Unboundedness of the large solutions of an asymmetric oscillator

In this paper, we consider the unboundedness problem of solutions for the following asymmetric oscillator:

(φp(x^′)^)′+(p−1)[αφp(x⁺)−βφp(x⁻)]=f(x,x^′,t),     

Unboundedness of solutions of a class of planar Hamiltonian systems

In this paper, the unboundedness of solutions for the following planar Hamilton system Ju ′ = ?H (u) + h (t) is discussed, where the function H (u) ∈ C²(R², R) is positive for u ≠ 0 and is positively (q, p)‐quasihomogeneous of quasi‐degree pq, where p > 1 and + = 1, h: S¹ → R² with h ∈ L^∞(0, 2π) is 2π ‐periodic and J is the standard symplectic matrix. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Quasi-periodic solutions of forced isochronous oscillators at resonance

We deal with the existence of quasi-periodic solutions of forced isochronous oscillators with a repulsive singularity, the nonlinearity is a bounded perturbation. Using a variant of Moser's twist theorem of invariant curves, due to Ortega [R. Ortega, Boundedness in a piecewise linear oscillator and a variant of the small twist theorem, Proc. London Math. Soc. 79 (1999) 381-413], we show that there are many quasi-periodic solutions and the boundedness of all solutions.     

共振条件下一类方程无界解和周期解的共存性

讨论了在共振条件下一类具有等时位势的方程无界解和周期解的共存性．利用Poincare映射轨道的性质,给出了无界解的存在性条件．在此条件下,Poincare-Bohl定理,得到了方程的一个周期解,进而说明共振条件下这类方程无界解和周期解的是可以共存的．最后,给出了一个无界解和周期解共存的具有等时位势的方程实例．     

Harmonic oscillators at resonance,perturbed by a non-linear friction force

This note is an addendum to the results of Lazer and Frederickson [1], and Lazer [4] on periodic oscillations, with linear part at resonance. We show that a small modification of the argument in [4] provides a more general result. It turns out that things are different for the corresponding Dirichlet boundary value problem.     

Existence of quasiperiodic solutions and Littlewood’s boundedness problem of super-linear impact oscillators

So far most application of Kolmogorov-Arnold-Moser (KAM) theory has been restricted to smooth dynamical systems. In this paper, it is shown by a series of transformations that how KAM theory can be used to analyze the dynamical behavior of Duffing-type equations with impact. The analysis is carried out for the example

(0.1)     

Multiple solutions for elliptic equations at resonance

We study an asymptotically linear elliptic equation at resonance, with an odd nonlinearity. By a penalization technique and suitable min-max theorems (which give Morse index estimates), we prove the existence of pairs of non trivial solutions, where N is, roughly speaking, the difference between the Morse indexes at zero and at infinity. Received December 1999     

Periodic solutions of singular second order equations at resonance

In this paper, we study the existence of positive periodic solutions for singular second order equations x" + n²/4x+h(x) = p(t), where h has a singularity at the origin and n is a positive integer. We give an explicit condition to ensure the existence of positive periodic solutions when h is an unbounded perturbation at infinity by using qualitative analysis and topological degree theory.     

Periodic solutions for neutral coupled oscillators network with feedback and time-varying delay

This paper is considered to be about the existence of periodic solutions for neutral coupled oscillators network with feedback control and time-varying delay (NCONFT). Based on the systematic method which is firstly applied for NCONFT and consisting of coincidence degree theory, graph theory, and Lyapunov method, some sufficient criteria are obtained to verify the existence of periodic solutions for NCONFT. What’s more, how coupling topology, feedback control, and time-varying delay affect the existence of periodic solutions for NCONFT can be shown by these sufficient criteria. Finally, a numerical simulation is offered to illustrate the effectiveness of our results.     

Multiple solutions for semilinear elliptic equations near resonance at higher eigenvalues

Using the minimax methods in critical point theory and a generalized Landesman-Lazer type condition, we obtain two solutions for a class of semilinear elliptic equations near resonance at higher eigenvalues.     

Regularity and decay of solutions of nonlinear harmonic oscillators

We prove sharp analytic regularity and decay at infinity of solutions of variable coefficients nonlinear harmonic oscillators. Namely, we show holomorphic extension to a sector in the complex domain, with a corresponding Gaussian decay, according to the basic properties of the Hermite functions in ${\mathbb{R}}^d$. Our results apply, in particular, to nonlinear eigenvalue problems for the harmonic oscillator associated to a real-analytic scattering, or asymptotically conic, metric in ${\mathbb{R}}^d$, as well as to certain perturbations of the classical harmonic oscillator.     

Boundedness of solutions for nonlinear reversible system at resonance

In this paper, we are concerned with the problem of boundedness of solutions for the following nonlinear p-Laplacian:

     

Nontrivial solutions of semilinear equations at resonance

In this paper we prove new existence results concerning nontrivial solutions to semilinear elliptic problem at resonance. The methods used here are based on combining the minimax methods and the Morse theory.