EXAMAG - Exascale simulations of the magnetic universe

对宇宙结构形成的模拟解决了多尺度、多物理学的巨大问题。这些计算目前处于当今超级计算机使用的最前沿，并且是未来使用exaflop计算平台的重要科学驱动力。然而，在这一领域的持续未来的成功需要新的数值方法，擅长在准确性，鲁棒性，并行可扩展性和物理保真度的星系和星星形成的相关过程的发展。在天体物理学家和应用数学家的跨学科和国际努力中，我们将在该项目中大幅改进天体物理移动网格代码AREPO并扩展其适用范围，目标是为即将到来的大型计算平台提供国际领先的应用代码。我们的工作新的，强大的高阶不连续Galerkin计划，更有效的解决方案的重力和各向异性运输的热量和相对论粒子，并提高理想磁流体力学的治疗精度。我们的目标是通过采用先进的混合并行化技术，结合充分利用向量指令和设备加速器的低级优化，大大提高原始性能和可扩展性的代码。我们将在当前最先进的超级计算机上应用我们的代码，对星系和原始星星的形成进行变革性的磁流体动力学模拟，扩展今天和未来几年可能的范围。我们还将努力公开发布AREPO和GADGET-4代码。

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 future 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 an interdisciplinary and international effort of astrophysicists and applied mathematicians we will in this project substantially improve the astrophysical moving-mesh code AREPO and extend its range of applicability, with the goal of producing an internationally leading application code for the upcoming large computing platforms. We work on new, powerful high-order discontinuous Galerkin schemes, on more efficient solvers for gravity and for anisotropic transport of heat and relativistic particles, and on an improvement of the accuracy of the treatment of ideal magnetohydrodynamics. We aim to drastically enhance the raw performance and scalability of the code by employing sophisticated hybrid parallelisation techniques combined with low-level optimizations that make full use of vector instructions and device accelerators. We will apply our code on current state-of-the art supercomputers to carry out transformative magnetohydrodynamic simulations of galaxy and primordial star formation, stretching the envelope of what is possible today and in the years to come. We will also work towards publicly releasing the AREPO and GADGET-4 codes.