Dra. Garcia-Saldaña, Johanna

In this paper, the existence of homoclinic orbits of the equilibrium point [Formula: see text] is demonstrated in the case of the Lü system for parameter values not reported by G. A. Leonov. In addition, some simulations are shown that agree with our theoretical analysis.

We provide normal forms and the global phase portraits on the Poincaré disk of the Abel quadratic differential equations of the second kind having a symmetry with respect to an axis or to the origin. Moreover, we also provide the bifurcation diagrams for these global phase portraits.