Evolution of collisional neutrino flavor instabilities in spherically symmetric supernova models

Understand

We implement a multi-group and discrete-ordinate neutrino transport model in spherical symmetry which allows to simulate collective neutrino oscillations by including realistic collisional rates in a self-consistent way.

• We utilize this innovative model, based on strategic parameter rescaling, to study a recently proposed collisional flavor instability caused by the asymmetry of emission and absorption rates between $\nu_e$ and $\bar\nu_e$ for four different static backgrounds taken from different stages in a core-collapse supernova simulation.
• Our results confirm that collisional instabilities generally exist around the neutrinosphere during the SN accretion and post-accretion phase, as suggested by [arXiv:2104.11369].
• However, the growth and transport of flavor instabilities can only be fully captured by models with global simulations as done in this work.