 Magnetized cold-plasma dielectric tensor

For $e^{-i\omega t}$, Gaussian units give $\mathbf{ϵ}=\mathbf{I}+4\pi i\mathbf{\sigma }/\omega$, where $\mathbf{\sigma }$ is the summed conductivity tensor. With the equilibrium magnetic field along $z$, write ${ϵ}_{xx}={ϵ}_{yy}=S$, ${ϵ}_{zz}=P$, and ${ϵ}_{xy}=-{ϵ}_{yx}=ig$. For signed cyclotron frequencies ${\Omega }_s=q_{s}B/(m_{s}c)$,Here ${\omega }_{ps}$ is the species plasma frequency. The two circular eigenvalues are $S\mp g$; defining the sign convention before naming their polarizations prevents ambiguity.