{"title":"用 Szász-Mirakjan-Kantorovich 算子对函数进行加权逼近的强反演不等式","authors":"Ivan Gadjev, Parvan E. Parvanov, Rumen Uluchev","doi":"10.1007/s00025-024-02179-3","DOIUrl":null,"url":null,"abstract":"<p>We investigate the weighted approximation of functions in <span>\\(L_p\\)</span>-norm by Kantorovich modifications of the classical Szász-Mirakjan operator, with weights of type <span>\\((1+x)^{\\alpha }\\)</span>, <span>\\(\\alpha \\in {\\mathbb {R}}\\)</span>. By using an appropriate <i>K</i>-functional we prove a strong converse inequality for the weighted error of approximation and characterize it exactly. We prove a Voronovskaya and Bernstein-type inequalities for the Szász-Mirakjan–Kantorovich operator.</p>","PeriodicalId":54490,"journal":{"name":"Results in Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Strong Converse Inequality for Weighted Approximation of Functions by the Szász–Mirakjan–Kantorovich Operator\",\"authors\":\"Ivan Gadjev, Parvan E. Parvanov, Rumen Uluchev\",\"doi\":\"10.1007/s00025-024-02179-3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We investigate the weighted approximation of functions in <span>\\\\(L_p\\\\)</span>-norm by Kantorovich modifications of the classical Szász-Mirakjan operator, with weights of type <span>\\\\((1+x)^{\\\\alpha }\\\\)</span>, <span>\\\\(\\\\alpha \\\\in {\\\\mathbb {R}}\\\\)</span>. By using an appropriate <i>K</i>-functional we prove a strong converse inequality for the weighted error of approximation and characterize it exactly. We prove a Voronovskaya and Bernstein-type inequalities for the Szász-Mirakjan–Kantorovich operator.</p>\",\"PeriodicalId\":54490,\"journal\":{\"name\":\"Results in Mathematics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2024-04-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Results in Mathematics\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1007/s00025-024-02179-3\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Results in Mathematics","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00025-024-02179-3","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
Strong Converse Inequality for Weighted Approximation of Functions by the Szász–Mirakjan–Kantorovich Operator
We investigate the weighted approximation of functions in \(L_p\)-norm by Kantorovich modifications of the classical Szász-Mirakjan operator, with weights of type \((1+x)^{\alpha }\), \(\alpha \in {\mathbb {R}}\). By using an appropriate K-functional we prove a strong converse inequality for the weighted error of approximation and characterize it exactly. We prove a Voronovskaya and Bernstein-type inequalities for the Szász-Mirakjan–Kantorovich operator.
期刊介绍:
Results in Mathematics (RM) publishes mainly research papers in all fields of pure and applied mathematics. In addition, it publishes summaries of any mathematical field and surveys of any mathematical subject provided they are designed to advance some recent mathematical development.