Qualitative properties of scalar-tensor theories of gravity

The qualitative properties of spatially homogeneous stiff perfect fluid and minimally coupled massless scalar field models within general relativity a re discussed. Consequently, by exploiting the formal equivalence under conf ormal transformations and field redefinitions of certain classes of theorie s of gravity, the asymptotic properties of spatially homogeneous models in a class of scalar-tensor theories of gravity that includes the Brans-Dicke theory can be determined. For example, exact solutions are presented, which are analogues of the general relativistic Jacobs stiff perfect fluid solut ions and vacuum plane wave solutions, which act as past and future attracto rs in the class of spatially homogeneous models in Brans-Dicke theory.