Questions tagged [number-theory]

A field of mathematics studying numbers, their properties and structures that arise from them.

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67
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3answers
9k views

What evidence is there that Fermat had a proof for his Last Theorem?

Aside from the fact that Fermat was a genius, is it probable that he actually did have a proof? Some specifics that I think would point one way or another: Would the mathematics of his day allow him ...
18
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1answer
3k views

Is the story about Fermat's writing on a margin true?

Is there any evidence that Fermat wrote on the margin of a book "I have discovered a truly marvelous demonstration of this proposition that this margin is too narrow to contain." Everyone ...
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2answers
689 views

Who was the first to show that this quintic equation has five radical roots?

Despite this is being a very trivial question, I would like to know who was the first (with reference evidence) to show that the following quintic equation has five radical roots: $$x^5 + x + 1 = 0$$ ...
2
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1answer
79 views

What is the history of these prime counting function approximations?

I am reading several sources and there seems to be a lack of clarity, and some contradiction, about the origins of the most recognised prime counting function approximations: $\pi(n) \sim \frac{n}{\...
8
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2answers
255 views

Who first identified $\frac{n}{\ln(n)}$ as an approximation of a prime counting function?

Gauss, in his 1849 letter to Encke, mentions that he noticed the primes have a density approx $\frac{1}{\ln(n)}$. In that letter, he also mentions an integral function for approximating the prime ...
1
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1answer
79 views

When and where was Legendre's Conjecture first published?

When and where did Legendre first publish or write about his conjecture that there is a prime between consecutive square numbers? $$n^2 < p < (n+1)^2$$ I have looked through edition 1 and 2 of ...
4
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1answer
143 views

Has any large group of people used a base other than 10, 20 and 60 for ordinary purposes?

Wikipedia's list of numeral systems lists only $10,20,60$ as having been used in history. There are about twenty-five sets of symbols there used by different groups of people, but only three different ...
0
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1answer
84 views

How were number symbols derived/shaped up?

This question was sitting on my to do list for sometime. So, as I was reading a book on history of science, I came across of a paragraph where the author attempted to give a historical development ...
10
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1answer
9k views

How much contribution did John Nash make to proving Riemann Hypothesis?

At quite the end of the movie "A Beautiful Mind", John Nash tells a student- "I am making progress" (to Riemann hypothesis) Actually, how much contribution he made to the proof of Riemann Hypothesis?
6
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2answers
411 views

Who extended the Euclidean algorithm to derive the Bezout identity?

Euclidean algorithm is an algorithm that produces the greatest common divisor of two integers. It was described by Euclid as early as in 300 BC. On the other hand, the extended Euclidean algorithm ...
4
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1answer
198 views

What changes in mathematics resulted in the change of the definition of primes and exclusion of 1?

Why 1 is not prime? I read in this article that G.H Hardy explicitly included 1 as a prime in the first 6 editions of "A Course in Pure Mathematics", published between 1908-1933. He updated ...
2
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0answers
82 views

Where is First-Order Peano Arithmetic first clearly formulated?

I really should know this, but ... When/where/by whom was first-order Peano Arithmetic first clearly and explicitly formulated in a recognizably modern form (perhaps exact notation apart) -- with the ...
0
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0answers
97 views

Does this mathematical result have a specific name?

I am not sure if it's new although it may be an easy consequence of some theorem or lemma.The result is as follows: By choosing a set of numbers between $0$ and $n$(for any $n$) picking each number at ...
3
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1answer
204 views

What is the basis of the claim that $F_5$ was fully factored in 1732?

The Wikipedia Page on Fermat numbers states that $F_5$ was "fully factored" in 1732. This appears to be the same time that Euler found that any factor of a Fermat number $F_n$ was of the form $$2^{n+...
1
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0answers
91 views

Why didn't the ancient Greeks consider 1 to be odd?

The Wikipedia page on parity currently says: The ancient Greeks considered 1, the monad, to be neither fully odd nor fully even Why didn't they consider 1 as odd? (I am assuming they already had the ...
1
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0answers
29 views

Timeline for the earliest work on Frobenius problems

If $a, b$ are positive and coprime integers, then the set of linear combinations of $a$ and $b$ with nonnegative coefficients is all integers past $(a - 1)(b - 1)$; i.e. $\{ \lambda_1 a + \lambda_2 b :...
6
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0answers
114 views

Did Hardy and Ramanujan miscalculate these values?

