Zobrazeno 1 - 10
of 55
pro vyhledávání: '"Regilene Oliveira"'
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2021, Iss 45, Pp 1-90 (2021)
During the last forty years the theory of integrability of Darboux, in terms of algebraic invariant curves of polynomial systems has been very much extended and it is now an active area of research. These developments are covered in numerous papers a
Externí odkaz:
https://doaj.org/article/d6788e0583d143208fd37a64c012c87f
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2021, Iss 6, Pp 1-56 (2021)
Let QSH be the family of non-degenerate planar quadratic differential systems possessing an invariant hyperbola. We study this class from the viewpoint of integrability. This is a rich family with a variety of integrable systems with either polynomia
Externí odkaz:
https://doaj.org/article/2c50055f7f8348a0b777cbb2e157437b
Autor:
Regilene Oliveira, Claudia Valls
Publikováno v:
Electronic Journal of Differential Equations, Vol 2020, Iss 55,, Pp 1-19 (2020)
We study the global dynamics of the classic May-Leonard model in $\mathbb{R}^3$. Such model depends on two real parameters and its global dynamics is known when the system is completely integrable. Using the Poincare compactification on $\mathbb R
Externí odkaz:
https://doaj.org/article/497279b376a44a2798dec9f1a1da47ba
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2018, Iss 37, Pp 1-27 (2018)
The concepts of persistent and weakly persistent centers were introduced in 2009 and the same concept was applied in the study of some families of differential equations in 2013. Such concept was generalized for complex planar differential systems in
Externí odkaz:
https://doaj.org/article/7840db017b1243c0a872ee8ba4ebed3f
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2021, Iss 45, Pp 1-90 (2021)
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
During the last forty years the theory of integrability of Darboux, in terms of algebraic invariant curves of polynomial systems has been very much extended and it is now an active area of research. These developments are covered in numerous papers a
Publikováno v:
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Universidade de São Paulo (USP)
instacron:USP
In this paper we study global dynamic aspects of the quadratic system \begin{document}$ \dot x = yz,\quad \dot y = x-y,\quad \dot z = 1-x(\alpha y+\beta x), $\end{document} where \begin{document}$ (x,y,z) \in \mathbb R^3 $\end{document} and \begin{do
Publikováno v:
Recercat. Dipósit de la Recerca de Catalunya
instname
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
Recercat: Dipósit de la Recerca de Catalunya
Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
São Paulo Journal of Mathematical Sciences
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
instname
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
Recercat: Dipósit de la Recerca de Catalunya
Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
São Paulo Journal of Mathematical Sciences
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
We study the bifurcation of limit cycles from the periodic orbits of 2n–dimensional linear centers $${\dot{x}} = A_0 x$$ when they are perturbed inside classes of continuous and discontinuous piecewise linear differential systems of control theory
Publikováno v:
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Universitat Autònoma de Barcelona
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
In the weak 16th Hilbert problem, the Poincare-Pontryagin-Melnikov function, M 1 ( h ) , is used for obtaining isolated periodic orbits bifurcating from centers up to a first-order analysis. This problem becomes more difficult when a family of center
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::381276a89b705513448c4b8b82f08fe8
https://ddd.uab.cat/record/250673
https://ddd.uab.cat/record/250673
Autor:
Jaume Llibre, Regilene Oliveira
Publikováno v:
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
Universidade de São Paulo (USP)
instacron:USP
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
In Leonov and Kuznetsov (2013), the authors shown numerically the existence of a limit cycle surrounding the unstable node that system (1) has in the positive quadrant for specific values of the parameters. System (1) is one of the Belousov-Zhabotins
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::51503d9f6ef3ab14f37ac6f4dc47f431
Publikováno v:
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Universidade de São Paulo (USP)
instacron:USP
Consider the class QS of all non-degenerate planar quadratic systems and its subclass QSE of all its systems possessing an invariant ellipse. This is an interesting family because on one side it is defined by an algebraic geometric property and on th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::eb65068e1260676588be21344433c46c