{"title":"关于三角多项式的一个不同度量不等式","authors":"V. Arestov, M. Deikalova","doi":"10.15826/umj.2022.2.003","DOIUrl":null,"url":null,"abstract":"We study the sharp inequality between the uniform norm and \\(L^p(0,\\pi/2)\\)-norm of polynomials in the system \\(\\mathscr{C}=\\{\\cos (2k+1)x\\}_{k=0}^\\infty\\) of cosines with odd harmonics. We investigate the limit behavior of the best constant in this inequality with respect to the order \\(n\\) of polynomials as \\(n\\to\\infty\\) and provide a characterization of the extremal polynomial in the inequality for a fixed order of polynomials.","PeriodicalId":36805,"journal":{"name":"Ural Mathematical Journal","volume":" ","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"ON ONE INEQUALITY OF DIFFERENT METRICS FOR TRIGONOMETRIC POLYNOMIALS\",\"authors\":\"V. Arestov, M. Deikalova\",\"doi\":\"10.15826/umj.2022.2.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We study the sharp inequality between the uniform norm and \\\\(L^p(0,\\\\pi/2)\\\\)-norm of polynomials in the system \\\\(\\\\mathscr{C}=\\\\{\\\\cos (2k+1)x\\\\}_{k=0}^\\\\infty\\\\) of cosines with odd harmonics. We investigate the limit behavior of the best constant in this inequality with respect to the order \\\\(n\\\\) of polynomials as \\\\(n\\\\to\\\\infty\\\\) and provide a characterization of the extremal polynomial in the inequality for a fixed order of polynomials.\",\"PeriodicalId\":36805,\"journal\":{\"name\":\"Ural Mathematical Journal\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-12-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Ural Mathematical Journal\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.15826/umj.2022.2.003\",\"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":"Ural Mathematical Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15826/umj.2022.2.003","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Mathematics","Score":null,"Total":0}
ON ONE INEQUALITY OF DIFFERENT METRICS FOR TRIGONOMETRIC POLYNOMIALS
We study the sharp inequality between the uniform norm and \(L^p(0,\pi/2)\)-norm of polynomials in the system \(\mathscr{C}=\{\cos (2k+1)x\}_{k=0}^\infty\) of cosines with odd harmonics. We investigate the limit behavior of the best constant in this inequality with respect to the order \(n\) of polynomials as \(n\to\infty\) and provide a characterization of the extremal polynomial in the inequality for a fixed order of polynomials.