On structure of topological entropy for tree-shifts of finite type

Abstract

This paper deals with the topological entropy for hom Markov shifts TM on d-tree. If M is a reducible adjacency matrix with q irreducible components M1,⋯,Mq, we show that h(TM)=max1≤i≤q⁡h(TMi) fails generally, and present a case study with full characterization in terms of the equality. Though that it is likely the sets {h(TM):M is binary and irreducible} and {h(TX):X is a one-sided shift} are not coincident, we show the two sets share the common closure. Despite the fact that such closure is proved to contain the interval [dlog⁡2,∞), numerical experiments suggest its complement contain open intervals.