Skip to main content
10 events
when toggle format what by license comment
Aug 30, 2022 at 21:03 comment added Chris Wuthrich @dandelion This is trivial: The composition of $\hat E[p] \cong E_1[p] \subset E[p]$ is an injective $\mathbb{Q}_p$-equivariant map. I actually view the isomorphism between $E_1(\mathbb{Q}_p)$ and $\hat E(p\mathbb{Z}_p)$ as an identification.
Aug 29, 2022 at 14:28 comment added Duality @Chris Wuthrich : $E_1[p] \cong \hat{E}[p]$ as a group is true, but from here, could you tell me how you prove set theoretic inclusion $E[p]⊇\hat{E}[p]$? Without proving this set theoretic inclusion, we cannot say $ \Bbb{Q}_p(E[p])⊇\Bbb{Q}_p( \hat{E}[p])$.
Aug 3, 2022 at 10:38 comment added Chris Wuthrich Sure, look at chapter VI and Proposition VII.2.2 in Silverman.
Aug 3, 2022 at 9:03 comment added Duality Oh, thank you. But is $ \Bbb{Q}_p(E[p])⊇\Bbb{Q}_p( \hat{E}[p])$ true in general?
Aug 2, 2022 at 23:51 comment added Chris Wuthrich If $E$ has good supersingular reduction, yes, $E[p]=\hat E[p]$ as Galois modules. If the reduction is good ordinary, then $0\to \hat E[p]\to E[p]\to \tilde E[p]\to 0$ is exact as Galois modules and so $\mathbb{Q}_p(E[p])$ is a bigger extension than the one for $\hat E$.
Aug 2, 2022 at 20:05 history edited Duality CC BY-SA 4.0
added 189 characters in body; edited title
Aug 2, 2022 at 20:01 history edited YCor CC BY-SA 4.0
removed capitals from title
Aug 2, 2022 at 19:38 history edited Duality
edited tags
S Aug 2, 2022 at 15:56 review First questions
Aug 2, 2022 at 15:59
S Aug 2, 2022 at 15:56 history asked Duality CC BY-SA 4.0