Lie-point Symmetries and Nonlinear Dynamical Systems (symmetry and Approximate Symmetries of Nonlinear Equations: Bifurcations, Center Manifolds, and Normal Form Reduction)
نویسندگان
چکیده
Nonlinear symmetries of nite dimensional dynamical systems are related to nonlinear normal forms and center manifolds in the neighbourhood of a singular point. Certain abstract results can be used algorith-mically to construct the normal forms and/or the center manifold up to a given order in the perturbation expansion. We also argue that for this task, approximate symmetries are as useful as exact ones.
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