Existence Of Periodic Solution Of Second Order Impulsive Differential Equations

This master thesis is concerned with the existence of periodic solutions for non-autonomous second order systems with impulses in the function and the derivative by using the critical point theory. This work is composed of three chapters.Chapter 1 introduces the background of this thesis and presents some preliminary results concerning critical point theory.Chapter 2 investigates the existence of periodic solutions for non-autonomous sec-ond order systems with impulses in the function and the derivative by using the least action principle. Some existence theorems are obtained without the coerciveness as-sumption. Some related results are generalized.Chapter 3 deals with the existence of periodic solutions for non-autonomous sec-ond order systems with impulses in the function and the derivative by using the saddle point theorem. A simple criterion is established.