Title:
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Compacta are maximally $G_\delta$-resolvable (English) |
Author:
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Juhász, István |
Author:
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Szentmiklóssy, Zoltán |
Language:
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English |
Journal:
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Commentationes Mathematicae Universitatis Carolinae |
ISSN:
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0010-2628 (print) |
ISSN:
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1213-7243 (online) |
Volume:
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54 |
Issue:
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2 |
Year:
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2013 |
Pages:
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259-261 |
Summary lang:
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English |
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Category:
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math |
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Summary:
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It is well-known that compacta (i.e. compact Hausdorff spaces) are maximally resolvable, that is every compactum $X$ contains $\Delta(X)$ many pairwise disjoint dense subsets, where $\Delta(X)$ denotes the minimum size of a non-empty open set in $X$. The aim of this note is to prove the following analogous result: Every compactum $X$ contains $\Delta_\delta(X)$ many pairwise disjoint $G_\delta$-dense subsets, where $\Delta_\delta(X)$ denotes the minimum size of a non-empty $G_\delta$ set in $X$. (English) |
Keyword:
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compact spaces |
Keyword:
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$G_\delta $-sets |
Keyword:
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resolvability |
MSC:
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03E10 |
MSC:
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54A25 |
MSC:
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54D30 |
idZBL:
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Zbl 06221267 |
idMR:
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MR3067708 |
. |
Date available:
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2013-06-25T12:54:14Z |
Last updated:
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2015-07-06 |
Stable URL:
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http://hdl.handle.net/10338.dmlcz/143274 |
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Reference:
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[1] Čech E., Pospíšil B.: Sur les espaces compacts.Publ. Fac. Sci. Univ. Masaryk 258 (1938), 1–14. Zbl 0019.08903 |
Reference:
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[2] Comfort W.W., Garcia-Ferreira S.: Resolvability: A selective survey and some new results.Topology Appl. 74 (1996), 149–167. Zbl 0866.54004, MR 1425934, 10.1016/S0166-8641(96)00052-1 |
Reference:
|
[3] El'kin A.G.: Resolvable spaces which are not maximally resolvable.Vestnik Moskov. Univ. Ser. I Mat. Meh. 24 (1969), no. 4, 66–70. Zbl 0243.54018, MR 0256331 |
Reference:
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[4] Juhász I.: Cardinal functions in topology – 10 years later.Mathematical Centre Tracts, 123, Mathematisch Centrum, Amsterdam, 1980. |
Reference:
|
[5] Juhász I.: On the minimum character of points in compact spaces.in: Proc. Top. Conf. (Pécs, 1989), 365–371, Colloq. Math. Soc. János Bolyai, 55, North-Holland, Amsterdam, 1993. Zbl 0798.54005, MR 1244377 |
Reference:
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[6] Juhász I., Szentmiklóssy Z.: Convergent free sequences in compact spaces.Proc. Amer. Math. Soc. 116 (1992), 1153–1160. Zbl 0767.54002, MR 1137223, 10.2307/2159502 |
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