A characterization of semiampleness and contractions of relative curves
Stefan Schroeer
Abstract
A line bundle with a base-point-free multiple is called semiample. I give a cohomological characterization of semiample line bundles. The result is a common generalization of the Fujita-Zariski criterion for semiampleness and the Grothendieck-Serre characterization of ampleness. Applying the Fujita-Zariski Theorem, I characterize contractible curves in 1-dimensional families.
Create a lesson
Related papers
The Tate Conjecture for Ordinary Calabi-Yau Threefolds
Lukas Brantner
Weighted, GIT and Néron--Tate heights on genus-two moduli and Jacobians
Sajad Salami
Monodromy of Tate-Linear varieties
Livia Grammatica
On the Cohomology Classes of Certain Eisenstein-Kronecker Forms
Zhixuan Sheng, Jie Zhou
Campana strong approximation on generalised Markoff surfaces
Dasheng Wei
Quillen's local parameter conjecture in dimension four
Yunpeng Li