Institute for Advanced Study/Princeton University Early Universe/Cosmology Lunch Discussion

Abstract: In this talk I will outline both the underlying theory and novel methods being developed by my group to enable Dark Energy Spectroscopic Instrument (DESI; 30 M galaxy spectra, 2020-2025) to reveal the dark (energy) and the invisible (neutrino mass). Dark energy drives cosmic expansion, so measuring the Universe's expansion history constrains dark energy.  I will present an ambitious agenda being undertaken by my group: how can we use 3, 4, 5, and 6-point functions to maximize the leverage of DESI on dark energy? I will show some preliminary measurements of these functions using a transformative algorithm my group has developed, based on angular momentum decomposition tools drawn from particle physics. In the last part of my talk, I will move to neutrinos, whose mass can be measured from their imprint on galaxy clustering. I will show a simple, analytic picture of both the development of neutrinos' spatial distribution in the early Universe, and of their late-time effects on the matter. I will close with mentioning a novel neutrino signature in the galaxy 3-point function identified by my group which will increase DESI's likelihood of making the first actual measurement of the neutrino mass.