Résumé
In this paper, we show that, if a group G acts geometrically on a geodesically complete CAT(0) space X which contains at least one point with a CAT(-1) neighborhood, then G must be either virtually cyclic or acylindrically hyperbolic. As a consequence, the fundamental group of a compact Riemannian manifold whose sectional curvature is non positive everywhere and negative in at least one point is either virtually cyclic or acylindrically hyperbolic. This statement provides a precise interpretation of an idea expressed by Gromov in his paper Asymptotic invariants of infinite groups.