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Sophie M
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Factor map between subshifts preserving topological pressure (or measure-theoretic entropy)

Let $G$ be a countable amenable group and let $X,Y$ be subshifts with finite alphabet over $G$. Suppose that $h(X) = h(Y)$ (equal topological entropy). I am interested in continuous factor maps $\pi: X \to Y$ that preserve topological pressure under pullback, in the sense that for a reasonably regular continuous potential $f: Y \to \mathbb{R}$, $P_X(f \circ \pi) = P_Y(f)$. Are there sufficient conditions known that imply this?

One sufficient condition would be for the pushforward by $\pi$ to preserve the entropy of every invariant measure on $X$. This would happen if $\pi$ were finite-to-one, or if either $X$ or $Y$ were uniquely ergodic, but less restrictive hypotheses would be nice.

Sophie M
  • 695
  • 4
  • 13