Michał Wojciechowski

collaborators

4 papers

math.FA2026

Nonexistence of Henkin type projections via a Wiener theorem for multipliers

Eduard Curcă, Michał Wojciechowski

Let $d \geq 2$ , $l \geq 0$ and suppose $X$ is one of the function spaces $W^{l, 1} (T^{d})$ , $W^{l, \infty} (T^{d})$ or $C^{l} (T^{d})$ . We extend a result of…

math.OA2026

Finite Riesz products and Ornstein non-inequalities on quantum tori

Christos P. Tantalakis, Michał Wojciechowski

We demonstrate a construction of products on the quantum torus $T_{θ}^{2}$ that generalises the usual construction of finite Riesz products on the commutative torus $\mathbb{T…

math.FA2025

Nevanlinna--Pick norms on scattered and Cantor spectra

Przemysław Ohrysko, Michał Wojciechowski

We introduce Nevanlinna--Pick norms associated with finite families of characters on a commutative semisimple Banach algebra $A$ and study the class $N P_{\infty}$ of algebras for whi…

math.FA2025

Factoring the Sobolev embedding operator

Krystian Kazaniecki, Aleksander Pawlewicz, Michał Wojciechowski

The paper studies the factorization and summing properties of the Sobolev embedding operator. We propose two different approaches. One shows that the Sobolev embedding operator $S:…