{ "id": "1504.00999", "version": "v1", "published": "2015-04-04T10:02:32.000Z", "updated": "2015-04-04T10:02:32.000Z", "title": "Parametrizing elliptic curves by modular units", "authors": [ "François Brunault" ], "comment": "7 pages, comments welcome!", "categories": [ "math.NT" ], "abstract": "It is well-known that every elliptic curve over the rationals admits a parametrization by means of modular functions. In this short note, we show that only finitely many elliptic curves over $\\mathbf{Q}$ can be parametrized by modular units. This answers a question raised by Zudilin in a recent work on Mahler measures. Further, we give the list of all elliptic curves $E$ of conductor up to $1000$ parametrized by modular units supported in the rational torsion subgroup of $E$. Finally, we raise several open questions.", "revisions": [ { "version": "v1", "updated": "2015-04-04T10:02:32.000Z" } ], "analyses": { "subjects": [ "11F03", "11G05", "11G16", "14H52" ], "keywords": [ "modular units", "parametrizing elliptic curves", "rational torsion subgroup", "rationals admits", "open questions" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150400999B" } } }