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Related papers: Selective covering properties of product spaces

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We study products of general topological spaces with Menger's covering property, and its refinements based on filters and semifilters. To this end, we extend the projection method from the classic real line topology to the Michael topology.…

General Topology · Mathematics 2017-01-04 Piotr Szewczak , Boaz Tsaban

We study productive properties of gamma spaces, and their relation to other, classic and modern, selective covering properties. Among other things, we prove the following results: 1. Solving a problem of F. Jordan, we show that for every…

Logic · Mathematics 2018-10-11 Arnold W. Miller , Boaz Tsaban , Lyubomyr Zdomskyy

We construct Menger subsets of the real line whose product is not Menger in the plane. In contrast to earlier constructions, our approach is purely combinatorial. The set theoretic hypothesis used in our construction is far milder than…

General Topology · Mathematics 2016-10-27 Piotr Szewczak , Boaz Tsaban

A set of reals $X$ is $\mathfrak{b}$-concentrated if it has cardinality at least $\mathfrak{b}$ and it contains a countable set $D\subseteq X$ such that each closed subset of $X$ disjoint with $D$ has size smaller than $\mathfrak{b}$. We…

General Topology · Mathematics 2025-11-13 Valentin Haberl , Piotr Szewczak , Lyubomyr Zdomskyy

We prove that assuming $\mathfrak{b}=\mathfrak{d}$, in the class of hereditarily Lindel\"of spaces, each productively Scheepers space is productively Hurewicz. The above statement remains true in the class of all general topological spaces…

General Topology · Mathematics 2026-02-19 Marta Kładź-Duda , Piotr Szewczak , Lyubomyr Zdomskyy

We consider products of sets of reals with a combinatorial structure based on scales parameterized by filters. This kind of sets were intensively investigated in products of spaces with combinatorial covering properties as Hurewicz,…

Combinatorics · Mathematics 2025-03-28 Michał Pawlikowski , Piotr Szewczak , Lyubomyr Zdomskyy

The theorem we prove is a slight strengthening of some results by Just, Miller, Scheepers and Szeptycki [JMSS]. We use the Michael technique instead of the combinatorial approach in the literature. Comments by the submitter: This short…

General Topology · Mathematics 2023-05-19 Jozef Chaber , Roman Pol

We prove that under certain set-theoretic assumptions every productively Lindel\"of space has the Hurewicz covering property, thus improving upon some earlier results of Aurichi and Tall.

General Topology · Mathematics 2014-06-04 Dušan Repovš , Lyubomyr Zdomskyy

This article is devoted to the interplay between forcing with fusion and combinatorial covering properties. We illustrate this interplay by proving that in the Laver model for the consistency of the Borel's conjecture, the product of any…

General Topology · Mathematics 2017-12-12 Dušan Repovš , Lyubomyr Zdomskyy

Hindman's celebrated Finite Sums Theorem, and its high-dimensional version due to Milliken and Taylor, are extended from covers of countable sets to covers of arbitrary topological spaces with Menger's classic covering property. The methods…

General Topology · Mathematics 2017-11-09 Boaz Tsaban

This article is devoted to the interplay between forcing with fusion and combinatorial covering properties. We discuss known instances of this interplay as well as present a new one, namely that in the Laver model for the consistency of the…

Logic · Mathematics 2019-11-13 Lyubomyr Zdomskyy

We provide new techniques to construct sets of reals without perfect subsets and with the Hurewicz or Menger covering properties. In particular, we show that if the Continuum Hypothesis holds, then there are such sets which can be mapped…

General Topology · Mathematics 2026-03-02 Piotr Szewczak , Tomasz Weiss , Lyubomyr Zdomskyy

We settle all problems posed by Scheepers, in his tribute paper to Gerlits, concerning the additivity of the Gerlits--Nagy property and related additivity numbers. We apply these results to compute the minimal number of concentrated sets of…

General Topology · Mathematics 2012-06-01 Boaz Tsaban , Lyubomyr Zdomskyy

We show that, under suitably general formulations, covering properties, accumulation properties and filter convergence are all equivalent notions. This general correspondence is exemplified in the study of products. Let $X$ be a product of…

General Topology · Mathematics 2023-03-28 Paolo Lipparini

Using a dictionary translating a variety of classical and modern covering properties into combinatorial properties of continuous images, we get a simple way to understand the interrelations between these properties in ZFC and in the realm…

Logic · Mathematics 2010-11-02 Boaz Tsaban , Lyubomyr Zdomskyy

We continue to investigate various diagonalization properties for sequences of open covers of separable metrizable spaces introduced in Part I. These properties generalize classical ones of Rothberger, Menger, Hurewicz, and Gerlits-Nagy. In…

Logic · Mathematics 2016-09-06 Winfried Just , Arnold W. Miller , Marion Scheepers , Paul J. Szeptycki

Menger's basis property is a generalization of $\sigma$-compactness and admits an elegant combinatorial interpretation. We introduce a general combinatorial method to construct non $\sigma$-compact sets of reals with Menger's property.…

General Topology · Mathematics 2010-11-02 Boaz Tsaban , Lubomyr Zdomsky

Using the idea of strong uniform convergence on bornology, Caserta, Di Maio and Ko\v{c}inac studied open covers and selection principles in the realm of metric spaces (associated with a bornology) and function spaces (w.r.t. the topology of…

General Topology · Mathematics 2020-06-02 Debraj Chandra , Pratulananda Das , Shunhankar Das

This article is a continuation of the study of bornological open covers and related selection principles in metric spaces done in (Chandra et al. 2020) using the idea of strong uniform convergence (Beer and Levi, 2009) on bornology. Here we…

General Topology · Mathematics 2020-06-03 Debraj Chandra , Pratulananda Das , Subhankar Das

Let $\mathcal{P}$ be a topological property. A.V. Arhangel'skii calls $X$ projectively $\mathcal{P}$ if every second countable continuous image of $X$ is $\mathcal{P}$. Lj.D.R. Ko$\check{c}$inac characterized the classical covering…

General Topology · Mathematics 2020-05-06 Alexander V. Osipov
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