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Related papers: A $\xi$-weak Grothendieck compactness principle

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We complete our recent classification of compact inner symmetric spaces with weakly complex tangent bundle by filling up a case which was left open, and extend this classification to the larger category of compact homogeneous spaces with…

Differential Geometry · Mathematics 2019-01-08 Andrei Moroianu , Uwe Semmelmann

We prove that a separable Banach space $E$ does not contain a copy of the space $\co$ of null-sequences if and only if for every doubly power-bounded operator $T$ on $E$ and for every vector $x\in E$ the relative compactness of the sets…

Functional Analysis · Mathematics 2013-01-29 Bálint Farkas

We study Banach spaces with a weak stable unit ball, that is Banach spaces where every convex combination of relatively weakly open subsets in its unit ball is again a relatively weakly open subset in its unit ball. It is proved that the…

Functional Analysis · Mathematics 2021-07-27 Ginés López-Pérez , Rubén Medina

It is shown that if $C$ is a nonempty convex and weakly compact subset of a Banach space $X$ with $M(X)>1$ and $T:C\rightarrow C$ satisfies condition $(C)$ or is continuous and satisfies condition $(C_{\lambda})$ for some $\lambda \in…

Functional Analysis · Mathematics 2015-11-24 Anna Betiuk-Pilarska , Andrzej Wiśnicki

In this paper we discuss the structure of weighted weak Lebesgue spaces and weighted weak Orlicz spaces on $\mathbb{R}^n$. First, we present sufficient and necessary conditions for inclusion relation between weighted weak Lebesgue spaces.…

Functional Analysis · Mathematics 2017-10-13 Al Azhary Masta , Ifronika , Muhammad Taqiyuddin

It is shown that any Banach space X of sufficiently large density contains an (infinite) unconditional sequence and a separable quotient. If a density of X is a weakly compact cardinal, then X contains an unconditional sequence of…

Functional Analysis · Mathematics 2007-05-23 Eugene Tokarev

Let $X$ be a ball quasi-Banach function space on ${\mathbb R}^n$. In this article, the authors introduce the weak Hardy-type space $WH_X({\mathbb R}^n)$, associated with $X$, via the radial maximal function. Assuming that the powered…

Classical Analysis and ODEs · Mathematics 2019-07-01 Yangyang Zhang , Songbai Wang , Dachun Yang , Wen Yuan

The abscissas of convergence, uniform convergence and absolute convergence of vector valued Dirichlet series with respect to the original topology and with respect to the weak topology $\sigma(X,X')$ of a locally convex space $X$, in…

Functional Analysis · Mathematics 2015-02-03 José Bonet

We prove that the class of Banach function lattices in which all relatively weakly compact sets are equi-integrable sets (i.e. spaces satisfying the Dunford-Pettis criterion) coincides with the class of 1-disjointly homogeneous Banach…

Functional Analysis · Mathematics 2019-12-18 Karol Lesnik , Lech Maligranda , Jakub Tomaszewski

We present a compensated compactness theorem in Banach spaces established recently, whose formulation is originally motivated by the weak rigidity problem for isometric immersions of manifolds with lower regularity. As a corollary, a…

Differential Geometry · Mathematics 2018-11-05 Gui-Qiang G. Chen , Siran Li

We work in set-theory without choice ZF. Denoting by AC(N) the countable axiom of choice, we show in ZF+AC(N) that the closed unit ball of a uniformly convex Banach space is compact in the convex topology (an alternative to the weak…

Functional Analysis · Mathematics 2008-12-18 Marianne Morillon

A compact space is said to be weakly Radon-Nikod\'ym if it is homeomorphic to a weak*-compact subset of the dual of a Banach space not containing an isomorphic copy of $\ell_1$. In this work we provide an example of a continuous image of a…

Functional Analysis · Mathematics 2015-09-18 Gonzalo Martínez-Cervantes

We show that for every weakly compact subset $K$ of $C[0,1]$ with finite Cantor-Bendixson rank, there is a reflexive Banach lattice $E$ and an operator $T:E\rightarrow C[0,1]$ such that $K\subseteq T(B_E)$. On the other hand, we exhibit an…

Functional Analysis · Mathematics 2016-03-18 J. Lopez-Abad , P. Tradacete

A theorem of Davis, Figiel, Johnson and Pe{\l}czy\'nski tells us that weakly-compact operators between Banach spaces factor through reflexive Banach spaces. The machinery underlying this result is that of the real interpolation method,…

Functional Analysis · Mathematics 2007-05-23 Matthew Daws

Let $(\Omega,\Sigma,\mu)$ be a finite measure space, $Z$ be a Banach space and $\nu:\Sigma \to Z^*$ be a countably additive $\mu$-continuous vector measure. Let $X \subseteq Z^*$ be a norm-closed subspace which is norming for $Z$. Write…

Functional Analysis · Mathematics 2019-11-01 José Rodríguez

In this short note, we prove that the set of elementary tensors is weakly closed in the projective tensor product of two Banach spaces. As a result, we are able to answer a question from the literature proving that if $(x_n) \subset X$ and…

Functional Analysis · Mathematics 2025-03-19 Colin Petitjean

We investigate weakly $G$-slim complexes, a more flexible variant of Helfer and Wise's slim complexes, which can be defined on any regular $G$-covering. We prove that if a $2$-complex $X$ associated to a group presentation is weakly…

Group Theory · Mathematics 2025-06-25 Agustín Nicolás Barreto , Elias Gabriel Minian

In this paper, a general hybrid fixed point theorem for the contractive mappings in generalized Banach spaces is proved via measure of weak non-compactness and it is further applied to fractional integral equations for proving the existence…

Functional Analysis · Mathematics 2024-01-17 Aref Jeribi , Najib Kaddachi , Zahra Laouar

This paper brings new results on the FPP in Banach spaces $X$ with a Schauder basis. We first deal with the problem of whether there is a Banach space isomorphic to $\co$ having the FPP. We show that the answer is negative if $X$ contains a…

Functional Analysis · Mathematics 2023-07-25 Cleon S. Barroso

There is a well-established homotopy theory of simplicial objects in a Grothendieck topos, and folklore says that the weak equivalences are axiomatisable in the geometric fragment of $L_{\omega_1, \omega}$. We show that it is in fact a…

Category Theory · Mathematics 2014-05-01 Zhen Lin Low