{ "id": "1008.4008", "version": "v1", "published": "2010-08-24T10:53:51.000Z", "updated": "2010-08-24T10:53:51.000Z", "title": "A new basis for the space of modular forms", "authors": [ "Shinji Fukuhara" ], "comment": "AMS-LaTeX, 6 pages", "categories": [ "math.NT" ], "abstract": "Let $G_{2n}$ be the Eisenstein series of weight $2n$ for the full modular group $\\Gamma=SL_2(\\ZZ)$. It is well-known that the space $M_{2k}$ of modular forms of weight $2k$ on $\\Gamma$ has a basis $\\{G_{4}^\\alpha G_{6}^\\beta\\ |\\ \\alpha,\\beta\\in\\ZZ,\\ \\alpha,\\beta\\geq 0,\\ 4\\alpha+6\\beta=2k\\}$. In this paper we will exhibit another (simpler) basis for $M_{2k}$. It is given by $\\{G_{2k}\\}\\cup\\{G_{4i}G_{2k-4i}\\ |\\ i=1,2,\\ldots,d_k\\}$ if $2k\\equiv 0\\pmod 4$, and $\\{G_{2k}\\}\\cup\\{G_{4i+2}G_{2k-4i-2}\\ |\\ i=1,2,\\ldots,d_k\\}$ if $2k\\equiv 2\\pmod 4$ where $d_k+1=\\dim_{\\CC} M_{2k}$.", "revisions": [ { "version": "v1", "updated": "2010-08-24T10:53:51.000Z" } ], "analyses": { "subjects": [ "11F11", "11F67", "11F30" ], "keywords": [ "modular forms", "full modular group", "eisenstein series", "well-known" ], "note": { "typesetting": "LaTeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1008.4008F" } } }