Quantum Kinetics in the Early Universe

In the early universe, the evolution of neutrino states are complicated by both their coherent quantum evolution and their de-coherent kinetic evolution. The results of this quantum kinetic evolution are manifest in precision cosmological measurements, and may be important in the production of dark matter or other beyond standard model processes. This talk will focus on the quantum kinetic evolution of neutrino states in the early universe, where the quantum mechanical oscillation rate and scattering rate are both fast compared to the dynamical expansion rate. In this regime, we notice that the states quickly evolve to a point where the coherent and de-coherent effects balance, attaining a local quantum kinetic equilibrium that slowly evolves with the expanding universe.