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Jul 30, 2014 at 16:59 answer added Ben Wieland timeline score: 3
Jul 30, 2014 at 15:25 answer added guest timeline score: 3
Jul 30, 2014 at 14:33 comment added Chris Wuthrich Ok, I saw 3 on the linked post. I would disagree with that "canonical volume" interpretation to be very good for understanding the regulator. There is an symmetric bilinear form on $E(\mathbb{Q})$ with values in $\mathbb{R}$ defined for instance in Silverman's book VIII.9. The target here is the completion where the $L$-series takes values. In the $p$-adic BSD conjecture, the leading term of the $p$-adic $L$-series is linked to the canonical $p$-adic regulator coming from a bilinear form with values in $\mathbb{Q}_p$.
Jul 30, 2014 at 14:17 comment added Chris Wuthrich ? Sorry, I don't understand this. If the rank is 1, you have a "stack" $\mathbb{R}//\mathbb{Z}$. What sort of measure to you put on this to get the canonical height of the generator ?
Jul 30, 2014 at 13:39 history edited David Roberts CC BY-SA 3.0
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Jul 30, 2014 at 13:35 comment added David Roberts Well, for instance, $Reg_E/\#E_{tors}(\mathbb{Q})$ is the volume of the stack $E(\mathbb{Q})\otimes \mathbb{R}//E(\mathbb{Q})$, do the other terms assemble into a measure of such a thing? Namely, is there a geometric object, say over adeles, such that this is the measure of it?
Jul 30, 2014 at 13:15 comment added Chris Wuthrich Even this formulation is uniform in the different completions. Sha is the kernel to all completions; the regulator is the determinant of the height, which is a sum over all completions; the Tamagawa numbers and the archemedian periods are gathered as an adelic measure over all places (in the number field case, the product does not split canonically).
Jul 30, 2014 at 12:25 comment added David Roberts I really don't know anything about this, I'm just asking if there's a more sophisticated formulation that doesn't make a distinction between different completions. Certainly I'm expecting a more fancy interpretation of the terms, cf the Tamagawa number conjecture.
Jul 30, 2014 at 12:21 history edited David Roberts CC BY-SA 3.0
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Jul 30, 2014 at 11:30 comment added Chris Wuthrich Another small correction: Sha also compares with the infintite place, not just finite primes.
Jul 30, 2014 at 11:28 comment added Chris Wuthrich What would be your uniform interpretation for the class number formula ?
Jul 30, 2014 at 11:26 comment added Joe Silverman First, you say denominator, but mean numerator. Second, I don't at all agree that the regulator compares the rational and the real points of $E$. But the canonical height (when written as a sum of local heights) is a sort of average measure of a rational point over how it sits in $E(\mathbb{Q}_v)$ for all places $v$, including the real place. But it's certainly not just the real place. I'm not sure whether this helps or hurts what you're looking for.
Jul 30, 2014 at 11:22 comment added David Roberts A single expression is perhaps too ambitious, but treating the different places in a uniform way is really what would be nice.
Jul 30, 2014 at 9:28 comment added Chris Wuthrich Yet, in the end, whatever formulation you will see, there will always be the input of several sides. The Bloch Kato conjecture will also put together comparison isomorphisms etc to get to a formulation. So I don't think there is a single expression that covers the full quotient.
Jul 30, 2014 at 9:26 comment added Chris Wuthrich Tate's original forumlation archive.numdam.org/ARCHIVE/SB/SB_1964-1966__9_/… using adelic integration uniformises $\Omega_E\cdot \prod c_p$ into one expression. Since the regulator measures something on the Mordell-Weil group modulo torsion, one could also consider the quotient of $\mathrm{Reg}_E/(\#E(\mathbb{Q})_{\mathrm{tors}}))^2$ as one thing.
Jul 30, 2014 at 7:57 history asked David Roberts CC BY-SA 3.0