×

Local dynamics of some algebraic maps. (English) Zbl 0946.34026

H. Zoladek [J. Differ. Equations 137, No. 1, 94-118 (1997; Zbl 0885.34034)] stated a nontrivial algebraic center-focus problem for the following implicitly defined map \(z\to w\) with \[ w+ z+ \sum^n_{i+ j= 2} a_{ij} z^i w^i= 0.\tag{1} \] The equation has an analytic solution of the form \(w=\widetilde f(z)= -z+\cdots\). In this paper, the authors study the map \(\widetilde f\) where \(\widetilde f\) is defined through the cubic case of equation (1) with \(n= 3\). They use algebraic tools, based on the Gröbner bases theory, and Lyapunov function methods to examine the center-focus problem and the problem of estimating the number of limit cycles near \(z= 0\).

MSC:

34C07 Theory of limit cycles of polynomial and analytic vector fields (existence, uniqueness, bounds, Hilbert’s 16th problem and ramifications) for ordinary differential equations
34C05 Topological structure of integral curves, singular points, limit cycles of ordinary differential equations
34C08 Ordinary differential equations and connections with real algebraic geometry (fewnomials, desingularization, zeros of abelian integrals, etc.)

Citations:

Zbl 0885.34034