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Related papers: Boundedness and surjectivity in Banach spaces

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We introduce the notion of a totally ($K$-) bounded element of a W*-probability space $(M, \varphi)$ and, borrowing ideas of Kadison, give an intrinsic characterization of the $^*$-subalgebra $M_{tb}$ of totally bounded elements. Namely, we…

Operator Algebras · Mathematics 2025-01-27 Jananan Arulseelan , Isaac Goldbring , Bradd Hart , Thomas Sinclair

We introduce a measure of super weak noncompactness $\Gamma$ defined for bounded linear operators and subsets in Banach spaces that allows to state and prove a characterization of the Banach spaces which are subspaces of a Hilbert generated…

Functional Analysis · Mathematics 2022-03-02 Guillaume Grelier , Matías Raja

In this paper we analyse when every element of $X\widehat{\otimes}_\pi Y$ attains its projective norm. We prove that this is the case if $X$ is the dual of a subspace of a predual of an $\ell_1(I)$ space and $Y$ is $1$-complemented in its…

Functional Analysis · Mathematics 2024-07-16 Luis C. García-Lirola , Juan Guerrero-Viu , Abraham Rueda Zoca

A banach space X is a normed vector space, which is complete with respect to the metric induced by the norm. Given a bounded linear operator T acting on a banach space X, T is said to attain its norm if there is a unit vector z in X, such…

Functional Analysis · Mathematics 2019-07-30 Samuel Gomez , James Rose , Ryan Maguire

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

In this paper we will characterize the completeness and barrelledness of a normed space through the strong p-Ces\`aro summability of series. A new characterization of weakly unconditionally Cauchy series and unconditionally convergent…

Functional Analysis · Mathematics 2024-02-12 Fernando León-Saavedra , Soledad Moreno-Pulido , Antonio Sala-Pérez

We modify the very well known theory of normed spaces $(E, \norm)$ within functional analysis by considering a sequence $(\norm_n : n\in\N)$ of norms, where $\norm_n$ is defined on the product space $E^n$ for each $n\in\N$. Our theory is…

Functional Analysis · Mathematics 2012-03-20 H. G. Dales , M. E. Polyakov

We define bidual bounded $uo$-convergence in vector lattices and investigate relations between this convergence and $b$-property. We prove that for a regular Riesz dual system $\langle X,X^{\sim}\rangle$, $X$ has $b$-property if and only if…

Functional Analysis · Mathematics 2020-09-17 Safak Alpay , Eduard Emelyanov , Svetlana Gorokhova

A Banach space $X$ is said to have property (K) if every $w^*$-convergent sequence in $X^*$ admits a convex block subsequence which converges with respect to the Mackey topology. We study the connection of this property with strongly weakly…

Functional Analysis · Mathematics 2016-01-25 Antonio Avilés , José Rodríguez

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

We study dentable maps from a closed convex subset of a Banach space into a metric space as an attempt of generalize the Radon-Nikod\'ym property to a "less linear" frame. We note that a certain part of the theory can be developed in rather…

Functional Analysis · Mathematics 2017-06-01 Luis García-Lirola , Matías Raja

In this paper the theory of uniformly convex metric spaces is developed. These spaces exhibit a generalized convexity of the metric from a fixed point. Using a (nearly) uniform convexity property a simple proof of reflexivity is presented…

Metric Geometry · Mathematics 2016-04-08 Martin Kell

If a separable Banach space $X$ is such that for some nonquasireflexive Banach space $Y$ there exists a surjective strictly singular operator $T:X\to Y$ then for every countable ordinal $\alpha $ the dual of $X$ contains a subspace whose…

Functional Analysis · Mathematics 2010-09-07 Mikhail I. Ostrovskii

The idea of convex sets and various related results in 2-Probabilistic normed spaces were established in [HR]. In this paper, We obtain the concepts of convex series closedness, convex series compactness, boundedness and their…

Functional Analysis · Mathematics 2017-08-04 P. K. Harikrishnan , Bernardo Lafuerza Guillen , K. T. Ravindran

In this paper we introduce the strong Bishop-Phelps-Bollob\'as property (sBPBp) for bounded linear operators between two Banach spaces $X$ and $Y$. This property is motivated by a Kim-Lee result which states, under our notation, that a…

Functional Analysis · Mathematics 2016-04-07 Sheldon Dantas

We study several classical concepts in the topic of strict convexity of norms in infinite dimensional Banach spaces. Specifically, and in descending order of strength, we deal with Uniform Rotundity (UR), Weak Uniform Rotundity (WUR) and…

Functional Analysis · Mathematics 2023-02-23 Petr Hájek , Andrés Quilis

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

Recently, J.X. Chen et al. introduced and studied the class of almost limited sets in Banach lattices. In this paper we establish some characterizations of almost limited sets in Banach lattices (resp. wDP* property of Banach lattices),…

Functional Analysis · Mathematics 2014-04-29 N. Machrafi , A. Elbour , M. Moussa

We show that for a Banach algebra $A$ with a bounded approximate identity, the amenability of the projective tensor product of A with A, the amenability of the projective tensor product of A with A^{op}and the amenability of A are…

Functional Analysis · Mathematics 2010-12-08 Miad Makareh Shireh

We investigate questions of maximal symmetry in Banach spaces and the structure of certain bounded non-unitarisable groups on Hilbert space. In particular, we provide structural information about bounded groups with an essentially unique…

Functional Analysis · Mathematics 2015-07-08 Valentin Ferenczi , Christian Rosendal