Oscillatory behaviour of higher order difference equations

This thesis consists of four chapters. The first chapter has been devoted to theintroduction. In the second chapter, some main topics for difference calculus, theoryof linear difference equations, solutions of linear homogeneous autonomousdifference equations, oscillations of difference equations have been given and someknown theorems and lemmas concerning these concepts have also been recalled. Inthe third chapter, the higher order nonlinear neutral delay difference equationis studied. In this chapter, sufficient conditions for oscillation of all solutions of (1)are given. In the four chapter, where our original results are given, the higher ordernonlinear delay difference equationis considered and sufficient conditions for oscillationof bounded solutions of this equation are given.