{"title":"非对称情况下比较定理与Kolmogorov不等式的强化","authors":"V. Kofanov, K.D. Sydorovych","doi":"10.15421/242204","DOIUrl":null,"url":null,"abstract":"We obtain the strengthened Kolmogorov comparison theorem in asymmetric case.In particular, it gives us the opportunity to obtain the following strengthened Kolmogorov inequality in the asymmetric case:$$\\|x^{(k)}_{\\pm }\\|_{\\infty}\\le \\frac{\\|\\varphi _{r-k}( \\cdot \\;;\\alpha ,\\beta )_\\pm \\|_{\\infty }}{E_0(\\varphi _r( \\cdot \\;;\\alpha ,\\beta ))^{1-k/r}_{\\infty }}|||x|||^{1-k/r}_{\\infty}\\|\\alpha^{-1}x_+^{(r)}+\\beta^{-1}x_-^{(r)}\\|_\\infty^{k/r}$$for functions $x \\in L^r_{\\infty }(\\mathbb{R})$, where$$|||x|||_\\infty:=\\frac12 \\sup_{\\alpha ,\\beta}\\{ |x(\\beta)-x(\\alpha)|:x'(t)\\neq 0 \\;\\;\\forallt\\in (\\alpha ,\\beta) \\}$$$k,r \\in \\mathbb{N}$, $k 0$, $\\varphi_r( \\cdot \\;;\\alpha ,\\beta )_r$ is the asymmetric perfect spline of Euler of order $r$ and $E_0(x)_\\infty $ is the best uniform approximation of the function $x$ by constants.","PeriodicalId":52827,"journal":{"name":"Researches in Mathematics","volume":"25 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Strengthening the Comparison Theorem and Kolmogorov Inequality in the Asymmetric Case\",\"authors\":\"V. Kofanov, K.D. Sydorovych\",\"doi\":\"10.15421/242204\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We obtain the strengthened Kolmogorov comparison theorem in asymmetric case.In particular, it gives us the opportunity to obtain the following strengthened Kolmogorov inequality in the asymmetric case:$$\\\\|x^{(k)}_{\\\\pm }\\\\|_{\\\\infty}\\\\le \\\\frac{\\\\|\\\\varphi _{r-k}( \\\\cdot \\\\;;\\\\alpha ,\\\\beta )_\\\\pm \\\\|_{\\\\infty }}{E_0(\\\\varphi _r( \\\\cdot \\\\;;\\\\alpha ,\\\\beta ))^{1-k/r}_{\\\\infty }}|||x|||^{1-k/r}_{\\\\infty}\\\\|\\\\alpha^{-1}x_+^{(r)}+\\\\beta^{-1}x_-^{(r)}\\\\|_\\\\infty^{k/r}$$for functions $x \\\\in L^r_{\\\\infty }(\\\\mathbb{R})$, where$$|||x|||_\\\\infty:=\\\\frac12 \\\\sup_{\\\\alpha ,\\\\beta}\\\\{ |x(\\\\beta)-x(\\\\alpha)|:x'(t)\\\\neq 0 \\\\;\\\\;\\\\forallt\\\\in (\\\\alpha ,\\\\beta) \\\\}$$$k,r \\\\in \\\\mathbb{N}$, $k 0$, $\\\\varphi_r( \\\\cdot \\\\;;\\\\alpha ,\\\\beta )_r$ is the asymmetric perfect spline of Euler of order $r$ and $E_0(x)_\\\\infty $ is the best uniform approximation of the function $x$ by constants.\",\"PeriodicalId\":52827,\"journal\":{\"name\":\"Researches in Mathematics\",\"volume\":\"25 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-07-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Researches in Mathematics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.15421/242204\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"Mathematics\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Researches in Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15421/242204","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Mathematics","Score":null,"Total":0}
Strengthening the Comparison Theorem and Kolmogorov Inequality in the Asymmetric Case
We obtain the strengthened Kolmogorov comparison theorem in asymmetric case.In particular, it gives us the opportunity to obtain the following strengthened Kolmogorov inequality in the asymmetric case:$$\|x^{(k)}_{\pm }\|_{\infty}\le \frac{\|\varphi _{r-k}( \cdot \;;\alpha ,\beta )_\pm \|_{\infty }}{E_0(\varphi _r( \cdot \;;\alpha ,\beta ))^{1-k/r}_{\infty }}|||x|||^{1-k/r}_{\infty}\|\alpha^{-1}x_+^{(r)}+\beta^{-1}x_-^{(r)}\|_\infty^{k/r}$$for functions $x \in L^r_{\infty }(\mathbb{R})$, where$$|||x|||_\infty:=\frac12 \sup_{\alpha ,\beta}\{ |x(\beta)-x(\alpha)|:x'(t)\neq 0 \;\;\forallt\in (\alpha ,\beta) \}$$$k,r \in \mathbb{N}$, $k 0$, $\varphi_r( \cdot \;;\alpha ,\beta )_r$ is the asymmetric perfect spline of Euler of order $r$ and $E_0(x)_\infty $ is the best uniform approximation of the function $x$ by constants.