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Related papers: Diameter two properties in James spaces

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In this article, we study the diameter two properties (D2Ps), the diametral diameter two properties (diametral D2Ps), and the Daugavet property in Orlicz-Lorentz spaces equipped with the Luxemburg norm. First, we characterize the…

Functional Analysis · Mathematics 2023-04-06 Anna Kamińska , Han Ju Lee , Hyung-Joon Tag

We prove that every separable Banach space containing $\ell_1$ can be equivalently renormed so that its bidual space is octahedral, which answers, in the separable case, a question by Godefroy in 1989. As a direct consequence, we obtain…

Functional Analysis · Mathematics 2021-07-01 Johann Langemets , Ginés López-Pérez

We continue the investigation of the behaviour of diameter two properties in tensor products of Banach spaces. Our main result shows that the symmetric strong diameter two property is stable by taking projective tensor products. We also…

Functional Analysis · Mathematics 2020-03-24 Johann Langemets

We prove that the diametral strong diameter 2 property of a Banach space (meaning that, in convex combinations of relatively weakly open subsets of its unit ball, every point has an "almost diametral" point) is stable under 1-sums, i.e.,…

Functional Analysis · Mathematics 2016-03-29 Rainis Haller , Katriin Pirk , Märt Põldvere

We study geometric properties of the Banach space $\mathcal{R}$ constructed recently by C.~Read (arXiv 1307.7958) which does not contain proximinal subspaces of finite codimension greater than or equal to two. Concretely, we show that the…

Functional Analysis · Mathematics 2018-01-12 Vladimir Kadets , Gines Lopez , Miguel Martin

We study transfinite analogues of the symmetric strong diameter two property. We investigate the stability of these properties under $c_0$, $\ell_\infty$ sums and under projective tensor products. Moreover, we characterize Banach spaces of…

Functional Analysis · Mathematics 2023-03-01 Stefano Ciaci

We introduce and study a strict monotonicity property of the norm in solid Banach lattices of real functions that prevents such spaces from having the local diameter two property. Then we show that any strictly convex 1-symmetric norm on…

Functional Analysis · Mathematics 2025-08-25 Trond A. Abrahamsen , Petr Hájek , Vegard Lima , Stanimir Troyanski

We discuss the geometry of Banach spaces whose norm is octahedral or, more generally, locally or weakly octahedral. Our main results characterize these spaces in terms of covering of the unit ball.

Functional Analysis · Mathematics 2014-10-15 Rainis Haller , Johann Langemets

Some necessary and sufficient conditions are found for Banach function lattices to have the Radon-Nikod\'ym property. Consequently it is shown that an Orlicz space $L_\varphi$ over a non-atomic $\sigma$-finite measure space $(\Omega,…

Functional Analysis · Mathematics 2023-01-04 Anna Kamińska , Han Ju Lee , Hyung-Joon Tag

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

We study some generalized metric properties of weak topologies when restricted to the unit sphere of some equivalent norm on a Banach space, and their relationships with other geometrical properties of norms. In case of dual Banach space…

Functional Analysis · Mathematics 2021-06-09 S. Ferrari , J. Orihuela , M. Raja

We study octahedral norms in the space of bounded linear operators between Banach spaces. In fact, we prove that $L(X,Y)$ has octahedral norm whenever $X^*$ and $Y$ have octahedral norm. As a consequence the space of operators $L(\ell_1…

Functional Analysis · Mathematics 2014-07-24 Julio Becerra Guerrero , Ginés López-Pérez , Abraham Rueda Zoca

We prove that in Lipschitz-free spaces the strong diameter two property, the diameter two property, and the local diameter two property coincide with their corresponding attaining variants.

Functional Analysis · Mathematics 2026-04-08 Jaan Kristjan Kaasik

In this article, we study the Daugavet property and the diametral diameter two properties in complex Banach spaces. The characterizations for both Daugavet and $\Delta$-points are revisited in the context of complex Banach spaces. We also…

Functional Analysis · Mathematics 2024-05-28 Han Ju Lee , Hyung-Joon Tag

In this paper, we investigate the relationship between the weak min-max property and the diameter uniformity of domains in Banach spaces with dimensions at least $2$. As an application, we show that diameter uniform domains are invariant…

Complex Variables · Mathematics 2021-04-27 Zhengyong Ouyang , Antti Rasila , Tiantian Guan

This work explores the equivalence of two sequential properties, $D$ and $D'$, for dual Banach spaces under the weak* topology. Property $D$ ensures that any totally scalarly measurable function is also scalarly measurable, while property…

Functional Analysis · Mathematics 2024-12-30 Paulo Akira F. Enabe

Given an Orlicz $N$-function $\varphi$ and a positive decreasing weight $w$, we present criteria of the diameter two property and of the Radon-Nikod\'ym property in Orlicz-Lorentz function and sequence spaces $\Lambda_{\varphi,w}$ and…

Functional Analysis · Mathematics 2017-06-23 Anna Kamińska , Hyung-Joon Tag

The aim of this note is to study some geometrical properties like diameter two properties, octahedrality and almost squareness in the setting of (symmetric) tensor product spaces. In particular, we show that the injective tensor product of…

Functional Analysis · Mathematics 2016-02-24 Johann Langemets , Vegard Lima , Abraham Rueda Zoca

We continue the investigation of the behaviour of octahedral norms in tensor products of Banach spaces. Firstly, we will prove the existence of a Banach space $Y$ such that the injective tensor products $l_1\widehat{\otimes}_\varepsilon Y$…

Functional Analysis · Mathematics 2016-12-28 Johann Langemets , Vegard Lima , Abraham Rueda Zoca

Let $M$ be a metric space and $X$ be a Banach space. In this paper we address several questions about the structure of $\mathcal F(M)\widehat{\otimes}_\pi X$ and $\mathop{Lip}(M,X)$. Our results are the following: (1) We prove that if $M$…

Functional Analysis · Mathematics 2023-10-27 Rubén Medina , Abraham Rueda Zoca