Neutrino fast flavor oscillations with moments: linear stability analysis and application to neutron star mergers

Understand

Providing an accurate modeling of neutrino physics in dense astrophysical environments such as binary neutron star mergers presents a challenge for hydrodynamic simulations.

• Nevertheless, understanding how flavor transformation can occur and affect the dynamics, the mass ejection, and the nucleosynthesis will need to be achieved in the future.
• Computationally expensive, large-scale simulations frequently evolve the first classical angular moments of the neutrino distributions.
• By promoting these quantities to matrices in flavor space, we develop a linear stability analysis of fast flavor oscillations using only the first two "quantum" moments, which notably requires generalizing the classical closure relations that appropriately truncate the hierarchy of moment equations in order to treat quantum flavor coherence.