论文标题
一个缓慢的时间转换的符号整合器，用于解决几个身体问题
A slow-down time-transformed symplectic integrator for solving the few-body problem
论文作者
论文摘要
处理几个体型动力学的准确有效方法对于模拟碰撞N体系统（如星形簇）和遵循紧凑型二进制的形成和演变很重要。我们描述了一种结合了时间转换的显式符号积分器（Preto＆Tremaine 1999; Mikkola＆Tanikawa 1999）和慢速下降方法（Mikkola＆Aarseth 1996）。前者可以节省哈密顿量和角度的长期进化，而后者则显着降低了弱扰动二元的计算成本。在这项工作中，详细分析了该算法的汉密尔顿方程。我们从数学上和数字上表明它可以像轨道平均方法一样正确地重现世俗进化，并且可以很好地保存角动量。对于弱扰动的二进制文件，该方法可以提供比经典算法更快的数量级性能。使用C ++语言编写的公开代码SDAR可在GitHub（https://github.com/lwang-astro/sdar）上获得。它可以用作单独的工具，也可以用作库插入其他$ n $ body代码的库。还支持浮动点的高精度至62位数字。
An accurate and efficient method dealing with the few-body dynamics is important for simulating collisional N-body systems like star clusters and to follow the formation and evolution of compact binaries. We describe such a method which combines the time-transformed explicit symplectic integrator (Preto & Tremaine 1999; Mikkola & Tanikawa 1999) and the slow-down method (Mikkola & Aarseth 1996). The former conserves the Hamiltonian and the angular momentum for a long-term evolution, while the latter significantly reduces the computational cost for a weakly perturbed binary. In this work, the Hamilton equations of this algorithm are analyzed in detail. We mathematically and numerically show that it can correctly reproduce the secular evolution like the orbit averaged method and also well conserve the angular momentum. For a weakly perturbed binary, the method is possible to provide a few order of magnitude faster performance than the classical algorithm. A publicly available code written in the c++ language, SDAR, is available on GitHub (https://github.com/lwang-astro/SDAR). It can be used either as a stand alone tool or a library to be plugged in other $N$-body codes. The high precision of the floating point to 62 digits is also supported.
