Varieties with Quadratic Entry
نویسندگان
چکیده
We continue the study, begun in [Ru], of secant defective manifolds having “simple entry loci”. We prove that such manifolds are rational and describe them in terms of tangential projections. Using also [IR], 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 dual defective manifolds should follow along the same lines.
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