F. Dai , A. Prymak , A. Shadrin , V.N. Temlyakov , S. Tikhonov
{"title":"On the cardinality of lower sets and universal discretization","authors":"F. Dai , A. Prymak , A. Shadrin , V.N. Temlyakov , S. Tikhonov","doi":"10.1016/j.jco.2022.101726","DOIUrl":null,"url":null,"abstract":"<div><p>A set <em>Q</em> in <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mo>+</mo></mrow><mrow><mi>d</mi></mrow></msubsup></math></span> is a lower set if <span><math><mo>(</mo><msub><mrow><mi>k</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>k</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>)</mo><mo>∈</mo><mi>Q</mi></math></span> implies <span><math><mo>(</mo><msub><mrow><mi>l</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>l</mi></mrow><mrow><mi>d</mi></mrow></msub><mo>)</mo><mo>∈</mo><mi>Q</mi></math></span> whenever <span><math><mn>0</mn><mo>≤</mo><msub><mrow><mi>l</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>≤</mo><msub><mrow><mi>k</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> for all <em>i</em>. We derive new and refine known results regarding the cardinality of the lower sets of size <em>n</em> in <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mo>+</mo></mrow><mrow><mi>d</mi></mrow></msubsup></math></span><span>. Next we apply these results for universal discretization of the </span><span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-norm of elements from <em>n</em><span>-dimensional subspaces of trigonometric polynomials generated by lower sets.</span></p></div>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4000,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Accounts of Chemical Research","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0885064X22000917","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
A set Q in is a lower set if implies whenever for all i. We derive new and refine known results regarding the cardinality of the lower sets of size n in . Next we apply these results for universal discretization of the -norm of elements from n-dimensional subspaces of trigonometric polynomials generated by lower sets.
期刊介绍:
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