School of Physics and Astronomy

Cosmology seminar: Cora Uhlemann (Cambridge)

23 January 2019

Time: 3:30 - 4:30pm
Speaker: Cora Uhlemann
Venue: GO Jones 5th floor

Title: Large-scale clustering with counts-in-cells statistics

Abstract: Cosmic structure formation describes how the initially almost uniform matter distribution observed in the cosmic microwave background (CMB) gave rise to the late-time cosmic web – an intricate pattern of galaxies on the sky. To connect the almost perfectly Gaussian statistics of the CMB to the highly non-Gaussian statistics of the cosmic web, we need to understand the gravitational clustering of matter. I will explain how spherical collapse, a nonlinear solution of gravitational collapse in spherical symmetry, can be used to accurately predict the statistics of densities in spheres. I will show that those counts-in-cells statistics capture essential non-Gaussian properties of the cosmic web, including peculiar regions of very high and low density. Finally, I will give an outlook how this can be applied to galaxy surveys and potentially intensity mapping to probe key properties of our Universe, from the origin of structure to the late-time expansion.