Sharp Constants of Approximation Theory. II. Invariance Theorems and Multivariate Inequalities of Different Metrics

Michael I. Ganzburg

Published 2019-01-14Version 1

We prove invariance theorems for general inequalities of different metrics and apply them to limit relations between the sharp constants in the multivariate Markov-Bernstein-Nikolskii type inequalities with the polyharmonic operator for algebraic polynomials on the unit sphere and the unit ball in $\R^m$ and the corresponding constants for entire functions of spherical type on $\R^m$. Certain relations in the univariate weighted spaces are discussed as well.