How to model light propagation in a clumpy universe?

Thu, 12/11/2015 - 12:00 - 13:00
Dr. Pierre Fleury, (IAP, UCT/UCW)

In standard cosmology, all the observations are interpreted as if light propagated through a perfectly homogeneous and isotropic universe. The great success of this hypothesis is actually very surprising, given the variety of scales which are probed by such observations, in particular when very narrow light beams are involved (e.g. in supernova observations). In this talk, I will first provide a partial explanation for the success of the standard model, and evaluate its domain of validity. I will then propose a new framework, called stochastic cosmological lensing, for going beyond, i.e. determining the corrections to observational data caused by the small-scale inhomogeneity of the Universe.