= Static mode lost by cancelling frequency
= Static modes lost by cancelling frequency
{synonym}
When a <dispersion relation> factors as $\omega P(\omega,k)=0$, dividing by $\omega$ discards a possible time-independent <Fourier mode>. This can remove a necessary <stationary solution> from an <initial value problem>. For instance, a constant-coefficient temporal equation $T^{(3)}+iaT''+bT'=0$ has a constant solution as well as the two exponential solutions from its quadratic factor. Three initial conditions generally require all three modes. Cancellation is valid only when a nonzero frequency has already been required.
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