{"title":"关于偏序集、子拟合框架中的链和子拟不可约框架上的有限拓扑","authors":"M. Andrew Moshier , Aleš Pultr","doi":"10.1016/j.topol.2025.109380","DOIUrl":null,"url":null,"abstract":"<div><div>We prove that (1) each well-ordered chain is a dense sublocale of a subfit frame, and (2) that an irreducible frame (a frame that cannot be decomposed into two smaller closed sublocales) can be subfit (although it cannot be fit or even prefit). The basic tool is to use order-cofinite topologies on posets (also known as weak topologies); we discuss these in some more detail, for instance showing their relation with the Bruns-Lakser hull.</div></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":"368 ","pages":"Article 109380"},"PeriodicalIF":0.6000,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On cofinite topologies on posets, chains in subfit frames, and subfit irreducible frames\",\"authors\":\"M. Andrew Moshier , Aleš Pultr\",\"doi\":\"10.1016/j.topol.2025.109380\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>We prove that (1) each well-ordered chain is a dense sublocale of a subfit frame, and (2) that an irreducible frame (a frame that cannot be decomposed into two smaller closed sublocales) can be subfit (although it cannot be fit or even prefit). The basic tool is to use order-cofinite topologies on posets (also known as weak topologies); we discuss these in some more detail, for instance showing their relation with the Bruns-Lakser hull.</div></div>\",\"PeriodicalId\":51201,\"journal\":{\"name\":\"Topology and its Applications\",\"volume\":\"368 \",\"pages\":\"Article 109380\"},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2025-04-01\",\"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/S0166864125001786\",\"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/S0166864125001786","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
On cofinite topologies on posets, chains in subfit frames, and subfit irreducible frames
We prove that (1) each well-ordered chain is a dense sublocale of a subfit frame, and (2) that an irreducible frame (a frame that cannot be decomposed into two smaller closed sublocales) can be subfit (although it cannot be fit or even prefit). The basic tool is to use order-cofinite topologies on posets (also known as weak topologies); we discuss these in some more detail, for instance showing their relation with the Bruns-Lakser hull.
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.