Center Problem for trigonometric Liénard systems

We give a complete algebraic characterization of the non-degenerated centers for planar trigonometric Liénard systems. The main tools used in our proof are the classical results of Cherkas on planar analytic Liénard systems and the characterization of some subfields of the quotient field of the ring...

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Bibliographic Details
Authors: Gasull, Armengol|||0000-0002-1719-8231; Giné, Jaume|||0000-0001-7109-2553; Valls, Clàudia|||0000-0001-8279-1229
Format: Article
Publication date:2017
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:182524
Online Access:https://ddd.uab.cat/record/182524
https://dx.doi.org/urn:doi:10.1016/j.jde.2017.05.008
Access Level:Open access
Keyword:Center problem
Trigonometric Liénard equation
Trigonometric polynomial
Description
Summary:We give a complete algebraic characterization of the non-degenerated centers for planar trigonometric Liénard systems. The main tools used in our proof are the classical results of Cherkas on planar analytic Liénard systems and the characterization of some subfields of the quotient field of the ring of trigonometric polynomials. Our results are also applied to some particular subfamilies of planar trigonometric Liénard systems. The results obtained are reminiscent of the ones for planar polynomial Liénard systems but the proofs are different.