{ "id": "0908.0289", "version": "v1", "published": "2009-08-03T16:07:55.000Z", "updated": "2009-08-03T16:07:55.000Z", "title": "A classification of terminal quartic 3-folds and applications to rationality questions", "authors": [ "Anne-Sophie Kaloghiros" ], "comment": "40 pages", "categories": [ "math.AG" ], "abstract": "This paper studies the birational geometry of terminal Gorenstein Fano 3-folds. If Y is not Q-factorial, in most cases, it is possible to describe explicitly the divisor class group Cl Y by running a Minimal Model Program (MMP) on X, a small Q-factorialisation of Y. In this case, Weil non-Cartier divisors are generated by \"topological traces \" of K-negative extremal contractions on X. One can show, as an application of these methods, that a number of families of non-factorial terminal Gorenstein Fano 3-folds are rational. In particular, I give some examples of rational quartic hypersurfaces with Cl Y of rank 2, and show that when Cl Y has rank greater than 6, Y is always rational.", "revisions": [ { "version": "v1", "updated": "2009-08-03T16:07:55.000Z" } ], "analyses": { "subjects": [ "14E30" ], "keywords": [ "rationality questions", "terminal quartic", "application", "classification", "divisor class group cl" ], "note": { "typesetting": "TeX", "pages": 40, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0908.0289K" } } }