{ "id": "1206.1990", "version": "v2", "published": "2012-06-10T02:58:49.000Z", "updated": "2013-09-30T03:49:09.000Z", "title": "On a generalization of the Mukai conjecture for Fano fourfolds", "authors": [ "Kento Fujita" ], "comment": "16 pages. v2: title changed, add references", "categories": [ "math.AG" ], "abstract": "Let X be a complex Fano manifold of dimension n. Let s(X) be the sum of l(R)-1 for all the extremal rays of X, the edges of the cone NE(X) of curves of X, where l(R) denotes the minimum of (-K_X \\cdot C) for all rational curves C whose class [C] belongs to R. We show that s(X)\\leq n if n\\leq 4. And for n\\leq 4, we completely classify the case the equality holds. This is a refinement of the Mukai conjecture on Fano fourfolds.", "revisions": [ { "version": "v2", "updated": "2013-09-30T03:49:09.000Z" } ], "analyses": { "subjects": [ "14J45", "14E30", "14J35" ], "keywords": [ "fano fourfolds", "mukai conjecture", "generalization", "complex fano manifold", "extremal rays" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1206.1990F" } } }