English

Large normalizers of ${\mathbb Z}^{d}$-odometers systems and realization on substitutive subshifts

Dynamical Systems 2024-11-11 v2

Abstract

For a Zd{\mathbb Z}^{d}-topological dynamical system (X,T,Zd)(X, T, {\mathbb Z}^{d}), an isomomorphism is a self-homeomorphism ϕ:XX\phi : X\to X such that for some matrix MGL(d,Z)M\in {\rm GL}(d,{\mathbb Z}) and any nZd{n}\in {\mathbb Z}^{d}, ϕTn=TMnϕ\phi\circ T^{{n}}=T^{M{n}}\circ \phi, where TnT^{n} denote the self-homeomorphism of XX given by the action of nZd{n}\in {\mathbb Z}^d. The collection of all the isomorphisms forms a group that is the normalizer of the set of transformations TnT^{n}. In the one-dimensional case, isomorphisms correspond to the notion of flip conjugacy of dynamical systems and by this fact are also called reversing symmetries. These isomorphisms are not well understood even for classical systems. We present a description of them for odometers and more precisely for constant-base Z2{\mathbb Z}^{2}-odometers, which is surprisingly not simple. We deduce a complete description of the isomorphisms of some minimal Zd{\mathbb Z}^{d}-substitutive subshifts. This enables us to provide the first example known of a minimal zero-entropy subshift with the largest possible normalizer group.

Keywords

Cite

@article{arxiv.2309.10156,
  title  = {Large normalizers of ${\mathbb Z}^{d}$-odometers systems and realization on substitutive subshifts},
  author = {Christopher Cabezas and Samuel Petite},
  journal= {arXiv preprint arXiv:2309.10156},
  year   = {2024}
}

Comments

30 pages, 4 figures