Invariant tori in nonlinear oscillations

• DOI: 10.1007/bf02889506
• Publication Date: 2008-04-10T12:51:23Z
• Authors: Bin Liu; Yiqian Wang
• Keywords: Duffing equation

The boundedness of all the solutions for semilinear Duffing equationx″ + ω2 x + φ(x) =p(t), ω ∈ ℝ+ℕ is proved, wherep (t) is a smooth 2π-periodic function and the perturbation ⌽(x) is bounded.