English
Related papers

Related papers: Boundaries for Banach spaces determine weak compac…

200 papers

We prove that the following three properties for a Banach space are all different from each other: every finite convex combination of slices of the unit ball is (1) relatively weakly open, (2) has nonempty interior in relative weak topology…

Functional Analysis · Mathematics 2017-03-10 Rainis Haller , Paavo Kuuseok , Märt Põldvere

In this paper we show that if $(y_n)$ is a seminormalized sequence in a Banach space which does not have any weakly convergent subsequence, then it contains a wide-$(s)$ subsequence $(x_n)$ which admits an equivalent convex basic sequence.…

Functional Analysis · Mathematics 2018-03-26 C. S. Barroso , V. Ferreira

We study the unknown differences between the size of slices and relatively weakly open subsets of the unit ball in Banach spaces. We show that every Banach space containing isomorphic copies of $c_0$ can be equivalently renormed so that…

Functional Analysis · Mathematics 2013-09-20 Julio Becerra Guerrero , Gines Lopez Perez , Abraham Rueda Zoido

A Banach space is locally almost square if, for every $y$ in its unit sphere, there exists a sequence $(x_n)$ in its unit sphere such that $\lim\|y\pm x_n\|=1$. A Banach space is weakly almost square if, in addition, we require the sequence…

Functional Analysis · Mathematics 2022-10-25 Stefano Ciaci

We introduce notions of compactness and weak compactness for multilinear maps from a product of normed spaces to a normed space, and prove some general results about these notions. We then consider linear maps $T:A\to B$ between Banach…

Functional Analysis · Mathematics 2009-01-23 M. J Heath

We study the class of compact convex subsets of a topological vector space which admits a strictly convex and lower semicontinuous function. We prove that such a compact set is embeddable in a strictly convex dual Banach space endowed with…

Functional Analysis · Mathematics 2015-10-28 L. García-Lirola , J. Orihuela , M. Raja

The notion of super weak compactness for subsets of Banach spaces is a strengthening of the weak compactness that can be described as a local version of super-reflexivity. A recent result of K. Tu which establishes that the closed convex…

Functional Analysis · Mathematics 2021-07-13 Gilles Lancien , Matias Raja

In this paper we survey known results of characterizations of reflexive Banach spaces, which are based on convergence of usual and generalized arithmetic mean (or Ces\`aro sum), weakly compact subsets, affine sets in a Banach space or its…

Functional Analysis · Mathematics 2025-03-17 Tianyi Zhou

In this paper, we study nonlinear embeddings between Banach spaces. More specifically, the goal of this paper is to study weaker versions of coarse and uniform embeddability, and to provide suggestive evidences that those weaker embeddings…

Functional Analysis · Mathematics 2017-04-20 Bruno de Mendonça Braga

We introduce and study Banach spaces which have property CWO, i.e., every finite convex combination of relatively weakly open subsets of their unit ball is open in the relative weak topology of the unit ball. Stability results of such…

Functional Analysis · Mathematics 2018-06-29 Trond Arnold Abrahamsen , Julio Becerra Guerrero , Rainis Haller , Vegard Lima , Märt Põldvere

In this paper the weak topology on a normed space is studied from the viewpoint of infinite-dimensional topology. Besides the weak topology on a normed space $X$ (coinciding with the topology of uniform convergence on finite subsets of the…

General Topology · Mathematics 2019-08-27 Taras Banakh

Let $X$ and $Y$ be separable Banach spaces. Suppose $Y$ either has a shrinking basis or $Y$ is isomorphic to $C(2^\mathbb{N})$ and $A$ is a subset of weakly compact operators from $X$ to $Y$ which is analytic in the strong operator…

Functional Analysis · Mathematics 2013-04-15 Kevin Beanland , Daniel Freeman

We prove that every Banach space containing a subspace isomorphic to $\co$ fails the fixed point property. The proof is based on an amalgamation approach involving a suitable combination of known results and techniques, including James's…

Functional Analysis · Mathematics 2018-08-15 Cleon S. Barroso

A Banach space contains either a minimal subspace or a continuum of incomparable subspaces. General structure results for analytic equivalence relations are applied in the context of Banach spaces to show that if $E_0$ does not reduce to…

Functional Analysis · Mathematics 2007-05-23 Christian Rosendal

Several recent papers investigated unbounded versions of order and norm convergences in Banach lattices. In this paper, we study the unbounded variant of weak convergence and its relationship with other convergences. In particular, we…

Functional Analysis · Mathematics 2017-09-05 Omid Zabeti

Known results are reviewed about the bounded and convex bounded variants, bT and cbT, of a topology T on a real Banach space. The focus is on the cases of T = w(P*, P) and of T = m(P*, P), which are the weak* and the Mackey topologies on a…

Functional Analysis · Mathematics 2020-09-15 Andrew J. Wrobel

We consider topological invariants on compact spaces related to the sizes of discrete subspaces (spread), densities of subspaces, Lindelof degree of subspaces, irredundant families of clopen sets and others and look at the following…

Functional Analysis · Mathematics 2012-09-20 Piotr Koszmider

Fixed point theory studies conditions under which nonexpansive maps on Banach spaces have fixed points. This paper examines the open question of whether every reflexive Banach space has the fixed point property. After surveying classical…

Functional Analysis · Mathematics 2025-09-17 Faruk Alpay , Hamdi Alakkad

Assuming the generalized continuum hypothesis we construct arbitrarily big indecomposable Banach spaces. i.e., such that whenever they are decomposed as $X\oplus Y$, then one of the closed subspaces $X$ or $Y$ must be finite dimensional. It…

Functional Analysis · Mathematics 2016-03-08 Piotr Koszmider , Saharon Shelah , Michał Świȩtek

Several recent papers investigated unbounded convergences in Banach lattices. Combine all unbounded convergences, including unbounded order (norm, absolute weak, absolute weak*) convergence, we characterize L-weakly compact sets, L-weakly…

Functional Analysis · Mathematics 2021-04-06 Zhangjun Wang , Zili Chen , Jinxi Chen