Let $M$ be a smooth complex projective variety and let $L$ be a line bundle on it. Rays-positive manifolds, namely pairs $(M,L)$ such that $L$ is numerically effective and $L cdot R > 0$ for all extremal rays $R$ on $M$, are studied. Several illustrative examples and some applications are provided. In particular, projective varieties with crepant singularities and of small degree with respect to the codimension are classified, and the non-negativity of the sectional genus $g(M, L)$ is proven, describing as well the pairs with $g(M, L) = 0, 1$.

Geometry of rays-positive manifolds

NOVELLI, CARLA
2012-01-01

Abstract

Let $M$ be a smooth complex projective variety and let $L$ be a line bundle on it. Rays-positive manifolds, namely pairs $(M,L)$ such that $L$ is numerically effective and $L cdot R > 0$ for all extremal rays $R$ on $M$, are studied. Several illustrative examples and some applications are provided. In particular, projective varieties with crepant singularities and of small degree with respect to the codimension are classified, and the non-negativity of the sectional genus $g(M, L)$ is proven, describing as well the pairs with $g(M, L) = 0, 1$.
2012
63
375
391
http://link.springer.com/article/10.1007/s13348-011-0048-6?LI=true
Quasi-polarized varieties; Kawamata rationality theorem; rays-positive line bundle; adjunction theory; sectional genus; pseudo-effectivity; crepant singularity
M. C. Beltrametti; A. L. Knutsen; A. Lanteri; NOVELLI, CARLA
File in questo prodotto:
File Dimensione Formato  
11 - 2012 - BKLN - Rays-positive Mfds.pdf

Accesso riservato

Tipo di file: PDF EDITORIALE
Dimensione 302.67 kB
Formato Adobe PDF
302.67 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
1108.0897-BKLN.pdf

Accesso aperto

Descrizione: preprint
Tipo di file: PREPRINT (PRIMA BOZZA)
Dimensione 262.57 kB
Formato Adobe PDF
262.57 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1852272
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 3
  • ???jsp.display-item.citation.isi??? 3
social impact