Wednesday, 12 March, 2014
Speaker: Eirik Endeve , CSM, ORNL
Title: Discontinuous Galerkin Methods for Simulation of Supernova Neutrino Transport
Abstract: Explosions of massive stars (i.e., core-collapse supernovae) are the dominant source of heavy elements in the Universe. As multi-messenger events, they are targeted by instruments covering most of the electromagnetic spectrum, as well as by gravitational wave and neutrino detectors. Multi-scale simulations are necessary to understand details of the explosion mechanism, and their connection to the observed signals. To this end, we are developing numerical methods for simulation of supernova neutrino transport. In this work, we aim to develop robust, high-order methods for phase space advection that preserve a maximum principle for the distribution function f (0 ≤ f ≤ 1 for neutrinos), and that are applicable to curvilinear phase space coordinates. Our numerical methods are based on the Runge-Kutta discontinuous Galerkin method. We discuss the physical model, the construction of maximum-principle-satisfying methods for phase space advection, and present numerical results from implementations in spherical and axial symmetry. Our results demonstrate that the method is high-order accurate and that the distribution function preserves the maximum principle. We also discuss challenges of simulating radiation propagating in a strong gravitational field.