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Title: A countably cellular topological group all of whose countable subsets are closed need not be $\mathbb{R}$-factorizable (English)
Author: Tkachenko, Mikhail
Language: English
Journal: Commentationes Mathematicae Universitatis Carolinae
ISSN: 0010-2628 (print)
ISSN: 1213-7243 (online)
Volume: 64
Issue: 1
Year: 2023
Pages: 127-135
Summary lang: English
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Category: math
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Summary: We construct a Hausdorff topological group $G$ such that $\aleph_1$ is a precalibre of $G$ (hence, $G$ has countable cellularity), all countable subsets of $G$ are closed and $C$-embedded in $G$, but $G$ is not $\mathbb{R}$-factorizable. This solves Problem 8.6.3 from the book ``Topological Groups and Related Structures" (2008) in the negative. (English)
Keyword: $\mathbb{R}$-factorizable
Keyword: cellularity
Keyword: $C$-embedded
Keyword: Sorgenfrey line
Keyword: $P$-group
Keyword: Dieudonné completion
Keyword: Hewitt--Nachbin completion
Keyword: Bohr topology
MSC: 22A05
MSC: 54D30
MSC: 54G20
MSC: 54H11
idZBL: Zbl 07790587
idMR: MR4631595
DOI: 10.14712/1213-7243.2023.016
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Date available: 2023-08-28T09:52:12Z
Last updated: 2024-02-13
Stable URL: http://hdl.handle.net/10338.dmlcz/151801
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Reference: [8] Xie L.-H., Yan P.-F.: The continuous $d$-open homomorphism images and subgroups of $\mathbb{R}$-factorizable paratopological groups.Topology Appl. 300 (2021), Paper No. 107627, 7 pages. MR 4281998
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