{ "id": "math/0608372", "version": "v2", "published": "2006-08-15T04:42:01.000Z", "updated": "2007-07-10T08:47:30.000Z", "title": "Period polynomials and explicit formulas for Hecke operators on Γ_0(2)", "authors": [ "Shinji Fukuhara", "Yifan Yang" ], "comment": "AMS-LaTeX, 30 pages, final version, to appear on the Mathematical Proceedings of the Cambridge Philosophical Society", "categories": [ "math.NT" ], "abstract": "Let S_{w+2}(\\Gamma_0(N)) be the vector space of cusp forms of weight w+2 on the congruence subgroup \\Gamma_0(N). We first determine explicit formulas for period polynomials of elements in S_{w+2}(\\Gamma_0(N)) by means of Bernoulli polynomials. When N=2, from these explicit formulas we obtain new bases for S_{w+2}(\\Gamma_0(2)), and extend the Eichler-Shimura-Manin isomorphism theorem to \\Gamma_0(2). This implies that there are natural correspondences between the spaces of cusp forms on \\Gamma_0(2) and the spaces of period polynomials. Based on these results, we will find explicit form of Hecke operators on S_{w+2}(\\Gamma_0(2)). As an application of our main theorems, we will also give an affirmative answer to a speculation of Imamo\\=glu and Kohnen on a basis of S_{w+2}(\\Gamma_0(2)).", "revisions": [ { "version": "v2", "updated": "2007-07-10T08:47:30.000Z" } ], "analyses": { "subjects": [ "11F25", "11F11", "11F67" ], "keywords": [ "period polynomials", "hecke operators", "cusp forms", "first determine explicit formulas", "eichler-shimura-manin isomorphism theorem" ], "note": { "typesetting": "LaTeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......8372F" } } }