Interpolation by Linear Functions on an $n$-Dimensional Ball

Mikhail Nevskii, Alexey Ukhalov

By $B=B(x^{(0)};R)$ we denote the Euclidean ball in ${\mathbb{R}}^n$ given by the inequality $\Vert x-x^{(0)}\Vert \le R$. Here $x^{(0)}\in {\mathbb{R}}^n,R>0$, $\|x\|:=\left(\sum_{i=1}^n x…