The space Cp(X) admits a dense exponentially separable subspace when X is metrizable

IF 0.6 4区 数学 Q3 MATHEMATICS
F. Hernández-Hernández, J.B. Ramírez-Chávez, R. Rojas-Hernández
{"title":"The space Cp(X) admits a dense exponentially separable subspace when X is metrizable","authors":"F. Hernández-Hernández,&nbsp;J.B. Ramírez-Chávez,&nbsp;R. Rojas-Hernández","doi":"10.1016/j.topol.2025.109434","DOIUrl":null,"url":null,"abstract":"<div><div>We prove that <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>(</mo><mi>X</mi><mo>)</mo></math></span> admits a dense exponentially separable for any metrizable space <em>X</em> and, answering a question in <span><span>[16]</span></span>, we give an example of a pseudocompact <em>ω</em>-monolithic space such that <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>(</mo><mi>X</mi><mo>)</mo></math></span> does not admit dense functionally countable subspaces. In a similar sense, solving consistently a problem in <span><span>[11]</span></span>, we prove that <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>(</mo><mi>X</mi><mo>)</mo></math></span> may not always contain a dense subspace of countable functional tightness. In other direction, and answering a question posed in <span><span>[6]</span></span>, we characterize compact spaces for which their Alexandroff doubles have a Lindelöf <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>; we also give a short proof of a result in <span><span>[19]</span></span> about a consistent characterization of the Lindelöf property in <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-spaces over Hattori spaces.</div></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":"370 ","pages":"Article 109434"},"PeriodicalIF":0.6000,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Topology and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0166864125002329","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0

Abstract

We prove that Cp(X) admits a dense exponentially separable for any metrizable space X and, answering a question in [16], we give an example of a pseudocompact ω-monolithic space such that Cp(X) does not admit dense functionally countable subspaces. In a similar sense, solving consistently a problem in [11], we prove that Cp(X) may not always contain a dense subspace of countable functional tightness. In other direction, and answering a question posed in [6], we characterize compact spaces for which their Alexandroff doubles have a Lindelöf Cp; we also give a short proof of a result in [19] about a consistent characterization of the Lindelöf property in Cp-spaces over Hattori spaces.
当X可度量时,空间Cp(X)允许一个稠密的指数可分子空间
我们证明了Cp(X)对于任何可度量空间X允许密集指数可分,并在[16]中回答了一个问题,给出了一个伪紧ω-单片空间的例子,使得Cp(X)不允许密集功能可数子空间。在类似意义上,通过一致性求解[11]中的一个问题,我们证明了Cp(X)不一定总是包含可数功能紧度的稠密子空间。在另一个方向上,并回答[6]中提出的一个问题,我们刻画了紧空间,它们的Alexandroff双精度具有Lindelöf Cp;我们也给出了[19]中关于cp -空间在Hattori空间上Lindelöf性质的一致刻画的一个结果的简短证明。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
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.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信