Talk:Heegner number

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 Field:  Number theory

What does the function denoted Q in this article refer to?

Quadratic Field

No, rational numbers. Charles Matthews 20:57, 12 Mar 2004 (UTC)

I had said that I would either create this page or work on it if someone else created it. Now, someone else has created it and I realize that this topic is way over my head. Nevertheless, I will continue my study of imaginary quadratic fields. PrimeFan 19:38, 13 Mar 2004 (UTC)

--- "Equivalently, its ring of integers has unique factorization"

Should "ring of integers" be "ring of ideals" or something similar? It's been a while since I've taken any number theory classes and I'm not entirely sure on this.

No, "ring of integers" is correct. See this article. An ""ideal" is a subset of a ring that is closed under addition, with the additional property that if any element in the ideal is multiplied by a ring element, the result still lies in the ideal. If we consider the ring of ordinary integers, then if n is any integer the set {..., −3n, −2n, −n, 0, n, 2n, 3n, ...} is an ideal because (a) it's closed under addition, and (b) if we multiply any multiple of n by an integer we obtain another multiple of n. (The concept of an ideal grew out of a desire to understand different sorts of algebraic numbers, where addition and multiplication aren't necessarily tied together the way they are in the natural numbers.) DavidCBryant 19:34, 8 January 2007 (UTC)

structure of the J(...)=x^3 term[edit]

I read today a recent post on sci.math.research by Titus P. on the additional structure of the integers obtained as exp(pi sqrt n), namely e^(pi sqrt n) - 744 = (12(a(n)^2-1))^3, where the a(n) are consequently extremely close to an integer for Heegner numbers (=3 mod 4). Could somebody sufficiently competent add one or 2 phrases (and/or xrefs) about that? — MFH:Talk 03:53, 16 April 2008 (UTC)

Mathworld neologism?[edit]

This term appears to be a neologism from mathworld. Google books returns two results, one the print version of mathworld, and the other some pop math book. Google scholar does no better, returning 3 results: all post-date the mathworld article. One result is published in a journal. The other two results are web-published. One references the other, which in turn references mathworld. Does anyone think this isn't a mathworld neologism? RobHar (talk) 03:12, 4 August 2009 (UTC)

I'll post to Wikipedia talk:WikiProject Mathematics, and if no one replies I'm going to nominate for deletion (and suggest merging content into Stark–Heegner theorem, Ramanujan's constant, and Formula for primes). RobHar (talk) 00:32, 5 August 2009 (UTC)
There are a little more Google Scholar and Books hits on "Heegner numbers" than "Heegner number". PrimeHunter (talk) 01:24, 5 August 2009 (UTC)
Definitely not a MathWorld neologism. The term "Heegner numbers" is used by Conway and Guy in The Book of Numbers here (maybe that was what you meant by "some pop math book" ?). This 1996 usage is cited in the MathWorld article, and I have added a ref to our article. Since we have Conway and Guy as a primary source and Weisstein and Sloane/OEIS as secondary sources (plus a few other Google Books hits), I think we can now count this as established terminology. Gandalf61 (talk) 08:43, 5 August 2009 (UTC)
Alright, thanks. I find it weird that "Heegner numbers" returned more results than "Heegner number". The pop math book I was referring to was "The Kingdom of Infinite Number: A Field Guide"; had the Conway book turned up with the "Heegner number" query, I would've been more accepting. The term is still clearly extremely rare and not used at all in the field, but oh well I guess. Thanks again. RobHar (talk) 14:50, 5 August 2009 (UTC)

I think it a useful article; if it exists, it needs a name. Is discriminants of complex quadratic fields of class number 1 really an improvement? Septentrionalis PMAnderson 15:46, 5 August 2009 (UTC)

I think that the entirety of the contents can quite nicely be merged into the three articles I mentioned above, thus rendering this article a mere definition of a rarely used term. RobHar (talk) 16:26, 5 August 2009 (UTC)
No, Ramanujan's constant should be merged here (there is no corresponding name for the other near-integers); any of this would be disproportionate in Formula for primes; and Stark-Heegner theorem is nicely complementary to this article. Septentrionalis PMAnderson 16:55, 5 August 2009 (UTC)
This may be a relatively recent neologism. But I don't find it to be of the vexing kind - it's not promoting anything, just giving a label to a short but significant list of discriminants. There is something to be said on both sides, but I think the status quo is OK. Charles Matthews (talk) 07:31, 6 August 2009 (UTC)
After actually bothering to read the notability guidelines for numbers, I see that this article as it stands violates criterion 4 of Wikipedia:Notability (numbers)#Notability of sequences of numbers, i.e.
Is there at least one commonly accepted name for this sequence?
There is clearly no commonly accepted name for this set of numbers. Do what you will with this. RobHar (talk) 15:21, 7 August 2009 (UTC)


Does anyone know why is so close to an integer? 4 T C 07:54, 8 January 2010 (UTC)

Good question. I've just checked it (using SpeedCrunch, if anyone's interested) and you're right, it is very close to one. It comes to approximately;


I don't know the reason for this either, and I'd be interested to know what it is (I'm guessing that with a result that close to being an integer, there's a reason for it).

Meltingpot (talk) 13:15, 9 February 2014 (UTC)

was this really conjectured by Gauss?[edit]

Can someone give an exact reference to the fact that this was conjectured by Gauss?

Gauss' class number one list, row I.1 in article 303 of Disquisitiones Arithmeticae, is: 1,2,3,4,7 and the completeness of this list was proved by Landau 1902 (see Goldfeld, Bull. AMS, 1985, p.26). Gauss is looking at a slightly different question, with nontrivial overlap, but different. Did he conjecture _elsewhere_ this Heegner list? (talk) 09:20, 26 October 2012 (UTC)

I don't know off-hand the answer to your question, but the point is that Gauss conjectured something which in modern terms is that those nine numbers give all imaginary quadratic fields of class number 1. It is very common in math to restate conjectures/theorems like this and still attribute them to the old folks. RobHar (talk) 07:16, 27 October 2012 (UTC)

don't put thousands separators under <math>![edit]

So reads a hidden comment throughout the article. I wonder whether there is any reason not to. I can only suppose that it's because something like <math>e^{\pi \sqrt{163}} = 262,537,412,640,768,743.99999999999925... </math> won't work but <math>e^{\pi \sqrt{163}} = 262{,}537{,}412{,}640{,}768{,}743.99999999999925... </math> does and is used on the article. Better still, though, we could have <math>e^{\pi \sqrt{163}} = 262\,537\,412\,640\,768\,743.999\,999\,999\,999\,25... </math> as in this version. The article is much more readable when numbers are formatted. Can anyone enlighten me as to whether there is some convention not to format numbers within <math> and why this would be so given that all <math> is is a tool for displaying formulae etc.? Jimp 13:10, 19 April 2015 (UTC)

Okay, I've found the reason and it was just as I'd suspected: "do not fall to such heresy as <math>262,537,412,640,768,743</math>! it is rendered with unreadable spaces after commas". <math>262{,}537{,}412{,}640{,}768{,}743.99999999999925</math>! (as used on the article) isn't nor is <math>262\,537\,412\,640\,768\,743.999\,999\,999\,999\,25</math>!. The latter is the most readable of the two (and better by far than <math>262537412640768743.99999999999925</math>!). Jimp 13:49, 19 April 2015 (UTC)