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A topological space $Y$ has the property (B) of Banakh if there is a countable family $\{A_n:n\in \mathbb{N}\}$ of closed nowhere dense subsets of $Y$ absorbing all compact subsets of $Y$. In this note we show that the space $C_p(X)$ of…

General Topology · Mathematics 2024-07-29 Mikołaj Krupski , Kacper Kucharski , Witold Marciszewski

Intermediate rings of real valued continuous functions with countable range on a Hausdorff zero-dimensional space $X$ are introduced in this article. Let $\Sigma_c(X)$ be the family of all such intermediate rings $A_c(X)$'s which lie…

General Topology · Mathematics 2019-12-05 Sudip Kumar Acharyya , Rakesh Bharati , A. Deb Ray

We show in detail that every compact countable subset of a metric space is homeomorphic to a countable ordinal number, which extends a result given by Mazurkiewicz and Sierpinski for finite-dimensional Euclidean spaces. In order to achieve…

General Topology · Mathematics 2019-11-12 Borys Álvarez-Samaniego , Andrés Merino

We say that a Tychonoff space $X$ is a $\kappa$-space if it is homeomorphic to a closed subspace of $C_p(Y)$ for some locally compact space $Y$. The class of $\kappa$-spaces is strictly between the class of Dieudonn\'{e} complete spaces and…

General Topology · Mathematics 2025-07-16 Saak Gabriyelyan , Evgenii Reznichenko

The main aim of the article is to show, in the absence of the Axiom of Choice, relationships between the following, independent of $\mathbf{ZF}$, statements: "Every countable product of compact metrizable spaces is separable (respectively,…

General Topology · Mathematics 2021-09-03 Kyriakos Keremedis , Eleftherios Tachtsis , Eliza Wajch

We prove that for any separable Banach space $X$, there exists a compact metric space which is homeomorphic to the Cantor space and whose Lipschitz-free space contains a complemented subspace isomorphic to $X$. As a consequence we give an…

Functional Analysis · Mathematics 2015-11-17 Petr Hájek , Gilles Lancien , Eva Pernecká

A random dense countable set is characterized (in distribution) by independence and stationarity. Two examples are `Brownian local minima' and `unordered infinite sample'. They are identically distributed; the former ad hoc proof of this…

Probability · Mathematics 2007-05-23 Boris Tsirelson

In this paper, we consider noncoherent random linear coding networks (RLCNs) as a discrete memoryless channel (DMC) whose input and output alphabets consist of subspaces. This contrasts with previous channel models in the literature which…

Information Theory · Computer Science 2010-01-13 Bartolomeu F. Uchoa-Filho , Roberto W. Nobrega

The aim of this paper is to continue the study of sg-compact spaces. The class of sg-compact spaces is a proper subclass of the class of hereditarily compact spaces. In our paper we shall consider sg-compactness in product spaces. Our main…

General Topology · Mathematics 2007-05-23 Julian Dontchev , Maximilian Ganster

We introduce a ZFC method that enables us to build spaces (in fact special dense subspaces of certain Cantor cubes) in which we have "full control" over all dense subsets. Using this method we are able to construct, in ZFC, for each…

General Topology · Mathematics 2007-05-23 Istvan Juhasz , Lajos Soukup , Zoltan Szentmiklossy

The concept of the strong Pytkeev property, recently introduced by Tsaban and Zdomskyy in [32], was successfully applied to the study of the space $C_c(X)$ of all continuous real-valued functions with the compact-open topology on some…

General Topology · Mathematics 2014-12-05 S. S. Gabriyelyan , J. Kakol

A condition, in two variants, is given such that if a property P satisfies this condition, then every logic which is at least as strong as first-order logic and can express P fails to have the compactness property. The result is used to…

Logic · Mathematics 2013-04-15 Vera Koponen

In this paper, we give a topological version of Scott convergence theorem for locally hypercompact spaces. We introduce the notion of $\mathcal{S}^*_X$-convergence on a $T_0$ topological space $X$, and define the notion of finitely…

General Topology · Mathematics 2023-08-09 Yuxu Chen , Hui Kou

High-density object counting in surveillance scenes is challenging mainly due to the drastic variation of object scales. The prevalence of deep learning has largely boosted the object counting accuracy on several benchmark datasets.…

Computer Vision and Pattern Recognition · Computer Science 2019-04-09 Muming Zhao , Jian Zhang , Chongyang Zhang , Wenjun Zhang

This paper is devoted to dualization of paracompactness to the coarse category via the concept of $R$-disjointness. Property A of G.Yu can be seen as a coarse variant of amenability via partitions of unity and leads to a dualization of…

Metric Geometry · Mathematics 2015-12-30 Jerzy Dydak

Visual counting, a task that aims to estimate the number of objects from an image/video, is an open-set problem by nature, i.e., the number of population can vary in [0, inf) in theory. However, collected data and labeled instances are…

Computer Vision and Pattern Recognition · Computer Science 2020-06-02 Haipeng Xiong , Hao Lu , Chengxin Liu , Liang Liu , Chunhua Shen , Zhiguo Cao

We characterize when the countable power of a Corson compactum has a dense metrizable subspace and construct consistent examples of Corson compacta whose countable power does not have a dense metrizable subspace. We also give several…

General Topology · Mathematics 2024-03-26 Arkady Leiderman , Santi Spadaro , Stevo Todorcevic

A reduction of properties (invariants) of compact sets of real numbers to properties of countable orders is presented here. Discussed here is also an embedding property of some compact sets that are called t$\mathbb R$-sets. Among others,…

General Topology · Mathematics 2026-02-18 Sławomir Kusiński , Szymon Plewik

A product of compact normal spaces is normal; the product of a countably infinite collection of non-trivial spaces is normal if and only if it is countably paracompact and each of its finite sub-products is normal; if all powers of a space…

General Topology · Mathematics 2020-02-10 N. Noble

One shows for Banach bundles in a certain class that having a second countable locally compact Hausdorff base space and separable fibers implies the separability of the Banach space of the all sections that vanish at infinity. In the…

Functional Analysis · Mathematics 2018-02-07 Aldo J. Lazar