarities between amenability and biamenability of Banach algebras, they lead to very different, and somewhat opposed,…

Functional Analysis · Mathematics 2020-11-26 Sedigheh Barootkoob

We prove that for any group G in a fairly large class of generalized wreath product groups, the associated von Neumann algebra L(G) completely "remembers" the group G. More precisely, if L(G) is isomorphic to the von Neumann algebra…

Operator Algebras · Mathematics 2012-08-21 Adrian Ioana , Sorin Popa , Stefaan Vaes

This note describes the first example of a group that is amenable, but cannot be obtained by subgroups, quotients, extensions and direct limits from the class of groups locally of subexponential growth. It has a balanced presentation…

Group Theory · Mathematics 2007-05-23 Laurent Bartholdi

We prove that for any infinite, maximal amenable subgroup $H$ in a hyperbolic group $G$, the von Neumann subalgebra $LH$ is maximal amenable inside $LG$. It provides many new, explicit examples of maximal amenable subalgebras in II$_1$…

Operator Algebras · Mathematics 2015-04-28 Rémi Boutonnet , Alessandro Carderi