Predicted (solid lines) and measured (dots) slope −η in the inertial range of the PS of the density field with the variance at different resolutions, taking p = 2. The black curve corresponds to the predicted evolution of the slope in the absence of dissipation (L_diss = 0). The gray shaded area corresponds to the region where the model does not predict the evolution of the slope because the invariance of M_inv is not verified for such a small variance. The error bars correspond to the ±1σ uncertainty estimated from the time variations of the measured quantities. The shaded areas around the solid curves correspond to different predictions of the model considering an uncertainty of 20% on the determination of the invariant around its predicted value α = 2 × 10⁻².