Approximate first integrals for a system of two coupled van der Pol oscillators with linear diffusive coupling
The authors construct approximate first integrals of perturbed ordinary differential equations without variational principle. The approximate partial Noether operators for two coupled van der Pol oscillators are constructed using the partial Lagrangian approach. These approximate partial Noether operators are not approximate symmetry generators of the given system of equations, therefore, they do not admit an approximate Lie algebra. The condition under which an approximate algebra can be generated, are given elsewhere.
scientific article; zbMATH DE number 5943177