Let be a continuous map on a compact metrizable space, let be continuous, and let be a closed subspace of continuous functions from to . We consider the set of all -invariant Borel probability measures such that for all in . Then we consider optimization problems of the form
where ranges over , denotes the entropy of with respect to , and is either or . Our main results concern the basic properties of such optimization problems, including feasibility, geometry of the solution set, uniqueness of solutions, and realizability. This talk is based on ongoing joint work with Shengwen Guo (UNC Charlotte).