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Related papers: A semifilter approach to selection principles

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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

According to a result of Kocinac and Scheepers, the Hurewicz covering property is equivalent to a somewhat simpler selection property: For each sequence of large open covers of the space one can choose finitely many elements from each cover…

General Topology · Mathematics 2010-11-02 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 provide simplified solutions of Menger's and Hurewicz's problems and conjectures, concerning generalizations of sigma-compactness. The reader who is new to this field will find a self-contained treatment in Sections 1, 2, and 5. Sections…

General Topology · Mathematics 2017-03-10 Boaz Tsaban

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

In this paper, we introduce the notions of Star-$\sigma\mathcal{K}$ and absolutely Star-$\sigma\mathcal{K}$ spaces which allow us to unify results among several properties in the theory of star selection principles on small spaces. In…

General Topology · Mathematics 2021-05-17 Javier Casas-de la Rosa , Sergio A. Garcia-Balan

We study the relation between the Hurewicz and Menger properties of filters considered topologically as subspaces of P(\omega) with the Cantor set topology.

General Topology · Mathematics 2018-09-19 Rodrigo Hernández-Gutiérrez , Paul J. Szeptycki

We study the preservation of selective covering properties, including classic ones introduced by Menger, Hurewicz, Rothberger, Gerlits and Nagy, and others, under products with some major families of concentrated sets of reals. Our methods…

General Topology · Mathematics 2014-02-18 Arnold W. Miller , Boaz Tsaban , 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

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

In this paper, we introduced $\alpha$-Hurewicz $\&$ $\theta$-Hurewicz properties in a topological space $X$ and investigated their relationship with other selective covering properties. We have shown that for an extremally disconnected…

General Topology · Mathematics 2023-07-04 Gaurav Kumar , Sumit Mittal , Brij K. Tyagi

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

The Hurewicz property is a classical generalization of $\sigma$-compactness and Sierpi\'nski sets (whose existence follows from CH) are standard examples of non-$\sigma$-compact Hurewicz spaces. We show, solving a problem stated by Szewczak…

General Topology · Mathematics 2025-03-18 Witold Marciszewski , Roman Pol , Piotr Zakrzewski

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 characterize the Hurewicz covering property in metrizable spaces in terms of properties of the metrics of the space. Then we show that a weak version of selective screenability, when combined with the Hurewicz property, implies selective…

General Topology · Mathematics 2007-12-10 Liljana Babinkostova

We prove that if X is a separable metric space with the Hurewicz covering property, then the Banach-Mazur game played on X is determined. The implication is not true when "Hurewicz covering property" is replaced with "Menger covering…

General Topology · Mathematics 2007-11-08 Marion Scheepers

We show that even for subsets X of the real line which do not contain perfect sets, the Hurewicz property does not imply the property S1(Gamma,Gamma), asserting that for each countable family of open gamma-covers of X, there is a choice…

General Topology · Mathematics 2011-08-08 Dušan Repovš , Boaz Tsaban , Lyubomyr Zdomskyy

In this paper, we introduced the mildly version of the Hurewicz basis covering property, studied by Babinkostova, Ko\v{c}inac, and Scheepers. A space $X$ is said to have mildly-Hurewicz property if for each sequence $\langle \mathcal{U}_n :…

General Topology · Mathematics 2022-02-28 Manoj Bhardwaj , Alexander V. Osipov

Using the property of being completely Baire, countable dense homogeneity and the perfect set property we will be able, under Martin's Axiom for countable posets, to distinguish non-principal ultrafilters on $\omega$ up to homeomorphism.…

General Topology · Mathematics 2019-12-11 Andrea Medini , David Milovich

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
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