{ "id": "1909.07468", "version": "v1", "published": "2019-09-16T20:31:29.000Z", "updated": "2019-09-16T20:31:29.000Z", "title": "Uniform bounds on the image of arboreal Galois representations attached to non-CM elliptic curves", "authors": [ "Michael Cerchia", "Jeremy Rouse" ], "comment": "While the main result is similar to some results of Lombardo and Tronto (1909.05376), our results were obtained independently and using somewhat different methods", "categories": [ "math.NT" ], "abstract": "Let $\\ell$ be a prime number and let $F$ be a number field and $E/F$ a non-CM elliptic curve with a point $\\alpha \\in E(F)$ of infinite order. Attached to the pair $(E,\\alpha)$ is the $\\ell$-adic arboreal Galois representation $\\omega_{E,\\alpha,\\ell^{\\infty}} : {\\rm Gal}(\\overline{F}/F) \\to \\mathbb{Z}_{\\ell}^{2} \\rtimes {\\rm GL}_{2}(\\mathbb{Z}_{\\ell})$ describing the action of ${\\rm Gal}(\\overline{F}/F)$ on points $\\beta_{n}$ so that $\\ell^{n} \\beta_{n} = \\alpha$. We give an explicit bound on the index of the image of $\\omega_{E,\\alpha,\\ell^{\\infty}}$ depending on how $\\ell$-divisible the point $\\alpha$ is, and the image of the ordinary $\\ell$-adic Galois representation. The image of $\\omega_{E,\\alpha,\\ell^{\\infty}}$ is connected with the density of primes $\\mathfrak{p}$ for which $\\alpha \\in E(\\mathbb{F}_{\\mathfrak{p}})$ has order coprime to $\\ell$.", "revisions": [ { "version": "v1", "updated": "2019-09-16T20:31:29.000Z" } ], "analyses": { "subjects": [ "11F80", "11G05", "12G05" ], "keywords": [ "non-cm elliptic curve", "uniform bounds", "adic arboreal galois representation", "adic galois representation", "order coprime" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }