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17 votes
2 answers
940 views

Has the following problem, resembling the lonely runner conjecture, been studied?

Given $n$, what is the smallest value $\delta_n$ satisfying the following: For any group of $n$ runners with constant but distinct speeds, starting from the same point and running clockwise along the ...
Arsenii Sagdeev's user avatar
17 votes
2 answers
3k views

Some unpublished notes of Hofstadter

I'm looking for some unpublished notes called "Eta Lore," which are apparently related to a talk Douglas Hofstadter first gave at the Stanford Math Club in 1963. I know these notes exist because they'...
17 votes
2 answers
2k views

Is every odd positive integer of the form $P_{n+m}-P_n-P_m$?

I am looking for a comment, reference, remark, or proof of three conjectures as follows: Conjecture 1: Let $x$ be an odd positive integer. Then there exist two integers $n, m \ge 2$ so that $$x=P_{n+...
Đào Thanh Oai's user avatar
17 votes
4 answers
10k views

Prime/undecomposable matrices

Prime matrices as defined in the following paper Prime matrices P. F. RIVETT AND N. I. P. MACKINNON carry over many properties of factorization as in natural numbers to matrices over the field of ...
Unknown's user avatar
  • 2,855
17 votes
1 answer
701 views

Combinatorics problem about sum of natural numbers

Following combinatorics problem is claimed to be an open problem in "The Princeton Companion to Mathematics" (pp. 6) Let $a_1,a_2,a_3,...$ be a sequence of positive integers, and suppose that each $...
rationalbeing's user avatar
17 votes
1 answer
1k views

Catalan's constant fast convergent series

NOTE. UPDATE 2 introduces proven series for Catalan's constant that is possibly the fastest currently known. Working with some conjectured continued fractions that were published here, I have found ...
Jorge Zuniga's user avatar
  • 2,836
17 votes
1 answer
882 views

Reference Request: Conductors of Twists of Hyperelliptic Curves

It is my understanding that if I twist a hyperelliptic curve of genus 2 whose Jacobian has conductor $N$ by a prime $p$ with $p\nmid N$, that the conductor of the Jacobian of the twist is expected to ...
Johnson-Leung's user avatar
17 votes
1 answer
1k views

Serre and Tate's conjectures on étale cohomology

In the appendix of Serre and Tate "Good Reduction of Abelian Varieties" [Annals of Mathematics 88 (1968), 492-517], the authors make the following conjectures. Suppose that $X$ is a smooth proper ...
Eric Larson's user avatar
  • 1,832
17 votes
0 answers
367 views

Average value of j-invariant at infinity

Let $\xi\in\mathbb{R}$ and consider the average value (with respect to hyperbolic length) of the $j$-invariant ($j(z)=q^{-1}+744+196884q+\ldots$, $q=e^{2\pi iz}$) along a geodesic aimed at $\xi$: $$ \...
yoyo's user avatar
  • 609
17 votes
0 answers
891 views

An elementary proof that, for every fixed $n \in \mathbf N^+$, there are infinitely many primes $\equiv -1 \bmod n$

This morning, I made a comment to a comment to a question of Ayman Moussa, only to point out that, among many others, there is an elementary proof of Dirichlet's theorem on the existence of infinitely ...
Salvo Tringali's user avatar
16 votes
1 answer
2k views

On J. T. Condict's Senior Thesis on Odd Perfect Numbers

I am trying to locate a copy of J. T. Condict's senior thesis on odd perfect numbers: J. Condict, On an odd perfect number's largest prime divisor, Senior Thesis, Middlebury College (1978). I am ...
Jose Arnaldo Bebita's user avatar
16 votes
3 answers
4k views

Is it known that the Collatz-like sequence with 7n+1 diverges to infinity starting with 7?

In this question I was wondering if the $3$ in the Collatz conjecture is arbitrary, and when I wrote that question I tried to change to $7n+1$ starting with the seed number $7$, the sequence appears ...
pie's user avatar
  • 541
16 votes
4 answers
1k views

Reference for a linear algebra result

I asked the following question (https://math.stackexchange.com/questions/1487961/reference-for-every-finite-subgroup-of-operatornamegl-n-mathbbq-is-con) on math.stackexchange.com and received no ...
Stanley Yao Xiao's user avatar
16 votes
1 answer
4k views

Order of magnitude of $\sum \frac{1}{\log{p}}$

Question: What is the order of magnitude of the following sum? $$ \sum_{\substack{p<n\\\text{$p$ prime}}} \frac{1}{\log{p}} $$ Additional information: Since $$ \sum_{\substack{p<n\\\text{...
Daniel Soltész's user avatar
16 votes
1 answer
1k views

Has this strong number theoretic conjecture of Euler been proved, and where could I find such a proof?

Polya cites this work of Euler as an example of a conjecture which Euler considered impossible to doubt, and yet still needing a demonstration. It is on pages 90-98 of "Induction and Analogy in ...
reuben hersh's user avatar
16 votes
1 answer
2k views

Reference to a Don Zagier result and the congruent number problem

I was looking for a reference/explanation as to how Don Zagier managed to find the side lengths of a rational right triangle with area 157. There have been many literature references to the fact that ...
user82634's user avatar
  • 163
16 votes
1 answer
1k views

On (a generalization of) the Gauss Circle Problem

Most (if not all) references I read about the Gauss Circle Problem that proves a bound below $O(R^{2/3})$ reduces the GCP to the Dirichlet Divisor Problem by the well known expression of $r_2(n)$, the ...
Fan Zheng's user avatar
  • 5,169
16 votes
1 answer
705 views

Connection between Bernoulli numbers and Riemann-Siegel theta function?

I have come across a strange approximation for the Riemann-Siegel theta function involving the Bernoulli numbers - namely that $$\frac{1}{2} \log \left| B_{2 n}\right|\approx \vartheta (2n)\ ,\quad n ...
martin's user avatar
  • 1,903
16 votes
1 answer
2k views

Reference for the `standard' Tate curve argument.

I'd like a reference (e.g. something published somewhere that I can cite in a paper) for the proof of the following: Let $E$ be an elliptic curve over $\mathbb Q$ with minimal discriminant $\Delta$...
David Zureick-Brown's user avatar
16 votes
1 answer
357 views

Galois cohomology for non-Galois extensions

If $L/K$ is a Galois extension with group $G$ then we can consider $H^*(G;L^\times)$. This is useful in algebraic number theory, and there are many results about it. Now let $L/K$ be a finite ...
Neil Strickland's user avatar
16 votes
0 answers
11k views

Deligne's letter to Jean-Pierre Serre

I'm looking for another letter of Pierre Deligne, this time to Jean-Pierre Serre (from around 1974 I think), in which he proves that the Galois representation associated to a certain Hecke eigenform ...
Przemyslaw Chojecki's user avatar
15 votes
4 answers
3k views

Collecting alternative proofs for the oddity of Catalan

Consider the ubiquitous Catalan numbers $C_n=\frac1{n+1}\binom{2n}n$. In this post, I am looking for your help in my attempt to collect alternative proofs of the following fact: $C_n$ is odd if and ...
T. Amdeberhan's user avatar
15 votes
4 answers
3k views

No Tonelli or Fubini

Whenever we can interchange summation (perhaps due to Tonelli-Fubini), good things happen. Otherwise, one has to struggle evaluating double sums in just one way, because the alternative results in a ...
15 votes
3 answers
1k views

Unit fraction, equally spaced denominators not integer

I've been looking at unit fractions, and found a paper by Erdős "Some properties of partial sums of the harmonic series" that proves a few things, and gives a reference for the following theorem: $$\...
mmm's user avatar
  • 305
15 votes
5 answers
2k views

Zeros of the derivative of Riemann's $\xi$-function

The Riemann xi function $\xi(s)$ is defined as $$ \xi(s)=\frac12 s(s-1)\pi^{-s/2}\Gamma(s/2)\zeta(s). $$ It is an entire function whose zeros are precisely those of $\zeta(s)$. Since $\xi$ is real ...
Stopple's user avatar
  • 11.1k
15 votes
2 answers
1k views

