Poseidon: A Relativistic Gravity Solver for Core Collapse Supernova Simulations*

The Poseidon code is being developed to solve the system of non-linear elliptic equations that define the general relativistic metric terms given by the Conformally Flat Approximation (CFA) to the Einstein equations. The code discretizes the CFA system of equations on a spherical polar grid using a mixed method consisting of an angular decomposition using spherical harmonic functions and a radial finite element expansion using Lagrange polynomials. The resulting system is then solved using a Newton-Raphson scheme

Poseidon is being developed to run within the CHIMERA core collapse supernova simulation code.  Therefore, it has been designed to run on shared and distributed memory systems.  This parallelization is achieved using MPI and OpenMP directives, and a distributed linear solve from the PETSc library.

Results will be presented showing comparisons between Poseidon’s CFA treatment and the so called “effective” potential currently used in CHIMERA, which is a modified Newtonian potential whose monopole moment is corrected using the Tolman-Oppenheimer-Volkoff (TOV) potential.