Examag: Towards exascale simulations of the magnetic universe

Abstract

Simulations of cosmic structure formation address multi-scale, multi-physics problems of vast proportions. These calculations are presently at the forefront of today’s use of supercomputers, and are important scientific drivers for the future use of exaflop computing platforms. However, continued success in this field requires the development of new numerical methods that excel in accuracy, robustness, parallel scalability, and physical fidelity to the processes relevant in galaxy and star formation. In the EXAMAG project, we have worked on improving and applying the astrophysical moving-mesh code AREPO with the goal to extend its range of applicability. We have also worked on developing new, powerful high-order discontinuous Galerkin schemes for astrophysics, on more efficient solvers for gravity, and on improvements of the accuracy of the treatment of ideal magnetohydrodynamics. In this context, we have also studied the applied mathematics required for higher-order discretization on dynamically moving meshes, thereby providing the foundations for much more efficient and accurate methods than are presently in use. Finally, we have worked towards publicly releasing two major community codes, AREPO and GADGET-4, which represent the state-of-the-art in the field.