Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8895914 | Journal of Algebra | 2018 | 31 Pages |
Abstract
Let E/Q be an elliptic curve and let Q(D4â) be the compositum of all extensions of Q whose Galois closure has Galois group isomorphic to a quotient of a subdirect product of a finite number of transitive subgroups of D4. In this article we first show that Q(D4â) is in fact the compositum of all D4 extensions of Q and then we prove that the torsion subgroup of E(Q(D4â)) is finite and determine the 24 possibilities for its structure. We also give a complete classification of the elliptic curves that have each possible torsion structure in terms of their j-invariants.
Related Topics
Physical Sciences and Engineering
Mathematics
Algebra and Number Theory
Authors
Harris B. Daniels,