Polarized Pushouts for Finite Fields
Algebraic Geometry
2007-05-23 v2
Abstract
Let p: Y--> X be a surjection between schemes projective over the algebraic closure of a finite field. Let L be a line bundle on X such that p^*(L) is globally generated. I give a natural necessary and sufficient condition under which some positive tensor power of L is globally generated. I apply this to give a sufficient condition for semi-ampleness of nef line bundles on the moduli space of stable pointed curves, in positive characteristic.
Cite
@article{arxiv.math/0204243,
title = {Polarized Pushouts for Finite Fields},
author = {Sean Keel},
journal= {arXiv preprint arXiv:math/0204243},
year = {2007}
}
Comments
Final Version. To appear in K60 volume of Communications in Algebra