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Compacta are maximally \(G_\delta \)-resolvable. - MaRDI portal

Compacta are maximally \(G_\delta \)-resolvable. (Q2856931)

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scientific article; zbMATH DE number 6221267
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English
Compacta are maximally \(G_\delta \)-resolvable.
scientific article; zbMATH DE number 6221267

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    30 October 2013
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    compact space
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    resolvable space
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    maximally resolvable space
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    \(G_{\delta }\)-set
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    Compacta are maximally \(G_\delta \)-resolvable. (English)
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    A space \(X\) is \(\kappa \)-resolvable if it contains \(\kappa \)-many mutually disjoint dense subsets and \(X\) is maximally resolvable if it is \(\Delta (X)\)-resolvable, where \(\Delta (X)\) denotes the minimal cardinality of a non-empty open set in \(X\). It is well known that each compact Hausdorff space is maximally resolvable and the aim of this short paper is to prove the following analogous result: Each compact Hausdorff space contains \(\Delta _{\delta }(X)\) many mutually disjoint \(G_{\delta }\)-dense subsets, that is to say, \(\Delta _{\delta }(X)\)-many mutually disjoint subsets which are dense in the topology generated by the \(G_{\delta }\)-subsets of \(X\) (where \(\Delta _{\delta }(X)\) denotes the minimum cardinality of a non-empty \(G_{\delta }\)-subset of \(X\)).
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