When I read Dickson's History Of The Theory Of Numbers Vol-2, I found that there seems to be a mistake in the approximation of partition numbers p(200). For this reason, I found the original text ...
20
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0answers
528 views

What is the modern significance of Theaetetus's classification of quadratic irrationals?

Before Eudoxus's theory of proportion there was a theory of irrationals based on continued fraction expansions, which Fowler calls anthyphairesis. Theaetetus is said to develop a classification of ...
3
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1answer
212 views

Why didn't Euclid try to assign numbers to lengths?

Preliminary note: With "Euclid" I don't mean a person but the mathematicians of the Euclidean period of which Euclid (if he had been one person) was a representative. I imagine that Euclid could have ...
0
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0answers
44 views

What existing theorems were utilized to develop the Prospect Theory formulated by Kahneman and Tversky?

According to this article, the the Prospect Theory is used in finance. As the article states: Prospect theory’s central formula lays out how we go with our gut when determining the value (V) of a ...
12
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1answer
2k views

What is the origin of the Collatz conjecture?

When was the $3x+1$ problem first proposed? At Wikipedia, I found the following statement (without citation): The Collatz conjecture is a conjecture in mathematics named after Lothar Collatz, who ...
0
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1answer
66 views

What are the direct predecessors of Lagrange's theory of quadratic forms?

I was reading Stillwell's Mathematics and its History, where Lagrange's theory of quadratic forms is synoptically presented, and I was wondering of what are the direct predecessors of the theory. ...
3
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1answer
104 views

Reference for Euler's Introductio in Analysin Infinitorum

In the following answer it has been claimed that "The reference here is not to Euler's 1737 "factorization" of the harmonic series but to 1748 Introductio in Analysin Infinitorum, where the identity ...
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0answers
48 views

Is there an English translation of Kronecker's proof of Infinitude of primes?

Is any English translation of the following paper available? H. Hasse, Vorlesungen ¨uber Zahlentheorie, Second edition, Springer-Verlag, New York, $1964$ (L. Kronecker, $269–273; 440–442; $ K. Hensel, ...
3
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1answer
212 views

Where in Gauss's nachlass apears his sketch of a geometric proof for the biquadratic reciprocity law?

According to p.200-202 of the book "Reciprocity Laws: From Euler to Eisenstein" by Franz Lemmermeyer, there are two proofs for the biquadratic reciprocity law in Gauss's nachlass: one is a cyclotomic ...
5
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1answer
671 views

Is there a translation of Gauss' work on Gaussian integers?

Gauss introduced the Gaussian integers in an 1832 Latin work named Theoria residuorum biquadraticorum. I believe there is a German translation available. Is there an English, or possibly French ...
3
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2answers
226 views

How long would it have taken Cole to multiply the factors of $M_{67}$ on a blackboard?

The famous anecdote of the 1903 announcement of the factorization of $2^{67}-1$ by Frank Nelson Cole has recently been discussed, for example in light of the announcement of another "twitter-sized" ...
10
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1answer
324 views

What were the initial applications of finite fields?

Finite fields, I believe, were introduced by Galois in his paper "Sur la théorie des nombres", found on page 398 of his Oeuvres. In this paper Galois introduces the idea of taking a polynomial ...
2
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1answer
310 views

Pythagorean and the number 17

I was looking for some properties of the prime numbers, and I found some curiosities of the number 17 in that site. One of them is this 17 was called by the Pythagoreans - opposition, obstruction,...
3
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1answer
100 views

When was the problem of factoring integers explicitly considered, what was the oldest factoring algorithm?

I know Gauss made it clear that he wanted an efficient solution to the problem in 1801. In his Disquisitiones Arithmeticae he calls all factoring algorithms "laborious and prolix", surely a 19th-...
5
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2answers
305 views

Who pioneered the study of the sedenions?

I found lots of background information about the discovery of both imaginary and complex numbers, and enough information about the first two types of hypercomplex numbers; quaternions and octonions (...
6
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2answers
2k views

When was the first recorded occurence of irrational and imaginary number usage in number theory?

