{ "id": "0706.4379", "version": "v1", "published": "2007-06-29T09:46:35.000Z", "updated": "2007-06-29T09:46:35.000Z", "title": "Quartic equations and 2-division on elliptic curves", "authors": [ "George H. Hitching" ], "comment": "20 pages", "categories": [ "math.AG" ], "abstract": "Let K be a field of characteristic different from 2 and C an elliptic curve over K given by a Weierstrass equation. To divide an element of the group C by 2, one must solve a certain quartic equation. We characterise the quartics arising from this procedure and find how far the quartic determines the curve and the point. We find the quartics coming from 2-division of 2- and 3-torsion points, and generalise this correspondence to singular plane cubics. We use these results to study the question of which degree 4 maps of curves can be realised as duplication of a multisection on an elliptic surface.", "revisions": [ { "version": "v1", "updated": "2007-06-29T09:46:35.000Z" } ], "analyses": { "subjects": [ "14H52", "14J27" ], "keywords": [ "elliptic curve", "quartic equation", "singular plane cubics", "weierstrass equation", "elliptic surface" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0706.4379H" } } }