{ "id": "1806.05552", "version": "v1", "published": "2018-06-14T13:53:30.000Z", "updated": "2018-06-14T13:53:30.000Z", "title": "A criterion for existence of Néron models of jacobians", "authors": [ "Giulio Orecchia" ], "comment": "35 pages. Comments are very welcome", "categories": [ "math.AG" ], "abstract": "N\\'eron models of abelian varieties do not necessarily exist if the base $S$ has dimension higher than 1. We introduce a new condition, called toric additivity, on a family of smooth curves having nodal reduction over a normal crossing divisor $D\\subset S$. The condition is necessary and sufficient for existence of a N\\'eron model of the jacobian of the family; it depends only on the Betti numbers of the dual graphs of the fibres of the family, or on the toric ranks of the fibres of the jacobian.", "revisions": [ { "version": "v1", "updated": "2018-06-14T13:53:30.000Z" } ], "analyses": { "subjects": [ "14H10", "14D06" ], "keywords": [ "néron models", "neron model", "dimension higher", "smooth curves", "nodal reduction" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable" } } }