The size and topology of quasi-Fatou components of quasiregular maps

TL;DR

This paper investigates the structure and size of quasi-Fatou components in the iteration of transcendental quasiregular maps, extending classical results from complex dynamics to higher dimensions.

Contribution

It generalizes known results about Fatou components to quasi-Fatou components in quasiregular maps, introducing novel techniques applicable even to entire functions.

Findings

Number of complementary components of quasi-Fatou components is bounded.

Bounded quasi-Fatou components with bounded complements have specific size properties.

Results extend classical complex dynamics to higher-dimensional quasiregular maps.

Abstract

We consider the iteration of quasiregular maps of transcendental type from $\mathbb{R}^d$ to $\mathbb{R}^d$. In particular we study quasi-Fatou components, which are defined as the connected components of the complement of the Julia set. Many authors have studied the components of the Fatou set of a transcendental entire function, and our goal in this paper is to generalise some of these results to quasi-Fatou components. First, we study the number of complementary components of quasi-Fatou components, generalising, and slightly strengthening, a result of Kisaka and Shishikura. Second, we study the size of quasi-Fatou components that are bounded and have a bounded complementary component. We obtain results analogous to those of Zheng, and of Bergweiler, Rippon and Stallard. These are obtained using novel techniques, and may be of interest even in the case of transcendental entire functions.