The Weak Solutions Of The Periodic Boundary Value Problem In A Banach Space

In the first chapter ,the following first order periodic boundary value problems in Banach space are considered:In the second chapter ,we consider the following second order periodic boundary value problems :In [15]its assumptions are so strong that we can accept them with difficulties.Here we use Green's function to obtain the solution in a integral form.By this,we can make the assumptions very simple,but we can obtain the same results.In addition we also consider a new situation that the lower solution is not less than the upper solution. Suppose the following assumptions are satisfied:useing the monotone iterative technique ,we have obtained the existence of the max-...