C.1 Cold plasma model

In the cold plasma model X^sC is independent of N. Also, X _xz^sC = X _yz^sC = 0 and X_xx^sC = X _yy^sC.

(146)

Therefore, P₃^C = P₁^C = 0 so that

with

(147)

where K_⊥^C = 1 + ∑ _sX_⊥^sC, K _∥^C = 1 + ∑ _sX_∥^sC, K _×^C = ∑ _sX_×^sC.