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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

Integral representations are obtained of positive additive functionals on finite products of the space of continuous functions (or of bounded Borel functions) on a compact Hausdorff space. These are shown to yield characterizations of the…

Functional Analysis · Mathematics 2013-12-17 Paolo Dulio , Richard J. Gardner , Carla Peri

Which Isbell--Mr\'owka spaces ($\Psi$-spaces) satisfy the star version of Menger's and Hurewicz's covering properties? Following Bonanzinga and Matveev, this question is considered here from a combinatorial point of view. An example of a…

General Topology · Mathematics 2015-08-17 Boaz Tsaban

We provide a comprehensive development of the basics of descriptive set theory for non-separable complete metric spaces whose weight is a singular cardinal $\lambda$ of countable confinality. Somewhat unexpectedly, the resulting theory is…

Logic · Mathematics 2025-11-21 Vincenzo Dimonte , Luca Motto Ros

In this paper we extend previous studies of selection principles for families of open covers of sets of real numbers to also include families of countable Borel covers. The main results of the paper could be summarized as follows: 1. Some…

General Topology · Mathematics 2010-08-02 Marion Scheepers , Boaz Tsaban

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

W. Hurewicz proved that analytic Menger sets of reals are $\sigma$-compact and that co-analytic completely Baire sets of reals are completely metrizable. It is natural to try to generalize these theorems to projective sets. This has…

General Topology · Mathematics 2018-03-12 Franklin D. Tall , Lyubomyr Zdomskyy

In Koeller \cite{koerprops} the twelve variants of the Reifenberg properties known to be instrumental in the theory of minimal surfaces were classified with respect to various Hausdorff measure based measure theoretic properties. The…

Metric Geometry · Mathematics 2011-01-20 Amos N. Koeller

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

Let P be the direct product of countably many copies of the additive group Z of integers. We study, from a set-theoretic point of view, those subgroups of P for which all homomorphisms to Z annihilate all but finitely many of the standard…

Logic · Mathematics 2009-09-25 Andreas Blass

It is known that both the Menger and Hurewicz property of a Tychonoff space $X$ can be described by the way $X$ is placed in its \v{C}ech-Stone compactification $\beta X$. We provide analogous characterizations for the projective versions…

General Topology · Mathematics 2024-05-08 Mikołaj Krupski , Kacper Kucharski

We give characterizations of the Borel sets potentially in some Wadge class, among the Borel sets with countable vertical sections of a product of two Polish spaces. To do this, we use some partial uniformization results.

Logic · Mathematics 2007-10-02 Dominique Lecomte

We introduce the split principles and show that they bear tight connections to large cardinal properties such as inaccessibility, weak compactness, subtlety, almost ineffability and ineffability, as well as classical combinatorial objects…

Logic · Mathematics 2024-11-26 Gunter Fuchs , Kaethe Minden

Hurewicz' characterized the dimension of separable metrizable spaces by means of finite-to-one maps. We investigate whether this characterization also holds in the class of compact F-spaces of weight c. Our main result is that, assuming the…

General Topology · Mathematics 2014-01-15 Klaas Pieter Hart , Jan van Mill

We study selection principles related to bornological covers using the notion of ideals. We consider ideals $\mathcal I$ and $\mathcal J$ on $\omega$ and standard ideal orderings $KB, K$. Relations between cardinality of a base of a…

General Topology · Mathematics 2024-03-08 D. Chandra , P. Das , S. Das

In this article we investigate which compact spaces remain compact under countably closed forcing. We prove that, assuming the Continuum Hypothesis, the natural generalizations to $\omega_1$-sequences of the selection principle and…

General Topology · Mathematics 2014-05-26 Rodrigo R. Dias , Franklin D. Tall

Dimensional types of metric scattered spaces are investigated. Revised proofs of Mazurkiewicz-Sierpi\'nski and Knaster-Urbanik theorems are presented. Embeddable properties of countable metric spaces are generalized onto uncountable metric…

General Topology · Mathematics 2015-05-01 Szymon Plewik , Marta Walczyńska

We show that separability and second-countability are first-order properties among topological spaces definable in o-minimal expansions of $(\mathbb{R},<)$. We do so by introducing first-order characterizations -- definable separability and…

Logic · Mathematics 2025-06-16 Pablo Andújar Guerrero

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

CONTENTS OF THE ISSUE: Hurewicz-like tests for Borel subsets of the plane; Ordered Spaces, Metric Preimages, and Function Algebras; On the independence of a generalized statement of Egoroff's theorem from ZFC, after T. Weiss; Forty…

General Topology · Mathematics 2008-12-31 Boaz Tsaban