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Given a category of objects, it is both useful and important to know if all the objects in the category may be realised as sub-objects -- via morphisms in the given category -- of a single object in that category enjoying some nice…

Functional Analysis · Mathematics 2019-07-18 M. A. Sofi

The aim of this note is to consider different notions for the Banach-Saks property in locally solid vector lattices as an extension for the known concepts of the Banach-Saks property in Banach lattices. We investigate relations between…

Functional Analysis · Mathematics 2020-10-27 Omid Zabeti

We extend to infinite dimensional Hilbert spaces a celebrated result, due to B. Polyak, about the convexity of the joint image of quadratic functions. We give sufficient conditions which assure that the joint image is also closed. However,…

Functional Analysis · Mathematics 2022-02-10 Maximiliano Contino , Guillermina Fongi , Santiago Muro

A branch of generalizations of the Banach Fixed Point Theorem replaces contractivity by a weaker but still effective property. The aim of the present note is to extend the contraction principle in this spirit for such complete semimetric…

Functional Analysis · Mathematics 2017-06-29 Mihály Bessenyei , Zsolt Páles

In the article we generalize the Marcinkiewicz sampling theorem in the context of Orlicz spaces. We establish conditions under which sampling theorem holds in terms of restricted submultiplicativity and supermultiplicativity of an…

Functional Analysis · Mathematics 2022-09-13 Aleksander Pawlewicz , Michał Wojciechowski

The main pupose of this paper is to fully characterize continuous concave functions $\psi $ such that the corresponding Marcinkiewicz Banach function space $M_{\psi }$ is a Grothendieck space.

Functional Analysis · Mathematics 2019-12-04 B. de Pagter , F. A. Sukochev

Several new characterizations of the Gelfand-Phillips property are given. We define a strong version of the Gelfand-Phillips property and prove that a Banach space has this stronger property iff it embeds into $c_0$. For an infinite compact…

Functional Analysis · Mathematics 2021-10-18 Taras Banakh , Saak Gabriyelyan

We prove the result stated in the title. This provides a first example of an infinite-dimensional Banach space whose Lipschitz free space is isomorphic to the free space of a compact set.

Functional Analysis · Mathematics 2019-11-14 Luis C. García-Lirola , Antonin Prochazka

This paper addresses the Asplund property for the space of continuous functions $C_k(X)$ equipped with the compact-open topology, when $X$ is an arbitrary Tychonoff space. Motivated by inconsistent definitions in prior literature extending…

Functional Analysis · Mathematics 2025-10-03 Marian Fabian , Jerzy Kcakol , Arkady Leiderman

We examine the analyticity of the class of separable Banach spaces possessing the $\pi$-property, defined in terms of convergence along a filter. Our results establish that this class is $\Sigma^1_3$ whenever the underlying filter is…

Functional Analysis · Mathematics 2025-09-01 Tomasz Kania , Jarosław Swaczyna

It is well known, as follows from the Banach-Steinhaus theorem, that if a sequence $\left\{y_{n}\right\}_{n=1}^{\infty}$ of linear continuous functionals in a Fr\'echet space converges pointwise to a linear functional $Y,$ $Y\left( x\right)…

Functional Analysis · Mathematics 2017-03-09 Ricardo Estrada , Jasson Vindas

The Erberlein-Smulian Theorem asserts that for complete normed spaces, that is Banach spaces, a subset is weak compact if and only if it is weak sequentially compact. In this paper it is shown that the completeness of the normed space is…

Functional Analysis · Mathematics 2007-05-23 Wha Suck Lee

In the setting of Banach lattices the weak (resp. positive) Grothendieck spaces have been defined. We localize such notions by defining new classes of sets that we study and compare with some quite related different classes. This allows us…

Functional Analysis · Mathematics 2021-01-19 Pablo Galindo , V. C. C. Miranda

The class of Hausdorff spaces that are continuous images of compact orderable spaces is studied by analyzing the relationship between the elements of this class and compact orderable spaces in a back-and-forth fashion. Structure results for…

General Topology · Mathematics 2016-11-15 Ahmad Farhat

Newtonian spaces generalize first-order Sobolev spaces to abstract metric measure spaces. In this paper, we study regularity of Newtonian functions based on quasi-Banach function lattices. Their (weak) quasi-continuity is established,…

Functional Analysis · Mathematics 2016-09-23 Lukáš Malý

There are presented certain results on extending continuous linear operators defined on spaces of E-valued continuous functions (defined on a compact Hausdorff space X) to linear operators defined on spaces of E-valued measurable functions…

Functional Analysis · Mathematics 2017-05-26 Piotr Niemiec

We prove two weak compactness criteria in Musielak-Orlicz spaces for $N$-functions satisfying the $\Delta_2$-condition. They extend criteria from And\^o for Orlicz spaces to this setting of non-symmetrical Banach function spaces. As…

Functional Analysis · Mathematics 2026-01-28 Mauro Sanchiz

In this short note, we give some new results on continuous bounded cohomology groups of topological semigroups with values in complex field. We show that the second continuous bounded cohomology group of a compact metrizable semigroup, is a…

Functional Analysis · Mathematics 2019-07-31 Maysam Maysami Sadr

We present new completeness conditions for exponential systems on the complex plane in Banach algebras of continuous functions on a compact with a connected complement that are simultaneously holomorphic in the interior of this compact if…

Complex Variables · Mathematics 2023-06-29 B. N. Khabibullin , E. G. Kudasheva

We establish a fixed point theorem for mappings of square matrices of all sizes which respect the matrix sizes and direct sums of matrices. The conclusions are stronger if such a mapping also respects matrix similarities, i.e., is a…

Functional Analysis · Mathematics 2012-10-22 Gulnara Abduvalieva , Dmitry S. Kaliuzhnyi-Verbovetskyi