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Related papers: The approximation property and Lipschitz mappings …

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We show that there are compact linear operators on Banach spaces which cannot be approximated by numerical radius attaining operators.

Functional Analysis · Mathematics 2017-04-25 Angela Capel , Miguel Martin , Javier Meri

This paper introduces a measure, called Lipschitz widths, of the optimal performance possible of certain nonlinear methods of approximation. It discusses their relation to entropy numbers and other well known widths such as the Kolmogorov…

Numerical Analysis · Mathematics 2021-11-03 Guergana Petrova , Przemyslaw Wojtaszczyk

The theory of compact linear operators acting on a Banach space has such a classical core and is familiar to many. Perhaps lesser known is the characterization theorem of Terzio\u{g}lu for compact maps. In this paper we consider…

Functional Analysis · Mathematics 2017-04-25 Asuman Guven Aksoy

We exhibit a new approach to the proofs of the existence of a large family of almost isometric ideals in nonseparable Banach spaces and existence of a large family of almost isometric local retracts in metric spaces. Our approach also…

Functional Analysis · Mathematics 2026-03-18 Leandro Candido , Marek Cúth , Ondřej Smetana

The notions of $p$-convexity and $q$-concavity are mostly known because of their importance as a tool in the study of isomorphic properties of Banach lattices, but they also play a role in several results involving linear maps between…

Functional Analysis · Mathematics 2014-06-25 Javier Alejandro Chávez-Domínguez

In their recent evaluation of time-frequency representations and structured sparsity approaches to audio inpainting, Lieb and Stark (2018) have used a particular mapping as a proximal operator. This operator serves as the fundamental part…

Audio and Speech Processing · Electrical Eng. & Systems 2020-10-15 Ondřej Mokrý , Pavel Rajmic

In this note, we will discuss how to relate an operator ideal on Banach spaces to the sequential structures it defines. Concrete examples of ideals of compact, weakly compact, completely continuous, Banach-Saks and weakly Banach-Saks…

Functional Analysis · Mathematics 2011-01-12 Ngai-Ching Wong

We study the relation between the linear stability of almost-symmetries and the geometry of the Banach spaces on which these transformations are defined. We show that any transformation between finite dimensional Banach spaces that…

Mathematical Physics · Physics 2019-07-15 Javier Cuesta

We present a sufficient condition for a Banach space to have the approximate hyperplane series property (AHSP) which actually covers all known examples. We use this property to get a stability result to vector-valued spaces of integrable…

Functional Analysis · Mathematics 2017-04-25 Yun Sung Choi , Sun Kwang Kim , Han Ju Lee , Miguel Martín

This chapter offers a detailed survey on intrinsically localized frames and the corresponding matrix representation of operators. We re-investigate the properties of localized frames and the associated Banach spaces in full detail. We…

Functional Analysis · Mathematics 2019-03-27 Peter Balazs , Karlheinz Gröchenig

It is folklore that the sum of two $M$-ideals (semi $M$-ideals) is also an $M$-ideal (a semi $M$-ideal). Numerous authors have attempted to investigate such properties of subspaces. This article explores two important facets of…

Functional Analysis · Mathematics 2026-05-12 Syamantak Das

This paper is a sequel to [6]. In that paper we transferred the discussions in [1] and [13] concerning almost invariant half-spaces for operators on complex Banach spaces to the context of operators on Hilbert space, and we gave easier…

Functional Analysis · Mathematics 2017-10-30 Il Bong Jung , Eungil Ko , Carl Pearcy

It is shown how to construct, given a Banach space which does not have the approximation property, another Banach space which does not have the approximation property but which does have the compact approximation property.

Functional Analysis · Mathematics 2009-09-25 George A. Willis

Let $X$, $Y$ be Banach spaces and let $\mathcal{L}(X,Y)$ be the space of bounded linear operators from $X$ to $Y$. We develop the theory of double operator integrals on $\mathcal{L}(X,Y)$ and apply this theory to obtain commutator estimates…

Functional Analysis · Mathematics 2016-04-22 Jan Rozendaal , Fedor Sukochev , Anna Tomskova

We show that no matter what subset of a normed space is given, a typical 1-Lipschitz mapping into a Banach space is non-differentiable at a typical point of the set in a very strong sense: the derivative ratio approximates, on arbitrary…

Functional Analysis · Mathematics 2025-04-08 Michael Dymond , Olga Maleva

Many elliptic boundary value problems exhibit an interior regularity property, which can be exploited to construct local approximation spaces that converge exponentially within function spaces satisfying this property. These spaces can be…

Numerical Analysis · Mathematics 2025-07-04 S. Aziz , M. Bauer , M. Bebendorf , T. Rau

In this paper, we introduce generalized Baskakov Kantorovich Stancu type operators and investigate direct result, local approximation and weighted approximation properties of these operators. Modulus of continuity, second modulus of…

Numerical Analysis · Mathematics 2015-08-06 Abdul Wafi , Nadeem Rao

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

The idea of best approximation in linear n-normed space is presented and some examples showing various possibilities of best approximations in linear n-normed space is given. Also, we study strictly convex n-norm and enquire about the…

Functional Analysis · Mathematics 2023-09-27 Prasenjit Ghosh , T. K. Samanta

We introduce certain linear positive operators and study some approximation properties of these operators in the space of functions, continuous on a compact set, of two variables. We also find the order of this approximation by using…

Classical Analysis and ODEs · Mathematics 2007-09-24 Fatma Tasdelen , Ali Olgun , Gulen Bascanbaz-Tunca