{ "id": "2105.13152", "version": "v1", "published": "2021-05-27T13:54:50.000Z", "updated": "2021-05-27T13:54:50.000Z", "title": "On Ramanujan's Modular Equations and Hecke Groups", "authors": [ "Md. Shafiul Alam" ], "categories": [ "math.NT", "math.CV" ], "abstract": "We study the relation between Hecke groups and the modular equations in Ramanujan's theories of signature 2, 3 and 4. The solution $(\\alpha,\\beta)$ to the generalized modular equation satisfies a polynomial equation $P(\\alpha,\\beta)=0$ and we determine the degree in each of $\\alpha$ and $\\beta$ of the polynomial $P(\\alpha,\\beta)$ in terms of the indices of Hecke subgroups. We establish some mutually equivalent statements related to Hecke subgroups and modular equations, and prove that $(\\alpha,\\beta)$ and $(1-\\beta,1-\\alpha)$ satisfy the same polynomial equation.", "revisions": [ { "version": "v1", "updated": "2021-05-27T13:54:50.000Z" } ], "analyses": { "subjects": [ "30F35", "11F06", "33C05" ], "keywords": [ "ramanujans modular equations", "hecke groups", "hecke subgroups", "polynomial equation", "generalized modular equation satisfies" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }