Pàgina inicial > Resultats de la cerca: Center-focus problem
  Consells de cerca
Cerca avançada
Cerca col·leccions:
Ordena'ls per: Mostrar els resultats: Format de visualizació:
Resultats globals: 12 registres trobats en 0.03 segons.
Articles, 12 registres trobats
Articles 12 registres trobats  1 - 10següent  anar al registre:
1.
11 p, 281.1 KB Cyclicity Near Infinity in Piecewise Linear Vector Fields Having a Nonregular Switching Line / Bastos, Jefferson L. R. (Universidade Estadual Paulista. Departamento de Matemática) ; Buzzi, Claudio (Universidade Estadual Paulista. Departamento de Matemática) ; Torregrosa, Joan (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
In this paper we recover the best lower bound for the number of limit cycles in the planar piecewise linear class when one vector field is defined in the first quadrant and a second one in the others. [...]
2023 - 10.1007/s12346-023-00817-9
Qualitative theory of dynamical systems, Vol. 22, Issue 4 (December 2023) , art. 125  
Registre complet - Creative Commons
2.
24 p, 407.3 KB Centers and limit cycles of vector fields defined on invariant spheres / Buzzi, Claudio (Universidade Estadual Paulista. Instituto de Biociências Letras e Ciências Exatas) ; Rodero, Ana Livia (Universidade Estadual Paulista. Instituto de Biociências Letras e Ciências Exatas) ; Torregrosa, Joan (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
The aim of this paper is the study of the center-focus and cyclicity problems inside the class X of 3-dimensional vector fields that admit a first integral that leaves invariant any sphere centered at the origin. [...]
2021 - 10.1007/s00332-021-09751-z
Journal of Nonlinear Science, Vol. 31, Issue 6 (December 2021) , art. 92  
Registre complet -
3.
9 p, 686.4 KB Chiellini Hamiltonian Liénard differential systems / Giné, Jaume (Universitat de Lleida. Departament de Matemàtica) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Valls, Clàudia 1973- (Universidade de Lisboa. Instituto Superior Técnico. Departamento de Matemática)
We characterize the centers of the Chiellini Hamiltonian Liénard second-order differential equations x' = y, y' = −f(x)y−g(x) where g(x) = f(x)(k−α(1 + α)Rf(x)dx) with α,k ∈ R. Moreover we study the phase portraits in the Poincaré disk of these systems when f(x) is linear.
2019
Electronic journal of differential equations, Vol. 2019, Issue 71 (2019) , p. 1-8
2 documents
Registre complet - Creative Commons
4.
20 p, 619.5 KB The center and cyclicity problems for quartic linear-like reversible systems / Da Cruz, Leonardo Pereira Costa (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Romanovski, Valery G. (University of Maribor. Center for Applied Mathematics and Theoretical Physics (Slovenia)) ; Torregrosa, Joan (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
In this paper we study a family of quartic linear-like reversible polynomial systems having a nondegenerate center at the origin. This family has degree one with respect to one of the variables. We are interested in systems in this class having two extra nondegenerate centers outside the straight line of symmetry. [...]
2020 - 10.1016/j.na.2019.111593
Nonlinear Analysis : Theory, Methods and Applications, Vol. 190 (January 2020) , art. 111593  
Registre complet - Creative Commons
5.
19 p, 441.0 KB Limit cycles in 4-star-symmetric planar piecewise linear systems / Buzzi, Claudio (Universidade Estadual Paulista. Departamento de Matemática (Brazil)) ; Medrado, Joao Carlos (Universidade Federal de Goiás. Instituto de Matemática e Estatística (Brazil)) ; Torregrosa, Joan (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
Our interest is centered in the study of the number of limit cycles for nonsmooth piecewise linear vector fields on the plane when the switching curve is xy=0. We consider the symmetric case. That is, one vector field defined in the odd quadrants and the other in the even ones. [...]
2020 - 10.1016/j.jde.2019.09.008
Journal of differential equations, Vol. 268, Issue 5 (February 2020) , p. 2414-2434  
Registre complet - Creative Commons
6.
