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Related papers: Diameter two properties and polyhedrality

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We extend some recent results on the Hausdorff convergence of level-sets for total variation regularized linear inverse problems. Dimensions higher than two and measurements in Banach spaces are considered. We investigate the relation…

Optimization and Control · Mathematics 2021-06-09 José A. Iglesias , Gwenael Mercier

In this paper we survey known results of characterizations of reflexive Banach spaces, which are based on convergence of usual and generalized arithmetic mean (or Ces\`aro sum), weakly compact subsets, affine sets in a Banach space or its…

Functional Analysis · Mathematics 2025-03-17 Tianyi Zhou

We study the best coapproximation problem in Banach spaces, by using Birkhoff-James orthogonality techniques. We introduce two special types of subspaces, christened the anti-coproximinal subspaces and the strongly anti-coproximinal…

Functional Analysis · Mathematics 2024-08-14 Shamim Sohel , Souvik Ghosh , Debmalya Sain , Kallol Paul

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

We collect several open questions in Banach spaces, mostly related to measure theoretic aspects of the theory. The problems are divided into five categories: miscellaneous problems in Banach spaces (non-separable $L^p$ spaces, compactness…

Functional Analysis · Mathematics 2016-07-27 Jose Rodriguez

We show that a geodesic metric space which does not admit bilipschitz embeddings into Banach spaces with the Radon-Nikod\'ym property does not necessarily contain a bilipschitz image of a thick family of geodesics. This is done by showing…

Metric Geometry · Mathematics 2014-11-14 Mikhail Ostrovskii

We consider the compactness of derivations from commutative Banach algebras into their dual modules. We show that if there are no compact derivations from a commutative Banach algebra, $A$, into its dual module, then there are no compact…

Functional Analysis · Mathematics 2009-11-02 Matthew J. Heath

Let X be a complex Banach space, in this work we characterize the property of Frechet differentiability for the dual space of X. In the following, we show that if the dual space of X is Gateaux differentiable, then the dual space of Lp(X)…

Functional Analysis · Mathematics 2024-03-26 Mohammad Daher

Andreu et al [2] and Sadovskii [11] used representation spaces to study measures of non-compactness and spectral radii of operators on Banach lattices. In this paper, we develop representation spaces based on the nonstandard hull…

Functional Analysis · Mathematics 2007-05-23 Vladimir G. Troitsky

We single out and study a natural class of Banach spaces -- almost square Banach spaces. In an almost square space we can find, given a finite set $x_1,x_2,\ldots,x_N$ in the unit sphere, a unit vector $y$ such that $\|x_i-y\|$ is almost…

Functional Analysis · Mathematics 2015-08-25 Trond A. Abrahamsen , Johann Langemets , Vegard Lima

As objects of study in functional analysis, Hilbert spaces stand out as special objects of study as do nuclear spaces in view of a rich geometrical structure they possess as Banach and Frechet spaces, respectively. On the other hand, there…

Functional Analysis · Mathematics 2013-10-29 M A Sofi

In this paper, we investigate homological properties of Banach algebras. We show that retractions Banach algebras preserve biprojectivity, contractibility and biflatness. We also prove that contractibility of second dual of a Banach algebra…

Functional Analysis · Mathematics 2022-11-01 M. J. Mehdipour , A. Rejali

Given a compact pseudo-metric space, we associate to it upper and lower dimensions, depending only on the metric. Then we construct a doubling metric for which the measure of a dillated ball is closely related to these dimensions.

Classical Analysis and ODEs · Mathematics 2007-05-23 Per Bylund , Jaume Gudayol

Cocompactness is a property of embeddings between two Banach spaces, similar to but weaker than compactness, defined relative to some non-compact group of bijective isometries. In presence of a cocompact embedding, bounded sequences (in the…

Functional Analysis · Mathematics 2016-01-20 Cyril Tintarev

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 prove the absence of a universal diameter bound on lengths of curves in a sweep-out of a Riemannian 2-sphere. If such bound existed it would yield a simple proof of existence of short geodesic segments and closed geodesics on a sphere of…

Differential Geometry · Mathematics 2011-06-01 Yevgeny Liokumovich

We show that every M\"untz space can be written as a direct sum of Banach spaces X and Y , where Y is almost isometric to a subspace of c and X is finite dimensional. We apply this to show that no M\"untz space is locally octahedral or…

Functional Analysis · Mathematics 2018-11-07 André Martiny

Motivated by the local theory of Banach spaces we introduce a notion of finite representability for metric spaces. This allows us to develop a new technique for comparing the generalized roundness of metric spaces. We illustrate this…

Functional Analysis · Mathematics 2016-08-15 Lukiel Levy-Moore , Margaret Nichols , Anthony Weston

In this paper, we investigate analytical and geometric properties of certain non-compact boundary-manifolds, namely manifolds of bounded geometry. One result are strong Bochner type vanishing results for the L^2-cohomology of these…

Geometric Topology · Mathematics 2007-05-23 Thomas Schick

The main objective of this article is to provide an alternative approach to the central result of [Eldred, A. Anthony, Kirk, W. A., Veeramani, P., Proximal normal structure and relatively nonexpansive mappings, Studia Math., vol 171(3),…

Functional Analysis · Mathematics 2022-06-30 Abhik Digar , G. Sankara Raju Kosuru