Speaker: Nikolai Meures
Location: African Instiute of Mathematical Sciences, Muizenberg, Cape Town, South Africa
At a time when galaxy surveys and other observations are reaching unprecedented sky coverage and precision, it is becoming crucial to investigate the non-linear effects of General Relativity on the growth of structures and on observations. Analytic inhomogeneous cosmological models are indispensable to investigate and understand these effects in a simplified context.

In this talk, I will present an exact inhomogeneous solution to Einstein’s equations (including dust and a cosmological constant), which can be used to model an arbitrary matter distribution along one line of sight. In particular, I will demonstrate how to split the dynamics of this model into background and deviations. In the limit of small deviations, the equations governing the growth of structure link up exactly with standard perturbation theory. I shall discuss several analytical tools which we have used to interpret this space-time, i.e. predict its early time and late time behaviour, the formation of singularities and its FLRW limit. I will conclude by showing some preliminary work on numerical light tracing within this framework and hence what effects we expect non-linear structure to have on observations.