{"title":"最老导数上具有非对称限制的函数的尖锐Remez型不等式","authors":"V. Kofanov, A. V. Zhuravel","doi":"10.15421/242304","DOIUrl":null,"url":null,"abstract":"For odd $r\\in \\mathbb{N}$; $\\alpha, \\beta >0$; $p\\in [1, \\infty]$; $\\delta \\in (0, 2 \\pi)$, any $2\\pi$-periodic function $x\\in L^r_{\\infty}(I_{2\\pi})$, $I_{2\\pi}:=[0, 2\\pi]$, and arbitrary measurable set $B \\subset I_{2\\pi},$ $\\mu B \\leqslant \\delta/\\lambda,$ where $\\lambda=$ $\\left({\\left\\|\\varphi_{r}^{\\alpha, \\beta}\\right\\|_{\\infty} \\left\\| {\\alpha^{-1}}{x_+^{(r)}} + {\\beta^{-1}}{x_-^{(r)}}\\right\\|_\\infty}{E^{-1}_0(x)_\\infty}\\right)^{1/r}$, we obtain sharp Remez type inequality $$E_0(x)_\\infty \\leqslant \\frac{\\|\\varphi_r^{\\alpha, \\beta}\\|_\\infty}{E_0(\\varphi_r^{\\alpha, \\beta})^{\\gamma}_{L_p(I_{2\\pi} \\setminus B_\\delta)}} \\left\\|x \\right\\|^{\\gamma}_{{L_p} \\left(I_{2\\pi} \\setminus B \\right)}\\left\\| {\\alpha^{-1}}{x_+^{(r)}} + {\\beta^{-1}}{x_-^{(r)}}\\right\\|_\\infty^{1-\\gamma},$$ where $\\gamma=\\frac{r}{r+1/p},$ $\\varphi_r^{\\alpha, \\beta}$ is non-symmetric ideal Euler spline of order $r$, $B_\\delta:= \\left[M- \\delta_2, M+ \\delta_1 \\right]$, $M$ is the point of local maximum of spline $\\varphi_r^{\\alpha, \\beta}$ and $\\delta_1 > 0$, $\\delta_2 > 0$ are such that $\\varphi_r^{\\alpha, \\beta}(M+ \\delta_1) = \\varphi_r^{\\alpha, \\beta}(M- \\delta_2), \\;\\; \\delta_1 + \\delta_2 = \\delta .$In particular, we prove the sharp inequality of Hörmander-Remez type for the norms of intermediate derivatives of the functions $x\\in L^r_{\\infty}(I_{2\\pi})$.","PeriodicalId":52827,"journal":{"name":"Researches in Mathematics","volume":"8 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A sharp Remez type inequalities for the functions with asymmetric restrictions on the oldest derivative\",\"authors\":\"V. Kofanov, A. V. Zhuravel\",\"doi\":\"10.15421/242304\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"For odd $r\\\\in \\\\mathbb{N}$; $\\\\alpha, \\\\beta >0$; $p\\\\in [1, \\\\infty]$; $\\\\delta \\\\in (0, 2 \\\\pi)$, any $2\\\\pi$-periodic function $x\\\\in L^r_{\\\\infty}(I_{2\\\\pi})$, $I_{2\\\\pi}:=[0, 2\\\\pi]$, and arbitrary measurable set $B \\\\subset I_{2\\\\pi},$ $\\\\mu B \\\\leqslant \\\\delta/\\\\lambda,$ where $\\\\lambda=$ $\\\\left({\\\\left\\\\|\\\\varphi_{r}^{\\\\alpha, \\\\beta}\\\\right\\\\|_{\\\\infty} \\\\left\\\\| {\\\\alpha^{-1}}{x_+^{(r)}} + {\\\\beta^{-1}}{x_-^{(r)}}\\\\right\\\\|_\\\\infty}{E^{-1}_0(x)_\\\\infty}\\\\right)^{1/r}$, we obtain sharp Remez type inequality $$E_0(x)_\\\\infty \\\\leqslant \\\\frac{\\\\|\\\\varphi_r^{\\\\alpha, \\\\beta}\\\\|_\\\\infty}{E_0(\\\\varphi_r^{\\\\alpha, \\\\beta})^{\\\\gamma}_{L_p(I_{2\\\\pi} \\\\setminus