I saw a letter of Euler to Lagrange congratulating him on his usage of imaginary numbers in the "analysis devoted to rational numbers alone", was that the first known such usage? What was the likely ...
23
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4answers
8k views

Ancient Chinese numbering system

It has been said that the invention of zero was a great leap forward, not only in abstract understanding, but in the ability to introduce place value notation and do computations; computing using ...
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0answers
75 views

History of Reciprocity Laws

Does anybody know a freely available overview of the history of Reciprocity Laws, especially the Cubic and Biquadratic ones? Wikipedia I know about Franz Lemmermeyer's book "Reciprocity Laws", but ...
12
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2answers
559 views

Were transcendental numbers considered rare, pre-Cantor?

Because the real numbers are uncountable and the real algebraic numbers are countable, there are uncountably many transcendental numbers. So there are far more transcendentals than rationals. With the ...
3
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2answers
667 views

Can Numerology be said to be the precursor of Number Theory?

My understanding is that alchemy was a precursor to modern chemistry. Some might say that numerology, similarly, was an earlier form of what is now known as number theory, but I feel like it's a more ...
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1answer
50 views
3
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1answer
197 views

What is the modern context of Gauss's work on triangles with integer sides and circumradius?

In chapter V of volume 2 of Dickson's "History of the theory of numbers" (p.191-195), which collects results on "rational" triangles (triangles with integer side lengths), apear several results on the ...
0
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0answers
126 views

Why isn't François Proth's name used for Gilbreath's conjecture as he discovered & published a proof 80 years earlier?

According to Wikipedia's Gilbreath's conjecture page, The statement is named after mathematician Norman L. Gilbreath who, in 1958, presented it to the mathematical community after observing the ...
5
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3answers
388 views

Who was L. Aubry?

In his magnificent book Number Theory: An approach through history, from Hammurapi to Legendre, André Weil quotes the article Solution de quelques questions d'analyse indéterminée, by L. Aubry (Sphinx-...
4
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1answer
179 views

Origin of the “law of quadratic reciprocity”

Today, "reciprocity" is the standard mathematical word used for quadratic reciprocity and its generalizations. I found that the name dates back to no later than 1832, when a paper of Dirichlet (...
0
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0answers
71 views

How did Hardy and Littlewood formulate the k-tuple conjecture?

Let $\mathcal{H}_k = (h_1,h_2,\cdots,h_k)$ be an admissible k-tuple. The k-tuple conjecture predicts that the number of primes $(b+h_1,b+h_2,\cdots,b+h_k)\in \mathbb{P}^k$ with $b+h_k \leq x$ is: $$\...
7
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4answers
210 views

How can we account for the independent inventions of place value all using the same direction?

I was looking up some ancient ways of writing numbers, to use as part of a lesson on the history of discovery of new numbers, for some young students. In particular I looked at the notation used by ...
3
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1answer
251 views

Gauss's proofs of quadratic reciprocity

Gauss gave 6 published and 2 unpublished proofs of quadratic reciprocity (see, e.g., here). I suspect this was to try to understand the "real reason" quadratic reciprocity holds (though please ...
7
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1answer
129 views

Who first proved that only primes of the form $4k+1$ divide odd integers of the form $n^2+1$?

I am writing a paper and I would like to cite the person(s) who proved that only primes of the form $4k+1$ can evenly divide odd integers of the form $n^2+1$? For example, if $n=8$, $n^2 + 1 = 65$ ...
7
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1answer
2k views

Was there a very early culture that's number system was 12-based, like ours is 10-based?

There are several uses of 12 in some old systems of measurement. Some of them make sense given current context (There are 12 lunar cycles per year), however some of them seem to be arbitrarily chosen. ...
0
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2answers
112 views

What is the intuition behind Brahmagupta’s rule for multiplying negative numbers?

The rule says: The product (or quotient) of two debts is a fortune What I’m struggling with is what exactly is the product of two debts? What accounting need forces one to multiply debts? How do ...
0
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0answers
78 views

Irrational numbers math in old Roman age [duplicate]

I know that Hippasus proved that $√2$ is irrational number. My question is how were they doing the mathmatical operations like multiplication for rational numbers like 1.41421356237 I can do ...
5
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1answer
325 views

Why did Euclid define “a unit” instead of “the unit”?

I know Euclid's Definition VII.1 of a unit only from English and German translations: A unit is (that) according to which each existing (thing) is said (to be) one. [translation by Fitzpatrick] ...
0
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0answers
82 views

Was 360 considered a magic number, possibly?

The number $360$ as the number of units into which the circle is divided has some nice properties: it has as many divisors as a number of its size can have it's nearly the number of days per year ...