Drift density waves in a differentially rotating axisymmetric disk galaxy

Drift density waves, which are specific for differentially rotating stellar systems and which are of great importance for both the evolution and the origin of various structural galactic formations, are studied in the case of plane geometry. The discussion is limited to slow waves under certain model assumptions. This allows simplification of the investigation using averaged epicyclic motion kinetic equation for stellar phase distribution function. Local instability of a system with respect to slow drift density waves is demonstrated.