Skip to main content

All Questions

Filter by
Sorted by
Tagged with
3 votes
0 answers
148 views

Solutions of a quadratic Diophantine equation over algebraic integers

The problem is not very exactly Diophantine in the classical way. I am trying to find some algebraic integer solutions in a number ring to a quadratic equation over the same ring. Precisely, let $\...
Yanlong Hao's user avatar
0 votes
2 answers
215 views

Papers related to a diophantine equations about Magic square of squares for $n=3$

The open problem of magic squares of squares explained here. Consider the following magic square of squares: $$ \begin{aligned} &a^2&b^2&&c^2\\\\ &d^2&e^2&&f^2\\\\ &...
William Mercer's user avatar
12 votes
1 answer
598 views

Fermat last theorem : proof of a criterion by Cauchy

In 13 Lectures on Fermat's Last Theorem, Ribenboim states the following theorem (on page 7) attributed to Cauchy: If the first case of Fermat's theorem fails for the exponent $p$, then the sum: $$ 1^{...
RUser4512's user avatar
  • 121
5 votes
5 answers
751 views

The diophantine equation $ \sum_{n=1}^{N} \frac{1}{x_{n}} = \prod_{k=1}^{N} \left(1-\frac{1}{x_{k}} \right) $

Background I wonder if there are any rational numbers such that their Egyptian fraction (sum) representations are equal to their Egyptian product analogue. In other words, I am curious1 about ...
Max Lonysa Muller's user avatar
4 votes
2 answers
343 views

Algorithm for computing rational points if the rank of Jacobian is 0

Is there a general algorithm that can compute in finite time all rational points on any curve of genus $g\geq 2$ whose Jacobian has rank $0$? If not, for what special cases such algorithm is known? ...
Bogdan Grechuk's user avatar
1 vote
0 answers
106 views

Mahler's proof of $S$-unit equation

Many modern proofs of the (ineffective) finiteness of solutions of the $S$-unit equation $x+y=1$ use Roth's theorem. In particular it is used Lang's version of Roth's theorem which takes in account ...
manifold's user avatar
  • 321
1 vote
2 answers
127 views

Number of integers $x \leq B$ such that $f(x)\mid g(x)$ for coprime polynomials $f,g$

Let $f, g \in \mathbb{Z}[x]$ be coprime polynomials. I am interested in an upper bound for $$ N(B) = \# \{ x \in [-B, B] \cap \mathbb{Z}: f(x)\mid g(x) \}. $$ I assume there must be something known ...
Johnny T.'s user avatar
  • 3,625
7 votes
3 answers
611 views

Question on a crucial lemma in Euler's approach to Fermat's Last Theorem for $n=3$

As many of you may know, the illustrious L. Euler put forward a proof of the case $n=3$ of Fermat's Last Theorem via infinite descent. The thing is that, at a certain point, he resorted to the ...
José Hdz. Stgo.'s user avatar
1 vote
0 answers
84 views

Beyond pure rational and integral solutions to cubic equations

I started reading Silverman and Tate’s introductory book on elliptic curves. In the introductory chapter they mention that for the Bachet equation $x^2 - y^3 = c$, there are infinitely many rational ...
John Jiang's user avatar
  • 4,466
1 vote
1 answer
364 views

Good references to study Baker's theory

I am studying diophantine equations and I need the theory of Bakers, Can you advise me about good books, or lectures on Baker's theory?
Alpha's user avatar
  • 17
1 vote
2 answers
349 views

Rational solutions to $P(x,y)=0$ for $P$ reducible over ${\mathbb C}$

There are facts in Mathematics that are so "obvious" and "well-known" that no-one includes a proper proof. An example is: Theorem: If polynomial $P(x,y)$ with rational coefficients ...
Bogdan Grechuk's user avatar
2 votes
0 answers
115 views

Reference request: "A result of Siegel" related to Ramanujan-Nagell type equations

Wikipedia refers to the Diophantine equation $ x^2 + D = AB^n $ as an "equation of Ramanujan–Nagell type". It also says that "A result of Siegel implies that the number of solutions in ...
Eric Nathan Stucky's user avatar
0 votes
0 answers
120 views

The strong twin conjecture can be transformed into the unsolvability of a particular Diophantine equation

Let us consider the strong twin conjecture: For all positive integer $n$ there exist a prime $p$ such that $$n+4<p<2^n2^4$$ and $p$ is a prime and $p+2$ is a prime Since the inequalities and the ...
Safwane's user avatar
  • 1,197
0 votes
0 answers
138 views

A diophantine equation involving partial sums of exponentials similar than the equation in Fermat's Last Theorem

I'm curious about the following diophantine equation from my invention: I don't know if this is in the literature, I wrote it using creativity in an attempt to write a variant of the equation in ...
user142929's user avatar
26 votes
1 answer
2k views

The "stubborn" solutions to sums of three cubes

It is conjectured (see [1]) that for any integer $k\not\equiv \pm 4\pmod 9$ there are infinitely many integer solutions to $$ a^3+b^3+c^3=k. $$ Numerical investigations of this conjecture show that ...
Alexander Kalmynin's user avatar
4 votes
0 answers
504 views

Collatz conjecture and a diophantine equation

Let $M \ge 2$. Inspired by the Collatz iteration / algorithm ($M=2$), I tried the following function: $$C_M(n) = n/M, \text{ if } n \equiv 0 \mod M, \text{ otherwise } (M+1)n+\{(M-n) \mod M \}$$ We ...
mathoverflowUser's user avatar
10 votes
5 answers
771 views

Reference request: Diophantine equations

I am looking for a textbook, or preferably lectures, on the subject of Diophantine equations. I am familiar with the basic principles of modular arithmetic, conics and the Hasse Principle, and the ...
Thomas's user avatar
  • 2,811
6 votes
2 answers
713 views

Origin and variations of problem on $4xy-x-y$ being square

One of the forms in which the Diophantine equation in question can be found in the literature is this: Solve the equation \begin{eqnarray}z^{2} = 4xy-x-y \qquad \qquad (\ast)\end{eqnarray} in ...
José Hdz. Stgo.'s user avatar
1 vote
1 answer
330 views

A paper by W. Ljunggren

I am looking for the following paper by Ljunggren, Wilhelm: "Zur Theorie der Gleichung $x^2 + 1 = Dy^4$", Avh. Norske Vid. Akad. Oslo. I., 1942 (5): 27 The main result of this paper which I am ...
Random's user avatar
  • 2,404
0 votes
0 answers
180 views

When is $\phi(a^n+b^n+c^n)=0\mod n$?

A corollary Zsigmondy's Theorem leads to the following congruence (one can look to $(24)$),$\phi(a^n+b^n)=0\mod n$ whenever $a, b$ are coprime and $n \neq 2$ and $(a,b)\neq(1,1)$. (Here $\phi$ is the ...
user avatar
8 votes
2 answers
643 views

Around the diophantine equation $\frac{a}{2b+3c}+\frac{b}{2c+3a}+\frac{c}{2a+3b}=\text{odd integer}$, over positive integers

I am interested to know if a similar theorem that shows this answer of the post Estimating the size of solutions of a diophantine equation (this MathOverflow, January 5th 2016) is feasible for a ...
user142929's user avatar
5 votes
1 answer
355 views

Research work on $ax^n-by^m=1$

I am looking for results on the equation $$ax^n-by^m=1 \tag 1 $$ where $\gcd(m,n)=1$ and $a,b,n,m$ are constants. I found literature for $ax^n-by^n=1$ (R. A. Mollin, D. T. Walker) but couldn't ...
Consider Non-Trivial Cases's user avatar
0 votes
1 answer
132 views

Different solution of power Diophantine equation based on constant term

Let us define a power Diophantine equation by 2 algebraic functions $f,g$ (having different degree) and by integers $k, l >0$ where, there are finite solutions for $f(x)+k=g(y)$, but there exists $...
Michael's user avatar
  • 267
4 votes
1 answer
319 views

What about $n^{\frac{1}{x}+\frac{1}{y}}+n^{\frac{1}{y}+\frac{1}{z}}=n^{\frac{1}{z}+\frac{1}{x}}$ over positive integers?

I've considered the following equation for positive integers $x,y,z\geq 1$, and for positive integers $n\geq 2$ $$n^{\frac{1}{x}+\frac{1}{y}}+n^{\frac{1}{y}+\frac{1}{z}}=n^{\frac{1}{z}+\frac{1}{x}},\...
user142929's user avatar
0 votes
0 answers
133 views

What about an alternative formulation for different prime constellations in the spirit of Suzuki's theorem for twin primes?

It is known that the twin prime conjecture is a special case of the $k$-tuple conjecture. See if you want the article with title k-Tuple Conjecture from the encyclopedia Wolfram MathWorld. On the ...
user142929's user avatar
-2 votes
1 answer
260 views

Is the conjecture $min(A,B) \le rad(ABC)$ new and correct? [closed]

$\DeclareMathOperator\rad{rad}$Conjecture: If $A, B, C$ are positive integers with $\gcd(A, B)=1$, $\gcd(B, C)=1$, and $\gcd(C, A)=1$, and if $A+B=C$, then $\min(A,B) \le \rad(ABC)$. If the ...
Đào Thanh Oai's user avatar
2 votes
0 answers
125 views

How many integers below $n$ can be expressed as a sum of $k$ $m$th powers?

