{"title":"On an Extremal Gheit Function and Its Applications","authors":"N.A. Ilyasov, A.R. Alimov","doi":"10.1134/S106192082560165X","DOIUrl":null,"url":null,"abstract":"<p> We find exact orders of decrease of quantities that characterize various properties of <span>\\(2\\pi\\)</span>-periodic summable functions on a class with given majorant of the second-order modulus of continuity. We show that all these quantities have the same order of decrease (with a single condition on the behavior of the majorant), which is attained on a singe extremal function. </p>","PeriodicalId":763,"journal":{"name":"Russian Journal of Mathematical Physics","volume":"33 1","pages":"1 - 11"},"PeriodicalIF":1.9000,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Mathematical Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1134/S106192082560165X","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, MATHEMATICAL","Score":null,"Total":0}
引用次数: 0
Abstract
We find exact orders of decrease of quantities that characterize various properties of \(2\pi\)-periodic summable functions on a class with given majorant of the second-order modulus of continuity. We show that all these quantities have the same order of decrease (with a single condition on the behavior of the majorant), which is attained on a singe extremal function.
期刊介绍:
Russian Journal of Mathematical Physics is a peer-reviewed periodical that deals with the full range of topics subsumed by that discipline, which lies at the foundation of much of contemporary science. Thus, in addition to mathematical physics per se, the journal coverage includes, but is not limited to, functional analysis, linear and nonlinear partial differential equations, algebras, quantization, quantum field theory, modern differential and algebraic geometry and topology, representations of Lie groups, calculus of variations, asymptotic methods, random process theory, dynamical systems, and control theory.