Solutions of two-point boundary value problems via phase-plane analysis

Abstract

We consider period annuli (continua of periodic solutions) in equations of the type $x''+g(x)=0$ and $x''+f(x) x'^2 + g(x)= 0,$ where $g$ and $f$ are polynomials. The conditions are provided for existence of multiple nontrivial (encircling more than one critical point) period annuli. The conditions are obtained (by phase-plane analysis of period annuli) for existence of families of solutions to the Neumann boundary value problems.

Keywords

• neumann boundary conditions
• phase portrait
• period annulus
• multiplicity of solutions