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Related papers: Operator ideals on non-commutative function spaces

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Letting $E$, $F$ be Banach spaces, the main two results of this paper are the following: (1) If every (linear bounded) operator $E\rightarrow F$ is unconditionally converging, then every polynomial from $E$ to $F$ is unconditionally…

Functional Analysis · Mathematics 2016-09-06 Manuel Gonzalez , Joaquin M. Gutierrez

It is shown that if $1<p<\infty$ and $X$ is a subspace or a quotient of an $\ell_p$-direct sum of finite dimensional Banach spaces, then for any compact operator $T$ on $X$ such that $\|I+T\|>1$, the operator $I+T$ attains its norm. A…

Functional Analysis · Mathematics 2012-09-07 Stanislav Shkarin

An algebra of bounded linear operators on a Banach space is said to be {\em strongly compact} if its unit ball is precompact in the strong operator topology, and a bounded linear operator on a Banach space is said to be {\em strongly…

Functional Analysis · Mathematics 2012-08-17 Miguel Lacruz , Maria del Pilar Romero de la Rosa

We show that if the Hardy-Littlewood maximal operator is bounded on a reflexive Banach function space $X(\mathbb{R})$ and on its associate space $X'(\mathbb{R})$, then the space $X(\mathbb{R})$ has an unconditional wavelet basis. As a…

Functional Analysis · Mathematics 2019-08-22 Cláudio A. Fernandes , Alexei Yu. Karlovich , Yuri I. Karlovich

A proper ideal $I$ in a commutative ring with unity is called a $z^\circ$-ideal if for each $a$ in $I$, the intersection of all minimal prime ideals in $R$ which contain $a$ is contained in $I$. For any totally ordered field $F$ and a…

General Topology · Mathematics 2017-12-25 Sagarmoy Bag , Sudip Kumar Acharyya , Dhananjoy Mandal

We present a sufficient condition for smoothness of bounded linear operators on Banach spaces for the first time. Let $T, A \in B(\mathbb{X}, \mathbb{Y}),$ where $\mathbb{X}$ is a real Banach space and $\mathbb{Y}$ is a real normed linear…

Functional Analysis · Mathematics 2024-07-30 Kallol Paul , Debmalya Sain , Puja Ghosh

A bounded operator on a real or complex separable infinite-dimensional Banach space $Z$ is universal in the sense of Glasner and Weiss if for every invertible ergodic measure-preserving transformation $T$ of a standard Lebesgue probability…

Dynamical Systems · Mathematics 2015-12-18 Sophie Grivaux

This is a survey article of geometric properties of noncommutative symmetric spaces of measurable operators $E(\mathcal{M},\tau)$, where $\mathcal{M}$ is a semifinite von Neumann algebra with a faithful, normal, semifinite trace $\tau$, and…

Operator Algebras · Mathematics 2017-04-10 Malgorzata Marta Czerwinska , Anna Kaminska

A pair of functions defined on a set X with values in a vector space E is said to be disjoint if at least one of the functions takes the value 0 at every point in X. An operator acting between vector-valued function spaces is disjointness…

Functional Analysis · Mathematics 2012-03-19 Denny H. Leung , Ya-Shu Wang

In this paper we provide necessary and sufficient conditions for the existence of non-norm-attaining operators in $\mathcal{L}(E, F)$. By using a theorem due to Pfitzner on James boundaries, we show that if there exists a relatively compact…

Functional Analysis · Mathematics 2021-02-15 Sheldon Dantas , Mingu Jung , Gonzalo Martínez-Cervantes

For $C^*$-algebras $A$ and $B$, we prove the slice map conjecture for ideals in the operator space projective tensor product $A \hat\otimes B$. As an application, a characterization of prime ideals in the Banach $\ast$-algebra $A\hat\otimes…

Operator Algebras · Mathematics 2011-06-17 Ranjana Jain , Ajay Kumar

We establish criteria for the stability of the essential spectrum for unbounded operators acting in Banach modules. The applications cover operators acting on sections of vector fiber bundles over non-smooth manifolds or locally compact…

Spectral Theory · Mathematics 2007-05-23 Vladimir Georgescu , Sylvain Golenia

Let $\mathcal{H}$ be a separable infinite-dimensional complex Hilbert space and let $\mathcal{J}$ be a two-sided ideal of the algebra of bounded operators $\mathcal{B}(\mathcal{H})$. The groups $\mathcal{G} \ell_\mathcal{J}$ and…

Functional Analysis · Mathematics 2023-07-06 Eduardo Chiumiento , Pedro Massey

The classical theorems of Banach and Stone, Gelfand and Kolmogorov, and Kaplansky show that a compact Hausdorff space $X$ is uniquely determined by the linear isometric structure, the algebraic structure, and the lattice structure,…

Functional Analysis · Mathematics 2013-10-29 Denny H. Leung , Lei Li

In this paper we study $R$-boundedness of operator families $\mathcal{T}\subset \calL(X,Y)$, where $X$ and $Y$ are Banach spaces. Under cotype and type assumptions on $X$ and $Y$ we give sufficient conditions for $R$-boundedness. In the…

Functional Analysis · Mathematics 2009-01-08 Mark Veraar , Tuomas Hytonen

In the nonlinear field of multilinear operators and homogeneous polynomials between Banach spaces, we develop a technique, based on the transformation of vector-valued sequences, to create new examples of hyper-ideals of multilinear…

Functional Analysis · Mathematics 2021-10-04 Geraldo Botelho , Raquel Wood

Let $\mathcal{M}$ be a von Neumann algebra, $\mathcal{I}$ a weak-operator dense ideal in $\mathcal{M}$, and $\Phi$ a unitarily invariant $\|\cdot\|$-dominating norm on $\mathcal{I}$. In this paper, we provide a necessary and sufficient…

Operator Algebras · Mathematics 2026-02-03 Minghui Ma , Rui Shi , Tianze Wang

We consider a class of bounded linear operators between Banach spaces, which we call operators with the Kato property, that includes the family of strictly singular operators between those spaces. We show that if $T:E\to F$ is a dense-range…

Functional Analysis · Mathematics 2025-06-30 Mar Jiménez Sevilla , Sebastián Lajara López , Miguel Ángel Ruiz Risueño

We develop general techniques and present an approach to solve the problem of constructing a maximal Banach ideal $({\frak A},{\bf A)}$ which does not satisfy a transfer of the norm estimation in the principle of local reflexivity to its…

Functional Analysis · Mathematics 2007-05-23 F. Oertel

Given a Banach space X and a bounded linear operator T on X, a subspace Y of X is almost invariant under T if TY is a subspace of Y+F for some finite-dimensional ``error'' F. In this paper, we study subspaces that are almost invariant under…

Functional Analysis · Mathematics 2009-09-21 Alexey I. Popov