Regularity, Linear Response Formula and Differentiability of the Free Energy for Non-uniformly Expanding Local Homeomorphisms

Abstract We study equilibrium states for an open class of non-uniformly expanding local homeomorphisms defined by a mild condition requiring that for some iterate each point admits at least one contracting inverse branch. We prove the existence and uniqueness of equilibrium states and the differentiability of statistical quantities (such as the equilibrium states and the free energy function) with respect to the dynamical system.