464 research outputs found
Threefolds with nef anticanonical bundles
We prove that the Albanese map of a smooth projective threefold, whose
anticanonical bundle is nef, is a surjective submersion. We also investigate
morphisms of threefolds to curves and surfaces whose relative anticanonical
bundle are nef.Comment: plainTex, 47 pages, change in the introduction, paper will be appear
in Collectanea mathematica 49, volume in honour of F.Serran
On the Cone conjecture for Calabi-Yau manifolds with Picard number two
Following a recent work of Oguiso, we calculate explicitly the groups of
automorphisms and birational automorphisms on a Calabi-Yau manifold with Picard
number two. When the group of birational automorphisms is infinite, we prove
that the Cone conjecture of Morrison and Kawamata holds.Comment: to appear in Math. Res. Let
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