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We give a survey of the known connections between regularity conditions and amenability conditions in the setting of uniform algebras. For a uniform algebra $A$ we consider the set, $A_{lc}$, of functions in $A$ which are locally constant…

Functional Analysis · Mathematics 2014-12-25 M. J. Heath , J. F. Feinstein

It is easy to see that every character (i.e. unital *-homomorphism to the complex numbers) of a commutative unital associative *-algebra is a pure state (i.e. extreme point in the convex set of all normalized positive linear functionals).…

Functional Analysis · Mathematics 2018-04-04 Matthias Schötz

In this note the result by A. Swift concerning the embeddability of countably branching bundle graphs into Banach spaces is extended from the context of reflexive spaces with an unconditional asymptotic structure to the context of dual…

Functional Analysis · Mathematics 2021-04-22 Yoël Perreau

We study the structure of separable elements in bipartite C$^{\ast}$-algebras, focusing on the existence and size of a separable neighbourhood around the identity element. While this phenomenon is well understood in the finite-dimensional…

Operator Algebras · Mathematics 2026-04-02 Mizanur Rahaman , Mateusz Wasilewski

In this paper the weak topology on a normed space is studied from the viewpoint of infinite-dimensional topology. Besides the weak topology on a normed space $X$ (coinciding with the topology of uniform convergence on finite subsets of the…

General Topology · Mathematics 2019-08-27 Taras Banakh

We introduce and study locally AW*-algebras (Baer locally C*-algebras) as a locally multiplicatively-convex generalization of AW*-algebras of Kaplansky. Among other basic properties of these algebras, it is established that: {\bullet} A…

Operator Algebras · Mathematics 2010-12-24 Alexander A. Katz

We study properties of the central sequence algebra of a C*-algebra, and we present an alternative approach to a recent result of Matui and Sato. They prove that every unital separable simple nuclear C*-algebra, whose trace simplex is…

Operator Algebras · Mathematics 2013-06-10 Eberhard Kirchberg , Mikael Rordam

A classification is given of certain separable nuclear C*-algebras not necessarily of real rank zero, namely, the class of separable simple C*-algebras which are inductive limits of continuous-trace C*-algebras whose building blocks have…

Operator Algebras · Mathematics 2007-05-23 George A. Elliott , Cristian Ivanescu

The paper is devoted to the convex-set counterpart of the theory of weak$^*$ derived sets initiated by Banach and Mazurkiewicz for subspaces. The main result is the following: For every nonreflexive Banach space $X$ and every countable…

Functional Analysis · Mathematics 2021-12-14 Mikhail I. Ostrovskii

The following topics are presented in these notes: Elements of Banach algebras, Banach algebras of the form $L^1(G)$, where $G$ is a locally compact group, spectrum of elements of Banach algebras, the spectral theory of compact operators on…

Operator Algebras · Mathematics 2021-10-13 Vahid Shirbisheh

In this paper, we deal with cohomological properties of weak amenability, cyclic amenability, cyclic weak amenability and point amenability of Banach algebras. We look at some hereditary properties of them and show that continuous…

Functional Analysis · Mathematics 2022-10-10 M. J. Mehdipour , A. Rejali

In this paper we study the nuclearity and weak containment property of reduced cross-sectional C*-algebras of Fell bundles over inverse semigroups. In order to develop the theory, we first prove an analogue of Fell's absorption trick in the…

Operator Algebras · Mathematics 2023-08-10 Alcides Buss , Diego Martínez

We consider three notions of divisibility in the Cuntz semigroup of a C*-algebra, and show how they reflect properties of the C*-algebra. We develop methods to construct (simple and non-simple) C*-algebras with specific divisibility…

Operator Algebras · Mathematics 2014-02-26 Leonel Robert , Mikael Rordam

A remarkable theorem of R. C. James is the following: suppose that $X$ is a Banach space and $C \subseteq X$ is a norm bounded, closed and convex set such that every linear functional $x^* \in X^*$ attains its supremum on $C$; then $C$ is a…

Functional Analysis · Mathematics 2016-09-06 Charles P. Stegall

In the main result of the paper we extend Rosenthal's characterization of Banach spaces with the Schur property by showing that for a quasi-complete locally convex space $E$ whose separable bounded sets are metrizable the following…

Functional Analysis · Mathematics 2018-09-25 Saak Gabriyelyan

Given two unital C*-algebras $A$ and $B$, we study, when it exists, the universal unital $C^*$-algebra $\mathcal{U}(A,B)$ generated by the coefficients of a unital $*$-homomorphism $\rho\,:\, A\rightarrow B\otimes\mathcal{U}(A,B)$. When $B$…

Operator Algebras · Mathematics 2024-12-02 Pierre Fima , Malay Mandal , Issan Patri

Let X be a path connected, compact metric space and let A be a unital separable simple nuclear Z-stable real rank zero C*-algebra. We classify all the unital *-embeddings (up to approximate unitary equivalence) of C(X) into A. Specifically,…

Operator Algebras · Mathematics 2007-09-11 P. W. Ng , Wilhelm Winter

Let $A$ be a commutative semisimple Banach algebra, $X$ be a locally compact Hausdorff topological space and $G$ be a locally compact topological group. In this paper, we investigate several properties of vector valued Banach algebras…

Functional Analysis · Mathematics 2022-01-04 Ali Rejali , Mitra Amiri

In this paper we study unitary Ramond twisted representations of minimal $W$-algebras. We classify all such irreducible highest weight representations with a non-Ramond extremal highest weight (unitarity in the Ramond extremal case, as well…

Representation Theory · Mathematics 2026-02-26 Victor G. Kac , Pierluigi Möseneder Frajria , Paolo Papi

Let $A$ be a Banach algebra with the second dual $A^{**}$. If $A$ has a bounded approximate identity $(=BAI)$, then $A^{**}$ is unital if and only if $A^{**}$ has a $weak^* bounded approximate $$identity(=W^*BAI)$. If $A$ is Arens regular…

Functional Analysis · Mathematics 2009-04-28 Kazem Haghnejad Azar , Abdolhamid Riazi