We investigate the use of spinors to describe the secular evolution of quasi-Keplerian systems. Evaluating their Poisson brackets, we show that the components of a properly chosen spinor are canonical variables. We illustrate this formalism using the classical problems of the orbital motion about an oblate planet and the Kozai–Lidov mechanism. Although the present formalism breaks down for circular or radial orbits, it may be of some practical utility in numerical recipes.

中文翻译：

---

带旋量的米兰科维奇方程

我们研究使用旋量来描述准开普勒系统的长期演化。评估它们的泊松括号，我们表明正确选择的旋量的分量是规范变量。我们使用扁球行星轨道运动的经典问题和科扎伊-利多夫机制来说明这种形式主义。尽管目前的形式主义对于圆形或径向轨道来说是不成立的，但它在数值方法中可能具有一些实际用途。