Subgrid modeling of neutrino oscillations in astrophysics

Approximating neutrino oscillations as subgrid physics is an appealing prospect for simulators of core-collapse supernovae and neutron-star mergers. Because flavor instabilities quickly lead to quasisteady states in oscillation calculations, it is widely believed that flavor mixing can be approximated in astrophysical simulations by mapping unstable states onto the appropriate asymptotic ones. Subgrid models of this kind, however, are not self-consistent. The miscidynamic theory of quantum-coherent gases furnishes a subgrid model that is.Comment: 11 page

Thermodynamics of oscillating neutrinos

The title theory is formulated. It entails a quantum-coherent variant of the Fermi-Dirac distribution and casts new light on neutrino oscillations. It might enable the incorporation of neutrino mixing into the modeling of core-collapse supernovae and neutron-star mergers.Comment: 7+2 pages, 1 figur

Collisional flavor swap with neutrino self-interactions

Neutrinos play pivotal roles in determining fluid dynamics, nucleosynthesis, and their observables in core-collapse supernova (CCSN) and binary neutron star merger (BNSM). In this Letter, we present a novel phenomenon, collisional flavor swap, in which neutrino-matter interactions trigger the complete interchange of neutrino spectra between two different flavors, aided by neutrino self-interactions. We find a necessary condition to trigger the collisional swap is occurrences of resonance-like collisional flavor instability. After the collisional swap, spectral-swap like features emerge in neutrino spectra. Since flavor swaps correspond to the most extreme case in flavor conversions, they have a great potential to affect CCSN and BNSM phenomena.Comment: 6 pages, 3 figures, submitted to PR