On the expressive power of quasiperiodic SFT
Abstract
In this paper we study the shifts, which are the shift-invariant and topologically closed sets of configurations over a finite alphabet in . The minimal shifts are those shifts in which all configurations contain exactly the same patterns. Two classes of shifts play a prominent role in symbolic dynamics, in language theory and in the theory of computability: the shifts of finite type (obtained by forbidding a finite number of finite patterns) and the effective shifts (obtained by forbidding a computably enumerable set of finite patterns). We prove that every effective minimal shift can be represented as a factor of a projective subdynamics on a minimal shift of finite type in a bigger (by ) dimension. This result transfers to the class of minimal shifts a theorem by M.Hochman known for the class of all effective shifts and thus answers an open question by E.Jeandel. We prove a similar result for quasiperiodic shifts and also show that there exists a quasiperiodic shift of finite type for which Kolmogorov complexity of all patterns of size is .
Keywords
Cite
@article{arxiv.1705.01876,
title = {On the expressive power of quasiperiodic SFT},
author = {Bruno Durand and Andrei Romashchenko},
journal= {arXiv preprint arXiv:1705.01876},
year = {2017}
}
Comments
22 pages, 8 figures. An extended version of a paper accepted for publication in the proceedings of MFCS 2017