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Related papers: On the existence of J-class operators

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We introduce the notions of tauberian, cotauberian and weakly compact pair of closed subspaces of a Banach space. The theory produced by these notions is richer than that of the corresponding operators since an operator can be regarded as a…

Functional Analysis · Mathematics 2026-03-31 Manuel González , Antonio Martínez-Abejón

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

Let l be a Banach sequence space with a monotone norm in which the canonical system (e_{n}) is an unconditional basis. We show that if there exists a continuous linear unbounded operator between l-K\"{o}the spaces, then there exists a…

Functional Analysis · Mathematics 2017-04-17 Elif Uyanık , Murat H. Yurdakul

Let $T$ be a quasinilpotent operator on a Banach space. Under assumptions of a certain nonsymmetry in the growth of the resolvent of $T$, it is proved that every operator in the commutant of $T$ is not unicellular. In particular, $T$ has…

Functional Analysis · Mathematics 2024-04-09 Maria F. Gamal'

Motivated by the equivalent definition of a continuous operator between Banach spaces in terms of weakly null nets, we introduce two types of continuous operators between Banach lattices using unbounded absolute weak convergence. We…

Functional Analysis · Mathematics 2020-04-07 Omid Zabeti

We present a general method for constructing operators without non-trivial invariant closed subsets on a large class of non-reflexive Banach spaces. In particular, our approach unifies and generalizes several constructions due to Read of…

Functional Analysis · Mathematics 2017-05-17 Sophie Grivaux , Maria Roginskaya

The powerful concept of an operator ideal on the class of all Banach spaces makes sense in the real and in the complex case. In both settings we may, for example, consider compact, nuclear, or $2$--summing operators, where the definitions…

Functional Analysis · Mathematics 2016-09-06 Joerg Wenzel

In this paper, we construct maximally monotone operators that are not of Gossez's dense-type (D) in many nonreflexive spaces. Many of these operators also fail to possess the Br{\o}nsted-Rockafellar (BR) property. Using these operators, we…

Functional Analysis · Mathematics 2011-08-09 Heinz H. Bauschke , Jonathan M. Borwein , Xianfu Wang , Liangjin Yao

Generalizing a recent result on lineability of sets of non-injective linear operators, we prove, for quite general linear spaces $A$ of maps from an arbitraty set to a sequence space, that, for every $0 \neq f \in A$, the subset of $A$ of…

Functional Analysis · Mathematics 2024-04-16 Mikaela Aires , Geraldo Botelho

The notion of linear Hahn-Banach extension operator was first studied in detail by Heinrich and Mankiewicz (1982). Previously, J. Lindenstrauss (1966) studied similar versions of this notion in the context of non separable reflexive Banach…

Functional Analysis · Mathematics 2017-10-10 Sudeshna Basu , Ajit Iqbal Singh

A bounded linear operator between Banach spaces is called {\it completely continuous} if it carries weakly convergent sequences into norm convergent sequences. Isolated is a universal operator for the class of non-completely-continuous…

Functional Analysis · Mathematics 2016-09-06 Maria Girardi , William B. Johnson

We prove, under certain conditions, the existence of zeros for a weakly continuous operator on a paracompact topological space into the dual of a Banach space.

Functional Analysis · Mathematics 2013-10-09 Biagio Ricceri

We furnish a simple way of constructing an unbounded closed linear operator in a complex Banach space, whose spectrum is an arbitrary nonempty closed, in particular compact, subset of the complex plane.

Functional Analysis · Mathematics 2021-07-26 Marat V. Markin

A reflexive hereditarily indecomposable Banach space $\mathfrak{X}_{_{^\text{ISP}}}$ is presented, such that for every $Y$ infinite dimensional closed subspace of $\mathfrak{X}_{_{^\text{ISP}}}$ and every bounded linear operator…

Functional Analysis · Mathematics 2014-11-04 Spiros A. Argyros , Pavlos Motakis

In this paper, to solve the invariant subspace problem, contraction operators are classified into three classes ; (Case 1) completely non-unitary contractions with a non-trivial algebraic element, (Case 2) completely non-unitary…

General Mathematics · Mathematics 2009-01-31 Yun-Su Kim

In this paper, we study the existence of infinite dimensional closed linear subspaces of a rearrangement invariant space on [0,1] every nonzero element of which does not belong to any included rearrangement invariant space of the same class…

Functional Analysis · Mathematics 2014-09-04 César Ruiz , Víctor M. Sánchez

In this work we provide a characterization of distinct type of (linear and non-linear) maps between Banach spaces in terms of the differentiability of certain class of Lipschitz functions. Our results are stated in an abstract bornological…

Functional Analysis · Mathematics 2021-10-04 Mohammed Bachir , Sebastián Tapia-García

We show that there is an operator space notion of Lipschitz embeddability between operator spaces which is strictly weaker than its linear counterpart but which is still strong enough to impose linear restrictions on operator space…

Operator Algebras · Mathematics 2022-11-28 Bruno de Mendonça Braga , Javier Alejandro Chávez-Domínguez , Thomas Sinclair

We prove the existence of the invariant subspaces of some operators in a real Banach space. For example, linear isometries have invariant subspaces

Functional Analysis · Mathematics 2010-12-21 K. V. Storozhuk

By a result of Johnson, the Banach space $F=(\bigoplus_{n=1}^\infty \ell_1^n)_{\ell_\infty}$ contains a complemented copy of $\ell_1$. We identify $F$ with a complemented subspace of the space of (bounded, linear) operators on the reflexive…

Functional Analysis · Mathematics 2013-02-27 Tomasz Kania