PSD and VFP (upper and lower panels, respectively) of an AGN with a BH mass of 10⁸ M_⊙. The PSD model parameters are: A = 0.02 Hz⁻¹, s = 1, and ν_b = 3 ⋅ 10⁻⁶ Hz (black solid lines). Black dashed lines indicate the PSD and VFP when we increase the PSD amplitude by a factor of 2. Red lines show the PSD and VFP when we increase the bend frequency (by a factor of 10), while the blue lines show the changes when we increase the high-frequency PSD slope from −2 to −3 (all the other parameters in this case are like those of the red lines). For the computation of the variance, we assumed ν_max = (1/250 s).