Abstract
The exact quantum kinetic equations for a two-flavor active-sterile neutrino system are used to provide a systematic derivation of approximate evolution equations for the relic neutrino asymmetry. An extension of the adiabatic approximation for matter-affected neutrino oscillations is developed which incorporates decoherence due to collisions. Exact and approximate expressions for the decoherence and repopulation functions are discussed. A first pass is made at an exact treatment of multi-flavor partially incoherent oscillations.
- Received 14 September 1998
DOI:https://doi.org/10.1103/PhysRevD.59.113001
©1999 American Physical Society