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7 votes
1 answer
683 views

The Gauss Circle Problem asymptotic in dimension

The circle problem in $k$ dimensions: "For $n>0$, how many points $z\in \ \mathbb{Z}^k$ have $\|z\|^2\leq n$?" For large $n$, the answer is $\approx n^{k/2}\cdot \operatorname{Vol}(B^k(0,1))+\...
Christian Chapman's user avatar
6 votes
2 answers
1k views

$\pi((n+1)^2)-\pi(n^2) \le \pi(n)$ for all $n \ge 370$?

There are some conjectures of the form: There always exist at least $X$ prime numbers between $A$ and $B$. Examples: Bertrand's postulate: for every $n>1$ there is always at least one prime $p$ ...
Đào Thanh Oai's user avatar
13 votes
1 answer
2k views

For a proof of the three-square theorem without using Dirichlet's theorem on primes in arithmetic progressions

The three-square theorem states that $n\in\mathbb N=\{0,1,2,\ldots\}$ is the sum of three squares if and only if it is not of the form $4^k(8m+7)$ ($k,m\in\mathbb N$). This was first proved by ...
Zhi-Wei Sun's user avatar
  • 15.6k
13 votes
2 answers
586 views

How does the Bernstein-Zelevinsky construction of irreducibles from supercuspidals parallel the representations of the Weil-Deligne group?

In the Corvallis article Number Theoretic Background, here is what John Tate has to say on the local Langlands correspondence for a $p$-adic field $F$: So, granting a correspondence between ...
D_S's user avatar
  • 6,180
3 votes
0 answers
139 views

L-functions for the Weil group over short exact sequences

Let $(\rho,V)$ be a continuous finite dimensional representation of the Weil group $W_F$ over a local field $F$. If $V$ decomposes as a direct sum $V_1 \oplus V_2$ of representations, then $$L(s,\...
D_S's user avatar
  • 6,180
19 votes
1 answer
1k views

Definitions of $\pi_1 \times \pi_2, \pi_1 \boxplus \pi_2, \pi_1 \boxtimes \pi_2$

Let $\pi_i$ be a smooth, admissible (possibly irreducible) representation of $\operatorname{GL}_{n_i}(k)$ for $k$ a $p$-adic field. I have seen the following representations defined in terms of $\...
D_S's user avatar
  • 6,180
4 votes
0 answers
313 views

Four-distance problem

A Problem due to Steinhaus is the following: do there exists a point in the plane at rational distance from the corners of the unit square? Please give me a reference if this problem is solved.
MasleniZZa's user avatar
0 votes
1 answer
322 views

On the largest prime factor of $1+n^k$

For every positive integer $n>1$ , let $f(n)$ denote the largest prime factor of $n$. How fast does $f(1+n^k)$ grow with respect to $k$ ? Is it true that $f(1+n^k) > 2k, \forall n >2, \forall ...
user avatar
0 votes
0 answers
142 views

Mobius function on values of an irreducible quadratic polynomial

Are there infinitely many integers $n$ for which $n^2 + 1$ is square-free, and has an even number of (necessarily distinct) prime factors ?
Pablo's user avatar
  • 11.3k
3 votes
1 answer
188 views

Reference request: denominators of lonely runner numbers

The lonely runner conjecture states that for $M=\{m_1,...,m_n\}$ a set of distinct positive integers the quantity $$ \kappa(M):=\sup_{t \in \mathbb{R}} \min_i ||tm_i|| $$ satisfies $\kappa(M) \geq \...
Christian Gaetz's user avatar
14 votes
0 answers
481 views

If $ab^2$ is a sum of three squares, then so is $a$. How to see it quickly?

