2003/09/30 by Shigetaka Fukuda
Mathematics · #math.AG #msc:14E30
published as Cent. Eur. J. Math. 2 (2004), no. 3, 377--381(electronic) · 4 pages, LaTeX2e, the published version
arxiv created 2004/09/25 · arxiv updated 2009/12/01
Let (X, Δ) be a four-dimensional log variety that is projective over the field of complex numbers. Assume that (X, Δ) is not Kawamata log terminal (klt) but divisorial log terminal (dlt). First we introduce the notion of "log quasi-numerically positive", by relaxing that of "numerically positive". Next we prove that, if the log canonical divisor KX + Δ is log quasi-numerically positive on (X, Δ) then it is semi-ample.