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It's a common observation in Lie theory that Cartan matrices and the Killing form are named after the wrong people; they were discovered by Killing and Cartan, respectively. I remember learning about many other examples of this phenomenon, but can't think of too many at the moment. Wikipedia has some examples here and here, but I'm curious about more obscure examples.

Bonus points for an interesting story behind why the concept was incorrectly named. Concepts that were deliberately named in honor of another mathematician don't count.

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closed as no longer relevant by Kevin H. Lin, unknown (google), Qiaochu Yuan, Zev Chonoles, Gjergji Zaimi Jul 9 '11 at 3:12

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By the way, in the mathematical community "Stiegler's law" is often referred to as "Arnol'd's law", inclusive of the corollary "Arnol'd's law applies to Arnol'd's law as well". – pasquale zito May 10 '10 at 20:24
To further complicate things, there is also Whitehead's law: "Everything of importance has been said before by someone who did not discover it." – bhwang May 10 '10 at 21:38
Oh gosh, I could not imagine that there are SO many wrong names. Perhaps some day there will be a big important Brandenburg theorem, of course just because another one has proven it. ;-) – Martin Brandenburg May 10 '10 at 23:09
Not that I have a problem with the question per se, but "the wrong people" is pretty ambiguous. The first person to study something might not be the most deserving -- often a crucial application or popularizations trumps the actual innovation. Nor is it necessarily the case that the intent of the naming was to honor the inventor -- frequently the naming is done for reasons of analogy ("Euler systems" come to mind). – Cam McLeman May 11 '10 at 1:10
Stigler's law is called Boyer's Law by H.C. Kennedy in "Who Discovered Boyer's Law?" (Amer. Math. Monthly vol. 79 1972, 66--67). It says that "Mathematical formulas and theorems are usually not named after their original discoverers." The label Boyer's law was chosen because Boyer gave many examples of this phenomenon in his book A History of Mathematics. – KConrad Sep 8 '10 at 17:12

56 Answers 56

Q: Who proved the Cayley-Hamilton Theorem?

A: Frobenius!

We now have the interesting question: Is this a maximal example of Stigler's law? That is, can we find distinct persons A, B, and C who are given credit for a result proven by D? Or A and B who are given credit for a result proven by C and D?

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And how long a directed cycle can we find in the graph where there is an edge from P to Q if P discovered/proved something attributed to Q? – Saul Glasman May 11 '10 at 9:00
What do you mean? That Frobenius was the first to prove it in full generality? Please supply a reference, as Cayley and Hamilton at least had proofs in dimension 2 and 3, if I recall correctly. – Guntram May 12 '10 at 22:41
Guys,I'm not sure,but I think Frobenius was the first to STATE the theorum in it's full generality,but he didn't succeed in giving a complete proof.That's why Arthur Cayley and Hamilton are given credit-they supplied the first general proof,improving on thier original proofs in low dimensions.I could be wrong about this,someone please chime in if you have the right answer and give a reference. – The Mathemagician Oct 13 '10 at 21:07
I was told this by an older algebra professor of mine. Here's a reference (although I'm not sure how authoritative mathpages really is, especially because it doesn't cite sources itself): – Dave Apr 16 '11 at 20:46

The Frobenius automorphism associated to a prime ideal in a Galois extension of number fields was actually developed by Dedekind, who wrote about it (and the associated ramification groups, later found by Hilbert) in a letter to Frobenius on June 8, 1882. Frobenius published this construction in a paper in 1896. Some citations:

  1. Frobenius, Collected Works, Vol. 2, pp. 719--733.

  2. van der Waerden, Modern Algebra, Vol. 1 (Spring 1966), p. 203.

  3. Zassenhaus, Canadian Math. Bulletin 18 (1975), p. 448.

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According to Wikipedia, Markov's inequality is due to Chebyshev, and Chebyshev's inequality is due to Bienaymé.

On top of that, Hölder's inequality was first proved by Rogers, and Jensen's inequality by Hölder. What a mess!

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Related mess: Lipschitz and Hölder functions. – Victor Protsak May 13 '10 at 0:11
Would it be terminally geeky to point out that these attributions to Markov et al form a chain? – smci Jan 18 '11 at 19:56

Our linear algebra professor had a joke he told every year at the same spot in the lectures, for some 30 or 40 years. He'd say in an absolutely dry voice and facing the blackboard: "And this is the Cauchy–Bunyakovsky–Schwarz inequality, named like this because it was first proved by Lebesgue". Apparently, Cauchy just did it just as an inequality for sums (ie findim spaces), and Bunyakovsky and Schwarz independently as an inequality for integrals (ie for L2).

