Michał Wojciechowski

collaborators

4 papers

math.OA2026

Finite Riesz products and Ornstein non-inequalities on quantum tori

Christos P. Tantalakis, MichaÅ Wojciechowski

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

math.FA2026

Nevanlinna--Pick norms on scattered and Cantor spectra

PrzemysÅaw Ohrysko, Przemysław Ohrysko, MichaÅ Wojciechowski +1

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.FA2026

Nonexistence of Henkin type projections via a Wiener theorem for multipliers

Eduard CurcÄ, MichaÅ 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.FA2025

Factoring the Sobolev embedding operator

Krystian Kazaniecki, Aleksander Pawlewicz, MichaÅ 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:…