Page 1 Next

Displaying 1 – 20 of 79

Showing per page

On a certain generalization of spherical twists

Yukinobu Toda (2007)

Bulletin de la Société Mathématique de France

This note gives a generalization of spherical twists, and describe the autoequivalences associated to certain non-spherical objects. Typically these are obtained by deforming the structure sheaves of ( 0 , - 2 ) -curves on threefolds, or deforming -objects introduced by D.Huybrechts and R.Thomas.

On Buchsbaum bundles on quadric hypersurfaces

Edoardo Ballico, Francesco Malaspina, Paolo Valabrega, Mario Valenzano (2012)

Open Mathematics

Let E be an indecomposable rank two vector bundle on the projective space ℙn, n ≥ 3, over an algebraically closed field of characteristic zero. It is well known that E is arithmetically Buchsbaum if and only if n = 3 and E is a null-correlation bundle. In the present paper we establish an analogous result for rank two indecomposable arithmetically Buchsbaum vector bundles on the smooth quadric hypersurface Q n ⊂ ℙn+1, n ≥ 3. We give in fact a full classification and prove that n must be at most...

On Clifford's theorem for rank-3 bundles.

Herbert Lange, Peter E. Newstead (2006)

Revista Matemática Iberoamericana

In this paper we obtain bounds on h0(E) where E is a semistable bundle of rank 3 over a smooth irreducible projective curve X of genus g ≥ 2 defined over an algebraically closed field of characteristic 0. These bounds are expressed in terms of the degrees of stability s1(E), s2(E). We show also that in some cases the bounds are best possible. These results extend recent work of J. Cilleruelo and I. Sols for bundles of rank 2.

On generation of jets for vector bundles.

Mauro C. Beltrametti, Sandra Di Rocco, Andrew J. Sommese (1999)

Revista Matemática Complutense

We introduce and study the k-jet ampleness and the k-jet spannedness for a vector bundle, E, on a projective manifold. We obtain different characterizations of projective space in terms of such positivity properties for E. We compare the 1-jet ampleness with different notions of very ampleness in the literature.

Currently displaying 1 – 20 of 79

Page 1 Next