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I wouldn't really call this "naming it after the wrong person". Lots of analytic facts come from natural generalizations of observations from finite dimensional vector space to $\ell_p$ spaces then to $L^p$ spaces. – Willie Wong May 11 '10 at 8:16

Stokes's theorem was stated by William Thomson (Lord Kelvin) in a letter to Stokes. The letter is reproduced on the cover of Spivak's Calculus on Manifolds. I believe the theorem was named after Stokes because he frequently put it on the Tripos exam in Cambridge.

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According to wikipedia: Stokes set the theorem as a question on the 1854 Smith's Prize exam, which led to the result bearing his name. – Regenbogen May 15 '10 at 17:08

The Pell equation was named so because Euler thought that John Pell was responsible for some key results involving this equation. While Pell was a notable mathematician, he had essentially no connection to the equation. The common belief is that Euler mistook Pell for Lord Brouncker who indeed had a number of results related to the "Pell" equation.

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I thought some Indian mathematicians had something to do with it. See André Weil's Number Theory, from Hammurapi to Legendre. – Chandan Singh Dalawat May 13 '10 at 2:49
And doesn't a particular case go back to Archimedes (the cattle problem) ? – Chandan Singh Dalawat May 13 '10 at 2:51

The most amazing example I know is the Cayley formula which was discovered by Carl Borchardt nearly 30 years earlier. Not only Cayley knew about this, in his paper he specifically wrote that this formula is due to Borchardt, and all he wants to do is give a new simple proof (without determinants as in the matrix tree theorem).

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Bézout's theorem

This result was discovered first by Newton in 1665. Even though MacLaurin (1720) and Leonhard Euler gave proofs, the theorem is usually attributted to Etienne Bézout who much later (1776) gave an incorrect proof of the result.

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I'm not entirely convince of this--at least, that Newton, MacLaurin, and Euler all gave correct proofs. Could you give a reference? – Charles Staats May 11 '10 at 2:43
I did not say they all gave correct proofs. Apparently the general Bezout's theorem was not fully established until Halphen's proof (1873). According to Abhyankar's (on Euler's argument from 1748 used a version of the resultant. – J.C. Ottem May 11 '10 at 8:11
As far as I know (wikipedia agrees), this theorem was actually first proved by the French mathematician Bachet de Mézirac (1581-1638). – Simon Pepin Lehalleur Aug 7 '10 at 19:55
Oh, I'm sorry, wrong Bezout's theorem... – Simon Pepin Lehalleur Aug 7 '10 at 19:59
Altough Bezout's formula (about gcd) is as I mentioned a good example of misattribution ! Bezout was a lucky guy, or a very good publicist. – Simon Pepin Lehalleur Aug 7 '10 at 20:02

The Cantor-Schroeder-Bernstein theorem was proved by Dedekind; this link is to Dedekind's collected works and there is an informative note at the end.

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If you search for almost any eponymous topic in Wikipedia, you'll find that it was first studied by someone else. For example, the Gaussian distribution (according to Wikipedia) was first studied by de Moivre. It seems that in many cases, naming the body of work was given to the person who first applied its study to some other field (using the earlier example, Gauss used the distribution in astronomy).

The common story goes that L'Hôpital bought "the rights" to L'Hôpital's rule, as he was a nobleman and not a mathematician by trade, although I am not sure about the veracity of that story.

Although I am no expert on the history of Mathematics, it seems as though ideas or formulae assumed their names from certain mathematicians due either to a.) the more notable application or publication of the theory or b.) attribution by mathematicians of a later generation to pay tribute to (or garner attention from) the work of their predecessors.

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It is "de Moivre". – ogerard May 10 '10 at 21:48
It's community wiki, so you can edit it to fix spelling (as I have, in this instance). – j.c. May 10 '10 at 21:53
L'Hopital hired Johann Bernoulli to teach him the calculus, and as allowed by their contract, wrote a book under his own name containing what he had learned, some of which were Bernoulli's original results. Wikipedia has references. – Nate Eldredge May 10 '10 at 22:03
Oops! Thanks for fixing the typo. Here is the Wikipedia page regarding the relationship between L'Hopital and Bernoulli:… – Ed Gorcenski May 11 '10 at 15:01
Damn,that was the one I was going to post! – The Mathemagician Aug 7 '10 at 19:00

The number of plane trees with no vertex of degree one and with $n$ endpoints is known as a Schröder number, from a 1870 paper by Ernst Schröder. In 1994 David Hough discovered that these numbers were known to Hipparchus (c. 190 - after 127 B.C.)! For a popular account, see For a more scholarly treatment, see

As an irrelevant aside, how do you make accent marks in MathOverflow? Schroder is supposed to have an umlaut over the o.

