  This dissertation investigates three main topics, all of which dealing with
alternative, higher-order gravity theories in four dimensions. Firstly, we
study the variational and conformal structure of those theories. Next, we
analyse their Hamiltonian formulation and in particular its relationship with
the famous ADM canonical version of general relativity. Finally, we study
higher-order spatially homogeneous cosmologies and exemplify how Hamiltonian
methods can be utilised to simplify the analysis of the associated field
equations.
