Three-flavor neutrino Boltzmann transport and flavor instabilities in long-lived neutron-star merger remnants
Binary neutron-star (BNS) mergers are multimessenger sources whose kilonova emission and nucleosynthesis depend sensitively on neutrino microphysics and flavor conversion. Most BNS merger simulations assume $\mu$-$\tau$ neutrino degeneracy in a two-flavor treatment. We investigate the fast flavor instability (FFI) and...