Phase trajectories for the n = −2 simulation B. The trajectories of the phases φ(k, τ) of individual Fourier modes for n = −2 are plotted vs. a(τ). The magnitudes k of the wavevectors are labeled in each panel; the full vectors were chosen as k = (0, 0, k). Within each panel, k increases in the following order: solid, dotted, dashed, long‐dashed, and dashed‐dotted curves. The phase is defined mod2π and is therefore constrained to lie between −π and π. At a = 0, the value of φ at the earliest time has been plotted again to show the expected linear behavior.