English

Schauder Basis with Finite Blaschke Products

Complex Variables 2026-02-03 v2 Functional Analysis

Abstract

We construct a Schauder basis for the space Hol(D)Hol(\mathbb D), the space of holomorphic functions on the closed unit disk, consisting entirely of finite Blaschke products. The expansion coefficients are given explicitly. Our result remains valid when Hol(D)Hol(\mathbb D) is equipped with a broader class of norms satisfying natural structural conditions. These conditions are satisfied by norms of classical function spaces such as the Hardy spaces HpH^p (1p1\leq p\leq \infty), the weighted Bergman spaces AαpA_\alpha^p (1p1\leq p\leq \infty, α>1\alpha>-1), and BMOA. We also establish the optimality of this framework by proving that such a basis cannot exist in larger spaces, such as the Hardy space HpH^p and the disc algebra A(D)A(\mathbb D).

Keywords

Cite

@article{arxiv.2507.13121,
  title  = {Schauder Basis with Finite Blaschke Products},
  author = {Emmanuel Fricain and Javad Mashreghi and Mostafa Nasri and Maëva Ostermann},
  journal= {arXiv preprint arXiv:2507.13121},
  year   = {2026}
}