Exploració per autor "Jorba, Angel"
Ara es mostren els items 9-27 de 27
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KAM Theory without action--angle variables
González, Alejandra; Jorba, Angel; Llave Canosa, Rafael de la; Villanueva Castelltort, Jordi (2003)
Article
Accés obertGiven a torus approximately invariant under a symplectic map, we find sufficient conditions for the existence of a true invariant torus close to the given one. We do not assume either that we are working on action-angle ... -
A la recerca de l'estabilitat efectiva dels asteroids trojans : algunes idees constructives de tècniques KAM sense ssar coordenades acció-angle
Jorba, Angel; Llave Canosa, Rafael de la; Villanueva Castelltort, Jordi (2000)
Text en actes de congrés
Accés obertXerrada pel Seminari de Sistemes Dinamics UB-UPC. Barcelona, dimecres 19 de gener de 2000. Els trojans son una familia d'asteroids amb orbites situades no molt lluny del punt $L_5$ del sistema Sol-Jupiter. Si integrem ... -
Lindstedt series for lower dimensional tori
Jorba, Angel; Llave Canosa, Rafael de la; Zou, Maorong (1995)
Article
Accés obertWe consider the existence and effective computation of low-dimensional (less independent frequencies than degrees of freedom) invariant tori of a near-integrable system. Lindstedt method is a systematic procedure to compute ... -
Lower and upper bounds for the splitting of separatrices of the pendulum under a fast quasiperiodic forcing
Delshams Valdés, Amadeu; Gelfreich, Vassili; Jorba, Angel; Martínez-Seara Alonso, M. Teresa (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 ... -
Nonlinear dynamics in an extended neighbourhood of the translunar equilibrium point
Jorba, Angel; Masdemont Soler, Josep (1995)
Article
Accés obert -
Normal-internal resonances in quasi-periodically forced oscillators: a conservative approach
Broer, H. W.; Hanssmann, Heinz; Jorba, Angel; Villanueva Castelltort, Jordi; Wagener, Florian (2003)
Article
Accés obertWe perform a bifurcation analysis of normal–internal resonances in parametrised families of quasi–periodically forced Hamiltonian oscillators, for small forcing. The unforced system is a one degree of freedom oscillator, ... -
Numerical computation of normal forms around some periodic orbits of the restricted three body problem
Jorba, Angel; Villanueva Castelltort, Jordi (1997)
Article
Accés obertIn this paper we introduce a general methodology for computing (numerically) the normal form around a periodic orbit of an autonomous analytic Hamiltonian system. The process follows two steps. First, we expand the ... -
On quasiperiodic perturbations of elliptic equilibrium points
Jorba, Angel; Simó Torres, Carlos (1995)
Article
Accés obertThis work focusses on quasiperiodic time-dependent perturbations of ordinary differential equations near elliptic equilibrium points. This means studying $$ \dot{x}=(A+\varepsilon Q(t,\varepsilon))x+\varepsilon ... -
On the normal behaviour of partially elliptic lower dimensional tori of hamiltonian systems
Jorba, Angel; Villanueva Castelltort, Jordi (1996)
Article
Accés obertThe purpose of this paper is to study the dynamics near a reducible lower dimensional invariant tori of a finite-dimensional autonomous Hamiltonian system with $\ell$ degrees of freedom. We will focus in the case in ... -
On the persistence of lower dimensional invariant tori under quasiperiodic perturbations
Jorba, Angel; Villanueva Castelltort, Jordi (1996)
Article
Accés obertIn this work we consider time dependent quasiperiodic perturbations of autonomous Hamiltonian systems. We focus on the effect that this kind of perturbations has on lower dimensional invariant tori. Our results show that, ... -
On the vertical families of two-dimensional tori near the triangular points of the bicircular problem
Castella Carlos, Enric; Jorba, Angel (1999)
Article
Accés obertThis paper focuses on some aspects of the motion of a small particle moving near the Lagrangian points of the Earth-Moon system. The model for the motion of the particle is the so-called Bicircular problem (BCP), that ... -
Quasi-periodic response solutions at normal-internal resonances
Broer, H. W.; Hanssmann, Heinz; Jorba, Angel; Villanueva Castelltort, Jordi; Wagener, Florian (2003)
Article
Accés obertIn the conservative dynamics of certain quasi-periodically forced oscillators, normal-internal resonances are considered in a bifurcational setting. The unforced system is a one degree of freedom oscillator, under forcing ... -
Splitting of separatrices for (fast) quasiperiodic forcing
Delshams Valdés, Amadeu; Gelfreich, Vassili; Jorba, Angel; Martínez-Seara Alonso, M. Teresa (1996)
Article
Accés obertWe consider fast quasiperiodic perturbations of a pendulum with two frequencies $(1,\gamma)$, where $\gamma$ is the golden mean number. For small perturbations such that its Fourier coefficients (the ones associated to ... -
Stability and asymptotic behaviour of the vertical family of periodic orbits around L_5 of the restricted three-body problem
Jorba, Angel; Villanueva Castelltort, Jordi (1997)
Article
Accés obertIn this work we study some numerical results about a family of periodic orbits of the Restricted Three Body Problem (RTBP). The family considered is one of the Lyapunov families related to the equlibrium point $L_5$. More ... -
Teoria Kam Sin Coordenadas Accion-Angulo
González, Alejandra; Jorba, Angel; Llave Canosa, Rafael de la; Villanueva Castelltort, Jordi (2001)
Article
Accés obertThe classical KAM methods, strongly supported on the use of canonical trans- formations in the action-angle context, are not effcient to be applied to a wide range of systems in which the Hamiltonian is known (for instance) ... -
The fine geometry of the Cantor families of invariant tori in hamiltonian systems
Jorba, Angel; Villanueva Castelltort, Jordi (2000)
Article
Accés obertThis work focuses on the dynamics around a partially elliptic, lower dimensional torus of a real analytic Hamiltonian system. More concretely, we investigate the abundance of invariant tori in the directions of the phase ... -
Unstable manifolds computation for the 2-D plane Poiseuille flow
Sánchez Casas, José Pablo; Jorba, Angel (2003)
Article
Accés obertWe follow the unstable manifold of periodic and quasi-periodic solutions for the Poiseuille problem, using two formulations: holding constant flux or mean pressure gradient. By means of a numerical integrator of the ... -
Unstable manifolds computation for the two-dimensional plane Poiseuille flow
Sánchez Casas, José Pablo; Jorba, Angel (2003)
Article
Accés obertIn this work we study some aspects of the dynamics of the plane Poiseuille problem in dimension 2, in what refers to the connection among different configurations of the flow. The fluid is confined in a channel of plane ... -
Unstable manifolds computation for the two-dimensional plane Poiseuille flow
Sánchez Casas, José Pablo; Jorba, Angel (2003)
Article
Accés obert