English

The Denjoy-Wolff Theorem in simply connected domains

Complex Variables 2024-09-19 v1

Abstract

We characterize the simply connected domains ΩC\Omega\subsetneq\mathbb{C} that exhibit the Denjoy-Wolff Property, meaning that every holomorphic self-map of Ω\Omega without fixed points has a Denjoy-Wolff point. We demonstrate that this property holds if and only if every automorphism of Ω\Omega without fixed points in Ω\Omega has a Denjoy-Wolff point. Furthermore, we establish that the Denjoy-Wolff Property is equivalent to the existence of what we term an ``HH-limit'' at each boundary point for a Riemann map associated with the domain. The HH-limit condition is stronger than the existence of non-tangential limits but weaker than unrestricted limits. As an additional result of our work, we prove that there exist bounded simply connected domains where the Denjoy-Wolff Property holds but which are not visible in the sense of Bharali and Zimmer. Since visibility is a sufficient condition for the Denjoy-Wolff Property, this proves that in general it is not necessary.

Keywords

Cite

@article{arxiv.2409.11722,
  title  = {The Denjoy-Wolff Theorem in simply connected domains},
  author = {Anna Miriam Benini and Filippo Bracci},
  journal= {arXiv preprint arXiv:2409.11722},
  year   = {2024}
}

Comments

23 pages, 2 figures