Magnetization current
= Magnetization current
{title2=$J_{\mathrm{mag}}^\mu$}
A relativistic <magnetization current> has the form $J_{\mathrm{mag}}^\mu=\partial_\nu M^{\nu\mu}$ for an antisymmetric <polarization-magnetization tensor>. It is identically conserved because commuting derivatives contract an antisymmetric tensor.