{"title":"关于整个Dirichlet级数的正则变分","authors":"P. Filevych, O. B. Hrybel","doi":"10.30970/ms.58.2.174-181","DOIUrl":null,"url":null,"abstract":"Consider an entire (absolutely convergent in $\\mathbb{C}$) Dirichlet series $F$ with the exponents $\\lambda_n$, i.e., of the form $F(s)=\\sum_{n=0}^\\infty a_ne^{s\\lambda_n}$, and, for all $\\sigma\\in\\mathbb{R}$, put $\\mu(\\sigma,F)=\\max\\{|a_n|e^{\\sigma\\lambda_n}:n\\ge0\\}$ and $M(\\sigma,F)=\\sup\\{|F(s)|:\\operatorname{Re}s=\\sigma\\}$. Previously, the first of the authors and M.M.~Sheremeta proved that if $\\omega(\\lambda)<C(\\rho)$, then the regular variation of the function $\\ln\\mu(\\sigma,F)$ with index $\\rho$ implies the regular variation of the function $\\ln M(\\sigma,F)$ with index $\\rho$, and constructed examples of entire Dirichlet series $F$, for which $\\ln\\mu(\\sigma,F)$ is a regularly varying function with index $\\rho$, and $\\ln M(\\sigma,F)$ is not a regularly varying function with index $\\rho$. For the exponents of the constructed series we have $\\lambda_n=\\ln\\ln n$ for all $n\\ge n_0$ in the case $\\rho=1$, and $\\lambda_n\\sim(\\ln n)^{(\\rho-1)/\\rho}$ as $n\\to\\infty$ in the case $\\rho>1$. In the present article we prove that the exponents of entire Dirichlet series with the same property can form an arbitrary sequence $\\lambda=(\\lambda_n)_{n=0}^\\infty$ not satisfying $\\omega(\\lambda)<C(\\rho)$. More precisely, if $\\omega(\\lambda)\\ge C(\\rho)$, then there exists a regularly varying function $\\Phi(\\sigma)$ with index $\\rho$ such that, for an arbitrary positive function $l(\\sigma)$ on $[a,+\\infty)$, there exists an entire Dirichlet series $F$ with the exponents $\\lambda_n$, for which $\\ln \\mu(\\sigma, F)\\sim\\Phi(\\sigma)$ as $\\sigma\\to+\\infty$ and $M(\\sigma,F)\\ge l(\\sigma)$ for all $\\sigma\\ge\\sigma_0$.","PeriodicalId":37555,"journal":{"name":"Matematychni Studii","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"On regular variation of entire Dirichlet series\",\"authors\":\"P. Filevych, O. B. Hrybel\",\"doi\":\"10.30970/ms.58.2.174-181\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Consider an entire (absolutely convergent in $\\\\mathbb{C}$) Dirichlet series $F$ with the exponents $\\\\lambda_n$, i.e., of the form $F(s)=\\\\sum_{n=0}^\\\\infty a_ne^{s\\\\lambda_n}$, and, for all $\\\\sigma\\\\in\\\\mathbb{R}$, put $\\\\mu(\\\\sigma,F)=\\\\max\\\\{|a_n|e^{\\\\sigma\\\\lambda_n}:n\\\\ge0\\\\}$ and $M(\\\\sigma,F)=\\\\sup\\\\{|F(s)|:\\\\operatorname{Re}s=\\\\sigma\\\\}$. Previously, the first of the authors and M.M.~Sheremeta proved that if $\\\\omega(\\\\lambda)<C(\\\\rho)$, then the regular variation of the function $\\\\ln\\\\mu(\\\\sigma,F)$ with index $\\\\rho$ implies the regular variation of the function $\\\\ln M(\\\\sigma,F)$ with index $\\\\rho$, and constructed examples of entire Dirichlet series $F$, for which $\\\\ln\\\\mu(\\\\sigma,F)$ is a regularly varying function with index $\\\\rho$, and $\\\\ln M(\\\\sigma,F)$ is not a regularly varying function with index $\\\\rho$. For the exponents of the constructed series we have $\\\\lambda_n=\\\\ln\\\\ln n$ for all $n\\\\ge n_0$ in the case $\\\\rho=1$, and $\\\\lambda_n\\\\sim(\\\\ln n)^{(\\\\rho-1)/\\\\rho}$ as $n\\\\to\\\\infty$ in the case $\\\\rho>1$. In the present article we prove that the exponents of entire Dirichlet series with the same property can form an arbitrary sequence $\\\\lambda=(\\\\lambda_n)_{n=0}^\\\\infty$ not satisfying $\\\\omega(\\\\lambda)<C(\\\\rho)$. More precisely, if $\\\\omega(\\\\lambda)\\\\ge C(\\\\rho)$, then there exists a regularly varying function $\\\\Phi(\\\\sigma)$ with index $\\\\rho$ such that, for an arbitrary positive function $l(\\\\sigma)$ on $[a,+\\\\infty)$, there exists an entire Dirichlet series $F$ with the exponents $\\\\lambda_n$, for which $\\\\ln \\\\mu(\\\\sigma, F)\\\\sim\\\\Phi(\\\\sigma)$ as $\\\\sigma\\\\to+\\\\infty$ and $M(\\\\sigma,F)\\\\ge l(\\\\sigma)$ for all $\\\\sigma\\\\ge\\\\sigma_0$.\",\"PeriodicalId\":37555,\"journal\":{\"name\":\"Matematychni Studii\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-01-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Matematychni Studii\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.30970/ms.58.2.174-181\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"Mathematics\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Matematychni Studii","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.30970/ms.58.2.174-181","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Mathematics","Score":null,"Total":0}
Consider an entire (absolutely convergent in $\mathbb{C}$) Dirichlet series $F$ with the exponents $\lambda_n$, i.e., of the form $F(s)=\sum_{n=0}^\infty a_ne^{s\lambda_n}$, and, for all $\sigma\in\mathbb{R}$, put $\mu(\sigma,F)=\max\{|a_n|e^{\sigma\lambda_n}:n\ge0\}$ and $M(\sigma,F)=\sup\{|F(s)|:\operatorname{Re}s=\sigma\}$. Previously, the first of the authors and M.M.~Sheremeta proved that if $\omega(\lambda)1$. In the present article we prove that the exponents of entire Dirichlet series with the same property can form an arbitrary sequence $\lambda=(\lambda_n)_{n=0}^\infty$ not satisfying $\omega(\lambda)