15 p, 363.9 KB Simultaneity of centres in Zq-equivariant systems / Giné, Jaume (Universitat de Lleida. Departament de Matemàtica) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Valls, Clàudia 1973- (Instituto Superior Técnico. Departamento de Matemática (Portugal))
We study the simultaneous existence of centres for two families of planar Zq-equivariant systems. First, we give a short review about Zq-equivariant systems. Next, we present the necessary and sufficient conditions for the simultaneous existence of centres for a Z2-equivariant cubic system and for a Z2- equivariant quintic system.
2018 - 10.1098/rspa.2017.0811
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 474, Issue 2213 (May 2018) , art. 20170811  
Registre complet -
7.
47 p, 952.2 KB An inverse approach to the center problem / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Ramírez, Rafael Orlando (Universitat Rovira i Virgili. Departament d'Enginyeria Informàtica i Matemàtiques) ; Ramírez, Valentín (Universitat de Barcelona)
We consider analytic or polynomial vector fields of the form X=(-y+X)∂∂x+(x+Y)∂∂y, where X= X(x, y)) and Y= Y(x, y)) start at least with terms of second order. It is well-known that X has a center at the origin if and only if X has a Liapunov-Poincaré local analytic first integral of the form H=12(x2+y2)+∑j=3∞Hj, where H = H (x, y) is a homogenous polynomial of degree j. [...]
2019 - 10.1007/s12215-018-0342-1
Rendiconti del Circolo Matematico di Palermo, Vol. 68, Issue 1 (April 2019) , p. 29-64  
Registre complet -
8.
15 p, 625.2 KB Centers and uniform isochronous centers of planar polynomial differential systems / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Ramírez, Rafael Orlando (Universitat Rovira i Virgili. Departament d'Enginyeria Informàtica i Matemàtiques) ; Ramírez, Valentín (Universitat de Barcelona) ; Sadovskaia, Natalia (Universitat Politècnica de Catalunya. Departament de Matemàtica Aplicada II)
For planar polynomial vector fields of the form \[ (-y X(x,y)) x (x Y(x,y)) y, \] where X and Y start at least with terms of second order in the variables x and y, we determine necessary and sufficient conditions under which the origin is a center or a uniform isochronous centers.
2018 - 10.1007/s10884-018-9672-0
Journal of dynamics and differential equations, Vol. 30, issue 3 (Sep. 2018) , p. 1295-1310  
Registre complet -
9.
15 p, 853.0 KB Centers for the Kukles homogeneous systems with even degree / Giné, Jaume (Universitat de Lleida. Departament de Matemàtica) ; Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Valls, Clàudia 1973- (Universidade de Lisboa. Departamento de Matemàtica)
2017 - 10.11948/2017093
Journal of applied analysis and computation, Vol. 7 Núm. 4 (2017) , p. 1534-1548  
Registre complet -
10.
19 p, 311.7 KB Center conditions and cyclicity for a family of cubic systems: computer algebra approach / Fercec, Brigita (University of Maribor(Slovenia).Center for Applied Mathematics and Theoretical Physics) ; Mahdi, Adam (University of North Carolina at Charlotte. Mathematics Department)
Using methods of computational algebra we obtain an upper bound for the cyclicity of a family of cubic systems. To that end we overcome the problem of nonradicality of the associated Bautin ideal by moving from the ring of polynomials to a coordinate ring. [...]
2013 - 10.1016/j.matcom.2013.02.003
Mathematics and computers in simulation, Vol. 87 (2013) , p. 55-67  
Registre complet -

Articles : 12 registres trobats   1 - 10següent  anar al registre:
Us interessa rebre alertes sobre nous resultats d'aquesta cerca?
Definiu una alerta personal via correu electrònic o subscribiu-vos al canal RSS.
Dipòsit Digital de Documents de la UAB :: Cerca :: Lliura :: Personalitza :: Ajuda
Powered by Invenio v1.1.6
Mantingut per ddd.bib@uab.cat  :: Metadades subjectes a:
Col·laborem