Exploració per autor "Delshams Valdés, Amadeu"
Ara es mostren els items 41-60 de 86
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Geometric properties of the scattering map of a normally hyperbolic invariant manifold
(Elsevier, 2008)
Article
Accés obertGiven a normally hyperbolic invariant manifold Λ for a map f , whose stable and unstable invariant manifolds intersect transversally, we consider its associated scattering map. That is, the map that, given an asymptotic ... -
Global instability in the restricted planar elliptic three body problem
(2018-01-01)
Article
Accés obertThe restricted planar elliptic three body problem (RPETBP) describes the motion of a massless particle (a comet or an asteroid) under the gravitational field of two massive bodies (the primaries, say the Sun and Jupiter) ... -
Homoclinic billiard orbits inside symmetrically perturbed ellipsoids
(2000)
Article
Accés obertThe billiard motion inside an ellipsoid of ${\bf R}^{3}$ is completely integrable. If the ellipsoid is not of revolution, there are many orbits bi-asymptotic to its major axis. The set of bi-asymptotic orbits is described ... -
Homoclinic orbits of twist maps and billiards
(1997)
Article
Accés obertThe splitting of separatrices for hyperbolic fixed points of twist maps with $d$ degrees of freedom is studied through a real-valued function, called the Melnikov potential. Its non-degenerate critical points are associated ... -
Homoclinic orbits to invariant tori in Hamiltonian systems
(1998)
Article
Accés obertWe consider a perturbation of an integrable Hamiltonian system which possesses invariant tori with coincident whiskers (like some rotators and a pendulum). Our goal is to measure the splitting distance between the perturbed ... -
Homoclinic orbits to invariant tori near a homoclinic orbit to center-center-saddle equilibrium
(2003)
Article
Accés obertWe consider a perturbation of an integrable Hamiltonian vector field with three degrees of freedom with a center–center–saddle equilibrium having a homoclinic orbit or loop. With the help of a Poincaré map (chosen based ... -
Influència de Poincaré sobre el problema dels tres cossos
(2004-01-29)
Audiovisual
Accés obertLa famosa memòria sobre el problema de tres cossos que Poincaré presentà en juny del 1988 al concurs commemoratiu dels 60 anys del Rei Òscar de Suècia va rebre el premi el 20 de gener del 1989. Ara bé, la primera versió ... -
Instability of high dimensional Hamiltonian systems: Multiple resonances do not impede diffusion
(2016-05-14)
Article
Accés obertWe consider models given by Hamiltonians of the form View the MathML sourceH(I,f,p,q,t;e)=h(I)+¿j=1n±(12pj2+Vj(qj))+eQ(I,f,p,q,t;e) Turn MathJax on where I¿I¿Rd,f¿TdI¿I¿Rd,f¿Td, p,q¿Rnp,q¿Rn, t¿T1t¿T1. These are higher ... -
Instability of high dimensional Hamiltonian systems: Multiple resonances do not impede diffusion
(2013-06)
Report de recerca
Accés obertAbstract. We consider models given by Hamiltonians of the form H ( I;';p;q;t ; " ) = h ( I )+ n X j =1 1 2 p 2 j + V j ( q j ) + "Q ( I;';p;q;t ; " ) where I 2I R d ;' 2 T d ... -
KAM theory and a partial justification of Greene's criterion for non-twist maps
(1999)
Article
Accés obertWe consider perturbations of integrable area preserving non twist maps of the annulus those are maps in which the twist condition changes sign These maps appear in a variety of applications notably transport in atmospheric ... -
Lower and upper bounds for the splitting of separatrices of the pendulum under a fast quasiperiodic forcing
(1997)
Article
Accés obertQuasiperiodic perturbations with two frequencies $(1/\varepsilon ,\gamma /\varepsilon )$ of a pendulum are considered, where $\gamma $ is the golden mean number. We study the splitting of the three-dimensional invariant ... -
Melnikov potential for exact symplectic maps
(1997)
Article
Accés obertThe splitting of separatrices of hyperbolic fixed points for exact symplectic maps of $n$ degrees of freedom is considered. The non-degenerate critical points of a real-valued function (called the Melnikov potential) are ... -
Mixed dynamics in reversible maps with gure-8 homoclinic connections
(2014)
Text en actes de congrés
Accés obertWe study dynamics and bifurcations of two-dimensional reversible maps having non-transversal heteroclinic cycles containing symmetric saddle periodic points. We consider one-parameter families of rev ersible maps unfolding ... -
Mixed dynamics of two-dimensional reversible maps with a symmetric couple of quadratic homoclinic tangencies
(American Institute of Mathematical Sciences, 2018-09)
Article
Accés obertWe study dynamics and bifurcations of 2-dimensional reversible maps having a symmetric saddle fixed point with an asymmetric pair of nontransversal homoclinic orbits (a symmetric nontransversal homoclinic figure-8). We ... -
On bifurcations of area-preserving and nonorientable maps with quadratic homoclinic tangencies
(Springer, 2014)
Article
Accés obertWe study bifurcations of nonorientable area-preserving maps with quadratic homoclinic tangencies. We study the case when the maps are given on nonorientable two-dimensional surfaces. We consider one- and two-parameter ... -
On bifurcations of homoclinic tangencies in area-preserving maps on non-orientable manifolds
(Springer, 2016)
Capítol de llibre
Accés restringit per política de l'editorialWe study bifurcations of non-orientable area-preserving maps with quadratic homoclinic tangencies. We study the case when the maps are given on non-orientable two-dimensional manifolds. We consider one and two parameter ... -
On Birkhoff's conjecture about convex billiards
(1995)
Article
Accés obertBirkhoff conjectured that the elliptic billiard was the only integrable convex billiard. Here we prove a local version of this conjecture: any non-trivial symmetric entire perturbation of an elliptic billiard is non-integrable. -
On dynamics and bifurcations of area-preserving maps with homoclinic tangencies
(2015-09-01)
Article
Accés obertWe study bifurcations of area-preserving maps, both orientable (symplectic) and non-orientable, with quadratic homoclinic tangencies. We consider one and two parameter general unfoldings and establish results related to ... -
On the scattering map and homoclinic connections between Lyapunov orbits
(2005-09)
Comunicació de congrés
Accés obertHomoclinic and heteroclinic connections between planar Lyapunov orbits of the Sun-Earth and Earth-Moon models can be found by using their hyperbolic invariant manifolds and Poincare section representations. These connections ... -
Orbits of unbounded energy in quasi-periodic perturbations of geodesic flows
(2003)
Article
Accés obertWe show that certain mechanical systems, including a geodesic °ow in any dimension plus a quasi-periodic perturbation by a potential, have orbits of unbounded energy. The assumptions we make in the case of geodesic °ows ...
