On the cyclicity of Kolmogorov polycycles

In this paper we study planar polynomial Kolmogorov's differential systems Xμ{x˙=f(x,y;μ),y˙=g(x,y;μ), with the parameter μ varying in an open subset Λ⊂RN. Compactifying Xμ to the Poincaré disc, the boundary of the first quadrant is an invariant triangle Γ, that we assume to be a hyperbolic polycycl...

Descripción completa

Detalles Bibliográficos
Autores: Marín, David|||0000-0003-4422-6418; Villadelprat Yagüe, Jordi|||0000-0002-1168-9750
Tipo de documento: Artículo
Fecha de publicación:2022
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Lenguaje:Inglés
OAI Identifier:oai:ddd.uab.cat:265184
Acceso en línea:https://ddd.uab.cat/record/265184
https://dx.doi.org/urn:doi:10.14232/ejqtde.2022.1.35
Nivel de acceso:Acceso abierto
Palabra clave:Limit cycle
Polycycle
Cyclicity
Asymptotic expansion
_version_ 1878729646825013248
author Marín, David|||0000-0003-4422-6418
author2 Villadelprat Yagüe, Jordi|||0000-0002-1168-9750
author2_role author
author_browse Marín, David|||0000-0003-4422-6418
Villadelprat Yagüe, Jordi|||0000-0002-1168-9750
author_facet Marín, David|||0000-0003-4422-6418
Villadelprat Yagüe, Jordi|||0000-0002-1168-9750
author_role author
collection Dipòsit Digital de Documents de la UAB
description In this paper we study planar polynomial Kolmogorov's differential systems Xμ{x˙=f(x,y;μ),y˙=g(x,y;μ), with the parameter μ varying in an open subset Λ⊂RN. Compactifying Xμ to the Poincaré disc, the boundary of the first quadrant is an invariant triangle Γ, that we assume to be a hyperbolic polycycle with exactly three saddle points at its vertices for all μ∈Λ. We are interested in the cyclicity of Γ inside the family {Xμ}μ∈Λ, i.e., the number of limit cycles that bifurcate from Γ as we perturb μ. In our main result we define three functions that play the same role for the cyclicity of the polycycle as the first three Lyapunov quantities for the cyclicity of a focus. As an application we study two cubic Kolmogorov families, with N=3 and N=5, and in both cases we are able to determine the cyclicity of the polycycle for all μ∈Λ, including those parameters for which the return map along Γ is the identity.
eu_rights_str_mv openAccess
format article
id ES_0c1cd7a2a46479ecd2a12f7f2ad3bae2
institution Universitat Autònoma de Barcelona
instname_str Universitat Autònoma de Barcelona
language eng
network_acronym_str ES
network_name_str España
oai_identifier_str oai:ddd.uab.cat:265184
publishDate 2022
publishDateSort 2022
reponame_str Dipòsit Digital de Documents de la UAB
spelling On the cyclicity of Kolmogorov polycycles Marín, David|||0000-0003-4422-6418 Villadelprat Yagüe, Jordi|||0000-0002-1168-9750 Limit cycle Polycycle Cyclicity Asymptotic expansion In this paper we study planar polynomial Kolmogorov's differential systems Xμ{x˙=f(x,y;μ),y˙=g(x,y;μ), with the parameter μ varying in an open subset Λ⊂RN. Compactifying Xμ to the Poincaré disc, the boundary of the first quadrant is an invariant triangle Γ, that we assume to be a hyperbolic polycycle with exactly three saddle points at its vertices for all μ∈Λ. We are interested in the cyclicity of Γ inside the family {Xμ}μ∈Λ, i.e., the number of limit cycles that bifurcate from Γ as we perturb μ. In our main result we define three functions that play the same role for the cyclicity of the polycycle as the first three Lyapunov quantities for the cyclicity of a focus. As an application we study two cubic Kolmogorov families, with N=3 and N=5, and in both cases we are able to determine the cyclicity of the polycycle for all μ∈Λ, including those parameters for which the return map along Γ is the identity. https://ddd.uab.cat/record/265184 https://dx.doi.org/urn:doi:10.14232/ejqtde.2022.1.35
spellingShingle On the cyclicity of Kolmogorov polycycles
Marín, David|||0000-0003-4422-6418
Limit cycle
Polycycle
Cyclicity
Asymptotic expansion
title On the cyclicity of Kolmogorov polycycles
title_full On the cyclicity of Kolmogorov polycycles
title_fullStr On the cyclicity of Kolmogorov polycycles
title_full_unstemmed On the cyclicity of Kolmogorov polycycles
title_short On the cyclicity of Kolmogorov polycycles
title_sort On the cyclicity of Kolmogorov polycycles
topic Limit cycle
Polycycle
Cyclicity
Asymptotic expansion
topic_facet Limit cycle
Polycycle
Cyclicity
Asymptotic expansion
url https://ddd.uab.cat/record/265184
https://dx.doi.org/urn:doi:10.14232/ejqtde.2022.1.35