Displaying similar documents to “Quadratic vector fields in the plane have a finite number of limit cycles”

Codimension 4 singularities on reflectionally symmetryc planar vector fields.

Freddy Dumortier, Santiago Ibáñez (1999)

Publicacions Matemàtiques

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The paper deals with the topological classification of singularities of vector fields on the plane which are invariant under reflection with respect to a line. As it has been proved in previous papers, such a classification is necessary to determine the different topological types of singularities of vector fiels on R whose linear part is invariant under rotations. To get the classification we use normal form theory and the the blowing-up method.

The explosion of singular cycles

Rodrigo Bamon, Rafael Labarca, Ricardo Mañé, Maria-José Pacífico (1993)

Publications Mathématiques de l'IHÉS

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Formation of Singularities for Weakly Non-Linear N×N Hyperbolic Systems

Boiti, Chiara, Manfrin, Renato (2001)

Serdica Mathematical Journal

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We present some results on the formation of singularities for C^1 - solutions of the quasi-linear N × N strictly hyperbolic system Ut + A(U )Ux = 0 in [0, +∞) × Rx . Under certain weak non-linearity conditions (weaker than genuine non-linearity), we prove that the first order derivative of the solution blows-up in finite time.

Psi-series of quadratic vector fields on the plane.

Amadeu Delshams, Arnau Mir (1997)

Publicacions Matemàtiques

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Psi-series (i.e., logarithmic series) for the solutions of quadratic vector fields on the plane are considered. Its existence and convergence is studied, and an algorithm for the location of logarithmic singularities is developed. Moreover, the relationship between psi-series and non-integrability is stressed and in particular it is proved that quadratic systems with psi-series that are not Laurent series do not have an algebraic first integral. Besides, a criterion about non-existence...

Poincaré-Hopf index and partial hyperbolicity

C. A Morales (2008)

Annales de la faculté des sciences de Toulouse Mathématiques

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We use the theory of partially hyperbolic systems [HPS] in order to find singularities of index 1 for vector fields with isolated zeroes in a 3 -ball. Indeed, we prove that such zeroes exists provided the maximal invariant set in the ball is partially hyperbolic, with volume expanding central subbundle, and the strong stable manifolds of the singularities are unknotted in the ball.