Talk Title and Abstract:
Exploring Fundamental Physics with Friends and Neighbors
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. The first and second parts of my talk will focus on novel standard rulers to make this measurement. I will begin with DESI's precursor, BOSS, and show how the first full measurement of correlations between triples of galaxies (the 3-point function) enabled detection of sound waves from the early Universe and their use to improve cosmic distance constraints. This is by way of motivation, to show what at minimum we can do with DESI, which is 30X as big as BOSS. I will then move to a more 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 present preliminary measurements of these functions based on 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 present 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 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.
Would you like to join this Zoom seminar? Please email Donna Hayes.