Work

Meromorphic functions whose action on their Julia sets is non-ergodic

Year: 2026

Type: article

Abstract: Nevanlinna functions are meromorphic functions with a finite number of asymptotic values and no critical values. Keen and Kotus (1995) proved that if the orbits of all the asymptotic values accumulate on a compact set on which the function acts as a repeller, then the function acts ergodically on its Julia set. Chen et al. (2024) proved the action of the function on its Julia set is still ergodic if some, but not all of the asymptotic values land on infinity, and the remaining ones land on a compact repeller. In this paper, we complete the characterization of ergodicity for Nevanlinna functions by proving that if all the asymptotic values land on infinity, then the Julia set is the whole sphere and the action of the map there is non-ergodic.

Source: Fundamenta Mathematicae

DOI: 10.4064/fm241227-7-5

Authors: Tao Chen, Yunping Jiang, Linda Keen

Institutions: LaGuardia Community College, The Graduate Center, CUNY, Queens College, CUNY, City University of New York

Language: English

Topic: Mathematical Dynamics and Fractals

Subfield: Mathematical Physics

Field: Mathematics

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Science Foundation, City University of New York, National Natural Science Foundation of China, Division of Mathematical Sciences

Awards: G1193761837, G202495085, G5996657695, Mathematical Sciences Research Institute (MSRI)