B_\\\\delta)}} \\\\left\\\\|x \\\\right\\\\|^{\\\\gamma}_{{L_p} \\\\left(I_{2\\\\pi} \\\\setminus B \\\\right)}\\\\left\\\\| {\\\\alpha^{-1}}{x_+^{(r)}} + {\\\\beta^{-1}}{x_-^{(r)}}\\\\right\\\\|_\\\\infty^{1-\\\\gamma},$$ where $\\\\gamma=\\\\frac{r}{r+1/p},$ $\\\\varphi_r^{\\\\alpha, \\\\beta}$ is non-symmetric ideal Euler spline of order $r$, $B_\\\\delta:= \\\\left[M- \\\\delta_2, M+ \\\\delta_1 \\\\right]$, $M$ is the point of local maximum of spline $\\\\varphi_r^{\\\\alpha, \\\\beta}$ and $\\\\delta_1 > 0$, $\\\\delta_2 > 0$ are such that $\\\\varphi_r^{\\\\alpha, \\\\beta}(M+ \\\\delta_1) = \\\\varphi_r^{\\\\alpha, \\\\beta}(M- \\\\delta_2), \\\\;\\\\; \\\\delta_1 + \\\\delta_2 = \\\\delta .$In particular, we prove the sharp inequality of Hörmander-Remez type for the norms of intermediate derivatives of the functions $x\\\\in L^r_{\\\\infty}(I_{2\\\\pi})$.\",\"PeriodicalId\":52827,\"journal\":{\"name\":\"Researches in Mathematics\",\"volume\":\"8 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-06-19\",\"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/10.15421/242304\",\"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/10.15421/242304","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Mathematics","Score":null,"Total":0}
A sharp Remez type inequalities for the functions with asymmetric restrictions on the oldest derivative
For odd $r\in \mathbb{N}$; $\alpha, \beta >0$; $p\in [1, \infty]$; $\delta \in (0, 2 \pi)$, any $2\pi$-periodic function $x\in L^r_{\infty}(I_{2\pi})$, $I_{2\pi}:=[0, 2\pi]$, and arbitrary measurable set $B \subset I_{2\pi},$ $\mu B \leqslant \delta/\lambda,$ where $\lambda=$ $\left({\left\|\varphi_{r}^{\alpha, \beta}\right\|_{\infty} \left\| {\alpha^{-1}}{x_+^{(r)}} + {\beta^{-1}}{x_-^{(r)}}\right\|_\infty}{E^{-1}_0(x)_\infty}\right)^{1/r}$, we obtain sharp Remez type inequality $$E_0(x)_\infty \leqslant \frac{\|\varphi_r^{\alpha, \beta}\|_\infty}{E_0(\varphi_r^{\alpha, \beta})^{\gamma}_{L_p(I_{2\pi} \setminus B_\delta)}} \left\|x \right\|^{\gamma}_{{L_p} \left(I_{2\pi} \setminus B \right)}\left\| {\alpha^{-1}}{x_+^{(r)}} + {\beta^{-1}}{x_-^{(r)}}\right\|_\infty^{1-\gamma},$$ where $\gamma=\frac{r}{r+1/p},$ $\varphi_r^{\alpha, \beta}$ is non-symmetric ideal Euler spline of order $r$, $B_\delta:= \left[M- \delta_2, M+ \delta_1 \right]$, $M$ is the point of local maximum of spline $\varphi_r^{\alpha, \beta}$ and $\delta_1 > 0$, $\delta_2 > 0$ are such that $\varphi_r^{\alpha, \beta}(M+ \delta_1) = \varphi_r^{\alpha, \beta}(M- \delta_2), \;\; \delta_1 + \delta_2 = \delta .$In particular, we prove the sharp inequality of Hörmander-Remez type for the norms of intermediate derivatives of the functions $x\in L^r_{\infty}(I_{2\pi})$.