Dissipation Instability in the Accretion Disk
  The model of a geometrically thin gaseous disk in the external gravitational potential is considered. The dinamics of small nonaxisymmetric perturbations in the plane of the accretion disk with dissipative effects is investigated. It is showed, that conditions of development and parameters of unstable oscillation modes in the opticaly thick accretion disk are strongly depended on the models of viscosity and opacity. 
A.V.Khoperskov, S.S.Khrapov (Department of Theoretical Physics,   Volgograde State University, Volgograd, Russia)