Transversal family of non-autonomous conformal iterated function systems

TL;DR

This paper investigates the Hausdorff dimension of limit sets in parameterized non-autonomous conformal iterated function systems with overlaps, establishing dimension results under transversality conditions without requiring the open set condition.

Contribution

It introduces a transversality condition framework for non-autonomous IFSs on $\

Findings

Hausdorff dimension equals the minimum of $m$ and Bowen dimension for almost every parameter.

Provides examples where transversality holds but open set condition fails.

Extends dimension theory to non-autonomous systems with overlaps.

Abstract

We study Non-autonomous Iterated Function Systems (NIFSs) with overlaps. A NIFS on a compact subset $X\subset\mathbb{R}^m$ is a sequence $\Phi=(\{\phi^{(j)}_{i}\}_{i\in I^{(j)}})_{j=1}^{\infty}$ of collections of uniformly contracting maps $\phi^{(j)}_{i}: X\rightarrow X$, where $I^{(j)}$ is a finite set. In comparison to usual iterated function systems, we allow the contractions $\phi^{(j)}_{i}$ applied at each step $j$ to depend on $j$. In this paper, we focus on a family of parameterized NIFSs on $\mathbb{R}^m$. Here, we do not assume the open set condition. We show that if a $d-$parameter family of such systems satisfies the transversality condition, then for almost every parameter value the Hausdorff dimension of the limit set is the minimum of $m$ and the Bowen dimension. Moreover, we give an example of a family $\{\Phi_t\}_{t\in U}$ of parameterized NIFSs such that $\{\Phi_t\}_{t\in U}$ satisfies the transversality condition but $\Phi_t$ does not satisfy the open set condition for any $t\in U$.