Self-similar measures with unusual local dimension properties

TL;DR

This paper constructs self-similar measures with complex local dimension sets, demonstrating the full range of possible configurations and analyzing their multifractal spectra and $L^q$-spectra.

Contribution

It provides explicit constructions of self-similar measures with diverse local dimension structures, including non-concave multifractal spectra and non-differentiable $L^q$-spectra.

Findings

Set of attainable local dimensions can be a union of intervals and points.

Constructed measures with non-concave multifractal spectrum.

Examples of measures with non-differentiable $L^q$-spectra.

Abstract

Let $\mu$ be a self-similar measure satisfying the finite type condition. It is known that the set of attainable local dimensions for such a measure is a union of disjoint intervals, where some intervals may be degenerate points. Despite this, it has not been shown if this full complexity of attainable local dimensions is achievable. In this paper we give two different constructions. The first is a measure $\mu$ where the set of all attainable local dimensions is the union of an interval union and an arbitrary number of disjoint points. The second is a measure $\mu$ where the set of all attainable local dimensions is the union of an arbitrary number of disjoint intervals. As an application to these construction, we study the multi-fractal spectrum $f_\mu(\alpha)$ and the $L^q$-spectrum $\tau_\mu(q)$ of these measures. We given an example of a $\mu$ where $f_\mu(\alpha)$ is not concave, and where $\tau_\mu(q)$ has two points of non-differentiability.