Example of fluctuation field generation. Left: Model 3D power spectrum described by an injection at k_inj and a classical Kolmogorov cascade on smaller scales (Eq. 4). The vertical dashed line shows the position of k_inj = (500 kpc)⁻¹. Right: Slice of the real-space velocity fluctuation field along the z axis generated from this power spectrum (Eq. 3) for a velocity dispersion σ_v = 300 km/s. The color code shows the velocity in km/s. The box size is 1.7 Mpc on a side.