On C*-algebras from homoclinic equivalences on subshifts of finite type

Abstract

Let G be an infinite countable group and A be a finite set. If ∑ ⊆ AG is a strongly irreducible subshift of finite type, we endow a locally compact and Hausdorff topology on the homoclinic equivalence relation ${\cal G}$ on ∑ and show that the reduced C*-algebra $C_r^*\left({\cal G} \right)$ of ${\cal G}$ is a unital simple approximately finite (AF)-dimensional C*-algebra. The shift action of G on ∑ induces a canonical automorphism action of G on the C*-algebra $C_r^*\left({\cal G} \right)$ . We give the notion of noncommutative dynamical entropy invariants for amenable group actions on C*-algebras, and show that, if G is an amenable group, then the noncommutative topological entropy of the canonical automorphism action of G on $C_r^*\left({\cal G} \right)$ is equal to the topology entropy of the shift action of G on ∑. We also establish the variational principle with respect to the noncommutative measure entropy and the topological entropy for the C*-dynamical system ( $C_r^*\left({\cal G} \right)$ , G).