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Related papers: Singular value functions for C\(^*\)-algebras

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Let $H(\mathbb{D})$ be the space of all analytic functions in the unit disc $\mathbb{D}$. For $g\in H(\mathbb{D})$, the generalized Hilbert operator $\mathcal{H}_{g}$ is defined by $$\mathcal{H}_{g}(f)(z)=\int_{0}^{1}f(t)g'(tz)dt, \ \ z\in…

Functional Analysis · Mathematics 2026-01-14 Pengcheng Tang

We present geometric characterizations of the partial isometries, unitaries, and invertible operators in C*-algebras and von Neumann algebras.

Operator Algebras · Mathematics 2007-05-23 Charles Akemann , Nik Weaver

Among all $C^\infty$-algebras we characterize those which are algebras of smooth functions on smooth separable Hausdorff manifolds.

Geometric Topology · Mathematics 2008-02-03 Peter W. Michor , Jiři Vanžura

We explore the recently introduced local-triviality dimensions by studying gauge actions on graph $C^*$-algebras, as well as the restrictions of the gauge action to finite cyclic subgroups. For $C^*$-algebras of finite acyclic graphs and…

Operator Algebras · Mathematics 2021-06-09 Alexandru Chirvasitu , Benjamin Passer , Mariusz Tobolski

Let $E$ and $F$ be Hilbert $C^*$-modules over a $C^*$-algebra $\CAlg{A}$. New classes of (possibly unbounded) operators $t:E\to F$ are introduced and investigated. Instead of the density of the domain $\Def(t)$ we only assume that $t$ is…

Operator Algebras · Mathematics 2015-07-09 René Gebhardt , Konrad Schmüdgen

We study operator spaces, operator algebras, and operator modules, from the point of view of the `noncommutative Shilov boundary'. In this attempt to utilize some `noncommutative Choquet theory', we find that Hilbert C$^*-$modules and their…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher

We give a solution, via operator spaces, of an old problem in the Morita equivalence of C*-algebras. Namely, we show that C*-algebras are strongly Morita equivalent in the sense of Rieffel if and only if their categories of left operator…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher

Let $A$ be a commutative Banach algebra and $X$ be a compact space. The class of Banach $A$-valued function algebras on $X$ consists of subalgebras of $C(X,A)$ with certain properties. We introduce the notion of $A$-characters on an…

Functional Analysis · Mathematics 2016-09-14 Mortaza Abtahi

We introduce unbounded multipliers on operator spaces. These multipliers generalize both, regular operators on Hilbert C*-modules and (bounded) multipliers on operator spaces.

Operator Algebras · Mathematics 2010-07-23 Hendrik Schlieter , Wend Werner

In the paper we describe the C*-algebras of noncommutative spherical tight frames over some C*-algebras and then apply to study the noncommutative version of the universal classifying space.

K-Theory and Homology · Mathematics 2007-05-23 Do Ngoc Diep

We prove a uniqueness theorem and give a characterization of simplicity for Steinberg algebras associated to non-Hausdorff ample groupoids. We also prove a uniqueness theorem and give a characterization of simplicity for the C*-algebra…

Operator Algebras · Mathematics 2019-05-17 Lisa Orloff Clark , Ruy Exel , Enrique Pardo , Aidan Sims , Charles Starling

We consider the Toeplitz operators on the weighted Bergman spaces over the unit ball $\mathbb{B}^n$ and their analytic continuation. We proved the commutativity of the $C^*-$algebras generated by the analytic continuation of Toeplitz…

Functional Analysis · Mathematics 2023-09-06 Khalid Bdarneh , Gestur Ólafsson

We prove a T(1) Theorem to completely characterize compactness of Calderon-Zygmund operators. The result provides sufficient and necessary conditions for the compactness of singular integral operators acting on L^p(R).

Classical Analysis and ODEs · Mathematics 2014-10-08 Paco Villarroya

This paper introduces and explores functions defined on \( H^* \)-normal spaces through the framework of \( H^* \)-open sets. We extend the concept of \( H^* \)-normality and investigate its connections with \( g \)-normal and classical…

General Topology · Mathematics 2025-07-10 Neeraj Kumar Tomar , M. C. Sharma , Amit Ujlayan

Classical pseudo-differential operators of order zero on a graded nilpotent Lie group $G$ form a $^*$-subalgebra of the bounded operators on $L^2(G)$. We show that its $C^*$-closure is an extension of a noncommutative algebra of principal…

Operator Algebras · Mathematics 2025-01-13 Eske Ewert

We revisit and connect several notions of algebraic multiplicities of zeros of analytic operator-valued functions and discuss the concept of the index of meromorphic operator-valued functions in complex, separable Hilbert spaces.…

Spectral Theory · Mathematics 2016-11-14 Jussi Behrndt , Fritz Gesztesy , Helge Holden , Roger Nichols

Let CBV denote the Banach algebra of all continuous real-valued functions of bounded variation, defined in [0,1]. We show that the set of strongly singular functions in CBV is nonseparably spaceable. We also prove that certain families of…

Functional Analysis · Mathematics 2013-01-23 Marek Balcerzak , Artur Bartoszewicz , Malgorzata Filipczak

We study the relationship between operator algebras, $C^*$ and von Neumann, acting on a Hilbert space and unitary representations of topological groups on the same space. We obtain certain correspondences between both these families of…

Operator Algebras · Mathematics 2025-05-08 Raul Quiroga-Barranco

The continuity of the core inverse and the dual core inverse is studied in the setting of C*-algebras. Later, this study is specialized to the case of bounded Hilbert space operators and to complex matrices. In addition, the…

Operator Algebras · Mathematics 2017-06-08 Julio Benítez , Enrico Boasso , Sanzhang Xu

We prove a Montel theorem for Hilbert space valued functions, and a non-commutative version of this theorem, by composing with unitaries to achieve convergence.

Functional Analysis · Mathematics 2017-06-20 Jim Agler , John E. McCarthy