Evaluating the integral $\int_{1}^{\infty}\frac{\{u\}}{u^{2}}\left(\log u\right)^{k}du.$

I am trying to find a formula for the following integral for non-negative integer $k$: $$\int_1^{\infty}\frac{\{u\}}{u^{2}}\left(\log u\right)^{k}du.$$ My first thought was to use the formula $$\...
Eric Naslund's user avatar
  • 11.4k
15 votes
1 answer
484 views

Looking for a paper on transfinite diameter by David Cantor

I have been reading about transfinite diameter and its applications to number theory and have been hunting for the following paper for quite a while: Cantor D.: On an extension of the definition of ...
asrxiiviii'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
15 votes
3 answers
1k views

Does anyone remember what happened to the experimental search for polynomial identities for $\pi$?

So a while back I was on the internet and had encountered a website containing an experimental search for identities for $\pi$. My memory was that the page belonged to either Jonathan Sondow or ...
Sidharth Ghoshal's user avatar
15 votes
1 answer
1k views

If the tensor product of two representations are crystalline, are the original representations crystalline?

Let $K$ be a finite extension of the $p$-adic numbers. Suppose that $V$ and $W$ are two (finite dimensional, $p$-adic) continuous representations of $G_K$. Suppose that $V \otimes W$ is crystalline. ...
user avatar
15 votes
4 answers
2k views

Are any good strategies known for Erdos-Turan conjecture on additive bases of order two?

The following problem can become a bit of an obsession. I'm curious if there are any serious strategies for attacking it. The problem is a certain Erdos-Turan conjecture. Let $ B \subseteq {\mathbb ...
Jon Bannon's user avatar
  • 7,067
15 votes
1 answer
943 views

BSD conjecture for rank 1 elliptic curves

Let $E/\mathbb{Q}$ be an elliptic curve. The weak Birch and Swinnerton-Dyer conjecture predicts that $$\text{ord}_{s=1}L(E, s)=\text{rank} E(\mathbb{Q}).$$ Thanks to the work of Gross-Zagier and ...
baobab's user avatar
  • 253
15 votes
1 answer
1k views

A p-adic analogue for a formula of Riemann?

This might be naive question but I was wondering whether a p-adic analogue of the following (shockingly) beautiful formula $$\zeta(s)\Gamma(s) = \int_0^\infty \frac{t^{s-1}}{e^t-1} dt$$ (vaild for $\...
user5831's user avatar
  • 2,029
15 votes
1 answer
954 views

Funktorialität in der Theorie der automorphen Formen

In 2010 Langlands wrote an article with the title Funktorialität in der Theorie der automorphen Formen: Ihre Entdeckung und ihre Ziele. On the IAS website, he says that This note ... was written ...
Chandan Singh Dalawat's user avatar
15 votes
1 answer
969 views

Counting lattice points inside a three-dimensional ellipsoid

I want to answer the following simple question: Given a three-dimensional ellipsoid defined by $Q(x, y, z) \leq Z$ for a positive definite quadratic form $Q$, how many lattice points in $\mathbb{Z}^...
Frank Thorne's user avatar
  • 7,347
15 votes
0 answers
673 views

Exposition of Drinfeld's proof of function field Langlands for GL(2)

I know, or think I know, the vague outline of the proof: the Galois-to-automorphic direction is "classical," i.e. follows from converse theorems due to Grothendieck et al., and for the ...
Avi's user avatar
  • 311
15 votes
0 answers
591 views

For how many primes does an elliptic curve over a totally imaginary field have supersingular reduction?

An elliptic curve over a finite field, $k$, of characteristic p is called supersingular if it has no $p$-torsion over $k^{\mathrm{alg}}$, or equivalently, if $\mathrm{End}(E)$ is an order in a ...
Lloyd Yu-West's user avatar
15 votes
0 answers
476 views

Any references on zeta-function like sums of inverse determinants over lattices of matrices?

