Periodic solutions of a nonlinear second-order differential equation with deviating argument

With the help of the coincidence degree continuation theorem, the existence of periodic solutions of a nonlinear second-order differential equation with deviating argument

x^″(t)+f₁(x(t))x^′(t)+f₂(x(t))(x^′(t)⁾²+g(x(t−τ(t)))=0,     

The pile driver problem via a fixed point argument

In this paper we study, via fixed point and subdifferential arguments, the existence of solutions for a variational inequality which models the dynamics of a pile penetrating into the ground through the action of a pile hammer. This line of reasoning reduces the variational inequality we considered to a nonlinear evolution equation involving a monotone operator.     

Periodic solutions of a functional equation with linearly deviating argument

Translated from Issledovaniya po Prikladnoi Matematike, No. 16, pp. 125–131, 1989.     

Periodic solutions for a kind of Rayleigh equation with a deviating argument

In this paper, we use the coincidence degree theory to establish new results on the existence of T-periodic solutions for the Rayleigh equation with a deviating argument of the form

x^″+f(x^′(t))+g(t,x(t−τ(t)))=p(t).     

Periodic solutions of a third order nonlinear differential equation

Summary The differential equation x‴ + ϕ(x′)x″ + ϕ(x)x′ + f(x)=p(t) is considered where the forcing term p is an ω-periodic function of t. In the special cases ϕ(x)=k² respectively ϕ(x′)=a the existence of periodic solutions is proved on the basis of the Lerag-Schauder fixed point technique. The conditions imposed on the nonlinear terms do not include the ultimate boundedness of all solutions. Entrata in Redazione il 18 settembre 1971.     

Periodic solutions of a 2nth-order nonlinear difference equation

In this paper, a 2 nth-order nonlinear difference equation is considered.Using the critical point theory, we establish various sets of sufficient conditions of the nonexistence and existence of periodic solutions.Results obtained complement or improve the existing ones.     

一类具复杂偏差变元的Duffing型方程的周期解

利用拓扑度方法研究卫类具复杂偏差变元的Duffing型泛函微分方程x″（t) g(x(x(t)))=p(t)周期解的存在性，得到了方程具有周期解的充分条件。     

New existing results for a system of nonlinear third-order differential equation via fixed point index

By using fixed point index theory, we investigate a system of nonlinear third-order differential equation. We give some sufficient conditions for the existence of at least one or two positive solutions to the system of nonlinear third-order differential equation. As applications, we also present two examples to demonstrate the main results.     

Periodic solutions for a kind of Liénard equation with a deviating argument

By means of continuation theorem of coincidence degree theory, we study a kind of Liénard equation with a deviating argument as follows

     

Periodic solutions for a kind of Liénard equation with a deviating argument

In this paper, the Liénard equation with a deviating argument

x^″(t)+_f1(t,x(t))x^′(t)+_f2(x(t))(x^′(t))²+g(t,x(t−τ(t)))=p(t)$x^{″}\left(t\right)+f_1(t,x\left(t\right))x^{\prime }\left(t\right)+f_2\left(x\left(t\right)\right){\left(x^{\prime }\left(t\right)\right)}^2+g(t,x(t-\tau \left(t\right)))=p\left(t\right)$

Asymptotic behavior of solutions of a nonlinear difference equation with continuous argument

We consider the difference equation with continuous argument

Periodic solutions of a nonlinear wave equation without assumption of monotonicity

Mathematische Annalen -     

Periodic solutions of a nonlinear second order differential equation with delay

It is proved that the autonomous difference-differential equation

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(0) has, for a broad class of functions f, a nonconstant periodic solution whenever the associated characteristic equation has a root with positive real part.     

Periodic solutions for a neutral nonlinear dynamical equation on a time scale

Let T be a periodic time scale. We use a fixed point theorem due to Krasnosel'ski? to show that the nonlinear neutral dynamic system with delay