Stability and Instability Divergence Conditions for Dynamical Systems

A novel method for stability and instability study of autonomous dynamical systems using the flow and divergence of the vector field is proposed. A relation between the method of Lyapunov functions and the proposed method is established. Bendixon and Bendixon-Dulac theorems for $n$th dimensional systems are extended. Based on the proposed method, the state feedback control law is designed. The control signal is obtained from the partial differential inequality. The examples illustrate the application of the proposed method and the existing ones.