Invariant tori and unboundedness for second order differential equations with asymmetric nonlinearities depending on the derivatives Original Research Article

In this paper, the boundedness and unboundedness of solutions of the oscillator x″+ax+−bx−+φ(x)ψ(x′)+f(x)+g(x′)=p(t)x″+ax+−bx−+φ(x)ψ(x′)+f(x)+g(x′)=p(t) Turn MathJax on are discussed under some suitable conditions.