Université de GenèveDépartement de Physique ThéoriqueCAP Genève

Cosmology beyond the average with one-point statistics

Date: 
16. December 2022 - 11:45
Speaker: 
Cora Uhlemann (University of Newcastle)
Abstract: Nonlinear gravitational collapse shaped the cosmic web of galaxies and created a plethora of different density environments - from voids through filaments to galaxy groups. To realise the full potential of upcoming galaxy surveys like Euclid and Rubin LSST, we need to dissect different density environments that are lumped together in traditional two-point statistics. This is particularly important for detecting extensions of LCDM including massive neutrinos, dynamical dark energy and modified gravity. I will show that one-point statistics not only provide information complementary to common two-point statistics, but also allow for accurate theoretical predictions of the late-time non-Gaussianity. I will explain how the cosmology dependence of one-point statistics of dark matter can be predicted from first principles and translated to weak lensing and galaxy clustering observables. As an example, we showed that using the lensing one-point PDF jointly with the two-point correlation could improve parameter constraints on nuLCDM/wCDM models by 40% when combined with Planck. We also developed a bias model for the galaxy PDF that is compatible with 2pt correlations and can extract density-split statistics from galaxy surveys.

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Département de Physique Théorique
Université de Genève
24, quai Ernest Ansermet
1211 Genève 4
Switzerland
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