{"title":"局部同构的无限林德洛夫 P 群是同构的","authors":"Mikhail Tkachenko","doi":"10.1016/j.topol.2024.109005","DOIUrl":null,"url":null,"abstract":"<div><p>We prove the statement formulated in the title of the article. Then we apply it to show that there exists Lindelöf <em>P</em>-groups <em>G</em> and <em>H</em> satisfying <span><math><mi>w</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>=</mo><mi>w</mi><mo>(</mo><mi>H</mi><mo>)</mo><mo>=</mo><mo>|</mo><mi>G</mi><mo>|</mo><mo>=</mo><mo>|</mo><mi>H</mi><mo>|</mo><mo>=</mo><msub><mrow><mi>ℵ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> such that <em>G</em> and <em>H</em> are not locally homeomorphic. This solves Problem 4.4.7 from the book (Arhangel'skii and Tkachenko, 2008 <span>[1]</span>) in the negative. Also, we present two homeomorphic complete Abelian <em>P</em>-groups one of which is <em>ω</em>-narrow and the other is not.</p></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":null,"pages":null},"PeriodicalIF":0.6000,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Locally homeomorphic infinite Lindelof P-groups are homeomorphic\",\"authors\":\"Mikhail Tkachenko\",\"doi\":\"10.1016/j.topol.2024.109005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We prove the statement formulated in the title of the article. Then we apply it to show that there exists Lindelöf <em>P</em>-groups <em>G</em> and <em>H</em> satisfying <span><math><mi>w</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>=</mo><mi>w</mi><mo>(</mo><mi>H</mi><mo>)</mo><mo>=</mo><mo>|</mo><mi>G</mi><mo>|</mo><mo>=</mo><mo>|</mo><mi>H</mi><mo>|</mo><mo>=</mo><msub><mrow><mi>ℵ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> such that <em>G</em> and <em>H</em> are not locally homeomorphic. This solves Problem 4.4.7 from the book (Arhangel'skii and Tkachenko, 2008 <span>[1]</span>) in the negative. Also, we present two homeomorphic complete Abelian <em>P</em>-groups one of which is <em>ω</em>-narrow and the other is not.</p></div>\",\"PeriodicalId\":51201,\"journal\":{\"name\":\"Topology and its Applications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2024-07-01\",\"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/S0166864124001901\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Topology and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0166864124001901","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
Locally homeomorphic infinite Lindelof P-groups are homeomorphic
We prove the statement formulated in the title of the article. Then we apply it to show that there exists Lindelöf P-groups G and H satisfying such that G and H are not locally homeomorphic. This solves Problem 4.4.7 from the book (Arhangel'skii and Tkachenko, 2008 [1]) in the negative. Also, we present two homeomorphic complete Abelian P-groups one of which is ω-narrow and the other is not.
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.