The Propeties And Applications Of Retarded Functional Differential Equations

In this thesis we consider two respects in retarded functional differential equations.We consider the unbounded operator perturbed dynamical system with small time-varied delay. We verify that, under these conditions, the solution of the equation may hold some asymptotic behaviors such that asymptotic almost periodicity, stability and periodicity.We investigate the existence of the periodic solution of the infinite delay equation by using fixed point theorem. We also show that under some conditions, the solution of this equation is of some asymptotic behaviors.