标题： 多流体hydrodynamics的变分描述：与规范场的耦合 显示英文标题

标题： Variational description of multi-fluid hydrodynamics: Coupling to gauge fields

摘要： 在这项工作中，我们将之前发展出的牛顿多流体力学形式主义加以扩展，以允许流体与电磁场和引力场之间的耦合。 这是通过使用标准的最小耦合方法，在对流变分原理内实现的。 除了总能量和动量守恒之外，我们还推导出了正则涡度和螺旋性的守恒定律，这些定律推广了无电荷流体对应的守恒量。 我们讨论了这一形式主义在电传导系统、磁流体力学和超导性中的应用。 这里导出的电导体方程比在标准描述中找到的那些方程更为一般化，因为在标准描述中忽略了拖曳效应，尽管在任何电传导的多组分系统中拖曳效应通常都会存在。 显示英文摘要

摘要： In this work we extend our previously developed formalism of Newtonian multi-fluid hydrodynamics to allow for coupling between the fluids and the electromagnetic and gravitational field. This is achieved within the convective variational principle by using a standard minimal coupling prescription. In addition to the conservation of total energy and momentum, we derive the conservation of canonical vorticity and helicity, which generalize the corresponding conserved quantities of uncharged fluids. We discuss the application of this formalism to electrically conducting systems, magnetohydrodynamics and superconductivity. The equations of electric conductors derived here are more general than those found in the standard description of such systems, in which the effect of entrainment is overlooked, despite the fact that it will generally be present in any conducting multi-constituent system.