A characterization of strongly countably complete topological groups

被引:6
|
作者
Tkachenko, Mikhail [1 ]
机构
[1] Univ Autonoma Metropolitana, Dept Matemat, Mexico City 09340, DF, Mexico
关键词
Compact; Countably compact; Pseudocompact; Strongly countably complete; Completely metrizable; Sequentially complete; Cech-complete; Feathered group; G(delta)-tightness; Moscow space; CONTINUITY;
D O I
10.1016/j.topol.2011.03.020
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
We prove that a topological group G is strongly countably complete (the notion introduced by Z. Frolik in 1961) iff G contains a closed countably compact subgroup H such that the quotient space G/H is completely metrizable and the canonical mapping pi : G -> G/H is closed. We also show that every strongly countably complete group is sequentially complete, has countable G(delta)-tightness, and its completion is a tech-complete topological group. Further, a pseudocompact strongly countably complete group is countably compact. An example of a pseudocompact topological Abelian group H with the Frechet-Urysohn property is presented such that H fails to be sequentially complete, thus answering a question posed by Dikranjan, Martin Peinador, and Tarieladze in [Appl. Categor. Struct. 15 (2007) 511-539]. (C) 2012 Elsevier B.V. All rights reserved.
引用
收藏
页码:2535 / 2545
页数:11
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