Varieties with Quadratic Entry Locus, Ii

We continue the study, begun in [Ru07], of secant defective man-ifolds having " simple entry loci ". We prove that such manifolds are rational and describe them in terms of tangential projections. Using also [IR07], their classification is reduced to the case of Fano manifolds of high index, whose Picard group is generated by the hyperplane section class. Conjecturally, the former should be linear sections of rational homogeneous manifolds. We also provide evidence that the classification of linearly normal dual defective man-ifolds with Picard group generated by the hyperplane section should follow along the same lines.