{ "id": "1701.02458", "version": "v1", "published": "2017-01-10T07:47:40.000Z", "updated": "2017-01-10T07:47:40.000Z", "title": "Bounds on 2-torsion in class groups of number fields and integral points on elliptic curves", "authors": [ "Manjul Bhargava", "Arul Shankar", "Takashi Taniguchi", "Frank Thorne", "Jacob Tsimerman", "Yongqiang Zhao" ], "comment": "12 pages", "categories": [ "math.NT" ], "abstract": "We prove the first known nontrivial bounds on the sizes of the 2-torsion subgroups of the class groups of cubic and higher degree number fields $K$ (the trivial bound being $O_{\\epsilon}(|{\\rm Disc}(K)|^{1/2+\\epsilon})$ by Brauer--Siegel). This yields corresponding improvements to: 1) bounds of Brumer and Kramer on the sizes of 2-Selmer groups and ranks of elliptic curves; 2) bounds of Helfgott and Venkatesh on the number of integral points on elliptic curves; 3) bounds on the sizes of 2-Selmer groups and ranks of Jacobians of hyperelliptic curves; and 4) bounds of Baily and Wong on the number of $A_4$-quartic fields of bounded discriminant.", "revisions": [ { "version": "v1", "updated": "2017-01-10T07:47:40.000Z" } ], "analyses": { "subjects": [ "11R29", "11G05" ], "keywords": [ "integral points", "class groups", "higher degree number fields", "yields corresponding improvements", "quartic fields" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }