Geodesics on nonstatic Lorentz manifolds of Reissner-Nordstrom type (Erratum).
Geodesics on open surfaces containing horns
Geodesics on product lorentzian manifolds
Geodesics on quadrics and a mechanical problem of C. Neumann.
Geodesics on S2 and periodic points of annulus homeomorphisms.
Geodesies on typical convex surfaces
Using Baire categories uniqueness of geodesic segments and existence of closed geodesics on typical convex surfaces are investigated.
Géodésiques pour des métriques riemanniennes semi-continues inférieurement
Geometric properties of a sequence of standard minimal immersions between spheres
Géométrie d'une famille de groupes agissant sur le produit de deux variétés d'Hadamard
Géométrie sous-riemannienne
Géométrie systolique et métriques polyèdrales sur les 3-variétés de Bieberbach
La systole d’une variété riemannienne compacte non simplement connexe est la plus petite longueur d’une courbe fermée non contractile ; le rapport systolique est le quotient . Sa borne supérieure, sur l’ensemble des métriques riemanniennes, est fini pour une large classe de variétés, dont les .On étudie le rapport systolique optimal des variétés de Bieberbach compactes, orientables de dimension qui ne sont pas des tores, et on démontre en utilisant des constructions de métriques polyèdrales...
Geometry of -step nilpotent groups with a left invariant metric
Geometry of compactifications of locally symmetric spaces
For a locally symmetric space , we define a compactification which we call the “geodesic compactification”. It is constructed by adding limit points in to certain geodesics in . The geodesic compactification arises in other contexts. Two general constructions of Gromov for an ideal boundary of a Riemannian manifold give for locally symmetric spaces. Moreover, has a natural group theoretic construction using the Tits building. The geodesic compactification plays two fundamental roles in...
Geometry of oblique projections
Let A be a unital C*-algebra. Denote by P the space of selfadjoint projections of A. We study the relationship between P and the spaces of projections determined by the different involutions induced by positive invertible elements a ∈ A. The maps sending p to the unique with the same range as p and sending q to the unitary part of the polar decomposition of the symmetry 2q-1 are shown to be diffeomorphisms. We characterize the pairs of idempotents q,r ∈ A with ||q-r|| < 1 such that...
Global Gronwall estimates for integral curves on Riemannian manifolds.
We prove Gronwall-type estimates for the distance of integral curves of smooth vector fields on a Riemannian manifold. Such estimates are of central importance for all methods of solving ODEs in a verified way, i.e., with full control of roundoff errors. Our results may therefore be seen as a prerequisite for the generalization of such methods to the setting of Riemannian manifolds.
Groupes du ping-pong et géodésiques fermées en courbure -1
Nous considérons une famille de groupes libres et discrets d’isométries orientées agissant sur la boule hyperbolique et contenant des transformations paraboliques; nous démontrons que le nombre de géodésiques fermées de de longueur au plus est équivalent à , où désigne l’exposant critique de la série de Poincaré.
Hardy inequalities in strips on ruled surfaces.
Harmonic analysis and Radon transforms on pencils of geodesics.
Harmonic Analysis for Vector Fields on Hyperbolic Spaces.
Harmonic Differentials and Closed Geodesics on a Riemann Surface.