{ "id": "2106.04579", "version": "v1", "published": "2021-06-08T15:09:40.000Z", "updated": "2021-06-08T15:09:40.000Z", "title": "On 7 division fields of CM elliptic curves", "authors": [ "Jessica Alessandrì", "Laura Paladino" ], "comment": "arXiv admin note: text overlap with arXiv:1808.00029", "categories": [ "math.NT" ], "abstract": "Let $\\mathcal{E}$ be a CM elliptic curve defined over a number field $K$, with Weiestrass form $y^3=x^3+bx$ or $y^2=x^3+c$. For every positive integer $m$, we denote by ${\\mathcal{E}}[m]$ the $m$-torsion subgroup of ${\\mathcal{E}}$ and by $K_m:=K({\\mathcal{E}}[m])$ the $m$-th division field, i.e. the extension of $K$ obtained by adding to it the coordinates of the points in ${\\mathcal{E}}[m]$. We classify all the fields $K_7$ in terms of generators, degrees and Galois groups. We also show some applications to the Local-Global Divisibility Problem and to modular curves and Shimura curves.", "revisions": [ { "version": "v1", "updated": "2021-06-08T15:09:40.000Z" } ], "analyses": { "keywords": [ "cm elliptic curve", "local-global divisibility problem", "th division field", "weiestrass form", "shimura curves" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }