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Related papers: On collectively L-weakly compact sets of operators

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In this paper, we introduce the notions uniformly p-convergent sets and weakly p-sequentially continuous differentiable mappings. Then we obtain a sufficient condition for those Banach spaces which either contain no copy of $\ell_1$ or have…

Functional Analysis · Mathematics 2020-01-01 Morteza Alikhani

In this paper, we investigate necessary and sufficient conditions on the boundedness of composition operators on the Orlicz-Morrey spaces. The results of boundedness include Lebesgue and generalized Morrey spaces as special cases. Further,…

Functional Analysis · Mathematics 2024-04-16 Masahiro Ikeda , Isao Ishikawa , Ryota Kawasumi

We provide explicit examples of positive and power-bounded operators on $c_0$ and $\ell^\infty$ which are mean ergodic but not weakly almost periodic. As a consequence we prove that a countably order complete Banach lattice on which every…

Functional Analysis · Mathematics 2018-03-07 Moritz Gerlach , Jochen Glück

The boundedness and compactness of weighted composition operators from $H^\infty$ to the Bloch space in the unit ball of Cn are investigated in this paper. In particular, some new characterizations for the boundedness and the essential norm…

Complex Variables · Mathematics 2018-01-08 Juntao Du , Songxiao Li

In this paper we recontextualize the theory of matrix weights within the setting of Banach lattices. We define an intrinsic notion of directional Banach function spaces, generalizing matrix weighted Lebesgue spaces. Moreover, we prove an…

Functional Analysis · Mathematics 2025-09-01 Zoe Nieraeth

We study best approximations to compact operators between Banach spaces and Hilbert spaces, from the point of view of Birkhoff-James orthogonality and semi-inner-products. As an application of the present study, some distance formulae are…

Functional Analysis · Mathematics 2021-04-30 Debmalya Sain

In this paper, we prove first that the iterates of a mean nonexpansive map defined on a weakly compact, convex set converge weakly to a fixed point in the presence of Opial's property and asymptotic regularity at a point. Next, we prove the…

Functional Analysis · Mathematics 2016-11-30 Torrey M. Gallagher

Let $A$ be a Banach algebra. For $f\in A^{\ast}$, we inspect the weak sequential properties of the well-known map $T_f:A\to A^{\ast}$, $T_f(a) = fa$, where $fa\in A^{\ast}$ is defined by $fa(x) = f(ax)$ for all $x\in A$. We provide…

Functional Analysis · Mathematics 2021-07-19 Onur Oktay

A classification of weakly compact multiplication operators on L(L_p), $1<p<\infty$, is given. This answers a question raised by Saksman and Tylli in 1992. The classification involves the concept of $\ell_p$-strictly singular operators, and…

Functional Analysis · Mathematics 2007-08-06 William B. Johnson , Gideon Schechtman

We show that every free semigroup algebras has a (strongly) unique Banach space predual. We also provide a new simpler proof that a weak*-closed unital operator operator algebra containing a weak* dense subalgebra of compact operators has a…

Operator Algebras · Mathematics 2019-08-15 Kenneth R. Davidson , Alex Wright

We describe boundedness and compactness properties for the operators obtained by the Weyl-Pedersen calculus in the case of the irreducible unitary representations of nilpotent Lie groups that are associated with flat coadjoint orbits. We…

Analysis of PDEs · Mathematics 2013-10-22 Ingrid Beltita , Daniel Beltita

Let $L$ be a length function on a group $G$, and let $M_L$ denote the operator of pointwise multiplication by $L$ on $\ell^2(G)$. Following Connes, $M_L$ can be used as a "Dirac" operator for the reduced group C*-algebra $C_r^*(G)$. It…

Operator Algebras · Mathematics 2019-08-15 Michael Christ , Marc A. Rieffel

In this paper, we study a class of Banach spaces, called \phi-spaces. In a natural way, we associate a measure of weak compactness in such spaces and prove an analogue of Sadovskii fixed point theorem for weakly sequentially continuous…

Functional Analysis · Mathematics 2007-05-23 Cleon S. Barroso , Donal O'Regan

We provide complete characterizations, on Banach spaces with cotype 2, of those linear operators which happen to be weakly mixing or strongly mixing transformations with respect to some nondegenerate Gaussian measure. These…

Functional Analysis · Mathematics 2011-12-07 Frédéric Bayart , Etienne Matheron

Let $B$ be a Banach $A-bimodule$. We introduce the weak topological centers of left module action and we show it by $\tilde{{Z}}^\ell_{B^{**}}(A^{**})$. For a compact group, we show that $L^1(G)=\tilde{Z}_{M(G)^{**}}^\ell(L^1(G)^{**})$ and…

Functional Analysis · Mathematics 2020-10-28 Mostfa Shams Kojanaghi , Kazem Haghnejad Azar

The aim of this article is to extend results of M.~Popov and second named author about orthogonally additive narrow operators on vector lattices. The main object of our investigations are an orthogonally additive narrow operators between…

Functional Analysis · Mathematics 2015-10-01 Xiao Chun Fang , Marat Pliev

We prove two weak compactness criteria in Musielak-Orlicz spaces for $N$-functions satisfying the $\Delta_2$-condition. They extend criteria from And\^o for Orlicz spaces to this setting of non-symmetrical Banach function spaces. As…

Functional Analysis · Mathematics 2026-01-28 Mauro Sanchiz

Let S be a dense sub-semigroup of the positive real numbers, and let X be a separable, reflexive Banach space. This note contains a proof that every weakly continuous contractive semigroup of operators on X over S can be extended to a…

Functional Analysis · Mathematics 2009-03-21 Eliahu Levy , Orr Shalit

Motivated by a seminal paper of professor M. Z. Nashed published in 1987 on classification of ill-posed linear operator equations and distinguishing two types of ill-posedness in Banach and Hilbert spaces, we present, illustrate and justify…

Functional Analysis · Mathematics 2025-11-11 Jens Flemming , Bernd Hofmann

This article presents a deep investigation of fixed points for multivalued weak contractions in cone metric spaces. We extend Berinde weak contraction principles to the multivalued setting in cone metric spaces, developing existence,…

Functional Analysis · Mathematics 2025-08-13 Elvin Rada