‎in this paper‎, ‎first we discuss a local stability analysis of model was introduced by p‎. ‎j‎. ‎mumby et‎. ‎al‎. ‎(2007)‎, ‎with $frac{gm^{2}}{m+t}$ as the functional response term‎. ‎we conclude that the grazing intensity is the important parameter to control the existence or extinction of the coral reef‎. ‎next‎, ‎we consider this model under the influence of the time delay as the bifurcat...

The oscillation of a class fourth-order nonlinear damped delay differential equations with distributed deviating arguments is the subject this research. We propose new explanation equation in terms similar well-studied second-order linear without damping. extended Riccati transformation, integral averaging approach, and comparison principles are used to provide some additional oscillatory crite...

This paper deals with the singularly perturbed boundary value problem for a linear second order differential-difference equation of the convection-diffusion type with small delay parameter. A fourth order finite difference method is developed for solving singularly perturbed differential difference equations. To handle the delay argument, we construct a special type of mesh, so that the term co...

In this paper, by combining a new maximum principle of fourth-order equations with the theory of eigenline problems, we develop a monotone method in the presence of lower and upper solutions for some fourth-order ordinary differential equation boundary value problem. Our results indicate there is a relation between the existence of solutions of nonlinear fourth-order equation and the first eige...

The objective of this article is to study the oscillation properties of the solutions to the fourth-order linear trinomial delay differential equation y(t) + p(t)y′(t) + q(t)y(τ(t)) = 0. Applying suitable comparison principles, we present new criteria for oscillation. In contrast with the existing results, we establish oscillation of all solutions, and essentially simplify the examination proce...

‎in this paper, we formulate the fourth order sturm-liouville problem (fslp) as a lie group matrix differential equation. by solving this ma- trix differential equation by lie group magnus expansion, we compute the eigenvalues of the fslp. the magnus expansion is an infinite series of multiple integrals of lie brackets. the approximation is, in fact, the truncation of magnus expansion and a gauss...