{"title":"Uniqueness of Meromorphic Functions with Respect to Their Shifts Concerning Derivatives","authors":"X. H. Huang","doi":"10.3103/s1068362324700031","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>An example in the article shows that the first derivative of <span>\\(f(z)=\\frac{2}{1-e^{-2z}}\\)</span> sharing <span>\\(0\\)</span> CM and <span>\\(1,\\infty\\)</span> IM with its shift <span>\\(\\pi i\\)</span> cannot obtain they are equal. In this paper, we study the uniqueness of meromorphic function sharing small functions with their shifts concerning its <span>\\(k\\)</span>th derivatives. We use a different method from Qi and Yang [1] to improves entire function to meromorphic function, the first derivative to the <span>\\(k\\)</span>th derivatives, and also finite values to small functions. As for <span>\\(k=0\\)</span>, we obtain: Let <span>\\(f(z)\\)</span> be a transcendental meromorphic function of <span>\\(\\rho_{2}(f)<1\\)</span>, let <span>\\(c\\)</span> be a nonzero finite value, and let <span>\\(a(z)\\not\\equiv\\infty,b(z)\\not\\equiv\\infty\\in\\hat{S}(f)\\)</span> be two distinct small functions of <span>\\(f(z)\\)</span> such that <span>\\(a(z)\\)</span> is a periodic function with period <span>\\(c\\)</span> and <span>\\(b(z)\\)</span> is any small function of <span>\\(f(z)\\)</span>. If <span>\\(f(z)\\)</span> and <span>\\(f(z+c)\\)</span> share <span>\\(a(z),\\infty\\)</span> CM, and share <span>\\(b(z)\\)</span> IM, then either <span>\\(f(z)\\equiv f(z+c)\\)</span> or</p><span>$$e^{p(z)}\\equiv\\frac{f(z+c)-a(z+c)}{f(z)-a(z)}\\equiv\\frac{b(z+c)-a(z+c)}{b(z)-a(z)},$$</span><p>where <span>\\(p(z)\\)</span> is a nonconstant entire function of <span>\\(\\rho(p)<1\\)</span> such that <span>\\(e^{p(z+c)}\\equiv e^{p(z)}\\)</span>.</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.3103/s1068362324700031","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
An example in the article shows that the first derivative of \(f(z)=\frac{2}{1-e^{-2z}}\) sharing \(0\) CM and \(1,\infty\) IM with its shift \(\pi i\) cannot obtain they are equal. In this paper, we study the uniqueness of meromorphic function sharing small functions with their shifts concerning its \(k\)th derivatives. We use a different method from Qi and Yang [1] to improves entire function to meromorphic function, the first derivative to the \(k\)th derivatives, and also finite values to small functions. As for \(k=0\), we obtain: Let \(f(z)\) be a transcendental meromorphic function of \(\rho_{2}(f)<1\), let \(c\) be a nonzero finite value, and let \(a(z)\not\equiv\infty,b(z)\not\equiv\infty\in\hat{S}(f)\) be two distinct small functions of \(f(z)\) such that \(a(z)\) is a periodic function with period \(c\) and \(b(z)\) is any small function of \(f(z)\). If \(f(z)\) and \(f(z+c)\) share \(a(z),\infty\) CM, and share \(b(z)\) IM, then either \(f(z)\equiv f(z+c)\) or
Abstract 文章中的一个例子表明,共享 \(0\) CM 和 \(1,\infty\) IM 的 \(f(z)=\frac{2}{1-e^{-2z}}\ 的第一导数与它的移\(\pi i\) 不能得到它们相等。在本文中,我们研究了分担小函数与它们的移(\(k\)th derivatives)的微函数的唯一性。我们采用了与齐和杨[1]不同的方法,将整个函数改进为分形函数,将第一导数改进为\(k\)三次导数,同时将有限值改进为小函数。对于 \(k=0\), 我们得到:设 \(f(z)\) 是 \(\rho_{2}(f)<;1), let \(c\) be a nonzero finite value, and let \(a(z)\not\equiv\infty、b(z)\not\equiv\infty\inhat{S}(f)\) 是两个不同的小函数,使得(a(z)\)是一个周期为(c)的周期函数,而(b(z)\)是(f(z)\)的任何小函数。如果 \(f(z)\) 和 \(f(z+c)\) 共享 \(a(z),\infty\)CM, and share \(b(z)\)IM, then either \(f(z)\equiv f(z+c)\) or$$e^{p(z)}equiv\frac{f(z+c)-a(z+c)}{f(z)-a(z)}equiv\frac{b(z+c)-a(z+c)}{b(z)-a(z)},$$where \(p(z)\) is a nonconstant entire function of \(\rho(p)<;1\) such that \(e^{p(z+c)}\equiv e^{p(z)}\).