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Related papers: Some strongly bounded classes of Banach spaces

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It is a longstanding problem whether every contractible Banach algebra is necessarily finite-dimensional. In this note, we confirm this for Banach algebras acting on Banach spaces with the uniform approximation property. This generalizes a…

Functional Analysis · Mathematics 2011-10-31 Narutaka Ozawa

It is shown that a separable Banach space $X$ can be given an equivalent norm $|\!|\!|\cdot |\!|\!|$ with the following properties:\quad If $(x_n)\subseteq X$ is relatively weakly compact and $\lim_{m\to\infty} \lim_{n\to\infty}\break…

Functional Analysis · Mathematics 2016-09-07 Edward Odell , Thomas Schlumprecht

In this paper Hilbert spaces are characterized among Banach spaces in terms of transitivity with respect to nicely behaved subgroups of the isometry group. For example, the following result is typical here: If X is a real Banach space…

Functional Analysis · Mathematics 2008-09-11 Jarno Talponen

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

We analyse several examples of separable Banach spaces, some of them new, and relate them to several dichotomies obtained in the previous paper Banach spaces without minimal subspaces, by classifying them according to which side of the…

Functional Analysis · Mathematics 2011-04-26 Valentin Ferenczi , Christian Rosendal

We characterise the class of those Banach spaces in which every convex combination of slices of the unit ball intersects the unit sphere as the class of those spaces in which every convex combination of slices of the unit ball contains two…

Functional Analysis · Mathematics 2019-01-24 Gines Lopez-Perez , Miguel Martin , Abraham Rueda Zoca

For each ordinal $\alpha< \omega_1$, we prove the existence of a separable, reflexive Banach space with a basis and Szlenk index $\omega^{\alpha+1}$ which is universal for the class of separable, reflexive Banach spaces $X$ such that the…

Functional Analysis · Mathematics 2013-08-27 Ryan Causey

Is shown that any separable superreflexive Banach space X may be isometrically embedded in a separable superreflexive Banach space Z=Z(X) (which, in addition, is of the same type and cotype as X) such that its conjugate admits a continuous…

Functional Analysis · Mathematics 2007-05-23 Eugene Tokarev

We study long chains of iterated weak* derived sets, that is sets of all weak* limits of bounded nets, of subspaces with the additional property that the penultimate weak* derived set is a proper norm dense subspace of the dual. We extend…

Functional Analysis · Mathematics 2024-08-05 Zdeněk Silber

We conjecture that whenever $M$ is a metric space of density at most continuum, then the space of Lipschitz functions is $w^*$-separable. We prove the conjecture for several classes of metric spaces including all the Banach spaces with a…

Functional Analysis · Mathematics 2025-03-14 Leandro Candido , Marek Cuth , Benjamin Vejnar

This paper deals with the problem of when, given a collection $\mathcal C$ of weakly compact operators between separable Banach spaces, there exists a separable reflexive Banach space $Z$ with a Schauder basis so that every element in…

Functional Analysis · Mathematics 2019-09-18 Leandro Antunes , Kevin Beanland , Bruno de Mendonça Braga

We show that if the Szlenk index of a Banach space $X$ is larger than the first infinite ordinal $\omega$ or if the Szlenk index of its dual is larger than $\omega$, then the tree of all finite sequences of integers equipped with the…

Functional Analysis · Mathematics 2017-09-27 F. Baudier , N. J. Kalton , G. Lancien

We show that the existence of a strongly convex function with a Lipschitz derivative on a Banach space already implies that the space is isomorphic to a Hilbert space. Similarly, if both a function and its convex conjugate are $C^2$ then…

Functional Analysis · Mathematics 2025-06-11 Nicolas Borchard , Gerd Wachsmuth

We introduce and study the notion of space of almost universal complemented disposition (a.u.c.d.) as a generalization of Kadec space. We show that every Banach space with separable dual is isometrically contained as a $1$-complemented…

Functional Analysis · Mathematics 2019-06-18 Jesús M. F. Castillo , Yolanda Moreno

Krivine and Maurey proved in 1981 that every stable Banach space contains almost isometric copies of $\ell_p$, for some $p\in[1,\infty)$. In 1983, Raynaud showed that if a Banach space uniformly embeds into a superstable Banach space, then…

Functional Analysis · Mathematics 2018-03-23 Bruno de Mendonça Braga , Andrew Swift

In continuation of the paper [3], we discuss various consequences of Hahn-Banach theorem for bounded b-linear functional in linear n-normed space and describe the notion of reflexivity of linear n-normed space with respect to bounded…

Functional Analysis · Mathematics 2024-10-29 Prasenjit Ghosh , Tapas Kumar Samanta

Given an infinite matrix $M=(m_{nk})$ we study a family of sequence spaces $\ell_M^p$ associated with it. When equipped with a suitable norm $\|\cdot\|_{M,p}$ we prove some basic properties of the Banach spaces of sequences…

Functional Analysis · Mathematics 2025-03-11 Arian Bërdëllima , Naim L. Braha

We provide a few characterizations of a strictly convex Banach space. Using this we improve the main theorem of [Digar, Abhik; Kosuru, G. Sankara Raju; Cyclic uniform Lipschitzian mappings and proximal uniform normal structure. Ann. Funct.…

Functional Analysis · Mathematics 2023-09-12 Abhik Digar , G. Sankara Raju Kosuru

We study almost square Banach spaces under a topological point of view. Indeed, we prove that the class of Banach spaces which admits an equivalent norm to be ASQ is that of those Banach spaces which contain an isomorphic copy of $c_0$. We…

Functional Analysis · Mathematics 2015-12-03 Julio Becerra Guerrero , Ginés López Pérez , Abraham Rueda Zoca

We prove strong convergence theorems of some iterative algorithms in a real uniformly smooth Banach space. The results presented extend, generalize and improve the corresponding results recently announced by many authors.

Functional Analysis · Mathematics 2015-08-28 Abba Auwalu