CCA Short Talk: Hiroki Nagakura

Supernova simulations with full Boltzmann neutrino transport

We developed a multi-dimensional neutrino-radiation-hydrodynamic code which solves first-principles Boltzmann equation for neutrino transport. In this seminar, I will present two recent results of our project: (1) axisymmetric core-collapse supernova (CCSN) simulations and (2) detailed comparisons with a Monte-Carlo neutrino transport. For the project (1), it is practically 6-dimensional (1 in time, 2 in spatial and 3 in momentum) problem even in axisymmetry. Those simulations have been carried out with a huge amount of computational resources in super computers such as “K” in Japan. One of our models shows a sign of successful CCSN explosion for the progenitor of 11.2 solar masses, meanwhile we also find some qualitative differences in terms of neutrino-radiation-field from other approximate methods. Our results give a significant caution to other CCSNe simulations. For the project (2), we carried out “apple-to-apple” comparisons with a different method in order to enhance the reliability of each method. Our code builds up with “Sn” method meanwhile the other code uses Monte-Carlo technique for neutrino transport. Despite of the fact that two codes use completely different numerical algorithms, we found remarkably good agreement in all spectral, angular and fluid quantities. After summarizing above results, I will also discuss a future perspective of our project.