Universal centers in the cubic trigonometric Abel equation

We study the center problem for the trigonometric Abel equation dρ/dθ=a1(θ)ρ2+a2(θ)ρ3,dρ/dθ=a1(θ)ρ2+a2(θ)ρ3, where a1(θ)a1(θ) and a2(θ)a2(θ) are cubic trigonometric polynomials in θθ. This problem is closely connected with the classical Poincaré center problem for planar polynomial vector fields. A...

Descripción completa

Detalles Bibliográficos
Autores: Giné, Jaume, Grau Montaña, Maite, Santallusia Esvert, Xavier
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:Universitat de Lleida (UdL)
Repositorio:Repositori Obert UdL
OAI Identifier:oai:repositori.udl.cat:10459.1/49426
Acceso en línea:https://doi.org/10.14232/ejqtde.2014.1.1
http://hdl.handle.net/10459.1/49426
Access Level:acceso abierto
Palabra clave:Trigonometria
Trigonometry
Center problem
Abel differential equation
Universal center
Composition condition
Polynomial differential equations
Descripción
Sumario:We study the center problem for the trigonometric Abel equation dρ/dθ=a1(θ)ρ2+a2(θ)ρ3,dρ/dθ=a1(θ)ρ2+a2(θ)ρ3, where a1(θ)a1(θ) and a2(θ)a2(θ) are cubic trigonometric polynomials in θθ. This problem is closely connected with the classical Poincaré center problem for planar polynomial vector fields. A particular class of centers, the so-called universal centers or composition centers, is taken into account. An example of non-universal center and a characterization of all the universal centers for such equation are provided.