Here $a, b$ are positive integers, and the squares are the squares of integers. This follows from Legendre's three squares theorem, but is there a direct way?
Fedor Petrov's user avatar
3 votes
0 answers
201 views

Growth Rate of the Square-Free Part

In the course of considering this Diophantine equation, I convinced myself that the following question is interesting: If $n$ is large, must it be the case that the square-free part of $2^n-1$ is ...
Richard Voepel's user avatar
4 votes
0 answers
190 views

Restricted Iwasawa theory

Let $p$ be a prime number, let $K$ be a number field, and let $L$ be a Galois extension of $K$ such that the Galois group $\Gamma$ of $L$ over $K$ is (continuously) isomorphic to the (additive) group $...
Pablo's user avatar
  • 11.3k
8 votes
2 answers
354 views

Let $f \in \mathbb{Z}[x]$. Does $\bar{f}$ have as many roots in $\mathbb{F}_p$ as $f$ has in $\mathbb{C}$ for infinitely many primes $p$?

Let $f \in \mathbb{Z}[x]$ be a nonconstant polynomial. Consider $\bar{f} \in \mathbb{F}_p[x].$ Let $\rho_p$ be the number of distinct roots of $\bar{f}$ in $\mathbb{F}_p$, and let $\rho$ be the number ...
Andrew James Kelley's user avatar
1 vote
1 answer
306 views

Basic question regarding notation of summation over primitive characters

This seems like a very standard notation in analytic number theory, and I see it a lot. But I was confused with it and I would greatly appreciate any clarification. When one writes sum of the shape $$...
Johnny T.'s user avatar
  • 3,625
3 votes
0 answers
154 views

Is there a name for sequences of integers reduced to their lowest prime divisors?

When trying to obtain the value of Jacobsthal's function for some $n$; to find the largest sequence of consecutive numbers that are all coprime to $n$, one approach (and the only direct approach that ...
Brad Graham's user avatar
6 votes
2 answers
782 views

Books building up to the Gross-Zagier formula

I am an undergrad extremely interested in some applications of the Gross-Zagier formula for elliptic curves. I have a strong foundation in group theory and abstract algebra, and an understanding of ...
TeaFor2's user avatar
  • 169
0 votes
1 answer
308 views

Have you seen this prime distribution before?

The basic question is : has this system been considered before, and how do I find it? References to the literature would be most welcome, but I am asking for reasonable search terms. I will try the ...
Gerhard Paseman's user avatar
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
2 votes
1 answer
191 views

Synchronised $\beta$-shifts

I have been reading some papers recently, in particular, Blanchard's paper $\beta$-expansions and symbolic dynamics which state that a $\beta$-shift $S_{\beta}$ is a synchronised shift if and only if ...
Rafael Alcaraz Barrera's user avatar
3 votes
1 answer
330 views

Growth Rate of Number of Divisors of Highly Composite Numbers

Let $H(k)$ be the $k^{th}$ highly composite number (HCN). What is an asymptotic estimate for the size of $H(k)$ in terms of $k.$ What is an asymptotic estimate for the size of $d(H(k))$ where $d(n)$ ...
kodlu's user avatar
  • 10.4k
4 votes
1 answer
292 views

References on Erdos conjecture on arithmetic progressions

Erdos conjectured that any set $ A $ of positive integers such that $ \sum_{n\in A}\dfrac{1}{n} $ diverges contains arbitrary long arithmetic progressions. The celebrated Green-Tao theorem is a ...
Sylvain JULIEN's user avatar
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
3 votes
1 answer
632 views

Is the sequence $(\log(n!)\mod1)_{n\in\mathbb N}$ dense in the interval $[0,1]$?