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Thanks for the pointer! I've been curious about how Hipparchus could have come upon this since seeing a note to this effect in one of your books. – Michael Lugo Oct 19 '10 at 1:14
@Richard: I manually insert the accent marks using a compose key (which can be set to any key in the GNOME environment), i.e., for ö, hit compose " o – Steven Sam Oct 19 '10 at 2:57
Huh. That we still don't know what might have been meant by "on the negative side" is pretty creepy. – Harry Altman Oct 19 '10 at 5:40

Chow varieties were invented by Van der Waerden (Chow was his student). And Hilbert schemes were invented by Grothendieck (who called them Hilbert schemes himself, however).

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An article in the current issue of American Mathematical MONTHLY (G. Folland, "A tale of topology," Am. Math. Monthly 117 (8) pp.663-672, Oct. 2010) quotes Walter Rudin as follows:

Thus it appears that Čech proved the Tychonoff theorem, whereas Tychonoff found the Čech compactification -- a good illustration of the historical reliability of mathematical nomenclature.

Folland's article suggests the truth is more complicated, as it usually is.

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I was once told that Riemann's integral is due to Darboux, while Lebesgue integral is due to Borel. Riemann invented the Cauchy integral instead.

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What is the "Cauchy integral"? I tried searching for it, but I only get results about the Cauchy integral theorem or formula... – Qiaochu Yuan May 11 '10 at 2:24
Say you want to integrate a fuction f on [0,1]. Then you define its integral, if it exists, as the limit of $\sum_{i = 0}^{n-1} f(i/n)/n$. Of course this does not make much sense unless f is continous. Still it is the most naif definition of integral one can come with and sometimes it works (and replacing the limit over n with the limit over the net of partitions of [0,1] almost gives you the right definition of Riemann's integral). – Andrea Ferretti May 11 '10 at 9:45
Are you sure that Darboux did not invent Darboux integral, and Riemann actually did invent Riemann integral? The definitions are different, although equivalent. – VA. May 12 '10 at 3:19
Well, I don't know Darboux integral, and sadly I don't remember the source where I read this, so I have no way to check. – Andrea Ferretti May 12 '10 at 10:30
Part of the confusion might be that textbooks such as Rudin develop the theory of the Riemann integral by using the Darboux integral. I also remember being told that Rudin goes on to assume that properties proven for the Darboux integral hold for the Riemann integral (and maybe even the Cauchy integral) without proving that this works. Sneaky. – Qiaochu Yuan May 13 '10 at 2:41

In my first algebra book the Eisenstein criterion for irreducibilty of a polynomial is named Schönemann criterion and is left as an exercise. This is confusing when all others are talking about the Eisenstein criterion ;-). In fact, here is a quote from Wikipedia:

The criterion is named after Ferdinand Eisenstein. It was published by T. Schönemann in Crelle's Journal 32 (1846), p. 100, and was popularized by Eisenstein in Crelle's Journal 39 (1850), pp. 166-169. Eisenstein's application of this theorem was to polynomials with coefficients in Z[i], not Z.

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To expand on Pasquale's comment, here's a quote from Arnold's article:

Similarly to the fact that America does not carry Columbus's name, mathematical results are almost never called by the names of their discoverers.

In order to avoid being misquoted, I have to note that my own achievements were for some unknown reason never expropriated in this way, although it always happened to both my teachers (Kolmogorov, Petrovskii, Pontryagin, Rokhlin) and my pupils. Prof. M. Berry once formulated the following two principles:

The Arnold Principle. If a notion bears a personal name, then this name is not the name of the discoverer.

The Berry Principle. The Arnold Principle is applicable to itself.

Perhaps somebody knows which results by Kolmogorov et. al. he is thinking of.

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Currying should, I believe, be referred to as Schönfinkeling.

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Thank $DEITY for the misattribution, then! :P – Mariano Suárez-Alvarez Oct 14 '10 at 15:58

In honour of the recently departed Benoit Mandelbrot, perhaps it is appropriate to offer up the example of the Mandelbrot set, the first pictures of which were drawn in 1978 by Robert Brooks and Peter Matelski (according to Wikipedia).

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Burnside's Lemma, which asserts that the number of orbits of a group action is the average number of fixed points, was known to Cauchy. Burnside himself even attributed it to Frobenius in his book.

