2 citations · 2 across the 5 of their papers we have counts for
5 papers
A remark on the Generalized Hodge Conjecture
Dario Portelli
Let X be a smooth, projective variety over the field of complex numbers. On the space H of its rational cohomology of degree i we have the arithmetic filtration F^p. On the other h…
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.
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…
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…
Threefolds in with a 3-dimensional family of plane curves
Emilia Mezzetti, Dario Portelli
A classification theorem is given of smooth threefolds of covered by a family of dimension at least three of plane integral curves of degree It is shown that…