Discrete Cosmological Models in the Brans-Dicke Theory of Gravity
  We consider the problem of building inhomogeneous cosmological models in
scalar-tensor theories of gravity. This starts by splitting the field equations
of these theories into constraint and evolution equations, and then proceeds by
identifying exact solutions to the constraints. We find exact, closed form
expressions for geometries that correspond to the initial data for cosmological
models containing regular arrays of point-like masses. These solutions extend
similar methods that have recently been applied to Einstein's equations, and
provides sufficient initial conditions to perform numerical integration of the
evolution equations. We use our new solutions to study the effects of
inhomogeneity in cosmologies governed by scalar-tensor theories of gravity,
including the spatial inhomogeneity allowed in Newton's constant. Finally, we
compare our solutions to their general relativistic counterparts, and
investigate the effect of changing the coupling constant between the scalar and
tensor degrees of freedom.
