Threefolds with nef anticanonical bundles

Abstract

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