Published Online: Jan 01, 2016
Page range: 79 - 86
Received: Oct 03, 2015
Accepted: Nov 19, 2015
DOI: https://doi.org/10.21042/AMNS.2016.1.00007
© 2016 J. Llibre, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
This is a brief survey on the centers of the analytic differential systems in ℝ2. First we consider the kind of integrability of the different types of centers, and after we analyze the focus–center problem, i.e. how to distinguish a center from a focus. This is a difficult problem which is not completely solved. We shall present some recent results using the divergence of the differential system.