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Related papers: Menger's covering property and groupwise density

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We introduce a density counterpart of the Scheepers covering property $\bigcup_{\mathrm{fin}}(\mathcal O,\Omega)$ and study its relations to known combinatorial density property. In particular, we show that it is equivalent to the…

General Topology · Mathematics 2025-10-14 Leandro Aurichi , Fortunato Maesano , Lyubomyr Zdomskyy

We prove that in the Miller model the Menger property is preserved by finite products of metrizable spaces. This answers several open questions and gives another instance of the interplay between classical forcing posets with fusion and…

General Topology · Mathematics 2018-09-25 Lyubomyr Zdomskyy

We provide new results on combinatorial characterizations of covering properties in end spaces and ray spaces. In particular, we characterize the Lindel\"of degree, the extent, the Rothberger property, $\sigma$-compactness and the Menger…

Combinatorics · Mathematics 2026-01-21 Rodrigo Rey Carvalho , Matheus Duzi , Vinicius de Oliveira Rodrigues

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

In this paper we suggest new effective criteria for the density property. This enables us to give a trivial proof of the original Anders\'en-Lempert result and to establish (almost free of charge) the algebraic density property for all…

Complex Variables · Mathematics 2009-11-13 Shulim Kaliman , Frank Kutzschebauch

We investigate the densities of the sets of abundant numbers and of covering numbers, integers $n$ for which there exists a distinct covering system where every modulus divides $n$. We establish that the set $\mathcal{C}$ of covering…

Number Theory · Mathematics 2026-02-12 Nathan McNew , Jai Setty

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

The_additivity_number_ of a topological property (relative to a given space) is the minimal number of subspaces with this property whose union does not have the property. The most well-known case is where this number is greater than…

General Topology · Mathematics 2010-11-02 Boaz Tsaban

We introduce the notion of the algebraic overshear density property which implies both the algebraic notion of flexibility and the holomorphic notion of the density property. We investigate basic consequences of this stronger property, and…

Complex Variables · Mathematics 2023-10-31 Rafael B. Andrist , Frank Kutzschebauch

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

We consider ``meager analogues'' of classical covering properties of Menger, Hurewicz and Rothberger. We show that Borel images of sets having ``our'' covering properties have these classical covering properties.

Logic · Mathematics 2007-05-23 Tomek Bartoszynski , Marion Scheepers

The idea of convex sets and various related results in 2-Probabilistic normed spaces were established in [HR]. In this paper, We obtain the concepts of convex series closedness, convex series compactness, boundedness and their…

Functional Analysis · Mathematics 2017-08-04 P. K. Harikrishnan , Bernardo Lafuerza Guillen , K. T. Ravindran

We investigate the reproducing properties of Gabor systems within the context of expansible groups. These properties are established in terms of density conditions. The concept of density that we employ mirrors the well-known Beurling…

Functional Analysis · Mathematics 2024-10-16 Emily King , Rocio Nores , Victoria Paternostro

We introduce a general notion of covering property, of which many classical definitions are particular instances. Notions of closure under various sorts of convergence, or, more generally, under taking kinds of accumulation points, are…

General Topology · Mathematics 2022-06-28 Paolo Lipparini

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

A generalization of the Lebesgue number lemma is obtained. It is proved that, if each countably infinite locally finite open cover of a chainable metric space $X$ has a Lebesgue number, then $X$ is totally bounded. A property of metric…

General Topology · Mathematics 2022-05-25 Ajit Kumar Gupta , Saikat Mukherjee

We give a few properties equivalent to the Bloch-Kato conjecture (now the norm residue isomorphism theorem).

Algebraic Geometry · Mathematics 2019-02-14 Bruno Kahn

We generalize the notion of the density property for complex manifolds to holomorphic fibrations, and introduce the notion of the fibred density property. We prove that the natural fibration of the spectral ball over the symmetrized…

Complex Variables · Mathematics 2016-04-07 Rafael B. Andrist , Frank Kutzschebauch

In this paper we consider some recent relative versions of Menger property called set strongly star Menger and set star Menger properties and the corresponding Hurewicz-type properties. In particular, using \cite {BMae}, we "easily" prove…

General Topology · Mathematics 2023-10-05 Maddalena Bonanzinga , Davide Giacopello , Fortunato Maesano

We construct, using mild combinatorial hypotheses, a real Menger set that is not Scheepers, and two real sets that are Menger in all finite powers, with a non-Menger product. By a forcing-theoretic argument, we show that the same holds in…

General Topology · Mathematics 2020-04-08 Piotr Szewczak , Boaz Tsaban , Lyubomyr Zdomskyy
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