English

On the membership of two-variable Rational Inner Functions in spaces of Dirichlet-type

Complex Variables 2026-04-17 v2

Abstract

We study membership of rational inner functions on the bidisk D2\mathbb{D}^2 in a scale of Dirichlet spaces considered by Bera, Chavan, and Ghara, and in higher-order variants of these spaces. We give a characterization for membership in terms of the geometric concept of contact order of a rational inner function at its singular points, and we further record some consequences and variants of our main result.

Keywords

Cite

@article{arxiv.2512.17388,
  title  = {On the membership of two-variable Rational Inner Functions in spaces of Dirichlet-type},
  author = {Athanasios Beslikas and Alan Sola},
  journal= {arXiv preprint arXiv:2512.17388},
  year   = {2026}
}

Comments

Accepted for publication in Studia Mathematica. In the published version of the article, we provided a more brief proof by using only one Blaschke factor per referee's request. In this version we still apply Referee's lemma and we keep the original proof, in order to showcase the usefullness of local factorizations in the RIF theory. Our main result now is a full characterization