English

Fractional type operators on Hardy spaces associated with ball quasi-Banach function spaces

Functional Analysis 2026-05-05 v1

Abstract

For 0α<n0 \leq \alpha < n and mN(1αn,+)m \in \mathbb{N} \cap \left(1 - \frac{\alpha}{n}, +\infty \right), we consider certain fractional type operators Tα,mT_{\alpha, m} generated by mm-orthogonal matrices and prove that, for 0<α<n0 < \alpha < n, Tα,mT_{\alpha, m} can be extended to a bounded operator HXYH_X \to Y and, for α=0\alpha = 0, T0,mT_{0, m} can be extended to a bounded operator HXXH_X \to X, where XX and YY are certain ball quasi-Banach spaces related to each other and HXH_X is the Hardy space associated with XX. In particular, our results apply to weighted Lebesgue spaces, variable Lebesgue spaces, Lorentz spaces and Orlicz spaces, the last two are new. Our proofs rely on the ssumption that XX is O(n)\mathcal{O}(n)-invariant, the theory of weighted Hardy spaces, the Rubio de Francia iteration algorithm and the finite atomic decomposition of HXH_X.

Keywords

Cite

@article{arxiv.2605.01092,
  title  = {Fractional type operators on Hardy spaces associated with ball quasi-Banach function spaces},
  author = {Pablo Rocha},
  journal= {arXiv preprint arXiv:2605.01092},
  year   = {2026}
}

Comments

25 pages

R2 v1 2026-07-01T12:45:58.565Z