Speaker: Pierre Fleury

Abstract:

In the standard cosmological framework, observations are interpreted as if light propagated through a smooth, fluid-filled universe. However, the typical light beams involved in astronomical observations—such as supernovae—are extremely narrow, and thus probe the Universe at scales where the fluid description should no longer be valid. In this talk, I will explain how the clumpiness of the distribution of matter can affect light propagation  through the cosmos, and thus the interpretation of our observations.