Topological conjugacy of topological Markov shifts and Ruelle algebras

Abstract

We will characterize topologically conjugate two-sided topological Markov shifts $(\bar{X}_A,\bar{\sigma}_A)$ in terms of the associated asymptotic Ruelle $C^*$-algebras ${\mathcal{R}}_A$ with its commutative $C^*$-subalgebras $C(\bar{X}_A)$ and the canonical circle actions. We will also show that extended Ruelle algebras ${\widetilde{\mathcal{R}}}_A$, which are purely infinite version of the asymptotic Ruelle algebras, with its commutative $C^*$-subalgebras $C(\bar{X}_A)$ and the canonical torus actions $\gamma^A$ are complete invariants for topological conjugacy of two-sided topological Markov shifts. We then have a computable topological conjugacy invariant, written in terms of the underlying matrix, of a two-sided topological Markov shift by using K-theory of the extended Ruelle algebra. The diagonal action of $\gamma^A$ has a unique KMS-state on ${\widetilde{\mathcal{R}}}_A$, which is an extension of the Parry measure on $\bar{X}_A$.