The cyclicity of the elliptic segment loops of the reversible quadratic Hamiltonian systems under quadratic perturbations

Denote by Q(H) and Q(R) the Hamiltonian class and reversible class of quadratic integrable systems. There are several topological types for systems belong to Q(H) boolean AND Q(R). One of them is the case that the corresponding system has two heteroclinic loops, sharing one saddle-connection, which is a line segment, and the other part of the loops is an ellipse. In this paper we prove that the maximal number of limit cycles, which bifurcate from the loops with respect to quadratic perturbations in a conic neighborhood of the direction transversal to reversible systems (called in reversible direction), is two. We also give the corresponding bifurcation diagram. (C) 2004 Elsevier Inc. All rights reserved.