标题： 一种用于相对论磁流体力学的算子分裂数值格式 显示英文标题

标题： An operator-splitting numerical scheme for relativistic magnetohydrodynamics

摘要： 我们描述了一种新颖的算子分裂方法，用于数值相对论磁流体力学，旨在将其适用范围扩展到超高磁化率领域。 在此方法中，电磁场被分解为受力自由成分（由力自由退化电动力学FFDE方程控制）和扰动成分（由从完整相对论磁流体力学系统导出的扰动方程控制）。 FFDE和扰动方程的组合系统同时进行积分，可以使用为双曲守恒律开发的各种数值技术。 在每次数值积分的时间步结束时，重新组合电磁场的力自由和扰动成分，并将结果视为下一时间步力自由成分的初始值，而扰动成分的初始值设置为零。 为了探索这种方法的潜力，我们构建了一个三阶WENO代码，用于进行一维和二维测试模拟。 它们的结果表明，这种算子分裂方法使我们能够绕过超高磁化情况下RMHD的刚性问题，在该情况下扰动成分变得非常小。 同时，代码 显示英文摘要

摘要： We describe a novel operator-splitting approach to numerical relativistic magnetohydrodynamics designed to expand its applicability to the domain of ultra-high magnetisation. In this approach, the electromagnetic field is split into the force-free component, governed by the equations of force-free degenerate electrodynamics (FFDE), and the perturbation component, governed by the perturbation equations derived from the full system of relativistic magnetohydrodynamics (RMHD). The combined system of the FFDE and perturbation equations is integrated simultaneously, for which various numerical techniques developed for hyperbolic conservation laws can be used. At the end of every time-step of numerical integration, the force-free and the perturbation components of the electromagnetic field are recombined and the result is regarded as the initial value of the force-free component for the next time-step, whereas the initial value of the perturbation component is set to zero. To explore the potential of this approach, we build a 3rd-order WENO code, which was used to carry out 1D and 2D test simulations. Their results show that this operator-splitting approach allows us to bypass the stiffness of RMHD in the ultra-high-magnetisation regime where the perturbation component becomes very small. At the same time, the cod