On harmonic approximation of Lipschitz functions on compacts in ${\mathbb{R}}^d$

Nikolai A. Shirokov, Andrei V. Vasin

Given a porous compact $K\subset {\mathbb{R}}^d$ and a continuity modulus $\omega$, we prove a quantitative Jackson-Bernstein type theorem on harmonic approximation. That is, a function…