{"title":"局部一元解析函数的一元准则","authors":"Zhenyong Hu, Jinhua Fan, Xiaoyuan Wang","doi":"10.1007/s11253-023-02250-2","DOIUrl":null,"url":null,"abstract":"<p>Suppose that <i>p</i>(<i>z</i>) = 1 + <i>zϕ″</i>(<i>z</i>)<i>/ϕ′</i>(<i>z</i>), where <i>ϕ</i>(<i>z</i>) is a locally univalent analytic function in the unit disk <b>D</b> with <i>ϕ</i>(0) = <i>ϕ′</i>(1) <i>−</i> 1 = 0<i>.</i> We establish the lower and upper bounds for the best constants <i>σ</i><sub>0</sub> and <i>σ</i><sub>1</sub> such that <span>\\({e}^{{-\\sigma }_{0}/2}<\\left|p\\left(z\\right)\\right|<{e}^{{\\sigma }_{0}/2}\\)</span> and |<i>p</i>(<i>w</i>)/<i>p</i>(<i>z</i>)| < <span>\\({e}^{{\\sigma }_{1}}\\)</span> for <i>z</i>, <i>w</i> ∈ <b>D</b>, respectively, imply the univalence of <i>ϕ</i>(<i>z</i>) in <b>D.</b></p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":"46 1","pages":""},"PeriodicalIF":0.5000,"publicationDate":"2023-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Univalence Criteria for Locally Univalent Analytic Functions\",\"authors\":\"Zhenyong Hu, Jinhua Fan, Xiaoyuan Wang\",\"doi\":\"10.1007/s11253-023-02250-2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Suppose that <i>p</i>(<i>z</i>) = 1 + <i>zϕ″</i>(<i>z</i>)<i>/ϕ′</i>(<i>z</i>), where <i>ϕ</i>(<i>z</i>) is a locally univalent analytic function in the unit disk <b>D</b> with <i>ϕ</i>(0) = <i>ϕ′</i>(1) <i>−</i> 1 = 0<i>.</i> We establish the lower and upper bounds for the best constants <i>σ</i><sub>0</sub> and <i>σ</i><sub>1</sub> such that <span>\\\\({e}^{{-\\\\sigma }_{0}/2}<\\\\left|p\\\\left(z\\\\right)\\\\right|<{e}^{{\\\\sigma }_{0}/2}\\\\)</span> and |<i>p</i>(<i>w</i>)/<i>p</i>(<i>z</i>)| < <span>\\\\({e}^{{\\\\sigma }_{1}}\\\\)</span> for <i>z</i>, <i>w</i> ∈ <b>D</b>, respectively, imply the univalence of <i>ϕ</i>(<i>z</i>) in <b>D.</b></p>\",\"PeriodicalId\":49406,\"journal\":{\"name\":\"Ukrainian Mathematical Journal\",\"volume\":\"46 1\",\"pages\":\"\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2023-11-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Ukrainian Mathematical Journal\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1007/s11253-023-02250-2\",\"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":"Ukrainian Mathematical Journal","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s11253-023-02250-2","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
Univalence Criteria for Locally Univalent Analytic Functions
Suppose that p(z) = 1 + zϕ″(z)/ϕ′(z), where ϕ(z) is a locally univalent analytic function in the unit disk D with ϕ(0) = ϕ′(1) − 1 = 0. We establish the lower and upper bounds for the best constants σ0 and σ1 such that \({e}^{{-\sigma }_{0}/2}<\left|p\left(z\right)\right|<{e}^{{\sigma }_{0}/2}\) and |p(w)/p(z)| < \({e}^{{\sigma }_{1}}\) for z, w ∈ D, respectively, imply the univalence of ϕ(z) in D.
期刊介绍:
Ukrainian Mathematical Journal publishes articles and brief communications on various areas of pure and applied mathematics and contains sections devoted to scientific information, bibliography, and reviews of current problems. It features contributions from researchers from the Ukrainian Mathematics Institute, the major scientific centers of the Ukraine and other countries.
Ukrainian Mathematical Journal is a translation of the peer-reviewed journal Ukrains’kyi Matematychnyi Zhurnal, a publication of the Institute of Mathematics of the National Academy of Sciences of Ukraine.