The Cosmological Energy Density of Neutrinos from Oscillation Measurements

Abstract

The emerging structure of the neutrino mass matrix, when combined with the primordial element abundances, places the most stringent constraint on the flavor asymmetries in the cosmological neutrino background and therefore its energy density. I review the mechanism of synchronized neutrino oscillations in the an early universe with degenerate (asymmetric) neutrino and antineutrino densities and the implications of refined measurements of neutrino parameters.

Comments: 4 pages, Proceedings of NuFact 03, 5th International Workshop on Neutrino Factories & Superbeams, 5-11 June 2003, Columbia University, New York