{"title":"度量空间间映射的距离函数和Lipschitz类","authors":"Marijan Marković","doi":"10.1112/mtk.70038","DOIUrl":null,"url":null,"abstract":"<p>We investigate when the local Lipschitz property of the real-valued function <span></span><math></math> implies the global Lipschitz property of the mapping <span></span><math></math> between the metric spaces <span></span><math></math> and <span></span><math></math>. Here, <span></span><math></math> denotes the distance of <span></span><math></math> from the non-empty set <span></span><math></math>. As a consequence, we find that an analytic function on a uniform domain of a normed space belongs to the Lipschitz class if and only if its modulus satisfies the same condition; in the case of the unit disk this result is proved by Dyakonov. We use the recently established version of a classical theorem by Hardy and Littlewood for mappings between metric spaces. This paper is a continuation of the recent article by the author [Marković, J. Geom. Anal. <b>34</b> (2024), https://doi.org/10.48550/arXiv.2405.11509].</p>","PeriodicalId":18463,"journal":{"name":"Mathematika","volume":"71 4","pages":""},"PeriodicalIF":0.8000,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The distance function and Lipschitz classes of mappings between metric spaces\",\"authors\":\"Marijan Marković\",\"doi\":\"10.1112/mtk.70038\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We investigate when the local Lipschitz property of the real-valued function <span></span><math></math> implies the global Lipschitz property of the mapping <span></span><math></math> between the metric spaces <span></span><math></math> and <span></span><math></math>. Here, <span></span><math></math> denotes the distance of <span></span><math></math> from the non-empty set <span></span><math></math>. As a consequence, we find that an analytic function on a uniform domain of a normed space belongs to the Lipschitz class if and only if its modulus satisfies the same condition; in the case of the unit disk this result is proved by Dyakonov. We use the recently established version of a classical theorem by Hardy and Littlewood for mappings between metric spaces. This paper is a continuation of the recent article by the author [Marković, J. Geom. Anal. <b>34</b> (2024), https://doi.org/10.48550/arXiv.2405.11509].</p>\",\"PeriodicalId\":18463,\"journal\":{\"name\":\"Mathematika\",\"volume\":\"71 4\",\"pages\":\"\"},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2025-08-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Mathematika\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/mtk.70038\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematika","FirstCategoryId":"100","ListUrlMain":"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/mtk.70038","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
研究了实值函数的局部Lipschitz性质何时蕴涵了度量空间与映射的全局Lipschitz性质。表示到非空集合的距离。因此,我们发现在赋范空间的一致域上的解析函数当且仅当其模满足相同的条件时属于Lipschitz类;在单位圆盘的情况下,这个结果由Dyakonov证明。我们使用Hardy和Littlewood最近建立的关于度量空间之间映射的经典定理的版本。本文是作者markovovic, J. Geom最近文章的延续。Anal. 34 (2024), https://doi.org/10.48550/arXiv.2405.11509]。
The distance function and Lipschitz classes of mappings between metric spaces
We investigate when the local Lipschitz property of the real-valued function implies the global Lipschitz property of the mapping between the metric spaces and . Here, denotes the distance of from the non-empty set . As a consequence, we find that an analytic function on a uniform domain of a normed space belongs to the Lipschitz class if and only if its modulus satisfies the same condition; in the case of the unit disk this result is proved by Dyakonov. We use the recently established version of a classical theorem by Hardy and Littlewood for mappings between metric spaces. This paper is a continuation of the recent article by the author [Marković, J. Geom. Anal. 34 (2024), https://doi.org/10.48550/arXiv.2405.11509].
期刊介绍:
Mathematika publishes both pure and applied mathematical articles and has done so continuously since its founding by Harold Davenport in the 1950s. The traditional emphasis has been towards the purer side of mathematics but applied mathematics and articles addressing both aspects are equally welcome. The journal is published by the London Mathematical Society, on behalf of its owner University College London, and will continue to publish research papers of the highest mathematical quality.