Isochronicity problem of a higher-order singular point for polynomial differential systems (Q970524)

The paper is devoted to the isochronicity problem of a higher-order singular point for a planar polynomial autonomous system. By applying a new recursive algorithm to compute period constants, the authors study this problem for the following real septic system \[ \begin{aligned} \frac{dx}{dt}&=-y(x^2 + y^2)+ \sum_{k+j=5}A_{kj}x^ky^j -\lambda y(x^2 + y^2)^3, \\ \frac{dy}{dt}&=x(x^2 + y^2)+ \sum_{k+j=5}B_{kj}x^ky^j +\lambda x(x^2 + y^2)^3. \end{aligned} \]