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Related papers: Diametral diameter two properties in Banach spaces

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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

In this paper we first take a detail survey of the study of the Banach-Saks property of Banach spaces and then show the Banach-Saks property of the product spaces generated by a finite number of Banach spaces having the Banach-Saks…

Functional Analysis · Mathematics 2007-05-23 Zhenglu Jiang , Xiaoyong Fu

This paper addresses the study and characterizations of variational convexity of extended-real-valued functions on Banach spaces. This notion has been recently introduced by Rockafellar, and its importance has been already realized and…

Optimization and Control · Mathematics 2023-08-29 Pham Duy Khanh , Vu Vinh Huy Khoa , Boris S. Mordukhovich , Vo Thanh Phat

These notes concern the nonlinear geometry of Banach spaces, asymptotic uniform smoothness and several Banach-Saks-like properties. We study the existence of certain concentration inequalities in asymptotically uniformly smooth Banach…

Functional Analysis · Mathematics 2018-08-10 Bruno de Mendonça Braga

We introduce a new class of quasi-Banach spaces as an extension of the classical Grand Lebesgue Spaces for small values of the parameter, and we investigate some its properties, in particular, completeness, fundamental function, operators…

Functional Analysis · Mathematics 2020-08-07 Maria Rosaria Formica , Eugeny Ostrovsky , Leonid Sirota

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

In this paper, we introduce a notion of geometric Banach property (T) for metric spaces, which jointly generalizes Banach property (T) for groups and geometric property (T) for metric spaces. Our framework is achieved by Banach…

Functional Analysis · Mathematics 2025-06-04 Liang Guo , Qin Wang

We show that the Lipschitz-free space with the Radon--Nikod\'{y}m property and a Daugavet point recently constructed by Veeorg is in fact a dual space isomorphic to $\ell_1$. Furthermore, we answer an open problem from the literature by…

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 show that there exists a Banach space in which every non-empty weakly open subset of its unit ball has radius one, the maximum possible value, but the infimum of the diameter of its slices is exactly one, so extremely far from its…

Functional Analysis · Mathematics 2025-10-20 Ginés López-Pérez , Esteban Martínez Vañó , Abraham Rueda Zoca

The aim of the present paper is to study the existence, uniqueness and some other properties of solutions of a certain partial dynamic integrodifferential equations. The Banach fixed point theorem and certain fundamental inequality with…

Dynamical Systems · Mathematics 2016-05-03 Deepak B. Pachpatte

We show that under minimal assumptions, the intrinsic metric induced by a strongly local Dirichlet form induces a length space. A main input is a dual characterization of length spaces in terms of the property that the 1-Lipschitz functions…

Metric Geometry · Mathematics 2009-03-23 Peter Stollmann

In this work we study three different versions of small diameter properties of the unit ball in a Banach space and its dual. The related concepts for all closed bounded convex sets of a Banach space was initiated and developed in \cite{B3},…

Functional Analysis · Mathematics 2021-08-21 Sudeshna Basu , Susmita Seal

We establish a general criterion for the existence of convex sets of fixed shape as, e.g., balls of a given radius, of maximal probability on Banach spaces. We also provide counterexamples showing that their existence my fail even in some…

Functional Analysis · Mathematics 2023-09-07 Bernd Schmidt

We study a local version of the ball-covering problem in Banach spaces, and obtain a complete solution to it in terms of the norm derivatives. We illustrate the advantage of the local approach by obtaining substantial refinements of several…

Functional Analysis · Mathematics 2024-08-02 Debmalya Sain

We study the best coapproximation problem in Banach spaces, by using Birkhoff-James orthogonality techniques. We introduce two special types of subspaces, christened the anti-coproximinal subspaces and the strongly anti-coproximinal…

Functional Analysis · Mathematics 2024-08-14 Shamim Sohel , Souvik Ghosh , Debmalya Sain , Kallol Paul

We separate the local diameter two property from the diameter two property and their weak-star counterparts from each other in spaces of Lipschitz functions. We characterise the $w^*$-LD$2$P, the $w^*$-D$2$P, the LD$2$P, and the SD$2$P in…

Functional Analysis · Mathematics 2025-01-20 Rainis Haller , Jaan Kristjan Kaasik , Andre Ostrak

Another proof that uniformly nonsquare Banach spaces have the fixed point property is presented.

Functional Analysis · Mathematics 2024-04-10 Tim Dalby

Several recent papers were devoted to various modifications of limited, Grothendieck, and Dunford--Pettis operators, etc., through involving the Banach lattice structure. In the present paper, it is shown that many of these operators appear…

Functional Analysis · Mathematics 2022-09-07 Eduard Emelyanov , Svetlana Gorokhova

This paper explores some important aspects of the theory of rearrangement-invariant quasi-Banach function spaces. We focus on two main topics. Firstly, we prove an analogue of the Luxemburg representation theorem for rearrangement-invariant…

Functional Analysis · Mathematics 2025-10-15 Anna Musilová , Aleš Nekvinda , Dalimil Peša , Hana Turčinová