Parry measure

Summary

The Parry measure is a special shift-invariant measure on an irreducible subshift of finite type. It is the unique invariant probability measure of maximal entropy. So its Kolmogorov–Sinai entropy equals the topological entropy $\log \lambda$, where $\lambda$ is the Perron eigenvalue of the transition matrix. It is a Markov measure built from the left and right Perron eigenvectors. It shows the variational principle for entropy at work in the simplest case.