Equilateral Triangulations and The Postcritical Dynamics of Meromorphic Functions

Abstract

We show that any dynamics on any planar set $S$ discrete in some domain $D$ can be realized by the postcritical dynamics of a function holomorphic in $D$, up to a small perturbation. A key step in the proof, and a result of independent interest, is that any planar domain $D$ can be equilaterally triangulated with triangles whose diameters $\to 0$ (at any prescribed rate) near $\partial D$.