涉及弱紧性的一些性质,IV:通过密集子空间定义的类紧性性质

IF 0.5 4区 数学 Q3 MATHEMATICS
J.A. Martínez-Cadena , Á. Tamariz-Mascarúa
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引用次数: 0

摘要

研究了满足相对紧性条件的密集子空间的存在性所引起的几个类紧性性质,即可数实紧空间、完全可数实紧空间、密集有界空间和序紧空间。这些类改进了诸如顺序紧性和ω有界性等经典概念,并承认自然的层次结构。我们建立了这些性质在完全开映射和积空间下的各种保存结果。在拓扑群的背景下,我们证明了如果H是拓扑群G的一个局部紧子群,那么相应的商映射π:G→G/H允许这些性质的局部版本从G/H转移到G。我们还分析了这些性质在多大程度上满足三维性质,并引入了一类pc -空间来表征这种转移的可能性。最后,我们讨论了密集ω有界的准拓扑群的结构问题,并提供了它们是拓扑的条件。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Some properties involving feeble compactness, IV: Compactness-like properties defined via dense subspaces
We study several compactness-like properties arising from the existence of dense subspaces satisfying relative compactness conditions, namely: countably pracompact, totally countably pracompact, densely ω-bounded, and sequentially pracompact spaces. These classes refine classical notions such as sequential compactness and ω-boundedness and admit a natural hierarchy. We establish various preservation results for these properties under perfect open mappings and product spaces. In the context of topological groups, we prove that if H is a locally compact subgroup of a topological group G, then the corresponding quotient mapping π:GG/H allows the transfer of local versions of these properties from G/H to G. We also analyze the extent to which these properties satisfy the three-space property and introduce the class of PC-spaces to characterize when such transfer is possible. Finally, we address structural questions on densely ω-bounded paratopological groups and provide conditions under which they are topological.
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来源期刊
CiteScore
1.20
自引率
33.30%
发文量
251
审稿时长
6 months
期刊介绍: Topology and its Applications is primarily concerned with publishing original research papers of moderate length. However, a limited number of carefully selected survey or expository papers are also included. The mathematical focus of the journal is that suggested by the title: Research in Topology. It is felt that it is inadvisable to attempt a definitive description of topology as understood for this journal. Certainly the subject includes the algebraic, general, geometric, and set-theoretic facets of topology as well as areas of interactions between topology and other mathematical disciplines, e.g. topological algebra, topological dynamics, functional analysis, category theory. Since the roles of various aspects of topology continue to change, the non-specific delineation of topics serves to reflect the current state of research in topology. At regular intervals, the journal publishes a section entitled Open Problems in Topology, edited by J. van Mill and G.M. Reed. This is a status report on the 1100 problems listed in the book of the same name published by North-Holland in 1990, edited by van Mill and Reed.
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