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math.AG2000
On threefolds covered by lines
Emilia Mezzetti, Dario Portelli
A classification theorem is given of projective threefolds that are covered by a two-dimensional family of lines, but not by a higher dimensional family.
math.AG1998
Linear systems representing threefolds which are scrolls on a rational surface
Emilia Mezzetti, Dario Portelli
Let X be a scroll over a rational surface. We construct a linear system of surfaces in P^3 yielding a birational map from P^3 to X. We apply this construction to the scrolls of Bor…
math.AG1998
On smooth rational threefolds of P^5 with rational non-special hyperplane section
Emilia Mezzetti, Dario Portelli
It is known that the smooth rational threefolds of P^5 having a rational non-special surface of P^4 as general hyperplane section have degree d=3,... ,7. We study such threefolds X…