“…In the opposite case, for low-speed or external pumping, the amplitude of the edge perturbation at the axis ( ) g 0 2 exceeds the amplitude of the internal perturbation ( ) g 0 1 , and the feedback is predominantly created by the edge perturbation. In the general case, the complex increment Γ, which is determined from relation (7), is formed jointly by all three types of perturbation. At the same time, each perturbation in turn depends on Γ.…”