An isomorphism between two elliptic curves $E$, $E'$ defined over a field $K$ is an isogeny $f:E\to E'$ such that there exist an isogeny $g:E'\to E$ with the compositions $g\circ f$ and $f\circ g$ being the identity maps. Equivalently, an isomorphism $E\to E'$ is an isogeny of degree $1$.
Isomorphism is an equivalence relation, the equivalnce classes being called isomorphism classes.
- Review status: reviewed
- Last edited by John Jones on 2018-06-19 22:24:01
- 2018-06-19 22:24:01 by John Jones (Reviewed)