2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/14464The stability of self-similar power-law disks to non-axially symmetrical disturbances of zero frequency (omega = 0) is discussed. It is established that marginally unstable modes either have (omega = 0) or consist of continua with modes of all frequencies becoming unstable together. A careful study of all modes close to omega = 0 yields a remarkable conclusion.22 pages, Tex, 4 Figures (gif files)Astrophysicstext