A shooting approach to layers and chaos for a forced Duffing equation

Abstract

We study equilibrium solutions for the problem $u_t={\epsilon}^2 u_{xx} -u^3 +\lambda u -cos(t)$,$u_x(0,t)=u_x(L,t)=0$. Using a shooting method we find solutions for all non-zero $\epsilon .$ For small $\epsilon $ we add to the solutions found by previous authors, especially Angennent, Mallet-Paret and Peletier, and Hale and Sakamoto, and also give new elementary ode proofs of their results. Among the new results is the existence of internal layer-type solutions. Considering the ode satisfied by equilibria, but on an infinite interval, we obtain chaos results for $\lambda \geq \lambda _{0}=\frac{3}{2^{2/3}}$ and $0<\epsilon \leq {1/4}.$ We also consider the problem of bifurcation of solutions as $\lambda $ increases from $0.$