Connections and regularity on the tangent and cotangent bundle.
Connections between symmetries and conservation laws.
Conservation Criteria, Canonical Transformations, and Integral Invariants in the Field Theory of Carathéodory for Multiple Integral Variational Problems. (Short Communication).
Conservation criteria, canonical transformations, and integral invariants in the field theory of Carathéodory for multiple integral variational problems.
Conservation laws and symmetry in economic growth models: a geometrical approach.
The aim of the present paper is twofold. On one hand, we present a classification of infinitesimal symmetries for Lagrangian systems, and the corresponding Noether theorems. The derivation of the result is made by using the symplectic techniques. Some of the results were previously obtained by other authors (see Prince (1985) for instance), and an exhaustive presentation can be found in de León and Martín de Diego (1995, 1996). Let us note that these results are true even if the Lagrangian function...
Construcción de campos vectoriales en base a integrales parciales dadas.
A mathematical model based on the principle of less contractions is proposed for the construction of velocity vector fields and forces from given integrals. Necessary algebraic conditions for the solution of the problem are deduced. In addition, the velocity vector field is extended in a neighbourhood of the integrals. Applications and examples are given.
Contact transformations in Wheeler-Feynman electrodynamics
Contribution to Theory of First Integrals for Nonholonomic Mechanical Systems
Convergence results for periodic solutions of nonautonomous Hamiltonian systems
We prove some stability results for a certain class of periodic solutions of nonautonomous Hamiltonian systems in the case of Hamiltonian functions either with subquadratic growth or homogeneous with superquadratic growth. Thus we extend to the nonautonomous case some results recently established by the Authors for the autonomous case.
Convergenza per l'equazione degli integrali primi associata al problema del rimbalzo
In this paper we present a few results on convergence for the prime integrals equations connected with the bounce problem. This approach allows both to prove uniqueness for the one-dimensional bounce problem for almost all permissible Cauchy data (see also [6]) and to deepen previous results (see [3], [5], [7]).
Could the classical relativistic electron be a strange attractor?
Critical diffusions
Critical Point Theorems for Indefinite Functionals.
Cruising in a central force field.
Description lagrangienne d'un boson scalaire à l'aide d'un triplet nucléaire
Differentiability of the transition semigroup of the stochastic Burgers equation, and application to the corresponding Hamilton-Jacobi equation
We consider a stochastic Burgers equation. We show that the gradient of the corresponding transition semigroup does exist for any bounded ; and can be estimated by a suitable exponential weight. An application to some Hamilton-Jacobi equation arising in Stochastic Control is given.
Differential dynamical systems in Lagrangian optimal control formulation. II. (Systemés dynamiques differéntielles á controle optimal formulation Lagrangienne. II.)
Differential equations with constraints in jet bundles: Lagrangian and Hamiltonian systems.
Diffusion times and stability exponents for nearly integrable analytic systems
For a positive integer n and R>0, we set . Given R>1 and n≥4 we construct a sequence of analytic perturbations (H j) of the completely integrable Hamiltonian on , with unstable orbits for which we can estimate the time of drift in the action space. These functions H j are analytic on a fixed complex neighborhood V of , and setting the time of drift of these orbits is smaller than (C(1/ɛ j)1/2(n-3)) for a fixed constant c>0. Our unstable orbits stay close to a doubly resonant surface,...
Dirac brackets in geometric dynamics