Speaker
Description
In this talk, I will discuss the impact of lepton flavour asymmetries on BBN and the CMB. I will show that solving the momentum averaged quantum kinetic equations describing neutrino oscillations and interactions is an accurate approximation to the full momentum-dependent system. Our formalism allow us to study the scenario of total vanishing lepton number, revealing a rich flavour structure in stark contradiction to the assumption of simple flavour equilibration. We then achieve a limit on the maximal primordial total lepton number L, while specific flavour directions can be even more constrained. I will also present the publicly available COFLASY code based on our momentum-averaged formalism, which is orders of magnitude faster than similar codes which solve the full-momentum dependent system.