Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-23T20:34:59.496Z Has data issue: false hasContentIssue false

On manifolds whose tangent bundle is big and 1-ample

Published online by Cambridge University Press:  08 September 2004

Luis Eduardo Solá Conde
Affiliation:
Departamento de Matematicas, Universidad Rey Juan Carlos, 28933 Mostoles, Madrid, Spain. E-mail: [email protected]
Jarosław A. Wiśniewski
Affiliation:
Institute of Mathematics, Warsaw University, Banacha 2, 02097 Warsaw, Poland. E-mail: [email protected]
Get access

Abstract

A line bundle over a complex projective variety is called big and 1-ample if a large multiple of it is generated by global sections and a morphism induced by the evaluation of the spanning sections is generically finite and has at most 1-dimensional fibers. A vector bundle is called big and 1-ample if the relative hyperplane line bundle over its projectivisation is big and 1-ample.

The main theorem of the present paper asserts that any complex projective manifold of dimension 4 or more, whose tangent bundle is big and 1-ample, is equal either to a projective space or to a smooth quadric. Since big and 1-ample bundles are ‘almost’ ample, the present result is yet another extension of the celebrated Mori paper ‘Projective manifolds with ample tangent bundles’ (Ann. of Math. 110 (1979) 593–606).

The proof of the theorem applies results about contractions of complex symplectic manifolds and of manifolds whose tangent bundles are numerically effective. In the appendix we re-prove these results.

Type
Research Article
Copyright
2004 London Mathematical Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)