双中子星并合电阻性GRMHD模拟的高效方法
An efficient approach to resistive GRMHD simulations of binary neutron star mergers
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中文总结 AI 辅助
本文提出一种避免矩阵求逆的流体框架公式，高效实现电阻性广义相对论磁流体动力学模拟，在保持精度的同时降低计算成本，并揭示双中子星并合中电阻效应可导致可测量的引力波信号差异。
中文摘要 AI 辅助
天体物理等离子体通常具有高导电性，但有限电阻率仍可影响强磁化系统的演化。在广义相对论磁流体动力学中捕捉这些效应在计算上具有挑战性，因为高导电性导致演化方程中出现刚性源项。标准数值方法依赖隐式-显式（IMEX）时间积分来维持稳定性，但这大幅增加了模拟的复杂性和计算成本。基于先前开发的电阻扩展升级（REGIME）框架，我们提出了一种新的流体框架公式，通过避免先前方法中所需的矩阵求逆，简化了领先阶电阻效应的纳入。该方法已在广义相对论磁流体动力学代码中实现，并通过一维电流片测试以及孤立磁化中子星和双中子星并合的模拟进行了验证。我们发现，新公式再现了预期的电阻行为，其精度与基于IMEX的方法相当，同时大幅降低了模拟的计算成本和复杂性。在双中子星并合中，有限电阻率导致并合后引力波信号和残余结构出现可测量的差异，表明即使在电导率较高的区域，电阻效应也能在并合后动力学中产生可测量的变化。
英文摘要
Astrophysical plasmas are often highly conducting, but finite resistivity can nevertheless influence the evolution of strongly magnetised systems. Capturing these effects in general relativistic magnetohydrodynamics is computationally challenging because high conductivity leads to stiff source terms in the evolution equations. Standard numerical approaches rely on implicit-explicit (IMEX) time integration to maintain stability, but this substantially increases the complexity and computational cost of the simulations. Building upon the previously developed Resistive Extension upGrade for Ideal MagnEtohydrodynamics (REGIME), we present a new fluid-frame formulation that simplifies the incorporation of leading-order resistive effects by avoiding matrix inversions required in previous approaches. The method is implemented in a general relativistic magnetohydrodynamics code and validated through one-dimensional current-sheet tests and simulations of isolated magnetised neutron stars and binary neutron star mergers. We find that the new formulation reproduces the expected resistive behaviour with accuracy comparable to IMEX-based methods, while substantially reducing the computational cost and complexity of the simulations. In binary neutron star mergers, finite resistivity leads to measurable differences in the post-merger gravitational-wave signal and remnant structure, showing that resistive effects can produce measurable changes in the post-merger dynamics even in the high-conductivity regime.
发表机构
- University of Southampton（南安普顿大学）
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