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I like the fact that this lemma is sometimes called "Burnside's Lemma" and sometimes "The lemma that is not Burnside's". – Konrad Waldorf May 10 '10 at 21:31
This example appears in one of the Wikipedia entries mentioned above, though. – José Hdz. Stgo. May 12 '10 at 20:37

And the Bianchi identities are due to Ricci (according to Levi-Civita).

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Banach algebras should probably be called Gelfand Algebras, or something similar. I'm not sure of the history here, but presumably the "Banach" is attached because this is the study of "complete" normed algebras. I don't believe that Banach actually did much work on algebras (as opposed to Banach spaces).

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I can see your point, but I prefer the name Banach algebra, at least in part because it is easier to learn: it's just a Banach space with a continuous (bilinear, associative) multiplication. – Jonas Meyer May 24 '10 at 5:47

The Vandermonde Determinant/Matrix. Apparently Vandermonde never explicitly discussed his eponymous determinant. According to Lebesgue in his survey of Vandermonde work, it was probably due to somebody misinterpreting Vandermonde's notation.

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Expanding on the example given in the original post, here's an excerpt from Borel's "Essays in the History of Lie Groups and Algebraic Groups" (p. 5):

It has been remarked that, as far as terminology is concerned, posterity has not been kind to [Killing]: Cartan subalgebras, Weyl groups, fundamental reflections, roots, and the Coxeter transformation first appeared in his papers in some form. On the other hand, what now goes by his name, the "Killing form" seems to be a misnomer, and it may well be that I am the culprit. Cartan, Chevalley and Weyl never used this terminology. Once, J.J. Duistermaat and J.A.C. Kolk pointed out to me that, to their knowledge, its first occurence is in a paper of mine (Sém. Bourbaki, Exp. 33, May 1951). I do not remember why I chose it, though I probably felt I was innovating, since it is between quotation marks. It is rather likely that discussions with some members of Bourbaki had influenced me, but I cannot blame it directly on Bourbaki, since "Killing form" appears in Bourbaki drafts only from 1952 on. It is true that Killing was the first to remark that the coefficients of the characteristic equation (of a regular semisimple element), i.e. the elementary symmetric functions of the roots, are invariant under the adjoint group, but he did not make much use of the remark and did not single out the sum of the squares of the roots, of which Élie Cartan made such fundamental use in his thesis (1894). It would be more correct to speak of the Cartan form.

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The Cayley numbers (also known as the Octonions) were discovered earlier by John T. Graves. The story is nicely explained in John C. Baez's paper, The Octonions, Bull. Amer. Math. Soc. 39 (2002), 145-205.

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Quoting from Alan Sokal's 2005 paper on the multivariate Tutte polynomial:

"The Potts model was invented in the early 1950s by Potts’ thesis advisor Domb. The $q = 2$ case, known as the Ising model, was invented in 1920 by Ising’s thesis advisor Lenz. (I hasten to add that these are the only two cases I know of where the thesis advisor’s invention was named after the graduate student, rather than the other way around.)"

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Zorn's lemma is neither due to zorn, nor is it a lemma. It is a theorem due to Kuratowski.

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  1. Cauchy–Riemann equations were known to d'Alembert and Euler.

  2. Two-dimensional Voronoi diagrams were used by Descartes, three-dimensional - by Dirichlet. Also should be noted, that this construction has several other names in physics: Wigner–Seitz cells, Thiessen polygons.

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I learnt about 1 from the treatise by A. Markushevic on Analytic Function Theory. In fact, in his books the denomination d'Alembert-Euler equations is the standard way to refer to them. – José Hdz. Stgo. May 12 '10 at 20:47
Very interesting! – timur Oct 14 '10 at 22:39

There was a paper published in 2006 entitled "Simpson's Paradox in the Farey Sequence". The paradox is not Simpson's nor is the sequence Farey's. Bonus points.

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The Banach-Steinhaus theorem was first proved by Hahn, the Hahn-Banach theorem was first proved by Helly.

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In logic:

  • Tarski's undefinability theorem was obtained by Gödel before Tarski, who obtained it independently. Gödel did not publish the theorem. See Roman Murawskia (1998), "Undefinability of truth. The problem of priority: Tarski vs Gödel", History and Philosophy of Logic, v. 19 n. 3. pp. 153-160

  • The result sometimes known as Gödel's diagonal lemma was first stated by Carnap. Gödel (1934) explicitly attributed the result to Carnap (see Kurt Gödel, Collected Works, v. 1, p. 363).

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