Diametral notions for elements of the unit ball of a Banach space

M Martín, Y Perreau, AR Zoca - arXiv preprint arXiv:2301.04433, 2023 - arxiv.org
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 …

Almost square and octahedral norms in tensor products of Banach spaces

J Langemets, V Lima, A Rueda Zoca - Revista de la Real Academia de …, 2017 - Springer
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 …

[HTML][HTML] Octahedral norms in duals and biduals of Lipschitz-free spaces

J Langemets, AR Zoca - Journal of Functional Analysis, 2020 - Elsevier
We continue with the study of octahedral norms in the context of spaces of Lipschitz
functions and in their duals. First, we prove that the norm of F (M)⁎⁎ is octahedral as soon …

Diameter 2 properties and convexity

TA Abrahamsen, P Hájek, O Nygaard… - arXiv preprint arXiv …, 2015 - arxiv.org
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 $\| IP\|= 1+\| P …

Diametral diameter two properties in Banach spaces

JB Guerrero, GL Pérez, AR Zoca - arXiv preprint arXiv:1509.02061, 2015 - arxiv.org
The aim of this note is to provide several variants of the diameter two properties for Banach
spaces. We study such properties looking for the abundance of diametral points, which …

Octahedrality in Lipschitz-free Banach spaces

JB Guerrero, G López-Pérez, AR Zoca - Proceedings of the Royal …, 2018 - cambridge.org
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, by analysing the weak-star strong …

Daugavet property in tensor product spaces

AR Zoca, P Tradacete, I Villanueva - … of the Institute of Mathematics of …, 2021 - cambridge.org
We study the Daugavet property in tensor products of Banach spaces. We show that-
preduals with the Daugavet property, in particular, spaces of continuous functions with this …

Small combination of slices, dentability and stability results of small diameter properties in Banach spaces

S Basu, S Seal - Journal of Mathematical Analysis and Applications, 2022 - Elsevier
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 …

[HTML][HTML] Big slices versus big relatively weakly open subsets in Banach spaces

JB Guerrero, G López-Pérez, AR Zoca - Journal of Mathematical Analysis …, 2015 - Elsevier
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 c 0 …

L-orthogonality, octahedrality and Daugavet property in Banach spaces

G López-Pérez, AR Zoca - Advances in Mathematics, 2021 - Elsevier
In contrast to the separable case, we prove that the existence of almost L-orthogonal vectors
in a nonseparable Banach space X (octahedrality) does not imply the existence of nonzero …