Parametric Center-Focus Problem for Abel Equation

M. Briskin, F. Pakovich, Y. Yomdin

The Abel differential equation $y^{\prime }=p(x)y^3+q(x)y^2$ with meromorphic coefficients $p,q$ is said to have a center on $[a,b]$ if all its solutions, with the initial value $y(a)$ s…