Dipòsit Digital de Documents de la UAB 143 registres trobats  1 - 10següentfinal  anar al registre: La cerca s'ha fet en 0.03 segons. 
1.
Invariants of polynomial vector fields / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Valls, Clàudia 1973- (Universidade de Lisboa. Instituto Superior Técnico. Departamento de Matemàtica)
We characterize the existence of first integrals and invariants (first integrals depending on the time) for the polynomial vector fields which are invariant under an involution.
2023 - 10.1016/j.jde.2023.05.024
Journal of differential equations, Vol. 365 (August 2023) , p. 895-904  
2.
Global centers of the generalized polynomial Liénard differential systems / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Valls, Clàudia 1973- (Universidade de Lisboa. Instituto Superior Técnico. Departamento de Matemàtica)
The global centers started to be studied seriously at the end of the XX century. In the last decades, the generalized polynomial Liénard differential systems have been studied intensively. In this paper we characterize all the generalized polynomial Liénard differential systems having a global center at the origin. [...]
2022 - 10.1016/j.jde.2022.05.013
Journal of differential equations, Vol. 330 (September 2022) , p. 66-80  
3.
31 p, 607.7 KB On the cyclicity of Kolmogorov polycycles / Marín Pérez, David (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Villadelprat Yagüe, Jordi (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Centre de Recerca Matemàtica
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. [...]
2022 - 10.14232/ejqtde.2022.1.35
Electronic Journal of Qualitative Theory of Differential Equations, Vol. 35 (2022) , p. 1-31  
4.
79 p, 1.0 MB The criticality of reversible quadratic centers at the outer boundary of its period annulus / Marín Pérez, David (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Villadelprat Yagüe, Jordi (Universitat Rovira i Virgili. Departament d'Enginyeria Informàtica i Matemàtiques) ; Centre de Recerca Matemàtica
This paper deals with the period function of the reversible quadratic centers where . Compactifying the vector field to , the boundary of the period annulus has two connected components, the center itself and a polycycle. [...]
2022 - 10.1016/j.jde.2022.05.026
Journal of differential equations, Vol. 332 (Sep. 2022) , p. 123-201  
5.
13 p, 535.8 KB Global phase portraits of a predator-prey system / Diz-Pita, Érika (Universidade de Santiago de Compostela. Departamento de Estatística, Análise Matemática e Optimización) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Otero-Espinar, M. Victoria (Universidade de Santiago de Compostela. Departamento de Estatística, Análise Matemática e Optimización)
We classify the global dynamics of a family of Kolmogorov systems depend-ing on three parameters which has ecological meaning as it modelizes a predator-prey system. We obtain all their topologically distinct global phase portraits in the positive quadrant of the Poincaré disc, so we provide all the possible distinct dynamics of these systems.
2022 - 10.14232/ejqtde.2022.1.16
Electronic Journal of Qualitative Theory of Differential Equations, Vol. 2022, Issue 16 (2022) , p. 1-13
2 documents
6.
38 p, 850.7 KB Phase portraits of a family of Kolmogorov systems depending on six parameters / Diz-Pita, Érika (Universidade de Santiago de Compostela. Departamento de Estatística, Análise Matemática e Optimización) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Otero Espinar, Maria Victoria (Universidade de Santiago de Compostela. Departamento de Estatística, Análise Matemática e Optimización)
We consider a general 3-dimensional Lotka-Volterra system with a rational first integral of degree two of the form H = xi yj zk. The restriction of this Lotka-Volterra system to each surface H(x, y, z) = h varying h ∈ R provide Kolmogorov systems. [...]
2021
Electronic journal of differential equations, Vol. 2021, Issue 35 (2021) , p. 1-38
2 documents
7.
52 p, 1.1 MB Quadratic systems with an invariant algebraic curve of degree 3 and a Darboux invariant / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Oliveira, Regilene (Universidade de São Paulo. Instituto de Ciências Matemáticas e Computação) ; Rodrigues, Camila A. B. (Universidade Federal de Santa Catarina. Departamento de Matemática (Brazil))
Let QS be the class of non-degenerate planar quadratic differential systems and QS3 its subclass formed by the systems possessing an invariant cubic f(x, y) = 0. In this article, using the action of the group of real affine transformations and time rescaling on QS, we obtain all the possible normalforms for the quadratic systems in QS3. [...]
2021
Electronic journal of differential equations, Vol. 2021, Issue 69 (2021) , p. 1-52
2 documents
8.
38 p, 2.1 MB Limit cycles of planar discontinuous piecewise linear hamiltonian systems without equilibria separated by reducible cubics / Benterki, Rebiha (Université Mohamed El Bachir El Ibrahimi. Département de Mathématiques (Algeria)) ; Jimenez Ruiz, Jeidy Johana (Universidade Federal do Oeste da Bahia (Brazil)) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
Due to their applications to many physical phenomena during these last decades the interest for studying the discontinuous piecewise differential systems has increased strongly. The limit cycles play a main role in the study of any planar differential system, but to determine the maximum number of limits cycles that a class of planar differential systems can have is one of the main problems in the qualitative theory of the planar differential systems. [...]
2021 - 10.14232/ejqtde.2021.1.69
Electronic Journal of Qualitative Theory of Differential Equations, Vol. 2021, Issue 69 (2021) , p. 1-38
2 documents
9.
Melnikov functions of arbitrary order for piecewise smooth differential systems in Rn and applications / Chen, Xingwu (Sichuan University. Department of Mathematics) ; Li, Tao (Southwestern University of Finance and Economics. School of Economic Mathematics) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
In this paper we develop an arbitrary order Melnikov function to study limit cycles bifurcating from a periodic submanifold for autonomous piecewise smooth differential systems in R with two zones separated by a hyperplane. [...]
2022 - 10.1016/j.jde.2022.01.019
Journal of differential equations, Vol. 314 (March 2022) , p. 340-369  
10.
28 p, 467.4 KB Invariant algebraic surfaces of polynomial vector fields in dimension three / Kruff, Niclas (Rheinisch-Westfälische Technische Hochschule Aachen. Lehrstuhl A für Mathematik) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Pantazi, Chara (Universitat Politècnica de Catalunya. Departament de Matemàtiques) ; Walcher, Sebastian (Rheinisch-Westfälische Technische Hochschule Aachen. Lehrstuhl A für Mathematik)
We discuss criteria for the nonexistence, existence and computation of invariant algebraic surfaces for three-dimensional complex polynomial vector fields, thus transferring a classical problem of Poincaré from dimension two to dimension three. [...]
2021 - 10.1007/s10884-021-10080-8
Journal of dynamics and differential equations, (October 2021)
2 documents

Dipòsit Digital de Documents de la UAB : 143 registres trobats   1 - 10següentfinal  anar al registre:
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