Carlsbergfondet - Astrophysical observations in relativistic inhomogeneous cosmological models

Astrophysical observational data is hinting at a breakdown of the standard model of cosmology and upcoming data will within the next decade put the model to the test with significant probability that fundamental aspects of the model will be falsified. However, the outcome of such a test is only really useful if we know how also alternatives to the standard model behave in relation to it. The aim of the project is therefore to construct exact solutions to the Einstein equation which exhibit specific features that make the models useful as virtual laboratories for studying observations in models of the Universe that are not based on the same assumptions as the current standard model of cosmology. Observations in the models will be computed by propagating thousands of light rays through the models and computing observational relations along these. The obtained relations will be compared to standard model predictions as well as predictions based on non-standard model schemes and with real observations. The comparisons will make it possible to identify relations between observables and specific model features, and by comparing with real observations these features can be constrained. It is expected that the project will lead to a significantly better understanding of non-standard cosmology and give cosmologists a more solid theoretical framework for interpreting astrophysical data from upcoming surveys, the results of which will determine the future direction of cosmological research.