Limit cycles for a class of discontinuous generalized Liénard polynomial differential equations

We divide R2 in l sectors S1, ..., Sl, with l > 1 even. We define in R2 a discontinuous differential system such that in each sector Sk, for k = 1, ..., l, is defined a smooth generalized Lienard polynomial differential equation ¨x + fi(x) ˙x + gi(x) = 0, i = 1, 2 alternatively, where fi and gi a...

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Detalhes bibliográficos
Autores: Llibre, Jaume|||0000-0002-9511-5999, Mereu, Ana Cristina
Formato: artículo
Fecha de publicación:2013
País:España
Recursos:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:150599
Acesso em linha:https://ddd.uab.cat/record/150599
Access Level:acceso abierto
Palavra-chave:Limit cycles
Non-smooth Liénard systems
Averaging theory
Descrição
Resumo:We divide R2 in l sectors S1, ..., Sl, with l > 1 even. We define in R2 a discontinuous differential system such that in each sector Sk, for k = 1, ..., l, is defined a smooth generalized Lienard polynomial differential equation ¨x + fi(x) ˙x + gi(x) = 0, i = 1, 2 alternatively, where fi and gi are polynomials of degree n−1 and m respectively. We apply the averaging theory of first order for discontinuous differential systems to this class of non-smooth generalized Lienard polynomial differential systems and we show that for any n and m there are such non-smooth Lienard polynomial equations having at least max{n, m} limit cycles. Note that this number is independent of l. Roughly speaking this result shows that the non-smooth classical (m = 1) Lienard polynomial differential systems can have at least the double number of limit cycles than the smooth ones, and that the non-smooth generalized Lienard polynomial differential systems can have at least one more limit cycle than the smooth ones. Of course, these comparisons are done with the present known results.