Automorphisms of projective manifolds

Let (M,P∇M) be a compact projective manifold and Aut(M,P∇M) its group of automorphisms. The purpose of this paper is to study the topological properties of (M,P∇M) if Aut(M,P∇M)) is not discrete by applying the results of [13] and the Benzekri's functor which associates to a projective manifold a radiant affine manifold. This enables us to show that the orbits of the connected component of Aut(M,P∇M) are immersed projective submanifolds. We also classify $3$-dimensional compact projective manifolds such that dim(Aut(M,P∇M))≥ 2.