Venue: Maths 103
The precise effect of inhomogeneity on the large-scale expansion of the Universe is an open question. In this talk I will outline how one can investigate such a problem by considering cosmological models in which the matter content is taken to be confined to regularly distributed discrete sources, rather than a perfect fluid. Using exact, fully relativistic, non-perturbative methods we determine a number of properties of such models, and can follow them throughout their entire evolution. We find that not all behaviour approaches that of the Friedmann solutions, and in particular that accelerating expansion is possible without any exotic matter content.