{ "id": "1811.10149", "version": "v1", "published": "2018-11-26T02:39:12.000Z", "updated": "2018-11-26T02:39:12.000Z", "title": "The average number of subgroups of elliptic curves over finite fields", "authors": [ "Corentin Perret-Gentil" ], "comment": "40 pages", "categories": [ "math.NT" ], "abstract": "By adapting the technique of David, Koukoulopoulos and Smith for computing sums of Euler products, and using their interpretation of results of Schoof \\`a la Gekeler, we determine the average number of subgroups (or cyclic subgroups) of an elliptic curve over a fixed finite field of prime size. This is in line with previous works computing the average number of (cyclic) subgroups of finite abelian groups of rank at most 2. A required input is a good estimate for the divisor function in both short interval and arithmetic progressions, that we obtain by combining ideas of Ivi\\'c--Zhai and Blomer.", "revisions": [ { "version": "v1", "updated": "2018-11-26T02:39:12.000Z" } ], "analyses": { "keywords": [ "average number", "elliptic curve", "finite abelian groups", "cyclic subgroups", "arithmetic progressions" ], "note": { "typesetting": "TeX", "pages": 40, "language": "en", "license": "arXiv", "status": "editable" } } }