28 citations · 61 across the 8 of their papers we have counts for
10 papers
Remarks on defective Fano manifolds
Paltin Ionescu, Francesco Russo
This note continues our previous work on special secant defective (specifically, conic connected and local quadratic entry locus) and dual defective manifolds. These are now well u…
Manifolds covered by lines and the Hartshorne Conjecture for quadratic manifolds
Paltin Ionescu, Francesco Russo
Small codimensional embedded manifolds defined byequations of small degree are Fano and covered by lines. They are complete intersections exactly when the variety of lines through…
On dual defective manifolds
Paltin Ionescu, Francesco Russo
An embedded manifold is dual defective if its dual variety is not a hypersurface. Using the geometry of the variety of lines through a general point, we characterize scrolls among…
Manifolds covered by lines, defective manifolds and a restricted Hartshorne Conjecture
Paltin Ionescu, Francesco Russo
Small codimensional embedded manifolds defined by equations of small degree are Fano and covered by lines. They are complete intersections exactly when the variety of lines through…
A view on extending morphisms from ample divisors
Mauro C. Beltrametti, Paltin Ionescu
The philosophy that ``a projective manifold is more special than any of its smooth hyperplane sections" was one of the classical principles of projective geometry. Lefschetz type r…
Varieties with quadratic entry locus, II
Paltin Ionescu, Francesco Russo
We continue the study, begun by the second author in math.AG/0701889, of secant defective manifolds having "simple entry loci". We prove that such manifolds are rational and descri…
Conic-connected Manifolds
Paltin Ionescu, Francesco Russo
We study a particular class of rationally connected manifolds, $X\subset \p^N$, such that two general points may be joined by a conic contained in . We prove that t…
Birational Geometry of Rationally Connected Manifolds via Quasi-lines
Paltin Ionescu
This is, mostly, a survey of results about the birational geometry of rationally connected manifolds, using rational curves analogous to lines in ({\it quasi-lines}…
On manifolds of small degree
Paltin Ionescu
Let be a complex projective manifold of degree and arbitrary dimension. The main result of this paper gives a classification of such manifolds (assumed moreover…
Rationality properties of manifolds containing quasi-lines
Paltin Ionescu, Daniel Naie
Let X be a complex, rationally connected, projective manifold. We show that X admits a modification X' that contains a quasi-line, ie a smooth rational curve whose normal bundle is…