Absolute wavenumber
= Absolute wavenumber
{title2=$k_0$}
An <absolute wavenumber> is a complex <wavenumber> at the selected zero-<group velocity> saddle of a <dispersion relation>. For the <linear complex Ginzburg-Landau equation>, $k_0=-U/[2(c_d-i)]$; the positive real part of the diffusion coefficient makes the Gaussian saddle accessible from the real Fourier contour.