Finite entropy for multidimensional cellular automata
Abstract
Let where is a countable group and is a finite set. A cellular automaton (CA) is an endomorphism (continuous, commuting with the action of ). Shereshevsky (1993) proved that for with no CA can be forward expansive, raising the following conjecture: For , the topological entropy of any CA is either zero or infinite. Morris and Ward (1998), proved this for linear CA's, leaving the original conjecture open. We show that this conjecture is false, proving that for any there exist a -dimensional CA with finite, nonzero topological entropy. We also discuss a measure-theoretic counterpart of this question for measure-preserving CA's. Our main tool is a construction of a CA by Kari (1994).
Keywords
Cite
@article{arxiv.math/0703167,
title = {Finite entropy for multidimensional cellular automata},
author = {Tom Meyerovitch},
journal= {arXiv preprint arXiv:math/0703167},
year = {2007}
}
Comments
17 pages, 11 figures; Added references, proposition 3.5 and correction of minor mistake in section 2