Wayne A. Johnson , Dae-Woong Lee , P. Christopher Staecker
{"title":"On digital H-spaces","authors":"Wayne A. Johnson , Dae-Woong Lee , P. Christopher Staecker","doi":"10.1016/j.topol.2025.109426","DOIUrl":null,"url":null,"abstract":"<div><div>We investigate properties of digital H-spaces in the graph theoretic model of digital topology. As in prior work, the results obtained often depend fundamentally on the choice between <span><math><msub><mrow><mi>NP</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>NP</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> product adjacencies. We explore algebraic properties of digital H-spaces preserved under digital homotopy equivalence, and we give a general construction that produces examples of digital H-spaces that are not homotopy-equivalent to digital topological groups in both categories. Further, we show that this construction essentially classifies all <span><math><msub><mrow><mi>NP</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-digital H-spaces. In a short appendix, we resolve a question that was left unresolved in <span><span>[16]</span></span>, and complete the full classification of digital topological groups.</div></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":"370 ","pages":"Article 109426"},"PeriodicalIF":0.6000,"publicationDate":"2025-05-19","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/S016686412500224X","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 investigate properties of digital H-spaces in the graph theoretic model of digital topology. As in prior work, the results obtained often depend fundamentally on the choice between and product adjacencies. We explore algebraic properties of digital H-spaces preserved under digital homotopy equivalence, and we give a general construction that produces examples of digital H-spaces that are not homotopy-equivalent to digital topological groups in both categories. Further, we show that this construction essentially classifies all -digital H-spaces. In a short appendix, we resolve a question that was left unresolved in [16], and complete the full classification of digital topological groups.
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.