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Related papers: Spaceability on some classes of Banach spaces

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We study ergodicity of composition operators on rearrangement-invariant Banach function spaces. More precisely, we give a natural and easy-to-check condition on the symbol of the operator which entails mean ergodicity on a very large class…

Functional Analysis · Mathematics 2025-10-15 Thomas Kalmes , Dalimil Peša

It is proved that a commutative algebra $A$ of operators on a reflexive real Banach space has an invariant subspace if each operator $T\in A$ satisfies the condition $$\|1- \varepsilon T^2\|_e \le 1 + o(\varepsilon) \text{ when }…

Functional Analysis · Mathematics 2022-09-23 V. I. Lomonosov , V. S. Shulman

The essence of the notion of lineability and spaceability is to find linear structures in somewhat chaotic environments. The existing methods, in general, use \textit{ad hoc} arguments and few general techniques are known. Motivated by the…

Functional Analysis · Mathematics 2015-10-01 Tony K. Nogueira , Daniel Pellegrino

Let $X$ and $Y$ be Banach spaces such that the ideal of operators which factor through $Y$ has codimension one in the Banach algebra $\mathscr{B}(X)$ of all bounded operators on $X$, and suppose that $Y$ contains a complemented subspace…

K-Theory and Homology · Mathematics 2015-04-06 Tomasz Kania , Piotr Koszmider , Niels Jakob Laustsen

A necessary and sufficient condition for fractional Orlicz-Sobolev spaces to be continuously embedded into $L^\infty(\mathbb R^n)$ is exhibited. Under the same assumption, any function from the relevant fractional-order spaces is shown to…

Functional Analysis · Mathematics 2022-07-22 Angela Alberico , Andrea Cianchi , Luboš Pick , Lenka Slavíková

We provide some necessary and sufficient conditions for a proper lower semicontinuous convex function, defined on a real Banach space, to be locally or globally Lipschitz continuous. Our criteria rely on the existence of a bounded selection…

Functional Analysis · Mathematics 2019-11-13 Bao Tran Nguyen , Pham Duy Khanh

Given a positive operator-valued measure $\nu$ acting on the Borel sets of a locally compact Hausdorff space $X$, with outcomes in the algebra $\mathcal B(\mathcal H)$ of all bounded operators on a (possibly infinite-dimensional) Hilbert…

Functional Analysis · Mathematics 2022-01-31 Sarah Plosker , Christopher Ramsey

There are two main aims of the paper. The first one is to extend the criterion for the precompactness of sets in Banach function spaces to the setting of quasi-Banach function spaces. The second one is to extend the criterion for the…

Functional Analysis · Mathematics 2017-01-11 António Caetano , Amiran Gogatishvili , Bohumír Opic

We present some old and new results on a class of invariant spaces of holomorphic functions on symmetric domains, both in their circular bounded realizations and in their unbounded realizations as Siegel domains of type II. These spaces…

Complex Variables · Mathematics 2026-04-21 Mattia Calzi

We prove that a non ergodic Banach space must be near Hilbert. In particular, $\ell_p$ ($2<p<\infty$) is ergodic. This reinforces the conjecture that $\ell_2$ is the only non ergodic Banach space. As an application of our criterion for…

Functional Analysis · Mathematics 2016-11-18 W. Cuellar-Carrera

For a certain class of algebras $\cal A$ we give a method for constructing Banach spaces $X$ such that every operator on $X$ is close to an operator in $\cal A$. This is used to produce spaces with a small amount of structure. We present…

Functional Analysis · Mathematics 2008-09-01 W. T. Gowers , B. Maurey

The notions of column and row operator space were extended by A. Lambert from Hilbert spaces to general Banach spaces. In this paper, we use column and row spaces over quotients of subspaces of general $L_p$-spaces to equip several Banach…

Functional Analysis · Mathematics 2008-11-23 Matthias Neufang , Volker Runde

In this paper we extend a result of Semrl stating that every 2-local automorphism of the full operator algebra on a separable infinite dimensional Hilbert space is an automorphism. In fact, besides separable Hilbert spaces, we obtain the…

Operator Algebras · Mathematics 2007-05-23 Lajos Molnar

In the short note we prove that for every $0<p<1$, there exists an infinite dimensional closed linear subspace of $\mathcal{L}\left( \ell_{p};\ell_{p}\right) $ every nonzero element of which is non $(r,s)$-absolutely summing operator for…

Functional Analysis · Mathematics 2019-02-27 Daniel Tomaz

In this paper, we study the boundedness of the Hilbert transformation in Lorentz function spaces, thereby complementing classical results of Boyd. We also characterize the optimal range of a triangular truncation operator in…

Functional Analysis · Mathematics 2021-01-11 F. Sukochev , K. Tulenov , D. Zanin

We characterize real Banach spaces $Y$ such that the pair $(\ell_\infty ^n, Y)$ has the Bishop-Phelps-Bollob\'as property for operators. To this purpose it is essential the use of an appropriate basis of the domain space $\R^n$. As a…

Functional Analysis · Mathematics 2021-06-14 M. D. Acosta , J. L. Dávila

It is proved that the relation of isomorphism between separable Banach spaces is a complete analytic equivalence relation, i.e., that any analytic equivalence relation Borel reduces to it. Thus, separable Banach spaces up to isomorphism…

Functional Analysis · Mathematics 2014-02-26 Valentin Ferenczi , Alain Louveau , Christian Rosendal

This paper is concerned with the differential sensitivity analysis of variational inequalities in Banach spaces whose solution operators satisfy a generalized Lipschitz condition. We prove a sufficient criterion for the directional…

Optimization and Control · Mathematics 2017-11-09 Constantin Christof , Gerd Wachsmuth

We consider problems concerning the partial order structure of the set of spreading models of Banach spaces. We construct examples of spaces showing that the possible structure of these sets include certain classes of finite semi-lattices…

Functional Analysis · Mathematics 2007-05-23 S. J. Dilworth , E. Odell , B. Sari

In the paper is considered two problems on extension of operators whose range space for the first problem (or domain space for the second one) belongs to the fixed class of finite equivalence, which is generated by a given Banach space $X$.…

Functional Analysis · Mathematics 2007-05-23 Eugene Tokarev