On nonsmooth perturbations of nondegenerate planar centers
The author studies the existence of limit cycles of discontinuous planar systems, which are small perturbations of a continuous system with a global center. In previous studies it was considered that the discontinuity set is a regular manifold, while here the assumption is that it is just a union of regular curves. The main tool used in the proof of the main result is the averaging method. Some applications are explained with careful details.
scientific article; zbMATH DE number 6381940