Compatibility of nonmaximal lips and origin cyclicity constructions
Determine whether a nonmaximal hierarchy of limit-cycle bifurcations near the Ilyashenko–Kotova lips in the perturbed polynomial Liénard family can be combined with additional limit cycles near the origin.
References
Whether a nonmaximal lips hierarchy can be combined with additional cycles near the origin is left open.
— Cyclicity of lips and center-focus problem near infinity
(2608.17773 - Chen et al., 18 Aug 2026) in Remark following Proposition \ref{prop:P3-not-origin-max}, Section 4, subsection “Cyclicity of a near-Hamiltonian system with lips”