English

Borel subsystems and ergodic universality for compact $\mathbb Z^d$-systems via specification and beyond

Dynamical Systems 2021-02-17 v2

Abstract

A Borel system (X,S)(X,S) is `almost Borel universal' if any free Borel dynamical system (Y,T)(Y,T) of strictly lower entropy is isomorphic to a Borel subsystem of (X,S)(X,S), after removing a null set. We obtain and exploit a new sufficient condition for a topological dynamical system to be almost Borel universal. We use our main result to deduce various conclusions and answer a number of questions. Along with additional results, we prove that a `generic' homeomorphism of a compact manifold of topological dimension at least two can model any ergodic transformation, that non-uniform specification implies almost Borel universality, and that 33-colorings in Zd\mathbb Z^d and dimers in Z2\mathbb Z^2 are almost Borel universal

Keywords

Cite

@article{arxiv.1903.05716,
  title  = {Borel subsystems and ergodic universality for compact $\mathbb Z^d$-systems via specification and beyond},
  author = {Nishant Chandgotia and Tom Meyerovitch},
  journal= {arXiv preprint arXiv:1903.05716},
  year   = {2021}
}

Comments

Revised after Referee's comments; 70 pages

R2 v1 2026-06-23T08:07:29.124Z