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Timeline for Action of a profinite group

Current License: CC BY-SA 3.0

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Apr 13, 2017 at 12:58 history edited CommunityBot
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May 1, 2014 at 9:49 comment added Jeremy Rickard That should read "does answer question 2 in the negative". I think the same example also answers question 3 in the negative.
May 1, 2014 at 9:38 comment added Jeremy Rickard Ignore my previous comment: I think I was confused, and Julian's example does answers question in the negative, even over $\mathbb{Z}_p$.
Apr 30, 2014 at 19:10 comment added Pablo What if $G$ is of order coprime to $p$? Can we say something in the $\mathbb{Z}_p$ case then?
Apr 30, 2014 at 18:46 comment added Jeremy Rickard In Julian's example, I think that $(p^2,1,0,0,\dots)$ and $(p^2,p,0,0,\dots)$ generate closed submodules with trivial intersection, so the counterexample that works over $\mathbb{F}_p$ doesn't seem to generalize in a straightforward way to $\mathbb{Z}_p$.
Apr 30, 2014 at 17:15 comment added Pablo Yes, you are right. I am still curious about the case of $\mathbb{Z}_p$. What happens there?
Apr 30, 2014 at 16:12 comment added Jeremy Rickard I hadn't noticed this question before. You probably realize this, but Julian's example, done over $\mathbb{F}_p$ instead of $\mathbb{Z}_p$, is precisely the Pontryagin dual of the example I gave in the other thread. Unfortunately, over $\mathbb{Z}_p$ it doesn't give an answer to question 2.
Apr 30, 2014 at 15:32 vote accept Pablo
May 1, 2014 at 11:27
Apr 30, 2014 at 15:32 history answered Pablo CC BY-SA 3.0