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Related papers: Almost Fra\"iss\'e Banach spaces

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Motivated by the famous Blanco-Koldobsky-Turn\v{s}ek characterization of isometries, we study the \textit{approximate preservation of Birkhoff-James orthogonality by a linear operator between Banach spaces}. In particular, we investigate…

Functional Analysis · Mathematics 2025-01-22 Kalidas Mandal , Jayanta Manna , Kallol Paul , Debmalya Sain

We show that quasi-minimizers of non-homogeneous energy functionals on metric measure spaces are locally H\"older continuous and satisfy the Harnack inequality. We assume that the spaces are doubling and support a Poincar\'e inequality. The…

Analysis of PDEs · Mathematics 2010-08-31 Jasun Gong , Juan J. Manfredi , Mikko Parviainen

We characterize the relatively compact subsets of $L^1\left(\| m \| \right),$ the quasi-Banach function space associated to the semivariation of a given vector measure $m$ showing that the strong connection between compactness, uniform…

Functional Analysis · Mathematics 2019-10-30 Ricardo del Campo , Antonio Fernández , Fernando Mayoral , Francisco Naranjo

We strengthen the property $\Delta$ of a function $f:[\omega_2]^2\rightarrow [\omega_2]^{\leq \omega}$ considered by Baumgartner and Shelah. This allows us to consider new types of amalgamations in the forcing used by Rabus, Juh\'asz and…

Functional Analysis · Mathematics 2010-09-17 Christina Brech , Piotr Koszmider

This paper is a continuation of our study of compact, power compact, Riesz, and quasicompact endomorphisms of commutative Banach algebras. Previously it has been shown that if $B$ is a unital commutative semisimple Banach algebra with…

Functional Analysis · Mathematics 2014-12-30 Joel F. Feinstein , Herbert Kamowitz

We provide an extension of the transference results of Beresnevich and Velani connecting homogeneous and inhomogeneous Diophantine approximation on manifolds and provide bounds for inhomogeneous Diophantine exponents of affine subspaces and…

Number Theory · Mathematics 2019-04-10 Anish Ghosh , Antoine Marnat

We define and discuss transfinite asymptotic notions of smoothability, type, and equal norm type. We prove distinctness of these notions for a proper class of ordinals and that each class is an ideal. We also extend some results of…

Functional Analysis · Mathematics 2018-05-09 R. M. Causey

We characterize projective and injective Banach modules in approximate terms, generalizing thereby a characterization of contractible Banach algebras given by F. Ghahramani and R. J. Loy. As a corollary, we show that each uniformly…

Functional Analysis · Mathematics 2019-05-01 A. Yu. Pirkovskii

We use Fra\" iss\'e theoretic methods to construct several universal and ultrahomogeneous Polish metric structures. Namely, universal and ultrahomogeneous Polish metric space equipped with countably many closed subsets of its powers,…

Logic · Mathematics 2013-05-03 Michal Doucha

We prove a general principle satisfied by weakly precompact sets of Lipschitz-free spaces. By this principle, certain infinite dimensional phenomena in Lipschitz-free spaces over general metric spaces may be reduced to the same phenomena in…

Functional Analysis · Mathematics 2021-08-12 Ramón J. Aliaga , Camille Noûs , Colin Petitjean , Antonín Procházka

The purpose of this paper is to study the notion of relative extreme amenability for pairs of topological groups. We give a characterization by a fixed point property on universal spaces. In addition we introduce the concepts of an…

Group Theory · Mathematics 2015-01-09 Yonatan Gutman , Lionel Nguyen Van Thé

Reconstruction property in Banach spaces introduced and studied by Casazza and Christensen in [1]. In this paper we introduce reconstruction property in Banach spaces which satisfy $\mathfrak{I}$-property. A characterization of…

Functional Analysis · Mathematics 2013-05-03 L. K. Vashisht , Geetika Khattar

Given a map $f \colon E \longrightarrow F$ between Banach spaces (or Banach lattices), a set $A$ of $E$-valued bounded sequences, ${\bf x} \in A$ and a vector topology $\tau$ on $F$, we investigate the existence of an infinite dimensional…

Functional Analysis · Mathematics 2025-05-07 Mikaela Aires , Geraldo Botelho

We introduce the concepts of growth and spectral bound for strongly continuous semigroups acting on Fr\'echet spaces and show that the Banach space inequality $s(A)\leqslant\omega_0(T)$ extends to the new setting. Via a concrete example of…

Functional Analysis · Mathematics 2016-09-12 Sven-Ake Wegner

We develop \emph{Fra\"iss\'e theory}, namely the theory of \emph{Fra\"iss\'e classes} and \emph{Fra\"iss\'e limits}, in the context of metric structures. We show that a class of finitely generated structures is Fra\"iss\'e if and only if it…

Logic · Mathematics 2014-09-09 Itaï Ben Yaacov

We give a new proof of a characterization of the closeness of the range of a continuous linear operator and of the closeness of the sum of two closed vector subspaces of a Banach space. Then we state sufficient conditions for the closeness…

Functional Analysis · Mathematics 2015-10-06 Joël Blot , Philippe Cieutat

We show that for any separable reflexive Banach space $X$ and a large class of Banach spaces $E$, including those with a subsymmetric shrinking basis but also all spaces $L_p$ for $1\leq p \leq \infty$, every bounded linear map ${\mathcal…

Functional Analysis · Mathematics 2023-11-22 Yemon Choi , Bence Horváth , Niels Jakob Laustsen

We obtain results on the existence and approximation of fixed points of enriched contractions in quasi-Banach spaces and thus extend the results obtained in the case of contractions defined on Banach spaces [Berinde, V.; P\u{a}curar, M.…

General Mathematics · Mathematics 2024-04-10 Vasile Berinde

We consider a class of bounded linear operators between Banach spaces, which we call operators with the Kato property, that includes the family of strictly singular operators between those spaces. We show that if $T:E\to F$ is a dense-range…

Functional Analysis · Mathematics 2025-06-30 Mar Jiménez Sevilla , Sebastián Lajara López , Miguel Ángel Ruiz Risueño

This paper explores the interactions of absolute continuity of the (quasi)norm with the concepts that are fundamental in the theory of rearrangement-invariant (quasi-)Banach function spaces, such as the Luxemburg representation or the…

Functional Analysis · Mathematics 2025-10-15 Dalimil Peša