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Related papers: On duality of diameter 2 properties

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We prove that there exists a finite-dimensional Banach space $X$ such that $L_1^\mathbb C([0,1])\widehat{\otimes}_\varepsilon X$ fails the strong diameter two property and $L_\infty^\mathbb C([0,1])\widehat{\otimes}_\pi X^*$ fails to have…

Functional Analysis · Mathematics 2024-06-21 Abraham Rueda Zoca

We demonstrate the result stated in the title, thus answering an open question asked by Julio Becerra Guerrero, Gin\'es L\'opez-P\'erez and Abraham Rueda Zoca in J. Conv. Anal. \textbf{25}, no. 3 (2018).

Functional Analysis · Mathematics 2021-09-13 Vladimir Kadets

We consider a certain type of geometric properties of Banach spaces, which includes for instance octahedrality, almost squareness, lushness and the Daugavet property. For this type of properties, we obtain a general reduction theorem,…

Functional Analysis · Mathematics 2017-11-27 Jan-David Hardtke

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

A Banach space has the weak fixed point property if its dual space has a weak$^*$ sequentially compact unit ball and the dual space satisfies the weak$^*$ uniform Kadec-Klee property; and it has the \fpp if there exists $\epsilon>0$ such…

Functional Analysis · Mathematics 2008-04-04 P. N. Dowling , B. Randrianantoanina , B. Turett

The aim of this note is to study octahedrality in vector valued Lipschitz-free Banach spaces on a metric space under topological hypotheses on it. As a consequence, we get that the space of Lipschitz functions on a metric space valued in a…

Functional Analysis · Mathematics 2016-05-17 Julio Becerra Guerrero , Ginés López-Pérez , Abraham Rueda Zoca

We introduce a vector-valued version of a uniform algebra, called the vector-valued function space over a uniform algebra. The diameter two properties of the vector-valued function space over a uniform algebra on an infinite compact…

Functional Analysis · Mathematics 2021-03-17 Han Ju Lee , Hyung-Joon Tag

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 introduce extensions of $\Delta$-points and Daugavet points in which slices are replaced by relative weakly open subsets (super $\Delta$-points and super Daugavet points) or by convex combinations of slices (ccs $\Delta$-points and ccs…

Functional Analysis · Mathematics 2023-01-12 Miguel Martin , Yoël Perreau , Abraham Rueda Zoca

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

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 solve some open problems regarding diameter two properties within the class of Banach spaces of real-valued Lipschitz functions by using the de Leeuw transform. Namely, we show that: the diameter two property, the strong diameter two…

Functional Analysis · Mathematics 2022-05-27 Rainis Haller , Andre Ostrak , Märt Põldvere

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 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

A $\Delta$-point $x$ of a Banach space is a norm one element that is arbitrarily close to convex combinations of elements in the unit ball that are almost at distance $2$ from $x$. If, in addition, every point in the unit ball is…

Functional Analysis · Mathematics 2018-12-07 Trond Arnold Abrahamsen , Rainis Haller , Vegard Lima , Katriin Pirk

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 note we study the inheritance of the slice diameter two property by ultrapower spaces. Given a Banach space $X$, we give a characterisation of when $(X)_\mathcal U$, the ultrapower of $X$ through a free ultrafilter $\mathcal U$, has…

Functional Analysis · Mathematics 2025-01-15 Abraham Rueda Zoca

We present an equivalent midpoint locally uniformly rotund (MLUR) renorming $X$ of $C[0,1]$ on which every weakly compact projection $P$ satisfies the equation $\|I-P\| = 1+\|P\|$ ($I$ is the identity operator on $X$). As a consequence we…

Functional Analysis · Mathematics 2015-06-18 Trond A. Abrahamsen , Peter Hájek , Olav Nygaard , Jarno Talponen , Stanimir Troyanski

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

In Euclidean spaces, every closed, bounded, convex set can be characterized by two equivalent notions of separation properties. This is not true in general for arbitrary Banach spaces. In this work, we present a ball separation…

Functional Analysis · Mathematics 2025-11-12 Sudeshna Basu , Susmita Seal