{ "id": "2107.05514", "version": "v1", "published": "2021-07-12T15:38:14.000Z", "updated": "2021-07-12T15:38:14.000Z", "title": "A positive proportion of quartic fields are not monogenic yet have no local obstruction to being so", "authors": [ "Levent Alpöge", "Manjul Bhargava", "Ari Shnidman" ], "comment": "14 pages, comments welcome", "categories": [ "math.NT", "math.AG" ], "abstract": "We show that a positive proportion of quartic fields are not monogenic, despite having no local obstruction to being monogenic. Our proof builds on the corresponding result for cubic fields that we obtained in a previous work. Along the way, we also prove that a positive proportion of quartic rings of integers do not arise as the invariant order of an integral binary quartic form despite having no local obstruction.", "revisions": [ { "version": "v1", "updated": "2021-07-12T15:38:14.000Z" } ], "analyses": { "subjects": [ "11R16", "11R45" ], "keywords": [ "local obstruction", "positive proportion", "quartic fields", "integral binary quartic form despite", "cubic fields" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }