On the number of limit cycles for some families of planar differential equations

The results included in this chapter involve an ad hoc compactification designed withtwo objectives. First, to unify the different behaviors of the functions in (4) satisfyingour hypothesis. And second, to make possible the comprehension of the global phaseportrait. The results of this chapter have...

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Bibliographic Details
Author: Pérez-González, Set|||0000-0002-1522-7086
Format: doctoral thesis
Publication Date:2012
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:106182
Online Access:https://ddd.uab.cat/record/106182
Access Level:Open access
Keyword:Sistemes dinàmics diferenciables
Cicles límits
Riemann-Hilbert, Problemes de
Description
Summary:The results included in this chapter involve an ad hoc compactification designed withtwo objectives. First, to unify the different behaviors of the functions in (4) satisfyingour hypothesis. And second, to make possible the comprehension of the global phaseportrait. The results of this chapter have also been done in collaboration with Pedro J.Torres. The aim of the third chapter is to obtain a global knowledge of the homoclinicconnection curve in the first quadrant of parameter space, where the limit cycles canappear, in the system associated to this Bogdanov-Takens normal form where the parameters,nandb, are real numbers. When the parameters vanish, theorigin shows a local structure of cusp point, a kind of degenerate singular point. But ifwe unfold this vector field, they appear several bifurcation curves, a Hopf bifurcation,a saddle-node bifurcation and a homoclinic connection curves.