“…For the case of (X, T ) a countable alphabet subshift of finite type, where X is non-compact and the entropy map µ → h(µ) is not upper semi-continuous, additional summability and boundedness hypotheses on the locally Hölder function f : X → R, together with primitivity assumptions on X, ensure existence and uniqueness of the equilibrium measures m tf , that the family (m tf ) does in fact have an accumulation point m, and that h(m) = lim t→∞ h(m tf ) = max{h(µ) : µ ∈ M max (f )} (see [62,92,123]), representing an analogue of Theorem 4.1. If in addition f is locally constant, Kempton [101] (see also [62]) has established the analogue of Theorem 4.2, guaranteeing the weak * convergence of (m tf ) as t → ∞. Iommi & Yayama [79] consider almost additive sequences F of continuous functions defined on appropriate countable alphabet subshifts of finite type, proving that the family of equilibrium measures (m tF ) is tight (based on [92]), hence has a weak * accumulation point, and that any such accumulation point is a maximizing measure for F (see also [47,63,150,161] for general ergodic optimization in the context of sequences of functions F).…”