Rigorous Hausdorff dimension estimates for conformal fractals

Vasileios Chousionis, Dmitriy Leykekhman, Mariusz Urbański, Erik Wendt

Published 2024-08-12Version 1

We develop a versatile framework which allows us to rigorously estimate the Hausdorff dimension of maximal conformal graph directed Markov systems in $\mathbb{R}^n$ for $n \geq 2$. Our method is based on piecewise linear approximations of the eigenfunctions of the Perron-Frobenius operator via a finite element framework for discretization and iterative mesh schemes. One key element in our approach is obtaining bounds for the derivatives of these eigenfunctions, which, besides being essential for the implementation of our method, are of independent interest.