English

A Base Point Free Theorem of Reid Type, II

Algebraic Geometry 2007-05-23 v4

Abstract

Let XX be a complete algebraic variety over {\bf C}. We consider a log variety (X,Δ)(X,\Delta) that is weakly Kawamata log terminal. We assume that KX+ΔK_X+\Delta is a {\bf Q}-Cartier {\bf Q}-divisor and that every irreducible component of Δ\lfloor \Delta \rfloor is {\bf Q}-Cartier. A nef and big Cartier divisor HH on XX is called {\it nef and log big} on (X,Δ)(X,\Delta) if HBH |_B is nef and big for every center BB of non-"Kawamata log terminal" singularities for (X,Δ)(X,\Delta). We prove that, if LL is a nef Cartier divisor such that aL(KX+Δ)aL-(K_X+\Delta) is nef and log big on (X,Δ)(X,\Delta) for some aa \in {\bf N}, then the complete linear system mL| mL | is base point free for m0m \gg 0.

Cite

@article{arxiv.math/9801113,
  title  = {A Base Point Free Theorem of Reid Type, II},
  author = {Shigetaka Fukuda},
  journal= {arXiv preprint arXiv:math/9801113},
  year   = {2007}
}

Comments

AMS-TeX v2.1, 8 pages, note new e-mail address <fukuda@ha.shotoku.ac.jp> on the 1st page of the manuscript

R2 v1 2026-07-22T17:57:33.041Z