Incidence manifolds

It is shown that there are differentiable manifolds which can be characterized only by the geometric and topological structure of their linear subspaces. More precisely, such a characterization is possible for Grassmann and C. Segre's product manifolds. The starting point of this investigation was a paper by J. Misfeld, G. Tallini and the author 10], the ideas in which were further developed in 15,16,17].Dedicated to Professor Giuseppe Tallini on his 60^th birthday