For $m,k \geq 2$, let $C_{m,k}(n)$ denote the number of positive integers less than or equal to $n$ which can be expressed as a sum of $k$ $m$th powers. I am interested in the asymptotic behavior of ...
aras's user avatar
  • 163
4 votes
1 answer
729 views

Is there a error/typo in the proof related to Goormaghtigh equation in Yann Bugeaud's paper?

I found the following theorem in a paper by Yann Bugeaud (page 12) , the theorem was not written in detail, to be specific,following two lines on page 13 were not understandable- I think this ...
Michael's user avatar
  • 267
6 votes
0 answers
410 views

Efficient solutions to general Bézout’s identity $a_1 b_1 + \dots + a_n b_n = 1$

Suppose I have integers $a_1, \dots, a_n$ which are coprime, meaning that $$a_1 b_1 + \dots + a_n b_n = 1$$ has a solution in integers $b_1, \dots, b_n$. I would like to get a bound saying ...
Kim's user avatar
  • 4,164
0 votes
1 answer
109 views

Reference request: Markoff type equations

Consider the equation $x^2+ay^2+bz^2=(1+a+b)xyz.$ If there are infinitely many integral solutions, then up to permutations $(a,b)=(1,1),(1,2),(2,3).$ I have found a presentation by Waldschmidt (https:/...
castor's user avatar
  • 298
4 votes
1 answer
217 views

Diophantine equation for generating computably enumerable set

By Matiyasevich's theorem, each member of computably enumerable set can be obtain from a diophantine equation system. For prime numbers, this system of diophantine equation is found. My question is: ...
Shahrooz's user avatar
  • 4,784
13 votes
1 answer
760 views

Infinitely many integer solutions to $X^4+Y^4-18Z^4= -16$

We found infinitely many integer solutions to $$X^4+Y^4-18Z^4= -16 \qquad (1)$$. The interesting part in this diophantine equation is the sum of the reciprocals of the degrees is $3/4 < 1$, which ...
joro's user avatar
  • 25.4k
8 votes
2 answers
1k views

How are such sets of natural numbers called?

I heard about this problem an year ago, but I just can't remember the name. The problem goes like this: study the sets $\{a_1,a_2,\dotsc,a_m\}\subseteq\mathbb{N}$ such that if $1\leq i<j\leq m$,...
SSHS_Space's user avatar
9 votes
1 answer
419 views

Infinitely many solutions to $a^4+b^4+c^4=18$ over $\mathbb{Z}[i]$

We got infinitely many solutions to $a^4+b^4+c^4=18$ over $\mathbb{Z}[i],i^2=-1$. Probably we can get infinitely many solutions to $a^5+b^5+c^5=N$ over $\mathbb{Z}[\alpha]$ for algebraic $\alpha$. ...
joro's user avatar
  • 25.4k
-4 votes
2 answers
272 views

Has nontrivial solution in positive integers of a diophantine equation: $x_1^2+x_2^2+x_3^2+x_4^2=y_1^2+y_2^2+y_3^2+y_4^2$ [closed]

Has nontrivial solution in positive integers of a diophantine equation as follows ? $$x_1^2+x_2^2+x_3^2+x_4^2=y_1^2+y_2^2+y_3^2+y_4^2$$ Where trivial solutions are $x_i=y_j$. Can you send me any ...
Cố Gắng Lên's user avatar
2 votes
0 answers
188 views

Solution of the Diophantine equation $x^4+y^4+z^4=2t^4$ are well-known? [closed]

Are solutions of the Diophantine equation $x^4+y^4+z^4=2t^4$ well-known? I give a solution: $x=m^2-n^2, y=m^2-2mn, z=n^2-2mn, t=m^2+n^2-mn$
Cố Gắng Lên's user avatar
15 votes
4 answers
575 views

Are all partial consecutive harmonic subsums distinct?

