English
Related papers

Related papers: Maximal amenable von Neumann subalgebras arising f…

200 papers

Given a discrete measured groupoid $\mathcal{G}$, we study properties of the corresponding von Neumann algebra $L(\mathcal{G})$ using the techniques of Popa's deformation/rigidity theory. More specifically, we define and study the Gaussian…

Operator Algebras · Mathematics 2025-09-19 Felipe Flores , James Harbour

We present families of pairs of finite von Neumann algebras $A\subset M$ where $A$ is a maximal injective masa in the type $\mathrm{II}_1$ factor $M$ with separable predual. Our results make use of the strong mixing and the asymptotic…

Operator Algebras · Mathematics 2010-08-05 Paul Jolissaint

We define a Banach algebra A to be dual if $A = (A_\ast)^\ast$ for a closed submodule $A_\ast$ of $A^\ast$. The class of dual Banach algebras includes all $W^\ast$-algebras, but also all algebras M(G) for locally compact groups G, all…

Functional Analysis · Mathematics 2007-05-23 Volker Runde

We investigate the use of Popa's asymptotic orthogonality to establish maximal amenability for amalgamated free product von Neumann algebras. Although new techniques have recently been developed to consider amalgamated free products, we…

Operator Algebras · Mathematics 2019-12-13 Brian Leary

We consider a paving property for a maximal abelian *-subalgebra (MASA) $A$ in a von Neumann algebra $M$, that we call so-paving, involving approximation in the so-topology, rather than in norm (as in classical Kadison-Singer paving). If…

Operator Algebras · Mathematics 2016-01-20 Sorin Popa , Stefaan Vaes

We demonstrate von Neumann algebra arising from an icc group $\Gamma$ in Chifan's, Ioana's, and Kida's class of poly-$\mathcal{C}_\text{rss} $, such as a poly-hyperbolic group with no amenable factors in its composition series, satisfies…

Operator Algebras · Mathematics 2018-02-27 Rolando de Santiago , Sujan Pant

In this talk, I will survey recent progress made on the classification of von Neumann algebras arising from countable groups and their actions on probability spaces. In particular, I will present the first results which provide classes of…

Operator Algebras · Mathematics 2012-12-04 Adrian Ioana

Consider an inclusion of diffuse von Neumann algebras A c M . We say that A c M has the absorbing amenability property if for any diffuse subalgebra B c A and any amenable intermediate algebra B c D c M we have that D is contained in A. We…

Operator Algebras · Mathematics 2015-12-16 Arnaud Brothier , Chenxu Wen

We undertake a comprehensive study of structural properties of graph products of von Neumann algebras equipped with faithful, normal states, as well as properties of the graph products relative to subalgebras coming from induced subgraphs.…

In this paper, we give another two characterizations of relative amenability on finite von Neumann algebras, one of which can be thought of as an analogue of injective operator systems. As an application, we prove a stable property of…

Operator Algebras · Mathematics 2018-07-06 Xiaoyan Zhou , Junsheng Fang

Amenable actions of locally compact groups on von Neumann algebras are investigated by exploiting the natural module structure of the crossed product over the Fourier algebra of the acting group. The resulting characterisation of…

Operator Algebras · Mathematics 2021-01-20 Andrew McKee , Reyhaneh Pourshahami

For a topological group $G$, amenability can be characterized by the amenability of the convolution Banach algebra $L^1(G)$. Here a Banach algebra $A$ is called amenable if every bounded derivation from $A$ into any dual--type…

Functional Analysis · Mathematics 2025-07-01 Hikaru Awazu

Supramenability of groups is characterised in terms of invariant measures on locally compact spaces. This opens the door to constructing interesting crossed product C*-algebras for non-supramenable groups. In particular, stable Kirchberg…

Operator Algebras · Mathematics 2013-12-09 Julian Kellerhals , Nicolas Monod , Mikael Rordam

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

We construct a singly generated subalgebra of ${\mathcal K}({\mathcal H})$ which is non-amenable, yet is boundedly approximately contractible. The example embeds into a homogeneous von Neumann algebra. We also observe that there are singly…

Operator Algebras · Mathematics 2013-11-13 Yemon Choi

We introduce the notions of approximate Connes-amenability and approximate strong Connes-amenability for dual Banach algebras. Then we characterize these two types of algebras in terms of approximate normal virtual diagonals and approximate…

Functional Analysis · Mathematics 2011-01-25 G. H. Esslamzadeh , B. Shojaee

We prove a weak form of the mean ergodic theorem for actions of amenable locally compact quantum groups in the von Neumann algebra setting.

Operator Algebras · Mathematics 2008-12-05 Rocco Duvenhage

We prove that amenability of a discrete group is equivalent to dimension flatness of certain ring inclusions naturally associated with measure preserving actions of the group. This provides a group-measure space theoretic solution to a…

Group Theory · Mathematics 2013-05-16 David Kyed , Henrik Densing Petersen

Suppose $M$ is a tracial von Neumann algebra embeddable into $\mathcal R^{\omega}$ (the ultraproduct of the hyperfinite $II_1$-factor) and $X$ is an $n$-tuple of selfadjoint generators for $M$. Denote by $\Gamma(X;m,k,\gamma)$ the…

Operator Algebras · Mathematics 2007-05-23 Kenley Jung

Let $M$ be a finite von Neumann algebra (resp. a type II$_{1}$ factor) and let $N\subset M$ be a II$_{1}$ factor (resp. $N\subset M$ have an atomic part). We prove that the inclusion $N\subset M$ is amenable implies the identity map on $M$…

Operator Algebras · Mathematics 2018-09-05 Xiaoyan Zhou , Junsheng Fang