{ "id": "math/0412279", "version": "v1", "published": "2004-12-14T13:30:39.000Z", "updated": "2004-12-14T13:30:39.000Z", "title": "On integral Hodge classes on uniruled or Calabi-Yau threefolds", "authors": [ "Claire Voisin" ], "categories": [ "math.AG" ], "abstract": "If X is a smooth projective complex threefold, the Hodge conjecture holds for degree 4 rational Hodge classes on X. Kollar gave examples where it does not hold for integral Hodge classes of degree 4, that is integral Hodge classes need not be classes of algebraic 1-cycles with integral coefficients. We show however that the Hodge conjecture holds for integral Hodge classes of degree 4 on a uniruled or a Calabi-Yau threefold.", "revisions": [ { "version": "v1", "updated": "2004-12-14T13:30:39.000Z" } ], "analyses": { "subjects": [ "14C25", "14J30", "14D07" ], "keywords": [ "integral hodge classes", "calabi-yau threefold", "hodge conjecture holds", "smooth projective complex threefold", "kollar gave examples" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math.....12279V" } } }