Differential type

Tensor type

Condensed type

$\nabla \cdot D=4\pi \rho$

$J^{\nu }={\partial }_{\mu }{F}^{\mu \nu }$

${\partial }_{\lambda }{\partial }_{\sigma }\left({\partial }^{\lambda }{\Lambda }^{\sigma }-{\partial }^{\sigma }{\Lambda }^{\lambda }\right)=0$

from

(4-2)

$\nabla \times H=\frac{4\pi }{c}J+\frac{1}{c}\frac{\partial D}{\partial t}$

$\nabla \times E=-\frac{1}{c}\frac{\partial B}{\partial t}$

$0={\partial }_{\lambda }{F}_{\mu \nu }+{\partial }_{\mu }{F}_{\nu \lambda }+{\partial }_{\nu }{F}_{\lambda \mu }$

$\nabla \cdot B=0$

$\nabla \cdot J+\frac{\partial \rho }{\partial t}=0$

${\partial }_{\lambda }{J}^{\lambda }=0$