2 papers
math.CV2025
The uniqueness problem for the 3-Point Nevanlinna-Pick extremal interpolation problem in the unit Euclidean ball $\Bn{d}$
Dariusz Piekarz
Agler and McCarthy studied the uniqueness of a 3-point interpolation problem in the bidisc. This note aims to solve an analogous problem in the unit Euclidean ball in an arbitrary…
math.CV2023
The von Neumann inequality for matrices in the unit Euclidean ball
Dariusz Piekarz
It is shown that the constant in von Neumann's inequality for d-tuples of commutative and row contractive matrices, as proved by Hartz, Richter, and Shalit in…