Power spectrum of the MAD parameters in the time interval 10⁴ t _g < t < 2 × 10⁴ t _g (1.5 × 10⁴ t _g to 2.5 × 10⁴ t _g for aM94b800). In all simulations, the power is concentrated in the low-frequency region, which corresponds to periods about 500–2000t _g . In the high-frequency region, the power spectrum decreases following ∼f ⁻¹. The dashed red line shows this evolution.