Triangular Gatzouras-Lalley-type planar carpets with overlaps

TL;DR

This paper extends the theory of Gatzouras-Lalley-type planar carpets by constructing overlapping self-affine carpets with lower triangular matrices, analyzing how overlaps affect the Hausdorff and box dimensions.

Contribution

It generalizes previous non-overlapping results to overlapping constructions, providing conditions under which overlaps do not reduce the attractor's dimension.

Findings

Overlaps can be controlled to preserve dimension under certain conditions.

Explicit examples demonstrate the applicability of the theoretical results.

The work includes extensions to three-dimensional systems.

Abstract

We construct a family of planar self-affine carpets with overlaps using lower triangular matrices in a way that generalizes the original Gatzouras--Lalley carpets defined by diagonal matrices. Assuming the rectangular open set condition, Bara\'nski proved for this construction that for typical parameters, which can be explicitly checked, the inequalities between the Hausdorff, box and affinity dimension of the attractor are strict. We generalize this result to overlapping constructions, where we allow complete columns to be shifted along the horizontal axis or allow parallelograms to overlap within a column in a transversal way. Our main result is to show sufficient conditions under which these overlaps do not cause the drop of the dimension of the attractor. Several examples are provided to illustrate the results, including a self-affine smiley, a family of self-affine continuous curves, examples with overlaps and an application of our results to some three-dimensional systems.