一类不连续平面二次微分系统的极限环

Limit cycles for a class of discontinuous planar quadratic differential system

本文考虑了一类不连续平面二次可积非Hamilton微分系统在二次扰动下的极限环个数问题.利用一阶平均法,我们得到了从该系统中心的周期环域至少可以分支出5个极限环的结论.该结果表明不连续二次微分系统比其相应光滑微分系统至少可以多分支出2个极限环.

In this paper, we consider the number of limit cycles for a class of discontinuous planar quadratic integrable non-Hamiltonian system under quadratic perturbation. Using the first order averaging method, we obtain that there are at least 5 limit cycles which can bifurcate from the period annulus of the center for this system. Our result also shows that the discontinuous quadratic system can have at least 2 more limit cycles than the smooth one.