ON THE NUMBER OF LIMIT CYCLES IN A LIÉNARD-LIKE PERTURBATION OF A
NON-LINEAR QUADRATIC ISOCHRONOUS CENTER
In this paper we estimate the maximum number of limit cycles that can
bifurcate from an integrable non-linear quadratic ischronous center,
when perturbed inside a class of Liénard-like polynomial differential
systems of arbitrary degree n. The main tool employed in this
study is the averaging theory of first order.