Hankel and Toeplitz determinants for a subclass of analytic functions

Q3 Mathematics Matematychni Studii Pub Date : 2023-12-18 DOI:10.30970/ms.60.2.132-137
V. MatematychniStudii., No 60, M. Buyankara, M.
{"title":"Hankel and Toeplitz determinants for a subclass of analytic functions","authors":"V. MatematychniStudii., No 60, M. Buyankara, M.","doi":"10.30970/ms.60.2.132-137","DOIUrl":null,"url":null,"abstract":"Let the function $f\\left( z \\right) =z+\\sum_{k=2}^{\\infty}a{_{k}}z {^{k}}\\in A$ be locally univalent for $z \\in \\mathbb{D}%:=\\{z \\in \\mathbb{C}:{|}z {|}<1\\}$ and $0\\leq\\alpha<1$.Then, $f$\\textit{\\ }$\\in $ $M(\\alpha )$ if and only if \\begin{equation*}\\Re\\Big( \\left( 1-z ^{2}\\right) \\frac{f(z )}{z }\\Big) >\\alpha,\\quad z \\in \\mathbb{D}.\\end{equation*}%Due to their geometrical characteristics, this class has a significantimpact on the theory of geometric functions. In the article we obtain sharp bounds for the second Hankel determinant \\begin{equation*}\\left\\vert H_{2}\\left( 2\\right) \\left( f\\right) \\right\\vert =\\left\\verta_{2}a_{4}-{a_{3}^{2}}\\right\\vert \\end{equation*}and some Toeplitz determinants \\begin{equation*}\\left\\vert {T}_{3}\\left( 1\\right) \\left( f\\right) \\right\\vert =\\left\\vert 1-2%{a_{2}^{2}}+2{a_{2}^{2}}a_{3}-{a_{3}^{2}}\\right\\vert,\\ \\\\left\\vert {T}_{3}\\left( 2\\right) \\left( f\\right) \\right\\vert =\\left\\vert {%a_{2}^{3}}-2a_{2}{a_{3}^{2}}+2{a_{3}^{2}}a_{4}-a_{2}{a_{4}^{2}}\\right\\vert \\end{equation*}of a subclass of analytic functions $M(\\alpha )$ in the open unit disk $%\\mathbb{D}$.","PeriodicalId":37555,"journal":{"name":"Matematychni Studii","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Matematychni Studii","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.30970/ms.60.2.132-137","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Mathematics","Score":null,"Total":0}
引用次数: 0

Abstract

Let the function $f\left( z \right) =z+\sum_{k=2}^{\infty}a{_{k}}z {^{k}}\in A$ be locally univalent for $z \in \mathbb{D}%:=\{z \in \mathbb{C}:{|}z {|}<1\}$ and $0\leq\alpha<1$.Then, $f$\textit{\ }$\in $ $M(\alpha )$ if and only if \begin{equation*}\Re\Big( \left( 1-z ^{2}\right) \frac{f(z )}{z }\Big) >\alpha,\quad z \in \mathbb{D}.\end{equation*}%Due to their geometrical characteristics, this class has a significantimpact on the theory of geometric functions. In the article we obtain sharp bounds for the second Hankel determinant \begin{equation*}\left\vert H_{2}\left( 2\right) \left( f\right) \right\vert =\left\verta_{2}a_{4}-{a_{3}^{2}}\right\vert \end{equation*}and some Toeplitz determinants \begin{equation*}\left\vert {T}_{3}\left( 1\right) \left( f\right) \right\vert =\left\vert 1-2%{a_{2}^{2}}+2{a_{2}^{2}}a_{3}-{a_{3}^{2}}\right\vert,\ \\left\vert {T}_{3}\left( 2\right) \left( f\right) \right\vert =\left\vert {%a_{2}^{3}}-2a_{2}{a_{3}^{2}}+2{a_{3}^{2}}a_{4}-a_{2}{a_{4}^{2}}\right\vert \end{equation*}of a subclass of analytic functions $M(\alpha )$ in the open unit disk $%\mathbb{D}$.
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
解析函数子类的汉克尔和托普利兹行列式
让函数 $f\left( z \right) =z+\sum_{k=2}^{\infty}a{_{k}}z {^{k}}\in A$ 对于 $z \in \mathbb{D}%:=\{z \in \mathbb{C}:{|}z {|}\alpha,\quad z \in \mathbb{D} 是局部等价的。\end{equation*}%由于它们的几何特征,这一类函数对几何函数理论有着重要影响。在这篇文章中,我们得到了第二个汉克尔行列式的尖锐边界 H_{2}\left( 2\right) \left( f\right) \right\vert =\left\verta_{2}a_{4}-{a_{3}^{2}}(right)vert =\left\vert 1-2%{a_{2}^{2}+2{a_{2}^{2}a_{3}-{a_{3}^{2} (right)vert、\left\vert {T}_{3}\left( 2\right) \left( f\right) \right\vert =\left\vert {%a_{2}^{3}}-2a_{2}{a_{3}^{2}}+2{a_{3}^{2}}a_{4}-a_{2}{a_{4}^{2}} (end{equation*})是开放单位盘 $%\mathbb{D}$ 中解析函数 $M(\alpha )$ 的子类。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
Matematychni Studii
Matematychni Studii Mathematics-Mathematics (all)
CiteScore
1.00
自引率
0.00%
发文量
38
期刊介绍: Journal is devoted to research in all fields of mathematics.
期刊最新文献
On the h-measure of an exceptional set in Fenton-type theorem for Taylor-Dirichlet series Almost periodic distributions and crystalline measures Reflectionless Schrodinger operators and Marchenko parametrization Existence of basic solutions of first order linear homogeneous set-valued differential equations Real univariate polynomials with given signs of coefficients and simple real roots
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1