Limit Cycles for two families of cubic systems

In this paper we study the number of limit cycles of two families of cubic systems introduced in previous papers to model real phenomena. The first one is motivated by a model of star formation histories in giant spiral galaxies and the second one comes from a model of Volterra type. To prove our re...

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Detalles Bibliográficos
Autores: Gasull, Armengol|||0000-0002-1719-8231, Prohens, Rafel|||0000-0003-1184-6311
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:150519
Acceso en línea:https://ddd.uab.cat/record/150519
https://dx.doi.org/urn:doi:10.1016/j.na.2012.07.012
Access Level:acceso abierto
Palabra clave:Cubic system
Kolmogorov system
Limit cycle
Bifurcation
Descripción
Sumario:In this paper we study the number of limit cycles of two families of cubic systems introduced in previous papers to model real phenomena. The first one is motivated by a model of star formation histories in giant spiral galaxies and the second one comes from a model of Volterra type. To prove our results we develop a new criterion on non-existence of periodic orbits and we extend a well-known criterion on uniqueness of limit cycles due to Kuang and Freedman. Both results allow to reduce the problem to the control of the sign of certain functions that are treated by algebraic tools. Moreover, in both cases, we prove that when the limit cycles exist they are non-algebraic.