Muñoz Hernández, EduardoAlberto Espuny Díaz, Elena López-Navarro, Ana Navarro-Quiles2026-04-102026-04-102021Muñoz-Hernández, Eduardo. «Subharmonics in a class of planar periodic predator-prey models». En: TEMat monográficos, 2 (2021): Proceedings of the 3rd BYMAT Conference, págs. 31-34.https://hdl.handle.net/20.500.14352/134611This contribution studies the existence of positive subharmonics ofarbitrary order in the planar periodic Volterra predator-prey model. When themodel isnon-degenerate, in the sense that the birth rate of the prey intersects thesupport of the death rate of the predator, as in [8], then the existence of positivesubharmonics can be derived from the Poincaré–Birkhoff theorem version [3].Nevertheless, in thedegeneratecase when these supports do not intersect, then,the Poincaré–Birkhoff theorem fails in general. Still in these degenerate situations,the techniques of [7] provide us with the existence of positive subharmonics ofarbitrary order.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/conference paper2660-6003https://temat.es/monograficos/article/view/vol2-p31https://temat.es/monograficos/issue/view/vol-2open access517Matemáticas (Matemáticas)1202.19 Ecuaciones Diferenciales Ordinarias