# Talk:Waves in plasmas

The equation $\omega^2 = \omega_i^2 = \Omega_c\omega_c$ for the lower-hybrid frequency does not make any sense at all: $\omega_i$ depends on the ion density but not the magnetic field, whereas $\Omega_c\omega_c$ depends on the magnetic field but not the ion density! A little digging into some text books says that it should be $\frac{1}{\omega^2} = \frac{1}{\omega_i^2} + \frac{1}{\Omega_c\omega_c}$. Usually one is very much smaller than the other and is ignored, but I feel that the general equation should be put here (and on the lower-hybrid page). I will edit shortly unless someone objects.129.78.64.103 (talk) 05:40, 10 November 2009 (UTC)