I'm sorry for the title, it was little difficult to phrase.. Let us consider a matrix lattice $L\subset M_n(\mathbb{C})$. By this I mean a discrete additive group in $M_n(\mathbb{C})$. Let us ...
user18180's user avatar
  • 201
14 votes
7 answers
3k views

A special type of generating function for Fibonacci

Notation. Let $[x^n]G(x)$ be the coefficient of $x^n$ in the Taylor series of $G(x)$. Consider the sequence of central binomial coefficients $\binom{2n}n$. Then there two ways to recover them: $$\...
T. Amdeberhan's user avatar
14 votes
4 answers
4k views

Deligne's letter to Piatetskii-Shapiro from 1973

Could anyone point me to a place where I could find Deligne's letter to Piatetskii-Shapiro from 1973? It is cited for example in Berkovich's "Vanishing cycles for formal schemes II".
14 votes
3 answers
2k views

Norms in quadratic fields

This should be well-known, but I can't find a reference (or a proof, or a counter-example...). Let $d$ be a positive square-free integer. Suppose that there is no element in the ring of integers of $\...
abx's user avatar
  • 38k
14 votes
4 answers
2k views

Partitions-sum of divisors identity

A few years ago I first read about the marvelous Euler identity: $\sum_{n\in\mathbb{N}}p(n)z^n=\prod_{k\geq1}\frac{1}{1-z^k}$, where $p(n)$ is the number of partitions of $n$ ($p(0)=1$ by convention)...
Gian Maria Dall'Ara's user avatar
14 votes
6 answers
10k views

Frobenius number for three numbers

Given integers $a,b,c$ such that $\gcd(a,b,c) = 1$, it is well known that there exists only a finite set of numbers $n$ such that $n$ is not expressible as $ax+by+cz$ for non negative integers $x$,$y$,...
Jernej's user avatar
  • 3,463
14 votes
4 answers
3k views

Jacobi's theorem on sums of two squares (reference request)

One of Jacobi's theorems states that the number of representations of a positive integer $n$ as a sum of two squares of integers equals $$4(d_1(n)-d_3(n)),$$ where the function $d_i$ counts the number ...
Dr. Pi's user avatar
  • 3,062
14 votes
3 answers
1k views

How many sequences of rational squares are there, all of whose differences are also rational squares?

After commenting on a question of Joseph O'Rourke's, I thought it interesting that a number theory result (artihmetic progressions of rational squares cannot be arbitrarily long) had applications to ...
Gerhard Paseman's user avatar
14 votes
1 answer
749 views

reference for: no finite set of positive (integer) binary quadratic forms represents all primes

This recent question asks for a set of forms (binary quadratic) representing all primes. Set of quadratic forms that represents all primes When the question was asked on MSE last month https://math....
Will Jagy's user avatar
  • 25.7k
14 votes
1 answer
495 views

powered partition function generator: 1/2 of them are zeros?

Ramanujan delivered his famous congruences $$p(5n+4)\equiv_50, \qquad p(7n+5)\equiv_70, \qquad p(11n+6)\equiv_{11}0$$ for the integer partitions with generating function $F(x)=\prod_{k=0}^{\infty}\...
T. Amdeberhan's user avatar
14 votes
4 answers
3k views

Fourier decay rate of Cantor measures

For $0<\theta<\frac{1}{2}$, denote by $C_\theta$ the Cantor set with dissection ratio $\theta$, i.e. the Cantor set obtained from dissection parttern $(\theta, 1-2\theta,\theta)$. It is known ...
Syang Chen's user avatar
14 votes
1 answer
1k views

Transcendence of $\Gamma(1/3), \Gamma(1/4)$

This is a re-post from MSE as I did not get even a single comment there. Wikipedia mentions that the transcendence of $\Gamma(1/3), \Gamma(1/4)$ was proved by G. V. Chudnovsky. Does anyone have a ...
Paramanand Singh's user avatar
14 votes
2 answers
858 views

References for particular topics related to Langlands

I have never really concentrated on Langlands, which explains my poor level of understanding of it. But I have read quite a few introductory papers related to Langlands, and to the circle of ideas ...
Callum Fitzpatrick's user avatar

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