{ "id": "1104.5031", "version": "v1", "published": "2011-04-26T20:44:37.000Z", "updated": "2011-04-26T20:44:37.000Z", "title": "Surjectivity of mod 2^n representations of elliptic curves", "authors": [ "Tim Dokchitser", "Vladimir Dokchitser" ], "comment": "3 pages", "journal": "Math. Zeitschrift, Vol. 272, Issue 3-4 (2012), 961-964", "doi": "10.1007/s00209-011-0967-7", "categories": [ "math.NT" ], "abstract": "For an elliptic curve E over Q, the Galois action on the l-power torsion points defines representations whose images are subgroups of GL_2(Z/l^n Z). There are three exceptional prime powers l^n=2,3,4 when surjectivity of the mod l^n representation does not imply that for l^(n+1). Elliptic curves with surjective mod 3 but not mod 9 representation have been classified by Elkies. The purpose of this note is to do this in the other two cases.", "revisions": [ { "version": "v1", "updated": "2011-04-26T20:44:37.000Z" } ], "analyses": { "subjects": [ "11G05", "11F80" ], "keywords": [ "elliptic curve", "surjectivity", "l-power torsion points defines representations", "exceptional prime powers", "galois action" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 3, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1104.5031D" } } }