{"title":"A degree-zero, monotone, surjective self-map of the Pontryagin surface","authors":"R. Daverman, T. L. Thickstun","doi":"10.4064/FM766-1-2021","DOIUrl":null,"url":null,"abstract":". This paper presents an example, as promised by the title, of a degree-zero, monotone, surjective map of the standard Pontryagin surface to itself. This exposes the need for some hypothesis concerning degree in results about when monotone self-maps of the Pontryagin surface can be approximated by homeomorphisms.","PeriodicalId":55138,"journal":{"name":"Fundamenta Mathematicae","volume":"1 1","pages":""},"PeriodicalIF":0.5000,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Fundamenta Mathematicae","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.4064/FM766-1-2021","RegionNum":3,"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
. This paper presents an example, as promised by the title, of a degree-zero, monotone, surjective map of the standard Pontryagin surface to itself. This exposes the need for some hypothesis concerning degree in results about when monotone self-maps of the Pontryagin surface can be approximated by homeomorphisms.
期刊介绍:
FUNDAMENTA MATHEMATICAE concentrates on papers devoted to
Set Theory,
Mathematical Logic and Foundations of Mathematics,
Topology and its Interactions with Algebra,
Dynamical Systems.