{"title":"一元函数的反对数系数的模差","authors":"Vasudevarao Allu, Amal Shaji","doi":"10.1016/j.jmaa.2024.129217","DOIUrl":null,"url":null,"abstract":"<div><div>Let <em>f</em> be analytic in the unit disk and <span><math><mi>S</mi></math></span> be the subclass of normalized univalent functions with <span><math><mi>f</mi><mo>(</mo><mn>0</mn><mo>)</mo><mo>=</mo><mn>0</mn></math></span>, and <span><math><msup><mrow><mi>f</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>(</mo><mn>0</mn><mo>)</mo><mo>=</mo><mn>1</mn></math></span>. Let <em>F</em> be the inverse function of <em>f</em>, given by <span><math><mi>F</mi><mo>(</mo><mi>w</mi><mo>)</mo><mo>=</mo><mi>w</mi><mo>+</mo><msubsup><mrow><mo>∑</mo></mrow><mrow><mi>n</mi><mo>=</mo><mn>2</mn></mrow><mrow><mo>∞</mo></mrow></msubsup><msub><mrow><mi>A</mi></mrow><mrow><mi>n</mi></mrow></msub><msup><mrow><mi>w</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span> defined on some disk <span><math><mo>|</mo><mi>w</mi><mo>|</mo><mo>≤</mo><msub><mrow><mi>r</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>(</mo><mi>f</mi><mo>)</mo></math></span>. The inverse logarithmic coefficients <span><math><msub><mrow><mi>Γ</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>, <span><math><mi>n</mi><mo>∈</mo><mi>N</mi></math></span>, of <em>f</em> are defined by the equation <span><math><mi>log</mi><mo></mo><mo>(</mo><mi>F</mi><mo>(</mo><mi>w</mi><mo>)</mo><mo>/</mo><mi>w</mi><mo>)</mo><mo>=</mo><mn>2</mn><msubsup><mrow><mo>∑</mo></mrow><mrow><mi>n</mi><mo>=</mo><mn>1</mn></mrow><mrow><mo>∞</mo></mrow></msubsup><msub><mrow><mi>Γ</mi></mrow><mrow><mi>n</mi></mrow></msub><msup><mrow><mi>w</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>,</mo><mspace></mspace><mo>|</mo><mi>w</mi><mo>|</mo><mo><</mo><mn>1</mn><mo>/</mo><mn>4</mn></math></span>. In this paper, we find the sharp upper and lower bounds for moduli difference of second and first inverse logarithmic coefficients, <em>i.e.,</em> <span><math><mo>|</mo><msub><mrow><mi>Γ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>|</mo><mo>−</mo><mo>|</mo><msub><mrow><mi>Γ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>|</mo></math></span> for functions in class <span><math><mi>S</mi></math></span> and for functions in some important subclasses of univalent functions.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"546 2","pages":"Article 129217"},"PeriodicalIF":1.2000,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Moduli difference of inverse logarithmic coefficients of univalent functions\",\"authors\":\"Vasudevarao Allu, Amal Shaji\",\"doi\":\"10.1016/j.jmaa.2024.129217\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Let <em>f</em> be analytic in the unit disk and <span><math><mi>S</mi></math></span> be the subclass of normalized univalent functions with <span><math><mi>f</mi><mo>(</mo><mn>0</mn><mo>)</mo><mo>=</mo><mn>0</mn></math></span>, and <span><math><msup><mrow><mi>f</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>(</mo><mn>0</mn><mo>)</mo><mo>=</mo><mn>1</mn></math></span>. Let <em>F</em> be the inverse function of <em>f</em>, given by <span><math><mi>F</mi><mo>(</mo><mi>w</mi><mo>)</mo><mo>=</mo><mi>w</mi><mo>+</mo><msubsup><mrow><mo>∑</mo></mrow><mrow><mi>n</mi><mo>=</mo><mn>2</mn></mrow><mrow><mo>∞</mo></mrow></msubsup><msub><mrow><mi>A</mi></mrow><mrow><mi>n</mi></mrow></msub><msup><mrow><mi>w</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span> defined on some disk <span><math><mo>|</mo><mi>w</mi><mo>|</mo><mo>≤</mo><msub><mrow><mi>r</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>(</mo><mi>f</mi><mo>)</mo></math></span>. The inverse logarithmic coefficients <span><math><msub><mrow><mi>Γ</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>, <span><math><mi>n</mi><mo>∈</mo><mi>N</mi></math></span>, of <em>f</em> are defined by the equation <span><math><mi>log</mi><mo></mo><mo>(</mo><mi>F</mi><mo>(</mo><mi>w</mi><mo>)</mo><mo>/</mo><mi>w</mi><mo>)</mo><mo>=</mo><mn>2</mn><msubsup><mrow><mo>∑</mo></mrow><mrow><mi>n</mi><mo>=</mo><mn>1</mn></mrow><mrow><mo>∞</mo></mrow></msubsup><msub><mrow><mi>Γ</mi></mrow><mrow><mi>n</mi></mrow></msub><msup><mrow><mi>w</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>,</mo><mspace></mspace><mo>|</mo><mi>w</mi><mo>|</mo><mo><</mo><mn>1</mn><mo>/</mo><mn>4</mn></math></span>. In this paper, we find the sharp upper and lower bounds for moduli difference of second and first inverse logarithmic coefficients, <em>i.e.,</em> <span><math><mo>|</mo><msub><mrow><mi>Γ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>|</mo><mo>−</mo><mo>|</mo><msub><mrow><mi>Γ</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>|</mo></math></span> for functions in class <span><math><mi>S</mi></math></span> and for functions in some important subclasses of univalent functions.</div></div>\",\"PeriodicalId\":50147,\"journal\":{\"name\":\"Journal of Mathematical Analysis and Applications\",\"volume\":\"546 2\",\"pages\":\"Article 129217\"},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2025-06-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Mathematical Analysis and Applications\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0022247X24011399\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/1/7 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Mathematical Analysis and Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022247X24011399","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/7 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
设f是单位圆盘上的解析函数,S是f(0)=0, f '(0)=1的归一化一元函数的子类。设F为F的反函数,由F(w)=w+∑n=2∞给出,在某个磁盘|上定义了w|≤r0(F)。f的逆对数系数Γn, n∈n定义为方程log (f (w)/w)=2∑n=1∞Γnwn,|w|<1/4。本文给出了二阶和一阶逆对数系数模差的明显上界和下界,即S类函数和一元函数的一些重要子类中的函数|Γ2| - |Γ1|。
Moduli difference of inverse logarithmic coefficients of univalent functions
Let f be analytic in the unit disk and be the subclass of normalized univalent functions with , and . Let F be the inverse function of f, given by defined on some disk . The inverse logarithmic coefficients , , of f are defined by the equation . In this paper, we find the sharp upper and lower bounds for moduli difference of second and first inverse logarithmic coefficients, i.e., for functions in class and for functions in some important subclasses of univalent functions.
期刊介绍:
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