Upper bounds for the number of zeroes for some Abelian integrals

Consider the vector field x' = -yG(x, y), y' = xG(x, y), where the set of critical points {G(x, y) = 0} is formed by K straight lines, not passing through the origin and parallel to one or two orthogonal directions. We perturb it with a general polynomial perturbation of degree n and study...

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Detalles Bibliográficos
Autores: Gasull, Armengol|||0000-0002-1719-8231, Torregrosa, Joan|||0000-0002-2753-1827
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:150551
Acceso en línea:https://ddd.uab.cat/record/150551
https://dx.doi.org/urn:doi:10.1016/j.na.2012.04.033
Access Level:acceso abierto
Palabra clave:Abelian integrals
Weak 16th Hilbert's Problem
Limit cycles
Chebyshev system
Number of zeroes of real functions
Descripción
Sumario:Consider the vector field x' = -yG(x, y), y' = xG(x, y), where the set of critical points {G(x, y) = 0} is formed by K straight lines, not passing through the origin and parallel to one or two orthogonal directions. We perturb it with a general polynomial perturbation of degree n and study which is the maximum number of limit cycles that can bifurcate from the period annulus of the origin in terms of K and n. Our approach is based on the explicit computation of the Abelian integral that controls the bifurcation and in a new result for bounding the number of zeroes of a certain family of real functions. When we apply our results for K ≤ 4 we recover or improve some results obtained in several previous works.