{ "id": "math/0311180", "version": "v1", "published": "2003-11-12T05:40:25.000Z", "updated": "2003-11-12T05:40:25.000Z", "title": "Vanishing cycles, the generalized Hodge Conjecture and Gröbner bases", "authors": [ "Ichiro Shimada" ], "comment": "30pages, 2 figures", "categories": [ "math.AG" ], "abstract": "Let $X$ be a general complete intersection of a given multi-degree in a complex projective space. Suppose that the anti-canonical line bundle of $X$ is ample. Using the cylinder homomorphism associated with the family of complete intersections contained in $X$, we prove that the vanishing cycles in the middle homology group of $X$ are represented by topological cycles whose support is contained in a proper Zariski closed subset $T\\subset X$ of certain codimension. In some cases, we can find such a Zariski closed subset $T$ with codimension equal to the upper bound obtained from the Hodge structure of the middle cohomology group of $X$ by means of Gr\\\"obner bases. Hence a consequence of the generalized Hodge conjecture is verified in these cases.", "revisions": [ { "version": "v1", "updated": "2003-11-12T05:40:25.000Z" } ], "analyses": { "subjects": [ "14C30", "14M10" ], "keywords": [ "generalized hodge conjecture", "vanishing cycles", "gröbner bases", "general complete intersection", "proper zariski closed subset" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2003math.....11180S" } } }