Neutrino decoupling and the transition to cold dark matter

Abstract

About 40 years ago, the neutrino was ruled out as the dark matter particle based on several arguments. Here I use the well-established concept of quantum uncertainties of position and momentum to describe the decoupling of neutrinos from the primordial plasma, which took place about half a second after the Big Bang. In this way I show that the main arguments against the neutrino are either wrong or have loopholes, and conclude that the neutrino urgently needs to be reconsidered, not as a 'hot', but as the 'cold' dark matter particle.

Comments: Proceedings paper of the invited talk at the 56th Rencontres de Moriond La Thuile, Aosta Valley, Italy, January 30 - February 6, 2022. Full proceedings available at: https://doi.org/10.58027/1e1n-7973