Corotating pulsar magnetosphere

In an idealized corotating pulsar magnetosphere, plasma moves with $\mathbf{u}=\mathbf{\Omega }\times \mathbf{r}$. In Gaussian units, ideal magnetohydrodynamics then gives $\mathbf{E}=-\mathbf{u}\times \mathbf{B}/c$.

The Goldreich-Julian density is the charge density needed to support corotation in an idealized pulsar magnetosphere. Where exterior currents vanish,in Gaussian units.