Tuomas Oikari

activity

20242026

collaborators

3 papers

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.FA2024

Testing compactness of linear operators

Timo S. Hänninen, Tuomas V. Oikari

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