APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Ming-Chung Chu (Chinese University of Hong Kong)
Title: The Degeneracy of Cosmic Neutrinos
Date (JST): Thu, Feb 23, 2017, 13:30 - 14:30
Place: Seminar Room A
Abstract: Neutrinos are produced abundantly in the Big Bang and account for a significant share of the energy density of matter in the universe. Yet, very little is known about cosmological neutrinos. We know that they have finite rest mass, but there are large uncertainties on the chemical potentials of the three flavors of neutrinos, which would contribute to the neutrino energy density and have significant impacts on major cosmological observables such as Big Bang Nucleosynthesis (BBN) yields, Cosmic Microwave Background Anisotropies (CMBA), Baryon Acoustic Oscillation (BAO) and large-scale structure distribution.
I will present some preliminary results of constraining neutrino chemical potentials using the PLANCK CMBA data, and comparing them to BBN constraints. I will discuss implications of finite cosmological neutrino chemical potentials.