Highest weak focus order for trigonometric Liénard equations

Given a planar analytic differential equation with a critical point which is a weak focus of order k, it is well known that at most k limit cycles can bifurcate from it. Moreover, in case of analytic Liénard differential equations this order can be computed as one half of the multiplicity of an asso...

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Detalles Bibliográficos
Autores: Gasull, Armengol|||0000-0002-1719-8231, Giné, Jaume|||0000-0001-7109-2553, Valls, Clàudia|||0000-0001-8279-1229
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:221357
Acceso en línea:https://ddd.uab.cat/record/221357
https://dx.doi.org/urn:doi:10.1007/s10231-019-00936-8
Access Level:acceso abierto
Palabra clave:Trigonometric Liénard equation
Weak focus
Cyclicity
Descripción
Sumario:Given a planar analytic differential equation with a critical point which is a weak focus of order k, it is well known that at most k limit cycles can bifurcate from it. Moreover, in case of analytic Liénard differential equations this order can be computed as one half of the multiplicity of an associated planar analytic map. By using this approach, we can give an upper bound of the maximum order of the weak focus of pure trigonometric Liénard equations only in terms of the degrees of the involved trigonometric polynomials. Our result extends to this trigonometric Liénard case a similar result known for polynomial Liénard equations.