Page "Upper hybrid oscillation" Paragraph 7

This oscillation is closely related to the plasma oscillation found in unmagnetized plasmas or parallel to the magnetic field, where the ω < sub > pe </ sub > term arises from the electrostatic restoring force and the 3k²v < sub > e, th </ sub > ² term arises from the restoring force of electron pressure.

In the upper hybrid oscillation there is an additional restoring force due to the Lorentz force.

Consider a plane wave where all perturbed quantities vary as exp ( i ( kx-ωt )).

If the displacement in the direction of propagation is δ < sub > x </ sub >, then