I will describe some recently proposed theoretical mechanisms which dramatically extend the viable parameter space for QCD axion dark matter. One of these mechanisms can be used to populate ultralight dark photons as dark matter. These explorations provide an extended target-space for experiments to hunt for axions and dark photons.
A number of interesting models of new physics, including composite Higgs and composite dark matter scenarios, imagine new strongly-coupled gauge interactions that give rise to compositeness. The phenomenology of these models is typically studied using low-energy effective theories, but calculations in the underlying strongly-coupled theory can predict low-energy constants from a handful of fundamental parameters, as well as giving new insights beyond the effective description. I will review recent efforts using lattice gauge theory to study theories beyond QCD, with an eye towards BSM physics.