Non-bifurcation of critical periods from semi-hyperbolic polycycles of quadratic centres

In this paper we consider the unfolding of saddle-node X=1xUa(x,y)(x(xμ-ε)∂x-Va(x)y∂y), parametrized by (ε,a) with ε≈0 and a in an open subset A of Rα, and we study the Dulac time T(s;ε,a) of one of its hyperbolic sectors. We prove (theorem 1.1) that the derivative ∂sT(s;ε,a) tends to -∞ as (s,ε)→(0...

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Detalhes bibliográficos
Autores: Marín, David|||0000-0003-4422-6418, Saavedra, M., Villadelprat Yagüe, Jordi|||0000-0002-1168-9750
Tipo de documento: artigo
Data de publicação:2023
País:España
Recursos:Universitat Autònoma de Barcelona
Repositório:Dipòsit Digital de Documents de la UAB
Idioma:inglês
OAI Identifier:oai:ddd.uab.cat:257112
Acesso em linha:https://ddd.uab.cat/record/257112
https://dx.doi.org/urn:doi:10.1017/prm.2021.72
Access Level:Acceso aberto
Palavra-chave:Period function
Saddle-node unfolding
Dulac time
Asymptotic expansions
Descrição
Resumo:In this paper we consider the unfolding of saddle-node X=1xUa(x,y)(x(xμ-ε)∂x-Va(x)y∂y), parametrized by (ε,a) with ε≈0 and a in an open subset A of Rα, and we study the Dulac time T(s;ε,a) of one of its hyperbolic sectors. We prove (theorem 1.1) that the derivative ∂sT(s;ε,a) tends to -∞ as (s,ε)→(0+,0) uniformly on compact subsets of A. This result is addressed to study the bifurcation of critical periods in the Loud's family of quadratic centres. In this regard we show (theorem 1.2) that no bifurcation occurs from certain semi-hyperbolic polycycles.