Light Particles and Heavy Integrals: Neutrino Effects on the Late-Time Power Spectrum and Bispectrum, and Parity-Violating Trispectrum from Axions during Inflation

by Zachary Slepian (UFL)

Thursday Jun 15, 2023, 2:00 PM → 3:00 PM Europe/Berlin

HS2 (Physikdepartment)

First, I will present a recent 2-fluid approach from my group enabling us to obtain a fairly simple, analytic treatment of the effect of massive neutrinos on the late-time matter power spectrum. This is the first fully analytic calculation of this effect going beyond the usual 1 - 8 fnu suppression, wherein we recursively solve the coupled equations using a Green's function approach. We recover the true power spectrum with remarkable fidelity given the simplicity of the approach. Second, I will discuss neutrino signatures in the bispectrum that are non-degenerate with galaxy biasing and can tighten neutrino mass constraints significantly with redshift surveys. Third, I will present recent progress in my group in computing the parity-violating trispectrum from axions during inflation. We have developed a method to reduce the high-dimensional (12D) loop integrals to 1 and 2D radial integrals, enabling fast and full exploration of the full shape of the parity-violating trispectrum, following up our recent apparent detection of parity-violation in the galaxy 4-point correlation function of SDSS BOSS.