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Related papers: Amenability and uniform Roe algebras

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We revisit G. Elek's notion of amenable representation type, where algebras are characterised by every indecomposable module being "almost" the direct sum of modules of bounded dimension. We give a new proof of his result that string…

Representation Theory · Mathematics 2022-08-19 Sebastian Eckert

We construct reduced and full semigroup C*-algebras for left cancellative semigroups. Our new construction covers particular cases already considered by A. Nica and also Toeplitz algebras attached to rings of integers in number fields due…

Operator Algebras · Mathematics 2012-02-23 Xin Li

Let A be a Banach algebra and I be a closed ideal of A. We say that A is amenable relative to I, if A/I is an amenable Banach algebra. We study the relative amenability of Banach algebras and investigate the relative amenability of…

Functional Analysis · Mathematics 2019-12-02 Hoger Ghahramani , Wania Khodakarami , Esmaeil Feizi

Using the methods of Ozawa [4] and Runde [5], we show that a type I von Neumann algebra is approximately amenable if and only if it is amenable.

Functional Analysis · Mathematics 2025-04-11 Yong Zhang

What is the probability that a random UHF algebra is of infinite type? What is the probability that a random simple AI algebra has at most $k$ extremal traces? What is the expected value of the radius of comparison of a random…

Operator Algebras · Mathematics 2023-08-16 Bhishan Jacelon

The present article is a review of recent developments concerning the notion of F{\o}lner sequences both in operator theory and operator algebras. We also give a new direct proof that any essentially normal operator has an increasing…

Operator Algebras · Mathematics 2013-04-12 Pere Ara , Fernando Lledó , Dmitry V. Yakubovich

We prove a functoriality result for the full C*-algebras of right-LCM monoids with respect to monoid inclusions that are closed under factorization and preserve orthogonality, and use this to show that if a right-LCM monoid is amenable in…

Operator Algebras · Mathematics 2020-01-15 Marcelo Laca , Boyu Li

We continue our study of the concepts of amenability and co-amenability for algebraic quantum groups in the sense of A. Van Daele and our investigation of their relationship with nuclearity and injectivity. One major tool for our analysis…

Operator Algebras · Mathematics 2007-05-23 E. Bedos , G. J. Murphy , L. Tuset

The local trajectories method establishes invertibility in algebras $\mathcal{B}= \alg(\mathcal{A}, U_G)$, for a unital $C^*$-algebra $\mathcal{A}$ with a non-trivial center, and a unitary group $U_g$, $g\in G$, with $G$ a discrete group,…

Operator Algebras · Mathematics 2024-12-24 M. Amélia Bastos , Catarina C. Carvalho , Manuel G. Dias

We consider inductive systems of C*-algebras with completely positive contractive connecting maps. We define a condition, called C*-encoding, which is sufficient for the limit of the system to be completely order isomorphic to a C*-algebra…

Operator Algebras · Mathematics 2023-06-26 Kristin Courtney

We introduce the notion of confined subalgebras in the context of the group von Neumann algebra. We also define Uniformly Recurrent States -- an operator-algebraic analog of Uniformly Recurrent Subgroups. Using this framework, we show that…

Operator Algebras · Mathematics 2026-04-21 Tattwamasi Amrutam , Yongle Jiang

Let $\frak{F}(X, A)$ be one of the Banach algebras $\hbox{Lip}(X, A)$ or $\hbox{lip}(X, A)$. In this paper, we show that $\frak{F}(X, A)$ is amenable if and only if $X$ is uniformly discrete and $A$ is amenable. We also prove that the…

Functional Analysis · Mathematics 2022-11-29 M. J. Mehdipour , A. Rejali

We propose a new framework that generalizes the parameters of neural network models to $C^*$-algebra-valued ones. $C^*$-algebra is a generalization of the space of complex numbers. A typical example is the space of continuous functions on a…

Machine Learning · Statistics 2022-08-15 Yuka Hashimoto , Zhao Wang , Tomoko Matsui

A subgroup of an amenable group is amenable. The $C^*$-algebra version of this fact is false. This was first proved by M.-D. Choi who proved that the non-nuclear $C^*$-algebra $C^*_r(\ZZ_2*\ZZ_3)$ is a subalgebra of the nuclear Cuntz…

Operator Algebras · Mathematics 2013-02-26 Guyan Robertson , Tim Steger

We study which von Neumann algebras can be embedded into uniform Roe algebras and quasi-local algebras associated to a uniformly locally finite metric space $X$. Under weak assumptions, these $\mathrm{C}^*$-algebras contain embedded copies…

Operator Algebras · Mathematics 2023-02-20 Florent P. Baudier , Bruno de Mendonça Braga , Ilijas Farah , Alessandro Vignati , Rufus Willett

We generalize the notion of a continuous field of C*-algebras to that of Hilbert C*-bimodules. Given a partially ordered set $P$ and a monotonically non-decreasing family of ternary rings of operators (TROs) assigned to the points of $P$,…

Operator Algebras · Mathematics 2026-03-25 Vladimir Manuilov

In Rufus Willett's and the authors paper "Bounded Derivations on Uniform Roe Algebras" we showed that all bounded derivations on a uniform Roe algebra $C^*_u(X)$ associated to a bounded geometry metric space $X$ are inner. This naturally…

Operator Algebras · Mathematics 2021-09-29 Matthew Lorentz

In this article we show that there are branching systems (which induce representations of the graph algebra $C^*(E)$) associated to each row-countable graph $E$. For row-countable graphs, we characterize the condition $(L)$ via branching…

Operator Algebras · Mathematics 2019-10-30 Ben hur Eidt , Danilo Royer

Let $X$ be a discrete metric space with bounded geometry. We show that if $X$ admits an "A-by-CE coarse fibration", then the canonical quotient map $\lambda: C^*_{\max}(X)\to C^*(X)$ from the maximal Roe algebra to the Roe algebra of $X$,…

Operator Algebras · Mathematics 2021-11-12 Liang Guo , Zheng Luo , Qin Wang , Yazhou Zhang

Moore characterized the amenability of automorphism groups of countable ultrahomogeneous structures by a Ramsey-type property. We extend this result to automorphism groups of metric Fra\"iss\'e structures, which encompass all Polish groups.…

Logic · Mathematics 2013-09-06 Adriane Kaïchouh
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