We derive the equations of motion of relativistic magnetohydrodynamics, as well as microscopic expressions for all of its transport coefficients, from the Boltzmann equation using the method of moments. In contrast to G. S. Denicol et al. [Phys. Rev. D 98, 076009 (2018).], where a single component gas was considered, we perform our derivation for a locally neutral fluid composed of two massless particle species with opposite charges. We demonstrate that the magnetohydrodynamical equations of motion become dramatically different for this more realistic system. The shear-stress tensor no longer obeys a single differential equation; it breaks into three nondegenerate components with respect to the magnetic field, each evolving according to different dynamical equations. For large magnetic fields, we further show that the solution of this theory displays oscillatory behavior that can no longer be described by an Israel-Stewart-like theory. Finally, we investigate the derived equations in a Bjorken flow scenario.

中文翻译：

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双组分气体玻尔兹曼方程的相对论耗散磁流体动力学

我们使用矩量法从玻尔兹曼方程推导了相对论磁流体动力学的运动方程，以及其所有输运系数的微观表达式。与 G. S. Denicol等人相反。 [物理。 Rev. D 98 , 076009 (2018).]，在考虑单一成分气体的情况下，我们推导了由两种带相反电荷的无质量粒子组成的局部中性流体。我们证明，对于这个更现实的系统，磁流体动力学运动方程变得显着不同。剪应力张量不再服从单个微分方程；它根据磁场分为三个非简并分量，每个分量根据不同的动力学方程演化。对于大磁场，我们进一步证明该理论的解表现出振荡行为，而这种振荡行为不再可以用类似以色列-斯图尔特的理论来描述。最后，我们研究了 Bjorken 流场景中的导出方程。