Tuomas Oikari

activity

20242026

collaborators

Showing math.CAShow all

6 papers · 1 filter

math.CA2026

Bounds for the maximal and Riesz potential operators with variable fractionality

Francisco Gonçalves, Tuomas Oikari

We prove $L^{p (\cdot)}$ -to- $L^{q (\cdot)}$ bounds for variable versions of the fractional maximal $M^{α (\cdot)}$ and Riesz potential $I^{α (\cdot)}$ operators. The changing fractiona…

math.CA2025

Domains with globally exponentially integrable parabolic forward-in-time BMO

Kim Myyryläinen, Tuomas Oikari, Olli Saari

We characterize those open sets of the space time in which parabolic forward-in-time BMO functions are in a certain forward-in-time exponential integrability class. The characteriz…

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…