On the number of limit cycles in generalized abel equations

Given p, q ∊ Z ≥ 2 with p ≠ q, we study generalized Abel differential equations (Equation presented), where A and B are trigonometric polynomials of degrees n, m ≥ 1, respectively, and we are interested in the number of limit cycles (i.e., isolated periodic orbits) that they can have. More concretel...

Descripción completa

Detalles Bibliográficos
Autores: Huang, Jianfeng, Torregrosa, Joan|||0000-0002-2753-1827, Villadelprat Yagüe, Jordi|||0000-0002-1168-9750
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:236658
Acceso en línea:https://ddd.uab.cat/record/236658
https://dx.doi.org/urn:doi:10.1137/20M1340083
Access Level:acceso abierto
Palabra clave:Generalized Abel equations
Melnikov theory
Second order perturbation
Limit cycles
Descripción
Sumario:Given p, q ∊ Z ≥ 2 with p ≠ q, we study generalized Abel differential equations (Equation presented), where A and B are trigonometric polynomials of degrees n, m ≥ 1, respectively, and we are interested in the number of limit cycles (i.e., isolated periodic orbits) that they can have. More concretely, in this context, an open problem is to prove the existence of an integer, depending only on p, q, m, and n and that we denote by H p,q(n, m), such that the above differential equation has at most H p,q(n, m) limit cycles. In the present paper, by means of a second order analysis using Melnikov functions, we provide lower bounds of H p,q(n, m) that, to the best of our knowledge, are larger than the previous ones appearing in the literature. In particular, for classical Abel differential equations (i.e., p = 3 and q = 2), we prove that H 3,2(n, m) ≥ 2(n + m) - 1.