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Related papers: Characterizations of ordered operator spaces

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The main goal of this paper is to discuss the recent advancements of operator means for accretive matrices in a more general setting. In particular, we present the general form governing the well established definition of geometric mean,…

Functional Analysis · Mathematics 2021-04-16 Yassine Bedrani , Fuad Kittaneh , Mohammed Sababheh

We investigate when a map on a selfadjoint operator space $E$ is an embedding, i.e., when its unitisation in the sense of Werner is completely isometric. Combining with results of Russell, of Ng, and of Dessi, the second and the last…

In this paper, we present new characterizations of normal and positive operators in terms of their powers. Among other things, we show that if $T^2$ is normal, $\mathcal{W}(T^{2k+1})$ lies on one side of a line passing through the origin…

Functional Analysis · Mathematics 2025-03-18 Hranislav Stanković

The main aim of this paper is to generalize the classical concept of positive operator, and to develop a general extension theory, which overcomes not only the lack of a Hilbert space structure, but also the lack of a normable topology. The…

Functional Analysis · Mathematics 2018-10-08 Zsigmond Tarcsay , Tamás Titkos

In this paper, we study {\it operator spaces\/} in the sense of the theory developed recently by Blecher-Paulsen [BP] and Effros-Ruan [ER1]. By an operator space, we mean a closed subspace $E\subset B(H)$, with $H$ Hilbert. We will be…

Functional Analysis · Mathematics 2016-09-06 Gilles Pisier

We characterize the pairs of operator spaces which occur as pairs of Morita equivalence bimodules between non-selfadjoint operator algebras in terms of the mutual relation between the spaces. We obtain a characterization of the operator…

Operator Algebras · Mathematics 2007-05-23 I. G. Todorov

The aim of the present paper is to define compact operators on asymmetric normed spaces and to study some of their properties. The dual of a bounded linear operator is defined and a Schauder type theorem is proved within this framework. The…

Functional Analysis · Mathematics 2007-05-23 Stefan Cobzaş

We study the spectral properties of positive absolutely minimum attaining operators defined on infinite dimensional complex Hilbert spaces and using that derive a characterization theorem for such type of operators. We construct several…

Spectral Theory · Mathematics 2017-11-07 J. Ganesh , G. Ramesh , D. Sukumar

A map between operator spaces is called completely coarse if the sequence of its amplifications is equi-coarse. We prove that all completely coarse maps must be $\mathbb R$-linear. On the opposite direction of this result, we introduce a…

Operator Algebras · Mathematics 2020-06-02 Bruno M. Braga , Javier Alejandro Chávez-Domínguez

We show that the symmetrized product $AB+BA$ of two positive operators $A$ and $B$ is positive if and only if $f(A+B)\leq f(A)+f(B)$ for all non-negative operator monotone functions $f$ on $[0,\infty)$ and deduce an operator inequality. We…

Functional Analysis · Mathematics 2012-03-21 M. S. Moslehian , H. Najafi

Three themes of general topology: quotient spaces; absolute retracts; and inverse limits - are reapproached here in the setting of metrizable uniform spaces, with an eye to applications in geometric and algebraic topology. The results…

Geometric Topology · Mathematics 2022-11-21 Sergey A. Melikhov

We examine k-minimal and k-maximal operator spaces and operator systems, and investigate their relationships with the separability problem in quantum information theory. We show that the matrix norms that define the k-minimal operator…

Operator Algebras · Mathematics 2011-02-08 Nathaniel Johnston , David W. Kribs , Vern I. Paulsen , Rajesh Pereira

In this paper, we characterize absolute norm-attainability for compact hyponormal operators. We give necessary and sufficient conditions for a bounded linear compact hyponormal operator on an infinite dimensional complex Hilbert space to be…

Functional Analysis · Mathematics 2019-03-29 Benard Okelo

We introduce a class of operators on abstract measure spaces, which unifies the Calder\'on-Zygmund operators on spaces of homogeneous type, the maximal functions and the martingale transforms. We prove that such operators can be dominated…

Classical Analysis and ODEs · Mathematics 2022-11-07 Grigori A. Karagulyan

An operator mean is a binary operation assigned to each pair of positive operators satisfying monotonicity, continuity from above, the transformer inequality and the fixed-point property. It is well known that there are one-to-one…

Functional Analysis · Mathematics 2014-08-26 Pattrawut Chansangiam

In this paper we study some geometric properties like parallelism, orthogonality and semi-rotundity in the space of bounded linear operators. We completely characterize parallelism of two compact linear operators between normed linear…

Functional Analysis · Mathematics 2024-08-13 Arpita Mal , Debmalya Sain , Kallol Paul

We give canonical forms of selfadjoint and isometric operators on a complex vector space $U$ with scalar product given by a positive semidefinite Hermitian form, and of Hermitian forms on $U$. For an arbitrary system of semiunitary spaces…

Representation Theory · Mathematics 2020-12-29 Victor A. Bovdi , Tetiana Klymchuk , Tetiana Rybalkina , Mohamed A. Salim , Vladimir V. Sergeichuk

This paper is devoted to the generalization of the theory of total positivity. We say that a linear operator A in R^n is generalized totally positive (GTP), if its jth exterior power preserves a proper cone K_j in the corresponding space…

Spectral Theory · Mathematics 2013-01-17 O. Y. Kushel

In this paper, we extend the notion of orthogonality to the general elements of an absolute matrix order unit space and relate it to the orthogonality among positive elements. We introduce the notion of a partial isometry in an absolute…

Functional Analysis · Mathematics 2019-12-13 Anil Kumar Karn , Amit kumar

Let $\mathcal{T}_{+}(E)$ be the tensor algebra of a $W^{*}$-correspondence $E$ over a $W^{*}$-algebra $M$. In earlier work, we showed that the completely contractive representations of $\mathcal{T}_{+}(E)$, whose restrictions to $M$ are…

Operator Algebras · Mathematics 2015-07-09 Paul S. Muhly , Baruch Solel