This textbook contains the lecture series originally delivered at the "Advanced Course on Limit Cycles of Differential Equations" in the Centre de Rechercha Mathematica Barcelona in 2006. It covers the center-focus problem for polynomial vector fields and the application of abelian integrals to limit cycle bifurcations. Both topics are related to the authors' interests in Hilbert's sixteenth problem, but would also be of interest to those working more generally in the qualitative theory of dynamical systems.

This book is mainly concerned with the bifurcation theory of ODEs. Chapters 1 and 2 of the book introduce two systematic methods of simplifying equations: center manifold theory and normal form theory, by which one may reduce the dimension of equations and change forms of equations to be as simple as possible. Chapters 3-5 of the book study in considerable detail the bifurcation of those one or two dimensional equations with one, two or several parameters.

This book is concerned with the bifurcation theory, the study of the changes in the structures of the solution of ordinary differential equations as parameters of the model vary.