First integrals for the Duffing-Van der Pol type oscillator.
First integrals for two linearly coupled nonlinear Duffing oscillators.
Fonctions de Mathieu et fonctions propres de l'oscillateur relativiste
Forced oscillations of first order nonlinear neutral differential equations.
Fractal analysis of Hopf bifurcation for a class of completely integrable nonlinear Schrödinger Cauchy problems.
Further results for some third order differential systems with nonlinear dissipation
We formulate nonuniform nonresonance criteria for certain third order differential systems of the form , which further improves upon our recent results in [12], given under sharp nonresonance considerations. The work also provides extensions and generalisations to the results of Ezeilo and Omari [5], and Minhós [9] from the scalar to the vector situations.