Let $b \gt a \geq 0$ be integers, and as elsewhere let $H_n$ be $\sum^n_{i=1} 1/i$. A partial consecutive harmonic subsum is a number $H(a,b)$ of the form $H_b - H_a$ (with $ H_0=0$). If $c=a$ and $...
Gerhard Paseman's user avatar
1 vote
0 answers
87 views

Diophantine equation $z=(ax+by+c)/(dxy)$, references? [closed]

I am looking for some sources (books or papers) which discuss the Diophantine equation $$ z=\frac{ax+by+c}{dxy} $$ where $a,b,c,d$ are given positive integers. Could anyone give some references? ...
asad's user avatar
  • 841
0 votes
1 answer
346 views

Upper bounds for solutions to a Pell-like equation

Let $N$ be a fixed positive integer that is not a square and $m$ be any nonzero integer. Let $x$ and $y$ be positive integers that solve $$x^2 - N y^2 = m^2$$ with $x + y$ minimal (in light of the ...
George Shakan's user avatar
7 votes
5 answers
941 views

Perfect powers in the solutions of a certain Pell equation

The fundamental solution of the Pell equation $$x^{2}-3y^{2}=1$$ is $2+\sqrt{3}$. It seems that if $x_{n}+y_{n}\sqrt{3}$, $x_{n}, y_{n} \in \mathbb{N}$, is a solution of the said Pell equation and $x_{...
Jamai-Con's user avatar
9 votes
1 answer
682 views

On the exact reference of a cute Diophantine problem

The problem asks to prove that the Diophantine equation $x^{3}+y^{3} = (x+y)^{2}+(xy)^{2}$ does not have any solutions in natural numbers $x, y$. I believe that this problem appeared in the section ...
José Hdz. Stgo.'s user avatar
3 votes
1 answer
247 views

4-th order diophantine equation

I met in many places the equation $(a^4-b^4)(c^4-d^4)=\square$ It is well known that this was investigated by Euler. But I was unable to find the general solution of this equation. Could you please ...
veg_nw's user avatar
  • 185
4 votes
1 answer
386 views

Is this problem of Schinzel and Tijdeman misquoted? It appears easy with Pell equations

In Diophantine equations over the twentieth century: a (very) brief overview , p. 5 Problem Let $f(x) \in \mathbf{Z}[x]$ be an irreducible polynomial of degree at least 2. Do the Diophantine ...
joro's user avatar
  • 25.4k
2 votes
1 answer
627 views

Particular case of Beal's Conjecture

Is it known that there exist no coprime positive integers $A$, $B$ and $C$ such that $A^3+B^4=C^3$? This is a particular case of Beal's Conjecture.
bobuhito's user avatar
  • 1,547
20 votes
2 answers
2k views

On a result attributed to W. Ljunggren and T. Nagell

I've read in a number of places that, building on previous work of T. Nagell, W. Ljunggren proved in 1 that the Diophantine equation $$\frac{x^{n}-1}{x-1} = y^{2}$$ doesn't admit solutions in ...
José Hdz. Stgo.'s user avatar
1 vote
2 answers
752 views

basis of the lattice generated by the integer points inside a subspace of R^L

Consider $K$ linearly independent vectors $\mathbf{a}_1, \mathbf{a}_2, ..., \mathbf{a}_K \in \mathbb{Z}^L$, where $1 \leq K<L $. Hence, the span of $\lbrace\mathbf{a}_1, \mathbf{a}_2, ..., \mathbf{...
mohsenh01's user avatar
4 votes
0 answers
332 views

Diophantine equations over cyclotomic fields

Let $\mathbb{Q}^{\text{ab}}$ be the compositum of all finite abelian extensions of $\mathbb{Q}$. Explicitly, $\mathbb{Q}^{\text{ab}}$ is the field obtained from $\mathbb{Q}$ by adjoining all roots of ...
Pablo's user avatar
  • 11.3k
1 vote
1 answer
250 views

Link between integral points on varieties and solutions to Diophantine equations

Let $k$ be a number field, $S$ a finite set of places of $k$ including the infinite ones and $F(X_1,\dots,X_n)$ a polynomial in $k[X_1,\dots,X_n]$. I am looking for notes, books or surveys detailing ...
Wesley Barnard's user avatar
2 votes
0 answers
207 views

n-ary quadratic forms with $S$-integer values

Let $Q(x_1,\ldots,x_n):=x_1^2+\cdots+x_n^2$ be an $n$-ary quadratic form. Given a finite set of (rational) primes $S$ is there an algorithm or theorem that describes all solutions to $Q(x_1,\ldots,...
Eric Rowell's user avatar
  • 1,639
1 vote
2 answers
751 views

Computational complexity of solution of Pell equation and more

What is computational complexity for computing integral solution of Pell equation .It seems to be in P ,and could any one give an algorithm and reference for proof of it's complexity? And more,could ...
XL _At_Here_There's user avatar