This paper investigates subcycling of particle orbits in variational, geometric particle-in-cell methods addressing the Vlasov--Maxwell system in magnetized plasmas. The purpose of subcycling is to allow different time steps for different particle species and, ideally, time steps longer than the electron gyroperiod for the global field solves while sampling the local cyclotron orbits accurately. The considered algorithms retain the electromagnetic gauge invariance of the discrete action, guaranteeing a local charge conservation law, while the variational approach provides a bounded long-time energy behavior.

中文翻译：

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变分几何电磁粒子单元方法中粒子轨道的亚循环

本文研究了在磁化等离子体中解决 Vlasov--Maxwell 系统的变分几何粒子单元方法中粒子轨道的亚循环。子循环的目的是允许不同粒子种类有不同的时间步长，理想情况下，时间步长比全局场求解的电子陀螺周期长，同时准确地采样局部回旋加速器轨道。所考虑的算法保留了离散动作的电磁规范不变性，保证了局部电荷守恒定律，而变分方法提供了有界的长期能量行为。