Simplicial minisuperspace models in the presence of a scalar field

We generalize simplicial minisuperspace models associated with restricting the topology of the universe to be that of a cone over a closed connected c ombinatorial 3-manifold by considering the presence of a massive scalar fie ld. By restricting all the interior edge lengths and all the boundary edge lengths to be equivalent and the scalar field to be homogeneous on the 3-sp ace, we obtain a family of two-dimensional models that includes some of the most relevant triangulations of the spatial universe. After studying the a nalytic properties of the action in the space of complex edge lengths we de termine its classical extrema. We then obtain steepest-descent contours of constant imaginary action passing through Lorentzian classical geometries y ielding a convergent wavefunction of the universe, dominated by the contrib utions coming from these extrema. By considering these contours we justify semiclassical approximations based on those classical solutions, clearly pr edicting classical spacetime in the late universe. These wavefunctions are then evaluated numerically. For all of the models examined we find wavefunc tions predicting Lorentzian oscillatory behaviour in the late universe.