Title: Flows For The Masses: The First non-Linear Perturbative Power Spectrum for Massive Neutrinos in Cosmology

Speaker: Professor Amol Upadhye (South-Western Institute For Astronomy Research, YNU)

Time: 14:00pm, April 23, 2024

Location: 5-516, PMO Xianlin Campus

Abstract: The neutrino mass sum is a fundamental particle physics parameter that will be measured cosmologically over the next several years, though a robust determination will require a precise understanding of neutrino clustering. Recently I developed a non-linear cosmological perturbation theory for massive neutrinos. It combines three ingredients: multi-fluid perturbation theories discretizing neutrinos' Fermi-Dirac distribution, Time-RG non-linear mode couplings, and Fast Fourier Transform acceleration. I will describe the resulting neutrino power spectrum, including its dependence upon time and neutrino momentum, and test it against N-body simulations. Finally, I will discuss ongoing and planned work on observable weak lensing predictions and improvements to N-body neutrino simulations.