ON THE DEGENERATE CENTER PROBLEM
Abstract
In this work, it is proved that any degenerate center is limit of a linear type center and when the degenerate center has an analytic first integral then it is limit of an analytic linear type center. A new method to detect integrability developed in [Giné & Santallusia, 2011] is applied to the degenerate center problem. Moreover, a review of the most important recent contributions to the degenerate center problem is given.