Glider automata on all transitive sofic shifts
: Kopra Johan
Publisher: Cambridge University Press
: 2022
Ergodic Theory and Dynamical Systems
: Ergodic Theory and Dynamical Systems
: 42
: 12
: 3716
: 3744
: 1469-4417
DOI: https://doi.org/10.1017/etds.2021.107
: https://doi.org/10.1017/etds.2021.107
: https://research.utu.fi/converis/portal/detail/Publication/67745009
For any infinite transitive sofic shift X we construct a reversible cellular automaton (that is, an automorphism of the shift X) which breaks any given finite point of the subshift into a finite collection of gliders traveling into opposing directions. This shows in addition that every infinite transitive sofic shift has a reversible cellular automaton which is sensitive with respect to all directions. As another application we prove a finitary version of Ryan’s theorem: the automorphism group Aut(X) contains a two-element subset whose centralizer consists only of shift maps. We also show that in the class of S-gap shifts these results do not extend beyond the sofic case.