Singularities of wave fronts at the boundary between two media
Solutions d'équations d'Hamilton-Jacobi et géométrie symplectique
Structures symplectiques singulières génériques
Soit une variété différentiable de dimension paire munie d’une 2-forme différentielle fermée générique . L’apparition éventuelle d’un lieu de dégénérescence du rang de est l’obstacle à ce que soit une structure symplectique. Nous étudions les propriétés géométriques de et nous caractérisons l’algèbre des hamiltoniennes admissibles de i.e. les fonctions différentiables qui possèdent un champ hamiltonien sur .
Sul problema del rimbalzo in un insieme convesso
In the present paper we seek the bounce trajectories in a convex set which assume assigned positions in two fixed time instants. We find sufficient conditions in order to obtain the existence of infinitely many bounce trajectories.
Symmetry transformation in extended phase space: the harmonic oscillator in the Husimi representation.
Transformations canoniques des systèmes dégénérés.
Ueber die Jacobi-Hamilton'sche Integrationsmethode der partiellen Differentialgleichungen erster Ordnung
Variational calculus in several variables : a hamiltonian approach
Waves of excitations in heterogeneous annular region, asymmetric arrangement
This paper deals with the propagation of waves around a circular obstacle. The medium is heterogeneous: the velocity is smaller in the inner region and greater in the outer region. The interface separating the two regions is also circular, and the obstacle is located eccentrically inside it. The different front portraits are classified.
Waves of excitations in heterogeneous annular region II. Strong asymmetry
Excitation wave propagation in a heterogeneous medium around a circular obstacle is investigated, when the obstacle is located very eccentrically with respect to the interfacial circle separating the slow inner and the fast outer region. Qualitative properties of the permanent wave fronts are described, and the calculated wave forms are presented.
Комплексный пространственно-временной лучевой метод и "квазифотоны"
Несколько замечаний об эллиптических координатах