{"title":"Approximation characteristics of the isotropic Nikol'skii-Besov functional classes","authors":"S. Yanchenko, O. Radchenko","doi":"10.15330/cmp.13.3.851-861","DOIUrl":null,"url":null,"abstract":"In the paper, we investigates the isotropic Nikol'skii-Besov classes $B^r_{p,\\theta}(\\mathbb{R}^d)$ of non-periodic functions of several variables, which for $d = 1$ are identical to the classes of functions with a dominant mixed smoothness $S^{r}_{p,\\theta}B(\\mathbb{R})$. We establish the exact-order estimates for the approximation of functions from these classes $B^r_{p,\\theta}(\\mathbb{R}^d)$ in the metric of the Lebesgue space $L_q(\\mathbb{R}^d)$, by entire functions of exponential type with some restrictions for their spectrum in the case $1 \\leqslant p \\leqslant q \\leqslant \\infty$, $(p,q)\\neq \\{(1,1), (\\infty, \\infty)\\}$, $d\\geq 1$. In the case $2<p=q<\\infty$, $d=1$, the established estimate is also new for the classes $S^{r}_{p,\\theta}B(\\mathbb{R})$.","PeriodicalId":42912,"journal":{"name":"Carpathian Mathematical Publications","volume":"36 1","pages":""},"PeriodicalIF":1.0000,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Carpathian Mathematical Publications","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15330/cmp.13.3.851-861","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
In the paper, we investigates the isotropic Nikol'skii-Besov classes $B^r_{p,\theta}(\mathbb{R}^d)$ of non-periodic functions of several variables, which for $d = 1$ are identical to the classes of functions with a dominant mixed smoothness $S^{r}_{p,\theta}B(\mathbb{R})$. We establish the exact-order estimates for the approximation of functions from these classes $B^r_{p,\theta}(\mathbb{R}^d)$ in the metric of the Lebesgue space $L_q(\mathbb{R}^d)$, by entire functions of exponential type with some restrictions for their spectrum in the case $1 \leqslant p \leqslant q \leqslant \infty$, $(p,q)\neq \{(1,1), (\infty, \infty)\}$, $d\geq 1$. In the case $2