English

Rotation numbers and rotation classes on one-dimensional tiling spaces

Dynamical Systems 2021-08-04 v1

Abstract

We extend rotation theory of circle maps to tiling spaces. Specifically, we consider a 1-dimensional tiling space Ω\Omega with finite local complexity and study self-maps FF that are homotopic to the identity and whose displacements are strongly pattern equivariant (sPE). In place of the familiar rotation number we define a cohomology class [μ][\mu]. We prove existence and uniqueness results for this class, develop a notion of irrationality, and prove an analogue of Poncar\'{e}'s Theorem: If [μ][\mu] is irrational, then FF is semi-conjugate to uniform translation on a space Ωμ\Omega_\mu of tilings that is homeomorphic to Ω\Omega. In such cases, FF is semi-conjugate to uniform translation on Ω\Omega itself if and only if [μ][\mu] lies in a certain subspace of the first cohomology group of Ω\Omega.

Keywords

Cite

@article{arxiv.2009.03111,
  title  = {Rotation numbers and rotation classes on one-dimensional tiling spaces},
  author = {José Aliste-Prieto and Betseygail Rand and Lorenzo Sadun},
  journal= {arXiv preprint arXiv:2009.03111},
  year   = {2021}
}
R2 v1 2026-06-23T18:21:43.065Z