The $G_\delta $-topology and incompactness of $\omega ^\alpha $

Isaac Gorelic

Displaying similar documents to “The $G_{δ}$ -topology and incompactness of $ω^{α}$ ”

The sizes of relatively compact $T_{1}$ -spaces

Winfried Just (1996)

Commentationes Mathematicae Universitatis Carolinae

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The relativization of Gryzlov’s theorem about the size of compact $T_{1}$ -spaces with countable pseudocharacter is false.

Local cardinal functions of H-closed spaces

Angelo Bella, Jack R. Porter (1996)

Commentationes Mathematicae Universitatis Carolinae

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The cardinal functions of pseudocharacter, closed pseudocharacter, and character are used to examine H-closed spaces and to contrast the differences between H-closed and minimal Hausdorff spaces. An H-closed space $X$ is produced with the properties that $| X | > 2^{2^{ψ (X)}}$ and $\bar{ψ} (X) > 2^{ψ (X)}$ .

Spaces with large star cardinal number

Yan-Kui Song (2012)

Commentationes Mathematicae Universitatis Carolinae

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In this paper, we prove the following statements: (1) For any cardinal $κ$ , there exists a Tychonoff star-Lindelöf space $X$ such that $a (X) \geq κ$ . (2) There is a Tychonoff discretely star-Lindelöf space $X$ such that $a a (X)$ does not exist. (3) For any cardinal $κ$ , there exists a Tychonoff pseudocompact $σ$ -starcompact space $X$ such that $st - l (X) \geq κ$ .

Displaying similar documents to “The G δ -topology and incompactness of ω α ”

The sizes of relatively compact T 1 -spaces

Local cardinal functions of H-closed spaces

Spaces with large star cardinal number

Displaying similar documents to “The $G_{δ}$ -topology and incompactness of $ω^{α}$ ”

The sizes of relatively compact $T_{1}$ -spaces