Sheaves and D-Modules on Lorentzian Manifolds

We introduce a class of causal manifolds which contains the globally hyperbolic spacetimes and we prove global propagation theorems for sheaves on such manifolds. As an application, we solve globally the Cauchy problem for hyperfunction solutions of hyperbolic systems.
v2: we added the hypothesis that the cone defining a causal manifold is nowhere empty and other minor corrections