conjugatepoints. Then d is a … We consider a Riemannian metric don Rn which is a lift of some metric d on Torn = Rn/Zn. Thus dis invariant under the action of Zn by integer translations. We denote by UTTorn and UTRn the unit tangent bundles for metrics d and d. … Hereafter, we assume that d does not have conjugatepoints and hence the length of every geodesic segment is just the distance between its endpoints. For (x, v) ∈ UTRn we define …
Theorem 1. Let Torn be an n-dimensional torus with a Riemannian metric d which does not have conjugate points. Then d is a flat metric.