Shifts of Finite Type on Locally Finite Groups

In this work, we prove that every SFT, sofic shift, and strongly irreducible shift on locally finite groups has strong dynamical properties. These properties include that every sofic shift is an SFT, every SFT is strongly irreducible, every strongly irreducible shift is an SFT, every SFT is entropy minimal, and every SFT has a unique measure of maximal entropy, among others. In addition, we show that if every SFT on a group is strongly irreducible, or if every sofic shift is an SFT, then the group must be locally finite, and this extends to all of the properties we explore. These results are collected in two main theorems which characterizes the local finiteness of groups by purely dynamical properties. In pursuit of these results, we present a formal construction of $\mathit{\text{free}}\mathit{\text{extension}}$ shifts on a group $G$, which takes a shift on a subgroup $H$ of $G$, and naturally extends it to a shift on all of $G$.