English

Pointwise normality and Fourier decay for self-conformal measures

Dynamical Systems 2021-10-14 v3 Classical Analysis and ODEs

Abstract

Let Φ\Phi be a C1+γC^{1+\gamma} smooth IFS on R\mathbb{R}, where γ>0\gamma>0. We provide mild conditions on the derivative cocycle that ensure that every self conformal measure is supported on points xx that are absolutely normal. That is, for integer p2p\geq 2 the sequence {pkx}kN\lbrace p^k x \rbrace_{k\in \mathbb{N}} equidistributes modulo 11. We thus extend several state of the art results of Hochman and Shmerkin about the prevalence of normal numbers in fractals. When Φ\Phi is self-similar we show that the set of absolutely normal numbers has full Hausdorff dimension in its attractor, unless Φ\Phi has an explicit structure that is associated with some integer n2n\geq 2. These conditions on the derivative cocycle are also shown to imply that every self conformal measure is a Rajchman measure, that is, its Fourier transform decays to 00 at infinity. When Φ\Phi is self similar and satisfies a certain Diophantine condition, we establish a logarithmic rate of decay.

Keywords

Cite

@article{arxiv.2012.06529,
  title  = {Pointwise normality and Fourier decay for self-conformal measures},
  author = {Amir Algom and Federico Rodriguez Hertz and Zhiren Wang},
  journal= {arXiv preprint arXiv:2012.06529},
  year   = {2021}
}

Comments

V3: Revised according to comments made by the referee and P\'{e}ter Varj\'{u}. To appear in Adv. Math

R2 v1 2026-06-23T20:54:34.444Z