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Related papers: Two aspects of small diameter properties

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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

The geometric notion of huskability initiated and developed in [B3], [BR] ,[EW], [GM] was subsequently extensively studied in the context of dentability and Radon Nikodym Property in [GGMS]. In this work, we introduce a new geometric…

Functional Analysis · Mathematics 2021-08-06 Sudeshna Basu , Susmita Seal

In this work, we study the non rough norms in Banach spaces with small diameter properties, namely the Ball Dentable Property (BDP), the Ball Huskable Property (BHP) and the Ball Small Combination of Slice Property (BSCSP). We introduce two…

Functional Analysis · Mathematics 2023-07-10 Sudeshna Basu , Susmita Seal

A Banach space has the ball huskable property ($BHP$) if the closed unit ball has weakly open sets of arbitrarily small diameter. We can analogously define $w^*$-$BHP$ in the dual space. In this short note, we study these properties in the…

Functional Analysis · Mathematics 2021-09-13 Sudeshna Basu , Susmita Seal

We study smoothness and strict convexity of (the bidual) of Banach spaces in the presence of diameter 2 properties. We prove that the strong diameter 2 property prevents the bidual from being strictly convex and being smooth, and we…

Functional Analysis · Mathematics 2016-10-11 Trond A. Abrahamsen , Vegard Lima , Olav Nygaard , Stanimir Troyanski

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 holds in the setting of Banach spaces with the Daugavet…

Functional Analysis · Mathematics 2016-04-18 Julio Becerra Guerrero , Ginés López Pérez , Abraham Rueda Zoca

It is known that a Banach space has the strong diameter 2 property (i.e. every convex combination of slices of the unit ball has diameter 2) if and only if the norm on its dual space is octahedral (a notion introduced by Godefroy and…

Functional Analysis · Mathematics 2013-11-12 Rainis Haller , Johann Langemets , Märt Põldvere

In this work, we introduce the notion of Ball dentable property in Banach spaces. We study certain stability results for the $w^*$-Ball dentable property leading to a discussion on Ball dentability in the context of ideals of Banach spaces.…

Functional Analysis · Mathematics 2020-12-02 Sudeshna Basu

We study Banach spaces with the property that, given a finite number of slices of the unit ball, there exists a direction such that all these slices contain a line segment of length almost 2 in this direction. This property was recently…

Functional Analysis · Mathematics 2018-04-06 Rainis Haller , Johann Langemets , Vegard Lima , Rihhard Nadel

We study approximation of operators between Banach spaces $X$ and $Y$ that nearly attain their norms in a given point by operators that attain their norms at the same point. When such approximations exist, we say that the pair $(X, Y)$ has…

Functional Analysis · Mathematics 2018-11-20 Sheldon Dantas , Vladimir Kadets , Sun Kwang Kim , Han Ju Lee , Miguel Martin

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

In this work, we study the stability properties of semi denting, semi PC, and semi SCS points, as well as their $w^*$-analogues, in Banach spaces, with respect to $l_p$-sums ( $1\leq p \leq \infty),$ ideals, and projective tensor products.

Functional Analysis · Mathematics 2026-02-16 Sudeshna Basu , Priyanka Priyadarshini Behera , Susmita Seal

In this paper, we are interested in studying two properties related to the denseness of the operators which attain their numerical radius: the Bishop-Phelps-Bollob\'as point and operator properties for numerical radius (BPBpp-nu and…

Functional Analysis · Mathematics 2020-10-02 Sheldon Dantas , Sun Kwang Kim , Han Ju Lee , Martin Mazzitelli

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

In this article, we study a version of the Bishop-Phelps-Bollob\'as property. We investigate a pair of Banach spaces $(X, Y)$ such that every operator from $X$ into $Y$ is approximated by operators which attains its norm at the same point…

Functional Analysis · Mathematics 2016-05-03 Sheldon Dantas , Sun Kwang Kim , Han Ju Lee

We extend the (attaining of) strong diameter two property to infinite cardinals. In particular, a Banach space has the 1-norming attaining strong diameter two property with respect to $\omega$ (1-ASD2P$_\omega$ for short) if every convex…

Functional Analysis · Mathematics 2021-10-01 Stefano Ciaci , Johann Langemets , Aleksei Lissitsin

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 investigate the Bishop-Phelps-Bollob\'as property for the numerical radius (BPBp-nu) through a Zizler-type perspective on the classical Bishop-Phelps-Bollob\'as property (BPBp). This approach allows us to establish two new results: the…

Functional Analysis · Mathematics 2026-04-09 Sun Kwang Kim , Han Ju Lee , Miguel Martin , Oscar Roldan

In this paper, we study the Bishop-Phelps-Bollob\'as property for operators (BPBp for short). To this end, we investigate the generalized approximate hyperplane series property (generalized AHSP for short) for a pair $(X,Y)$ of Banach…

Functional Analysis · Mathematics 2025-10-30 Thiago Grando , Elisa R. Santos

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
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