Classification of global phase portraits of a system of Liénard type
This paper concerns a classification of global phase portraits generated by a Liénard differential equation, the two functions of which satisfy conditions called ``deformed mirror symmetry'' for the phase trajectories. These conditions lead to non-dissipative trajectories, for which the authors define separatrices limiting regions of the phase plane, where the qualitative behavior of solutions remain the same. The different classes identified are illustrated by examples with continuous but piecewise differentiable data. References do not quote publications from the former Soviet Union, where the research groups have been very active in the nonlinear dynamics field since 1935.
scientific article; zbMATH DE number 811586