Tuomas Oikari

activity

20192026

most citedFractional Bloom boundedness and compactness of commutators

8 citations · 20 across the 15 of their papers we have counts for

collaborators

Showing 2024Show all

6 papers · 1 filter

math.FA2024

Testing compactness of linear operators

Timo S. Hänninen, Tuomas Oikari, Tuomas V. Oikari

Let $(F_{i})$ be a sequence of sets in a Banach space $X$ . For what sequences does the condition $i \to \infty lim f_{i} \in F_{i} sup ∥ T f_{i} ∥_{Y} = 0$ hold for every Banach space $…

math.CA2024

On the compactness of the bi-commutator

Henri Martikainen, Tuomas Oikari

We prove compactness results and characterizations for the bi-commutator $[T_{1}, [b, T_{2}]]$ of a symbol $b$ and two non-degenerate Calderón-Zygmund singular integral operators $T_1,…

math.CA2024

Curved commutators in the plane

Kangwei Li, Henri Martikainen, Tuomas Oikari

We complete the $L^{p}$ boundedness theory of commutators of Hilbert transforms along monomial curves by providing the previously missing lower bounds. This optimal result now covers…

math.CA2024

Note on the compactness of commutators

Tuomas Oikari

The optimal sufficient conditions for the $L^{p}$ -to- $L^{q}$ compactness of commutators of singular integral operators of both Calderón-Zygmund and of rough type are shown in the diffe…

math.CA2024

Traces of vanishing Hölder spaces

Kaushik Mohanta, Carlos Mudarra, Tuomas Oikari

For an arbitrary subset $E \subset R^{n},$ we introduce and study the three vanishing subspaces of the Hölder space $C ˙^{0, ω} (E)$ consisting of those functions for which…

math.FA2024

Approximation in Hölder Spaces

Carlos Mudarra, Tuomas Oikari

We introduce new vanishing subspaces of the homogeneous Hölder space $C ˙^{0, ω} (X, Y)$ in the generality of a doubling modulus $ω$ and normed spaces $X$ and $Y .$ For many couple…