On the Landau-Kolmogorov inequality between $\| f' \|_{\infty}$, $\| f \|_{\infty}$ and $\| f''' \|_1$

We solve the Landau-Kolmogorov problem on finding sharp additive inequalities that estimate $\| f' \|_{\infty}$ in terms of $\| f \|_{\infty}$ and $\| f''' \|_1$. Simultaneously we solve related problems of the best approximation of first order differentiation operator $D^1$ by l...

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Bibliographic Details
Published in:Researches in Mathematics
Main Author: D. Skorokhodov
Format: Article
Language:English
Published: Oles Honchar Dnipro National University 2019-07-01
Subjects:
Online Access:https://vestnmath.dnu.dp.ua/index.php/rim/article/view/113
Description
Summary:We solve the Landau-Kolmogorov problem on finding sharp additive inequalities that estimate $\| f' \|_{\infty}$ in terms of $\| f \|_{\infty}$ and $\| f''' \|_1$. Simultaneously we solve related problems of the best approximation of first order differentiation operator $D^1$ by linear bounded ones and the best recovery of operator $D^1$ on elements of a class given with error.
ISSN:2664-4991
2664-5009