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Related papers: Narrow operators on lattice-normed spaces

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The object of this paper is to prove a version of the Beurling-Helson-Lowdenslager invariant subspace theorem for operators on certain Banach spaces of functions on a multiply connected domain in the complex plane. The norms for these…

Functional Analysis · Mathematics 2016-07-06 Yanni Chen , Don Hadwin , Zhe Liu , Eric Nordgren

For locally convex spaces $X$ and $Y$, the continuous linear map $T:X \to Y$ is said to be bounded if it maps zero neighborhoods of $X$ into bounded sets of $Y$. We denote $(X,Y) \in \mathcal{B}$ when every operator between $X$ and $Y$ is…

Functional Analysis · Mathematics 2016-05-03 Ersin Kızgut , Elif Uyanık , Murat Yurdakul

A continuous operator $T$ between two Banach lattices $E$ and $F$ is called almost order-weakly compact, whenever for each almost order bounded subset $A$ of $E$, $T(A)$ is a relatively weakly compact subset of $F$. In Theorem 4, we show…

Functional Analysis · Mathematics 2022-01-10 Mina Matin , Mina Matin , Kazem Haghnejad Azar , Ali Ebadi

A thorough investigation is made of the optimal domain space of generalized Volterra operators, Ces\`aro operators and other operators when they act in various Banach spaces of analytic functions. Of particular interest is the situation…

Functional Analysis · Mathematics 2026-04-02 Angela A. Albanese , José Bonet , Werner J. Ricker

The numerical range of a bounded linear operator on a complex Banach space need not be convex unlike that on a Hilbert space. The aim of this paper is to study operators $T$ on $ \ell^2_p $ for which the numerical range is convex. We also…

Functional Analysis · Mathematics 2024-08-13 Kalidas Mandal , Aniket Bhanja , Santanu Bag , Kallol Paul

This article introduces classes of normal and unitary operators on smooth Banach spaces, providing extensions of the classical notions of normal and unitary operators from Hilbert spaces to the smooth Banach space setting. The proposed…

Functional Analysis · Mathematics 2026-05-18 Mohammed Shameem , Deepesh K P

Let $\mu$ be a non-negative Radon measure on ${\mathbb R}^d$ which only satisfies the polynomial growth condition. Let ${\mathcal Y}$ be a Banach space and $H^1(\mu)$ the Hardy space of Tolsa. In this paper, the authors prove that a linear…

Functional Analysis · Mathematics 2009-06-09 Dachun Yang , Dongyong Yang

In this paper we study the reflexivity of a unital strongly closed algebra of operators with complemented invariant subspace lattice on a Banach space. We prove that if such an algebra contains a complete Boolean algebra of projections of…

Functional Analysis · Mathematics 2013-06-11 Florence Merlevède , Costel Peligrad , Magda Peligrad

We introduce and study the class of weak almost limited operators. We establish a characterization of pairs of Banach lattices $E$, $F$ for which every positive weak almost limited operator $T:E\rightarrow F$ is almost limited (resp. almost…

Functional Analysis · Mathematics 2014-03-18 A. Elbour , N. Machrafi , M. Moussa

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

In this article, we give a representation for compact operators acting between reflexive Banach spaces, which generalizes the representation given by Edmunds et al. for compact operators between reflexive Banach spaces with strictly convex…

Functional Analysis · Mathematics 2023-08-16 G. Ramesh , M. Veena Sangeetha , Shanola S. Sequeira

We give a self-contained and introductory account of some basic functional analytic tools needed to understand maximal monotone operators in Hilbert spaces. We review domains of (possibly unbounded) operators, closed sets and closed…

Functional Analysis · Mathematics 2025-12-02 Hikmatullo Ismatov

We consider the shift operator $M_z$, defined on the Bloch space and the little Bloch space and we study the corresponding lattice of invariant subspaces. The index of a closed invariant subspace $E$ is defined as $\text{ind}(E) =…

Functional Analysis · Mathematics 2024-09-06 Nikiforos Biehler

We consider abstract Banach spaces of analytic functions on general bounded domains that satisfy only a minimum number of axioms. We describe all invertible (equivalently, surjective) weighted composition operators acting on such spaces.…

Functional Analysis · Mathematics 2022-08-23 Alejandro Mas , Dragan Vukotić

It is known that for Banach valued functions there are several approaches to define a Sobolev class. We compare the usual definition via weak derivatives with the Reshetnyak-Sobolev space and with the Newtonian space; in particular, we…

Functional Analysis · Mathematics 2020-09-22 Nikita Evseev

In the continuum the definitions of the covariant Dirac operator and of the gauge covariant derivative operator are tightly intertwined. We point out that the naive discretization of the gauge covariant derivative operator is related to the…

High Energy Physics - Lattice · Physics 2013-05-01 Claude Roiesnel

The basic results for nonlinear operators are given. These results include nonlinear versions of classical uniform boundedness theorem and Hahn-Banach theorem. Furthermore, the mappings from a metrizable space into another normed space can…

Functional Analysis · Mathematics 2019-05-28 Wen Hsiang Wei

The coarse geometric Novikov conjecture provides an algorithm to determine when the higher index of an elliptic operator on a noncompact space is nonzero. The purpose of this paper is to prove the coarse geometric Novikov conjecture for…

Operator Algebras · Mathematics 2007-05-23 Gennadi Kasparov , Guoliang Yu

The paper is devoted to the relationship between almost limited operators and weakly compacts operators. We show that if $F$ is a $\sigma $-Dedekind complete Banach lattice then, every almost limited operator $T:E\rightarrow F $ is weakly…

Functional Analysis · Mathematics 2014-03-17 A. Elbour , N. Machrafi , M. Moussa

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