supported by National Natural Science Foundation of China (Grant No. 10671020)
In this paper we investigate the perturbations from a kind of quartic Hamiltonians under general cubic polynomials. It is proved that the number of isolated zeros of the related abelian integrals around only one cente...
This work was supported by the National Natural Science Foundation of China(Grant No.10671020)
In this paper, we investigate the number and the distribution of the limit cycles bifurcated from a kind of degenerate planar polycycles through three singular points: a saddle-node P 0, a fine saddle P 1 with finite ...