In this paper we prove that for a complete manifold without conjugate points with sectional curvatures bounded below by $-c^2$ and whose geodesic flow is of Anosov type, then constant of contraction of the flow is $\geq e^{-c}$. Moreover, if M has finite volume the equality is hold if and only if the sectional curvature is constant. We also show some results similar to Oseledet's theorem for Anosov geodesic flows on a complete surface with finite volume. 查看全文>>