الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 32 |  |  |
| | | from | 32 | | |
Abstract
The thesis consists of five chapters:
Introduction, this Section contains some basic definitions, and some important theorems which will be used throughout the next chapters.
In chapter1, we study the oscillation criteria for second order half - linear difference equation with distributed deviating, by using a Riccati transformation technique.
In chapter 2, we discuss oscillatory behavior of solutions of second order half- linear neutral delay and mixed neutral type difference equations. By using the method of Riccati transformation technique.
In chapter 3, we establish some new sufficient conditions for third order nonlinear delay and neutral delay difference equations which insure that every solution of this equations either oscillates or converges to zero, by a Riccati transformation technique and via comparison with first order oscillatory difference equations.
In chapter 4, by comparison with some first difference equations whose oscillatory characters are known and by means of a Riccati transformation technique, we obtain several new sufficient conditions for the oscillation of all solutions of the third order nonlinear delay and mixed neutral difference equations.
Finally in chapter 5, by a Riccati transformation technique, we consider the oscillation of third order half-linear and nonlinear neutral delay difference equation with distributed deviating arguments. Our results improve and extend some known results for oscillation of the second and third order neutral difference equations. Some of our results are illustrated by some examples.
The results extended and improved some results of oscillation that obtained before and these results will be illustrated by some examples.