Direct prime subshifts and canonical covers
: Kopra Johan
Publisher: CAMBRIDGE UNIV PRESS
: 2023
Ergodic Theory and Dynamical Systems
: ERGODIC THEORY AND DYNAMICAL SYSTEMS
: ERGOD THEOR DYN SYST
: PII S0143385722000335
: 20
: 0143-3857
: 1469-4417
DOI: https://doi.org/10.1017/etds.2022.33
: https://research.utu.fi/converis/portal/detail/Publication/175399025
We present a new sufficient criterion to prove that a non-sofic half-synchronized subshift is direct prime. The criterion is based on conjugacy invariant properties of Fischer graphs of half-synchronized shifts. We use this criterion to show as a new result that all n-Dyck shifts are direct prime, and we also give new proofs of direct primeness of non-sofic beta-shifts and non-sofic S-gap shifts. We also construct a class of non-sofic synchronized direct prime subshifts which additionally admit reversible cellular automata with all directions sensitive.