Almost Regular Closedness of the Connectedness Locus for Pairs of Affine Maps on $\mathbb{R}^2$

Abstract

We study the connectedness locus $\mathcal{N}$ for the family of iterated function systems of pairs of homogeneous affine-linear maps in the plane. We prove this set is regular closed (i.e., it is the closure of its interior) away from the diagonal, except possibly for isolated points, which we conjecture do not exist. We provide an overview of the "method of traps", introduced by Calegari et al. (2017), which lies at the heart of our proof.