Modèles locaux de structures de Poisson singulières en dimension 3
Multibump solutions for Hamiltonian systems with fast and slow forcing
Si dimostra l'esistenza di infinite soluzioni «multi-bump» - e conseguentemente il comportamento caotico - per una classe di sistemi Hamiltoniani del secondo ordine della forma per sufficientemente piccolo. Qui , e sono funzioni strettamente positive e periodiche e è un potenziale superquadratico (ad esempio ).
Multi-symplectic Fourier pseudospectral method for the nonlinear Schrödinger equation.
Non singular Hamiltonian systems and geodesic flows on surfaces with negative curvature.
We extend here results for escapes in any given direction of the configuration space of a mechanical system with a non singular bounded at infinity homogeneus potential of degree -1, when the energy is positive. We use geometrical methods for analyzing the parallel and asymptotic escapes of this type of systems. By using Riemannian geometry methods we prove under suitable conditions on the potential that all the orbits escaping in a given direction are asymptotically parallel among themselves. We...
Normal forms of vector fields on Poisson manifolds
We study formal and analytic normal forms of radial and Hamiltonian vector fields on Poisson manifolds near a singular point.
On -tensor fields on symplectic manifolds
Two symplectic structures on a manifold determine a (1,1)-tensor field on . In this paper we study some properties of this field. Conversely, if is (1,1)-tensor field on a symplectic manifold then using the natural lift theory we find conditions under which , is symplectic.
On dissipative phenomena of the interaction of Hamiltonian systems.
On Lagrange epimorphisms and Lagrange submersions.
On order 5 symplectic explicit Runge-Kutta Nyström methods.
On some completions of the space of hamiltonian maps
In one of his papers, C. Viterbo defined a distance on the set of Hamiltonian diffeomorphisms of endowed with the standard symplectic form . We study the completions of this space for the topology induced by Viterbo’s distance and some others derived from it, we study their different inclusions and give some of their properties. In particular, we give a convergence criterion for these distances that allows us to prove that the completions contain non-ordinary elements, as for example, discontinuous...
On the classical and quantum evolution of lagrangian half-forms in phase space
On the minimal action function of autonomous lagrangians associated to magnetic fields
On the weak robustness of fuzzy matrices
A matrix in -algebra (fuzzy matrix) is called weakly robust if is an eigenvector of only if is an eigenvector of . The weak robustness of fuzzy matrices are studied and its properties are proved. A characterization of the weak robustness of fuzzy matrices is presented and an algorithm for checking the weak robustness is described.
On three-periodic trajectories of multi-dimensional dual billiards.
Poisson structures on having only two symplectic leaves: the origin and the rest
Examples of Poisson structures with isolated non-symplectic points are constructed from classical r-matrices.
Potentials unbounded below.
Reconstruction phases for Hamiltonian systems on cotangent bundles.
Symplectic Capacities in Manifolds
Symplectic capacities coinciding on convex sets in the standard symplectic vector space are extended to any subsets of symplectic manifolds. It is shown that, using embeddings of non-smooth convex sets and a product formula, calculations of some capacities become very simple. Moreover, it is proved that there exist such capacities which are distinct and that there are star-shaped domains diffeomorphic to the ball but not symplectomorphic to any convex set.
Symplectic field theory approach to studying ergodic measures related with nonautonomous Hamiltonian systems.
Symplectic Topology and Extemal Rays.