Asian Journal of Mathematics

Volume 23 (2019)

Number 1

Local dimensions of measures of finite type on the torus

Pages: 127 – 156

DOI: https://dx.doi.org/10.4310/AJM.2019.v23.n1.a7

Authors

Kathryn E. Hare (Department of Pure Mathematics, University of Waterloo, Ontario, Canada)

Kevin G. Hare (Department of Pure Mathematics, University of Waterloo, Ontario, Canada)

Kevin R. Matthews (Department of Pure Mathematics, University of Waterloo, Ontario, Canada)

Abstract

The structure of the set of local dimensions of a self-similar measure has been studied by numerous mathematicians, initially for measures that satisfy the open set condition and, more recently, for measures on $\mathbb{R}$ that are of finite type.

In this paper, our focus is on finite type measures defined on the torus, the quotient space $\mathbb{R/Z}$. We give criteria which ensures that the set of local dimensions of the measure taken over points in special classes generates an interval. We construct a non-trivial example of a measure on the torus that admits an isolated point in its set of local dimensions. We prove that the set of local dimensions for a finite type measure that is the quotient of a self-similar measure satisfying the strict separation condition is an interval. We show that sufficiently many convolutions of Cantor-like measures on the torus never admit an isolated point in their set of local dimensions, in stark contrast to such measures on $\mathbb{R}$. Further, we give a family of Cantor-like measures on the torus where the set of local dimensions is a strict subset of the set of local dimensions, excluding the isolated point, of the corresponding measures on $\mathbb{R}$.

Keywords

multi-fractal analysis, local dimension, IFS, finite type, quotient space

2010 Mathematics Subject Classification

11R06, 28A78, 28A80

The research of K. E. Hare and K. R. Matthews was supported by NSERC Grant 44597-2011. The research of K. G. Hare was supported by NSERC Grant RGPIN-2014-03154.

Received 18 July 2016

Accepted 27 July 2017

Published 3 May 2019