Conservation of pseudo-norm in symmetric quantum mechanics
Nous illustrons une classification des espace-temps (2+1) globalement hyperboliques a courboure constant, en terms de certaines structures projectives complexes portées par les surfaces de niveau de leur temps cosmologique canonique. Ceci derive d’une theorie des rotations de Wick canoniques, developpée en collaboration avec Riccardo Benedetti [6], qui sera egalement brievement illustrée.
In this paper we obtain an interesting relation between the covariant derivatives of the Jacobi operator valid for all geodesic on the flag manifold . As a consequence, an explicit expression of the Jacobi operator independent of the geodesic can be obtained on such a manifold. Moreover, we show the way to calculate the Jacobi vector fields on this manifold by a new formula valid on every g.o. space.
It is still an open question whether a compact embedded hypersurface in the Euclidean space with constant mean curvature and spherical boundary is necessarily a hyperplanar ba1l or a spherical cap, even in the simplest case of a compact constant mean curvature surface in R3 bounded by a circle. In this paper we prove that this is true for the case of the scalar curvature. Specifica1ly we prove that the only compact embedded hypersurfaces in the Euclidean space with constant scalar curvature and...
L’objet de cette étude est de trouver des constantes explicites (dépendant d’un minimum d’invariants riemanniens et les plus faibles possible) dans différents types d’inégalités de Sobolev.