Boundary value problems of third-order differential equations have received much attention due to their applications to applied mathematics and physics and so on.Recently,people have found boundary value problems of third-order differential equations with periodic boundary conditions have more important practical significance.Therefore,this type of problems has turned into the focus which has been studied.In this paper,we are concerned with the existence of positive solutions for the following third-order periodic boundary value problem(?)where (?)and (?)In chapter 1,we introduce the historical background of problems that will be discussed and list some necessary preliminary knowledge needed in this present thesis.In chapter 2,by using the fixed point index theory in cones,we study the existence of positive solutions to the above third-order periodic boundary value problem. |