01315nas a2200229 i 4500 acta62274 20260224081030.0 190930s2019 hu o 000 eng d 1417-3875 10.14232/ejqtde.2019.1.50 doi SZTE Egyetemi Kiadványok Repozitórium hun eng Shao Yi The bifurcation of limit cycles of two classes of cubic isochronous systems [elektronikus dokumentum] / Shao Yi 2019 1-15 Electronic journal of qualitative theory of differential equations In this paper, we study the bifurcation of limit cycles of the periodic annulus of two classes of cubic isochronous systems. By using complete elliptic integrals of the first, second kinds and the Chebyshev criterion, we show that the upper bound for the number of limit cycles which appear from the periodic annuli of the two systems are at least three under cubic perturbations. Moreover, there exists a perturbation that give rise to exactly i limit cycles bifurcating from the period annulus for each i = 0, 1, 2, 3. Bifurkáció, Perturbáció Lai Yongzeng aut A Chunxiang aut http://acta.bibl.u-szeged.hu/62274/1/ejqtde_2019_050_001-015.pdf Dokumentum-elérés