Effective Projections on Group Shifts to Decide Properties of Group Cellular Automata

التفاصيل البيبلوغرافية
العنوان: Effective Projections on Group Shifts to Decide Properties of Group Cellular Automata
المؤلفون: Béaur, Pierre, Kari, Jarkko
سنة النشر: 2023
المجموعة: Computer Science
مصطلحات موضوعية: Computer Science - Formal Languages and Automata Theory, Computer Science - Discrete Mathematics, 37B50, F.4.3, G.2.1
الوصف: Many decision problems concerning cellular automata are known to be decidable in the case of algebraic cellular automata, that is, when the state set has an algebraic structure and the automaton acts as a morphism. The most studied cases include finite fields, finite commutative rings and finite commutative groups. In this paper, we provide methods to generalize these results to the broader case of group cellular automata, that is, the case where the state set is a finite (possibly non-commutative) finite group. The configuration space is not even necessarily the full shift but a subshift -- called a group shift -- that is a subgroup of the full shift on Z^d, for any number d of dimensions. We show, in particular, that injectivity, surjectivity, equicontinuity, sensitivity and nilpotency are decidable for group cellular automata, and non-transitivity is semi-decidable. Injectivity always implies surjectivity, and jointly periodic points are dense in the limit set. The Moore direction of the Garden-of-Eden theorem holds for all group cellular automata, while the Myhill direction fails in some cases. The proofs are based on effective projection operations on group shifts that are, in particular, applied on the set of valid space-time diagrams of group cellular automata. This allows one to effectively construct the traces and the limit sets of group cellular automata. A preliminary version of this work was presented at the conference Mathematical Foundations of Computer Science 2020.
Comment: Extended version of the MFCS 2020 paper titled "Decidability in group shifts and group cellular automata"
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2301.11133
رقم الأكسشن: edsarx.2301.11133
قاعدة البيانات: arXiv