{"title":"Trigonometric Polynomials with Frequencies in the Set of Cubes","authors":"M. R. Gabdullin, S. V. Konyagin","doi":"10.1134/s0001434624030052","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p> We prove that for any <span>\\(\\varepsilon>0\\)</span> and any trigonometric polynomial <span>\\(f\\)</span> with frequencies in the set <span>\\(\\{n^3: N \\leq n\\leq N+N^{2/3-\\varepsilon}\\}\\)</span> one has </p><span>$$\\|f\\|_4 \\ll \\varepsilon^{-1/4}\\|f\\|_2$$</span><p> with implied constant being absolute. We also show that the set <span>\\(\\{n^3: N\\leq n\\leq N+(0.5N)^{1/2}\\}\\)</span> is a Sidon set. </p>","PeriodicalId":18294,"journal":{"name":"Mathematical Notes","volume":null,"pages":null},"PeriodicalIF":0.6000,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Notes","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1134/s0001434624030052","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
We prove that for any \(\varepsilon>0\) and any trigonometric polynomial \(f\) with frequencies in the set \(\{n^3: N \leq n\leq N+N^{2/3-\varepsilon}\}\) one has
$$\|f\|_4 \ll \varepsilon^{-1/4}\|f\|_2$$
with implied constant being absolute. We also show that the set \(\{n^3: N\leq n\leq N+(0.5N)^{1/2}\}\) is a Sidon set.
期刊介绍:
Mathematical Notes is a journal that publishes research papers and review articles in modern algebra, geometry and number theory, functional analysis, logic, set and measure theory, topology, probability and stochastics, differential and noncommutative geometry, operator and group theory, asymptotic and approximation methods, mathematical finance, linear and nonlinear equations, ergodic and spectral theory, operator algebras, and other related theoretical fields. It also presents rigorous results in mathematical physics.