Results 1 to 10 of about 427 (213)
Continuous Selections and Extremally Disconnected Spaces [PDF]
Mathematics, 2023 This paper deals with extremally disconnected spaces and extremally disconnected P-spaces. A space X is said to be extremally disconnected if, for every open subset V of X, the closure of V in X is also an open set.
Manuel Sanchís, Sanchís Manuel
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Compact and extremally disconnected spaces [PDF]
International Journal of Mathematics and Mathematical Sciences, 2004 Viglino defined a Hausdorff topological space to be C-compact if each closed subset of the space is an H-set in the sense of Veličko. In this paper, we study the class of Hausdorff spaces characterized by the property that each closed subset is an S-set ...
Bhamini M. P. Nayar
doaj +4 more sources
On extremally disconnected topological groups
Topology and Its Applications, 2006 We introduce the notion of a partially selective ultrafilter and prove that (a) if G is an extremally disconnected topological group and p is a converging nonprincipal ultrafilter on G containing a countable discrete subset, then p is partially selective,
Yevhen Zelenyuk
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A new construction of extremally disconnected topologies
Topology and Its Applications, 1994 We present a general method of constructing extremally disconnected topologies, by which we get countably compact, homogeneous, extremally disconnected Tychonoff spaces of any cardinality κ with κω=κ, and two such spaces whose product is not countably ...
Kato, Akio, Akio Kato
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Extremally disconnected spaces, subspaces and retracts
Topology and Its Applications, 1993 A characterization of compact subspaces of extremally disconnected spaces is given which is similar to Gleason's characterization that the extremally disconnected spaces are projective for the class of compact spaces.
J Vermeer
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S4.3 and hereditarily extremally disconnected spaces
Georgian Mathematical Journal, 2015 The modal logic S4.3 defines the class of hereditarily extremally disconnected spaces (HED-spaces). We construct a countable HED-subspace X of the Gleason cover of the real closed unit interval [0,1] such that S4.3 is the logic of ...
Guram Bezhanishvili +2 more
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On some classes of sets in extremally disconnected spaces
Demonstratio Mathematica, 2011 In the present paper several characterizations of the classical notion of extremally disconnected spaces are obtained. A few relationships for finite products of extremally disconnected spaces are also studied.
Zbigniew Duszyński
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Dense extremally disconnected subspaces [PDF]
Proceedings of the American Mathematical Society, 1994 We prove that every compact Basically Disconnected space of π \pi -weight ω 1 {\omega _1} has a dense Extremally Disconnected subspace. In Boolean algebraic terms: every σ
J. van Mill, A. Dow
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An extremally disconnected Dowker space [PDF]
Proceedings of the American Mathematical Society, 1982 We give an example of an extremally disconnected Dowker space. Our basic tool is that every P P -space can be C ∗ {C^\ast } -embedded in an extremally disconnected compactum.
Jan van Mill, Alan Dow
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A note on extremally disconnected spaces [PDF]
Proceedings of the American Mathematical Society, 1980 A topological space X is said to be locally S-closed if each point of X has an open neighborhood which is an S-closed subspace of X. In this note it is shown that every locally S-closed weakly Hausdorff (or almost-regular) space is extremally ...
Takashi Noiri
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