Limit cycles bifurcating from a perturbed quartic center

Limit Cycles Bifurcating from a Perturbed Quartic Center

We consider the quartic center ẋ = −yf(x, y), ẏ = xf(x, y), with f(x, y) = (x+a)(y+b)(x+c) and abc 6= 0. Here we study the maximum number σ of limit cycles which can bifurcate from the periodic orbits of this quartic center when we perturb it inside the class of polynomial vector fields of degree n, using the averaging theory of first order. We prove that 4[(n− 1)/2] + 4 ≤ σ ≤ 5[(n− 1)/2 + 14, ...

Limit cycles bifurcating from a degenerate center

We study the maximum number of limit cycles that can bifurcate from a degenerate center of a cubic homogeneous polynomial differential system. Using the averaging method of second order and perturbing inside the class of all cubic polynomial differential systems we prove that at most three limit cycles can bifurcate from the degenerate center. As far as we know this is the first time that a com...

A quartic system with 26 limit cycles

Limit Cycles Bifurcating from Planar Polynomial Quasi–homogeneous Centers

In this paper we find an upper bound for the maximum number of limit cycles bifurcating from the periodic orbits of any planar polynomial quasi-homogeneous center, which can be obtained using first order averaging method. This result improves the upper bounds given in [7].

Bifurcation of limit cycles from a quadratic reversible center with the unbounded elliptic separatrix

The paper is concerned with the bifurcation of limit cycles in general quadratic perturbations of a quadratic reversible and non-Hamiltonian system, whose period annulus is bounded by an elliptic separatrix related to a singularity at infinity in the poincar'{e} disk. Attention goes to the number of limit cycles produced by the period annulus under perturbations. By using the appropriate Picard...