On the computation of Lyapunov exponents for forced vibration of a Lennard-Jones oscillator

In this paper, we introduce a modified Lyapunov vector method for retrieving the leading Lyapunov exponent for a dynamical system with strong nonlinear forces. Performances of the proposed method and the classical QR method are compared. This method is applied to the computation of Lyapunov exponents of a mechanical oscillator under the influence of van der Waals forces. The advantage of this approach lies in the property of preserving the norm of the solution vector.