论文标题
评估用于无碰撞N体型模拟的分层哈密顿分裂积分器
Assessing the Hierarchical Hamiltonian Splitting Integrator for Collisionless N-body Simulations
论文作者
论文摘要
在某些天体物理N体问题中，大型动态范围导致使用自适应多时间步骤。但是，寻找最佳策略仍然具有挑战性。我们使用直接求和代码来量化分层哈密顿分裂（HHS）集成器的性能。我们将HHS与恒定的全局时间阶段Leakfrog Integrator和自适应One（AKDK）进行了比较。我们发现HHS大约是可逆的，而AKDK却没有。因此，可以找到参数的组合，其中能量漂移对HHS的较小程度相当较小，从而产生更好的性能。我们得出的结论是，HHS是AKDK的有吸引力的替代品，这对于直接总和和P3M代码肯定是有利的。另外，我们发现Gadget4（Tree/FMM）HHS实现的优势值得进一步探索。
The large dynamic range in some astrophysical N-body problems led to the use of adaptive multi-time-steps; however, the search for optimal strategies is still challenging. We numerically quantify the performance of the hierarchical Hamiltonian Splitting (HHS) integrator for collisionless simulations using a direct summation code. We compare HHS with the constant global time-step leapfrog integrator, and with the adaptive one (AKDK). We find that HHS is approximately reversible, whereas AKDK not. Therefore, it is possible to find a combination of parameters where the energy drift is considerably milder for HHS, resulting in a better performance. We conclude that HHS is an attractive alternative to AKDK, and it is certainly advantageous for direct summation and P3M codes. Also, we find advantages with GADGET4 (Tree/FMM) HHS implementation that are worth exploring further.
