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Related papers: Some properties of selectively star-ccc spaces

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In this paper, the author represent a unification and extension of concepts previously studied by several authors. By establish connections between the chain condition, selectively star-ccc properties and star-Lindel\"of properties, the…

General Topology · Mathematics 2023-12-05 Yuan Sun

We investigate star-covering properties of $\Psi$-like spaces. We show star-Lindel\"ofness is reflected by open perfect mappings. In addition, we offer a new equivalence of CH.

General Topology · Mathematics 2011-03-30 L. P. Aiken

n this article, firstly, we introduce the notion of star modules with respect to a balanced pair and obtain some properties. We mainly give the relationship between n-X star modules and n-X tilting modules [9], and a new characterization of…

Category Theory · Mathematics 2022-05-20 Peiyu Zhang , Dajun Liu , Jiaqun Wei

In this paper we investigate the properties of function spaces using the selection principles.

General Topology · Mathematics 2017-10-25 Alexander V. Osipov

In this paper, we investigate what selection principles properties are possessed by small (with respect to the bounding and dominating numbers) unions of spaces with certain (star) selection principles.. Furthermore, we give several results…

General Topology · Mathematics 2022-11-01 Javier Casas-de la Rosa , William Chen-Mertens , Sergio Garcia-Balan

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

Given a topological property $\mathcal{P}$, a space $X$ is called star-$\mathcal{P}$ if for any open cover $\mathcal{U}$ of the space $X$, there exists a set $Y\subseteq X$ with property $\mathcal{P}$ such that $St(Y,\mathcal{U})=X$; the…

General Topology · Mathematics 2023-01-24 Javier Casas-de la Rosa , Ángel Tamariz-Mascarúa

Characterizations of paracompact finite $C$-spaces via continuous selections are given. We apply these results to obtain some properties of finite $C$-spaces. Factorization theorems and a completion theorem for finite $C$- spaces are also…

General Topology · Mathematics 2016-09-07 Vesko Valov

A space $ X $ is said to be set star-Lindel\"{o}f (resp., set strongly star-Lindel\"{o}f) if for each nonempty subset $ A $ of $ X $ and each collection $ \mathcal{U} $ of open sets in $ X $ such that $ \overline{A} \subseteq \bigcup…

General Mathematics · Mathematics 2021-06-30 Sumit Singh

This paper addresses several questions of Feng, Gruenhage, and Shen which arose from Michael's theory of continuous selections from countable spaces. We construct an example of a space which is $L$-selective but not $\mathbb{Q}$-selective…

General Topology · Mathematics 2019-10-24 William Chen-Mertens , Paul J. Szeptycki

In this paper we define some combinatorial principles to characterize spaces $X$ whose hyperspace satisfies some variation of some classical star selection principle. Specifically, the variations characterized are the selective and absolute…

General Topology · Mathematics 2023-01-30 Javier Casas-de la Rosa

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

Motivated by the definition of classical star selection principles, Cruz-Castillo, Ram\'irez-P\'aramo and Tenorio defined some selection principles and posed several questions about relationships between these notions and some of the…

General Topology · Mathematics 2021-09-27 Javier Casas de la Rosa

The selective abundance of C, N, O (almost solar) with respect to that of other elements (underabundant) in lambda Boo stars has been interpreted as a characteristic peculiarity of these objects, when considered as single stars. We show…

Astrophysics · Physics 2009-11-10 R. Faraggiana , P. Bonifacio

Stars have proven to be surprisingly prolific radio sources and the added sensitivity of the Square Kilometer Array will lead to advances in many directions. This chapter discusses prospects for studying the physics of stellar atmospheres…

Astrophysics · Physics 2009-11-10 S. M. White

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

This article, written for Scolarpedia, provides a brief introduction into the subject of cosmic strings, together with a review of their main properties, cosmological evolution and observational signatures.

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Tanmay Vachaspati , Levon Pogosian , Daniele Steer

We define the notion of extrinsic symplectic symmetric spaces and exhibit some of their properties. We construct large families of examples and show how they fit in the perspective of a complete classification of these manifolds. We also…

Symplectic Geometry · Mathematics 2009-11-13 Michel Cahen , Simone Gutt , Nicolas Richard , Lorenz Schwachhoefer

We hypothesise that properties of space could underly some patterns observed in nature. We explore the possibility that the observed variety of matter particles and the pattern of their properties arise due to the non-orientability of the…

General Physics · Physics 2007-05-23 V. N. Yershov

The star versions of the Scheepers property, namely star-Scheepers, strongly star-Scheepers and new star-Scheepers property have been introduced. We explore further ramifications concerning critical cardinalities. Quite a few interesting…

General Topology · Mathematics 2023-11-10 Debraj Chandra , Nur Alam
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