The Athena++ Adaptive Mesh Refinement Framework: Multigrid Solvers for Self-gravity

Abstract We describe the implementation of multigrid solvers in Athena++ adaptive mesh refinement (AMR) framework and their application to solution Poisson equation for self-gravity. The new are built on top AMR hierarchy TaskList efficient parallelization. adopt a conservative formulation Laplacian operator that avoids artificial accelerations at level boundaries. Periodic, fixed, zero-gradient boundary conditions implemented, as well open based multipole expansion. Hybrid parallelization using both Message Passing Interface OpenMP is adopted, we present results tests demonstrating accuracy scaling methods. On uniform grid, show significantly outperforms methods fast Fourier transforms, requires only small fraction computing time required by (highly optimized) magnetohydrodynamic solver Athena++. As demonstration capabilities methods, test calculation magnetized protostellar collapse an mesh.