Nuritidinov / Salakutin 
snuit2006@mail.ru       
EAS Symp.6:Dynamics of Galaxies and Galactic Nuclei.   
oral    
Ring mode instability on the background of non-stationary galaxy model  
1) S.Nuritidinov, 2) Mariam Sultana, 3) K.Mirtadjiwa /Astronomical institute of Uzbakistan Acad.Sci.(Tashkand),Fedearal Urdu University(Karachi),National University of Uzbakistan(Tashkand)    Upto day the origin theory of ring like structures in galaxies is based on the stationary models. However the equilibrium and stationary are strong ideal. The Hubble space telescope (HST) shows the galactic structure birth take place for earlier non stationary stages of their evolution. That\'s why, we study gravitational instabilities on the back ground of non linear, non stationary model. In particular, in this work, we study ring-like modes in two non- stationary models. Its found a dependence of initial virial ratio on rotation parameter and other dependence for the grouth rate on other physical parameters.