Threefolds of non negative Kodaira dimension with sectional genus less than or equal to 15

Elvira Laura Livorni; Andrew John Sommese

Displaying similar documents to “Threefolds of non negative Kodaira dimension with sectional genus less than or equal to 15”

On the dimension of the adjoint linear system for threefolds

M. C. Beltrametti, A. J. Sommese (1995)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

Similarity:

Threefolds with nef anticanonical bundles.

Thomas Peternell, Fernando Serrano (1998)

Collectanea Mathematica

Similarity:

In this paper we study the global structure of projective threefolds X whose anticanonical bundle -KX is nef.

Subsheaves of the cotangent bundle

Paolo Cascini (2006)

Open Mathematics

Similarity:

For any smooth projective variety, we study a birational invariant, defined by Campana which depends on the Kodaira dimension of the subsheaves of the cotangent bundle of the variety and its exterior powers. We provide new bounds for a related invariant in any dimension and in particular we show that it is equal to the Kodaira dimension of the variety, in dimension up to 4, if this is not negative.

Seshadri positive submanifolds of polarized manifolds

Lucian Bădescu, Mauro Beltrametti (2013)

Open Mathematics

Similarity:

Let Y be a submanifold of dimension y of a polarized complex manifold (X, A) of dimension k ≥ 2, with 1 ≤ y ≤ k−1. We define and study two positivity conditions on Y in (X, A), called Seshadri A-bigness and (a stronger one) Seshadri A-ampleness. In this way we get a natural generalization of the theory initiated by Paoletti in [Paoletti R., Seshadri positive curves in a smooth projective 3-fold, Atti Accad. Naz. Lincei Cl. Sci. Fis. Mat. Natur. Rend. Lincei (9) Mat. Appl., 1996, 6(4),...

Classification of projective surfaces with small sectional genus : char $p$ > $0$

M. Andreatta, E. Ballico (1990)

Rendiconti del Seminario Matematico della Università di Padova

Similarity:

Minimal sections of conic bundles

Atanas Iliev (1999)

Bollettino dell'Unione Matematica Italiana

Similarity:

Sia $p : X \to P^{2}$ un fibrato in coniche standard con curva discriminante $Δ$ di grado $d$ . La varietà delle sezioni minime delle superfici $p^{- 1} (C)$ , dove $C$ è una curva di grado $d - 3$ , si spezza in due componenti $C_{+}$ e $C_{-}$ . Si prova che, mediante la mappa di Abel-Jacobi $Φ$ , una di queste componenti domina la Jacobiana intermedia $J X$ , mentre l'altra domina il divisore theta $Θ \subset J X$ . Questi risultati vengono applicati ad alcuni threefold di Fano birazionalmente equivalenti a un fibrato in coniche. In particolare si prova che...

Ample vector bundles with zero loci having a bielliptic curve section.

Antonio Lanteri, Hidetoshi Maeda (2003)

Collectanea Mathematica

Similarity:

Threefolds with big and nef anticanonical bundles II

Priska Jahnke, Thomas Peternell, Ivo Radloff (2011)

Open Mathematics

Similarity:

In a follow-up to our paper [Threefolds with big and nef anticanonical bundles I, Math. Ann., 2005, 333(3), 569–631], we classify smooth complex projective threefolds Xwith −K X big and nef but not ample, Picard number γ(X) = 2, and whose anticanonical map is small. We assume also that the Mori contraction of X and of its flop X + are not both birational.