Homoclinics for singular strong force Lagrangian systems in $${\mathbb {R}}^N$$

We will be concerned with the existence of homoclinics for Lagrangian systems in $${\mathbb {R}}^N$$ R N ($$N\ge 3 $$ N ≥ 3 ) of the form $$\frac{d}{dt}\left( \nabla \Phi (\dot{u}(t))\right) +\nabla _{u}V(t,u(t))=0$$ d dt ∇ Φ ( u ˙ ( t ) ) + ∇ u V ( t , u ( t ) ) = 0 , where $$t\in {\mathbb {R}}$$ t ∈ R , $$\Phi {:}\,{\mathbb {R}}^N\rightarrow [0,\infty )$$ Φ : R N → [ 0 , ∞ ) is a G-function in the sense of Trudinger, $$V{:}\,{\mathbb {R}}\times \left( {\mathbb {R}}^N{\setminus }\{\xi \} \right) \rightarrow {\mathbb {R}}$$ V : R × R N \ { ξ } → R is a $$C^2$$ C 2 -smooth potential with a single well of infinite depth at a point $$\xi \in {\mathbb {R}}^N{\setminus }\{0\}$$ ξ ∈ R N \ { 0 } and a unique strict global maximum 0 at the origin. Under a strong force type condition around the singular point $$\xi $$ ξ , we prove the existence of a homoclinic solution $$u{:}\,{\mathbb {R}}\rightarrow {\mathbb {R}}^N{\setminus }\{\xi \}$$ u : R → R N \ { ξ } via minimization of an action integral.

Existence of at Least One Homoclinic Solution for a Nonlinear Second-Order Difference Equation

This paper presents sufficient conditions for the existence of at least one homoclinic solution for a nonlinear second-order difference equation with p-Laplacian. Our technical approach is based on variational methods. An example is offered to demonstrate the applicability of our main results.

Melnikov Method for a Class of Planar Hybrid Piecewise-Smooth Systems

In this paper, we extend the well-known Melnikov method for smooth systems to a class of periodic perturbed planar hybrid piecewise-smooth systems. In this class, the switching manifold is a straight line which divides the plane into two zones, and the dynamics in each zone is governed by a smooth system. When a trajectory reaches the separation line, then a reset map is applied instantaneously before entering the trajectory in the other zone. We assume that the unperturbed system is a piecewise Hamiltonian system which possesses a piecewise-smooth homoclinic solution transversally crossing the switching manifold. Then, we study the persistence of the homoclinic orbit under a nonautonomous periodic perturbation and the reset map. To achieve this objective, we obtain the Melnikov function to measure the distance of the perturbed stable and unstable manifolds and present the theorem for homoclinic bifurcations for the class of planar hybrid piecewise-smooth systems. Furthermore, we employ the obtained Melnikov function to detect the chaotic boundaries for a concrete planar hybrid piecewise-smooth system.

Novel Hyperbolic Homoclinic Solutions of the Helmholtz-Duffing Oscillators

The exact and explicit homoclinic solution of the undamped Helmholtz-Duffing oscillator is derived by a presented hyperbolic function balance procedure. The homoclinic solution of the self-excited Helmholtz-Duffing oscillator can also be obtained by an extended hyperbolic perturbation method. The application of the present homoclinic solutions to the chaos prediction of the nonautonomous Helmholtz-Duffing oscillator is performed. Effectiveness and advantage of the present solutions are shown by comparisons.

Existence of Generalized Homoclinic Solutions of Lotka-Volterra System under a Small Perturbation

This paper investigates Lotka-Volterra system under a small perturbationvxx=-μ(1-a2u-v)v+ϵf(ϵ,v,vx,u,ux),uxx=-(1-u-a1v)u+ϵg(ϵ,v,vx,u,ux). By the Fourier series expansion technique method, the fixed point theorem, the perturbation theorem, and the reversibility, we prove that nearμ=0the system has a generalized homoclinic solution exponentially approaching a periodic solution.

From homoclinics to quasi-periodic solutions for ordinary differential equations

We consider the quasi-periodic solutions bifurcated from a degenerate homoclinic solution. Assume that the unperturbed system has a homoclinic solution and a hyperbolic fixed point. The bifurcation function for the existence of a quasi-periodic solution of the perturbed system is obtained by functional analysis methods. The zeros of the bifurcation function correspond to the existence of the quasi-periodic solution at the non-zero parameter values. Some solvable conditions of the bifurcation equations are investigated. Two examples are given to illustrate the results.