On the quantized dynamics of factorial languages

TL;DR

This paper investigates the properties of quantized dynamics in factorial languages, showing how local piecewise conjugacy affects entropy, graph isomorphisms, and language classifications, with implications for sofic and irreducible subshifts.

Contribution

It establishes the relationship between local piecewise conjugacy and graph isomorphisms in factorial languages, revealing preservation of soficity and entropy, and characterizing factorial languages of type 1.

Findings

Local piecewise conjugacy induces a bijection between allowable words of same length.

It preserves entropy in factorial languages.

For sofic factorial languages, it translates to unlabeled graph isomorphism of follower set graphs.

Abstract

We study local piecewise conjugacy of the quantized dynamics arising from factorial languages. We show that it induces a bijection between allowable words of same length and thus it preserves entropy. In the case of sofic factorial languages we prove that local piecewise conjugacy translates to unlabeled graph isomorphism of the follower set graphs. Moreover it induces an unlabeled graph isomorphism between the Fischer covers of irreducible subshifts. We verify that local piecewise conjugacy does not preserve finite type nor irreducibility; but it preserves soficity. Moreover it implies identification (up to a permutation) for factorial languages of type $1$ if, and only if, the follower set function is one-to-one on the symbol set.