English

Rigidity in dynamics and M\"obius disjointness

Dynamical Systems 2024-03-19 v3

Abstract

Let (X,T)(X, T) be a topological dynamical system. We show that if each invariant measure of (X,T)(X, T) gives rise to a measure-theoretic dynamical system that is either: a. rigid along a sequence of "bounded prime volume" or b. admits a polynomial rate of rigidity on a linearly dense subset in C(X)C(X), then (X,T)(X, T) satisfies Sarnak's conjecture on M\"obius disjointness. We show that the same conclusion also holds if there are countably many invariant ergodic measures, and each of them satisfies a. or b. This recovers some earlier results and implies Sarnak's conjecture in the following new cases: for almost every interval exchange map of dd intervals with d2d \geq 2, for C2+ϵC^{2+\epsilon}-smooth skew products over rotations and C2+ϵC^{2+\epsilon}-smooth flows (without fixed points) on the torus. In particular, these are improvements of earlier results of respectively Chaika-Eskin, Wang and Huang-Wang-Ye. We also discuss some purely arithmetic consequences for the Liouville function.

Keywords

Cite

@article{arxiv.1905.13256,
  title  = {Rigidity in dynamics and M\"obius disjointness},
  author = {Adam Kanigowski and Mariusz Lemańczyk and Maksym Radziwiłł},
  journal= {arXiv preprint arXiv:1905.13256},
  year   = {2024}
}

Comments

First version had a gap in the proof of Theorem 3.1. The gap is fixed in the current version (at a cost of a slightly weaker statement)

R2 v1 2026-06-23T09:33:54.460Z