Absolute value of the mass accretion rate Green’s functions in the frequency domain calculated (a) for the case of GPD α-disk (red solid curves), and (b) for the case of accretion disk with increased kinematic viscosity at the inner disk parts (black dashed curves). Different curves are given for various radial coordinates of initial perturbation: R′ = 20,  10,  5,  3,  2R_in (from left to the right). All Green’s functions are calculated for R = R_in, that is, they describe suppression of variability at the inner radius of the accretion disk. Frequencies are normalized to the viscous frequency at the inner radius.