جستجوی مقالات مرتبط با کلیدواژه « periodic solutions » در نشریات گروه « ریاضی »

We study a new (3+1)-dimensional novel KP-like equation. We show that this equation admits topological soliton solutions. These will be attained via the aid of ansatz methods. Furthermore, mixed solutions consisting of singular and periodic solutions and others are derived. Moreover, other analytical solutions based on modern group analysis are derived.  In addition,  low-order conservation laws are constructed.

In  this paper, we are concerned with the  existence  of renormalized solution for a  nonlinear periodic  parabolic problem associated to the equation\begin{equation}\frac{\partial u}{\partial t}-A(u)+g(x,t,u,\nabla u)=f\in L^{1} \end{equation}where  $A(u)$ is the  m-Laplacian operator defined on $ W^{1,x}_{0}L_{M}(\mathcal{Q})$.

This work deals with the existence of periodic solutions (EPSs) to a third order nonlinear delay differential equation (DDE) with multiple constant delays. For the considered DDE, a theorem is proved, which includes sufficient criteria related to the EPSs. The technique of the proof depends on Lyapunov-Krasovskiˇı functional (LKF) approach. The obtained result extends and improves some results that can be found in the literature. In a particular case of the considered DDE, an example is provided to show the applicability of the main result of this paper.

In this article, a class of first order neutral delay differential equations with iterative terms is investigated. The proofs of the existence of positive periodic solutions rely on the Krasnoselskii's fixed point theorem together with the Green's functions method. Furthermore, by the aid of the Banach fixed point theorem and under an extra condition, we establish the existence, uniqueness and stability results. We provide an example to show the accuracy of the conditions of the obtained findings which extend and generalize earlier ones in the literature.

The aim of this paper is to study the dynamics of the system of two rational difference equations: xn+1=αn+yn−kyn,yn+1=αn+xn−kxn,n=0,1,… where {αn}n≥0 is a two periodic sequence of nonnegative real numbers and the initial conditions xi,yi are arbitrary positive numbers for i=−k,−k+1,−k+2,…,0 and k∈N. We investigate the boundedness character of positive solutions. In addition, we establish some sufficient conditions under which the local asymptotic stability and the global asymptotic stability are assured. Furthermore, we determine the rate of the convergence of the solutions. Some numerical are considered in order to confirm our theoretical results.

This paper studies the generalized version of theZakharov-Kuznetsov Benjamin-Bona-Mahoney equation. The functionalvariable method as well as the simplest equation method areapplied to obtain solitons and singular periodic solutions to theequation. There are several constraint conditions that arenaturally revealed in order for these specialized type ofsolutions to exist. The results of this paper generalizes theprevious results that are reported in earlier publications.

In this paper the periodic solutions of fourth order delay differential equation of the form x. ... (t)+ax. .. (t)+f(x ¨ (t−τ(t)))+g(x ˙ (t−τ(t)))+h(x(t−τ(t)))=p(t) is investigated. Some new positive periodic criteria are given.

We study the existence of periodic solutions of the totally nonlinear neutral difference equation with variable delay 4x (t) = −a (t) x 3 (t + 1) + c (t) 4x (t − g (t)) + G t, x3 (t), x3 (t − g (t))
, ∀t ∈ Z. We invert the given equation to construct a fixed point mapping expressed as a sum of a large contraction and a compact map. We show that such a sum of mappings fits very nicely into the framework of Krasnoselskii-Burton’s fixed point theorem so that the existence of periodic solutions is readily concluded. The obtained results extend the work of Ardjouni and Djoudi [1]. Keywords: Fixed point, Large contraction, Periodic solutions, Totally nonlinear neutral differential equations