Limit cycle bifurcations near a 2-polycycle or double 2-polycycle of planar systems (Q2637060)

This article deals with the investigation of bifurcation of limit cycles for a near-Hamiltonian system. Using the method of stability-changing of a homoclinic loop, the authors obtain some new results on the number of limit cycles in a neighborhood of a 2-polycycle or double 2-polycycle. Moreover, a new way to find alien limit cycles is considered.