SÉMINAIRE DU GRECO
"Relativistic cosmological large scale structures at oneloop" 

Clément Stahl 

In this talk, I will discuss some aspects of nonlinear structure formation. The calculation of the bispectrum usually involves linear physics on large scales and nonlinear (but Newtonian) physics on small scales. However, in the squeezed limit, the bispectrum (unlike the power spectrum) couples large scales with small scales. I will present the calculation of the nonlinear relativistic corrections to the dynamics of dark matter perturbations. They are of the same order of magnitude, in the squeezed limit, than a primordial local nonGaussianity signal. Such signal is expected to be within the accuracy of the next generation of LSS surveys.


lundi 25 novembre 2019  11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris 
