2011/09/29 by Maoan Han, Han, Maoan, Valery G. Romanovski +1 · 1 citation
Mathematics · #Advanced Differential Equations and Dynamical Systems #Classical Analysis and ODEs (math.CA) #FOS: Mathematics
paper · pdf · doi:10.48550/arxiv.1109.6473
openalex publication_date 2011/09/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, we study the analytical property of the Poincare return map and the generalized focal values of an analytical planar system with a nilpotent focus or center. Then we use the focal values and the map to study the number of limit cycles of this kind of systems with parameters, and obtain some new results on the lower and upper bounds of the maximal number of limit cycles near the nilpotent focus or center.