Canonical forms for -structures in pseudo-riemannian manifolds
Closed geodesics, periods and arithmetic of modular forms.
Cohomologie bornée des surfaces et courants géodésiques
Collective geodesic flows
We show that most compact semi-simple Lie groups carry many left invariant metrics with positive topological entropy. We also show that many homogeneous spaces admit collective Riemannian metrics arbitrarily close to the bi-invariant metric and whose geodesic flow has positive topological entropy. Other properties of collective geodesic flows are also discussed.
Conditions under which a Geodesic Flow is Anosov.
Correspondances géodésiques entre les surfaces euclidiennes à singularités coniques.
A. J. Montesinos has shown that a geodesic correspondence between two complete Riemannian manifolds with transitive topological geodesic flow is a homothety. In this paper we prove a similar result for a conformal geodesic correspondence between two singular flat surfaces with conical singularities and negative concentrated curvature.
Courants ergodiques et répartition géométrique.