论文标题
可逆的时间阶段适应几个体系的集成
Reversible time-step adaptation for the integration of few-body systems
论文作者
论文摘要
时间步骤标准在直接N体代码中起着至关重要的作用。如果不仔细选择，它将导致能量误差的世俗漂移。共享的自适应时间步骤标准通常采用最小成对时间步，这在时间步骤的时间演变中遭受了不连续性的影响。这对时间步长对称算法的功能具有很大的影响。我们提供了先前发现的新演示，即N体系统中所有成对时间步的平均平均值，可以提高能源节约水平。此外，我们通过考虑加权时间步骤和9种对称方法的3种方法来比较27个不同时间步长标准的性能。我们提出了强烈混乱的几体系统的性能测试，包括不稳定的三元组，谐振链中的巨型行星和当前的太阳系。我们发现，谐波对称方法（我们的符号中的方法A3和B3）是最坚固的，从某种意义上说，对称时间步长保持接近时间步长函数。此外，基于我们的太阳系实验，我们发现我们基于直接成对平均的新加权方法（我们的符号中的方法W2）比其他方法略首选。
The time step criterion plays a crucial role in direct N-body codes. If not chosen carefully, it will cause a secular drift in the energy error. Shared, adaptive time step criteria commonly adopt the minimum pairwise time step, which suffers from discontinuities in the time evolution of the time step. This has a large impact on the functioning of time step symmetrisation algorithms. We provide new demonstrations of previous findings that a smooth and weighted average over all pairwise time steps in the N-body system, improves the level of energy conservation. Furthermore, we compare the performance of 27 different time step criteria, by considering 3 methods for weighting time steps and 9 symmetrisation methods. We present performance tests for strongly chaotic few-body systems, including unstable triples, giant planets in a resonant chain, and the current Solar System. We find that the harmonic symmetrisation methods (methods A3 and B3 in our notation) are the most robust, in the sense that the symmetrised time step remains close to the time step function. Furthermore, based on our Solar System experiment, we find that our new weighting method based on direct pairwise averaging (method W2 in our notation), is slightly preferred over the other methods.
