Role of collective neutrino flavor oscillations in core-collapse supernova shock revival

Abstract

We explore the effects of collective neutrino flavor oscillations due to neutrino-neutrino interactions on the neutrino heating behind a stalled core-collapse supernova shock. We carry out axisymmetric (two-dimensional) radiation-hydrodynamic core-collapse supernova simulations, tracking the first 400 ms of the post-core-bounce evolution in $11.2\mathrm{\text{\ensuremath{-}}}{M}_{\ensuremath{\bigodot}}$ and $15\mathrm{\text{\ensuremath{-}}}{M}_{\ensuremath{\bigodot}}$ progenitor stars. Using inputs from these two-dimensional simulations, we perform neutrino flavor oscillation calculations in multienergy single-angle and multiangle single-energy approximations. Our results show that flavor conversions do not set in until close to or outside the stalled shock, enhancing heating by not more than a few percent in the most optimistic case. Consequently, we conclude that the postbounce preexplosion dynamics of standard core-collapse supernovae remains unaffected by neutrino oscillations. Multiangle effects in regions of high electron density can further inhibit collective oscillations, strengthening our conclusion.