This question was raised in the comment by Todd Trimble at how to proof there is a natural number n, the first four digits of n! Is 2018?. I thought the question may be posted separately, as even ...
Iosif Pinelis's user avatar
2 votes
1 answer
241 views

2-parts of class numbers of binary quadratic forms for non-fundamental discriminants

I need a formula for the 2-adic valuation of the number of proper equivalence classes of primitive positive definite binary quadratic forms of discriminant $-D$, call it $h_0(-D)$. I'm sure the answer ...
MHMertens's user avatar
  • 189
7 votes
3 answers
530 views

Lower bound for the fractional part of $(4/3)^n$

My son, who is 16, is doing some independent research. A lower bound depending on $n$ for $\left\{ \left( \frac{4}{3} \right)^n \right\}=\left( \frac{4}{3} \right)^n-\left\lfloor \left(\frac{4}{3} \...
Yiftach Barnea's user avatar
3 votes
0 answers
198 views

On the equation $x^3+y^3+z^3-2xyz=N$

The following question was asked at MSE without any solution: Show that the equation $x^3+y^3+z^3-2xyz=1$ have infinitely many integer solutions $(x,y,z)$. A more general question was also ...
jack's user avatar
  • 3,153
11 votes
1 answer
328 views

Critical points of Dirichlet L functions

Let $L(s,\chi)$ denote a Dirichlet $L$-function for a real-valued non-principal character $\chi$. This has limiting value $L(\infty,\chi) = 1$ and we are interested in how this limit is approached ...
user2052's user avatar
  • 1,411
4 votes
0 answers
104 views

Asymptotics of the dimensions of the plus and minus space of Atkin-Lehner

Let $S_2^{+}(p)$ be the space of newforms of level $p$ that have Atkin-Lehner eigenvalue +1, and $S_2^{-}(p)$ be the space that have Atkin-Lehner eigenvalue $-1$. What is known about the asymptotics ...
Watson Ladd's user avatar
  • 2,429
6 votes
1 answer
287 views

Number of solutions for the inequality with square roots

Let $M$ be some large real number and $\delta>0$. I would like to estimate the number of solutions for the inequality $$|\sqrt{n_1}+\sqrt{n_2}-\sqrt{n_3}-\sqrt{n_4}|<\delta\sqrt{M},$$ where $...
Alexander Kalmynin's user avatar
3 votes
1 answer
189 views

The Golay-Rudin-Shapiro sequence as “Hankel transform”

Let ${\left( {{a_n}} \right)_{n \geqslant 0}}$ be a sequence of real numbers and ${H_n} = \det \left( {{a_{i + j}}} \right)_{i,j = 0}^{n - 1}$ the $n-$th Hankel determinant. The sequence ${\left( {{...
Johann Cigler's user avatar
8 votes
1 answer
811 views

Primes of the form $x^2 + y^2 + 1$

There are infinitely many primes of the form $x^2+y^2+1$, as proved by Bredihin. Motohashi improved the result by showing that there were $\gg x/\log^2 x$ such primes up to $x$. But we expect $\Theta(...
Charles's user avatar
  • 9,114
13 votes
1 answer
358 views

Cartography of the duals of GL, PGL, SL, etc

A short version of this question could be What are the duals of $PGL(2,\mathbf{Q}_p)$, $PGL(2,\mathbf{R})$ and $PGL(2,\mathbf{C})$? I should obviously add some precisions. there are different ...
Desiderius Severus's user avatar
2 votes
1 answer
334 views

Intuition behind the proof of key step in Minkowski's second inequality on successive minima

I recently knew of this note in which Prof. M. Henk presents a proof of Minkowski's second inequality on successive minima which is (purportedly) based on ideas in Minkowski's original proof. Let me ...
José Hdz. Stgo.'s user avatar
6 votes
1 answer
714 views

Best estimate of the Mertens function without assuming the Riemann Hypothesis

I'm searching the best known upper bound for the Mertens function, but without assuming the Riemann hypothesis. Landau, in 1901, have proved that $M(x)= O(x \exp(-c\sqrt{\ln x})$, but I am unable to ...
Claudeh5's user avatar
  • 173
2 votes
2 answers
509 views

Question about Zeta Function of Singular Plane Curve

I am working on a project which involves learning about the zeta function (weil zeta function) for plane curves, but I do not know much algebraic geometry. (I do not know anything about schemes). I ...
maddels's user avatar
  • 53
1 vote
2 answers
259 views

Does the set of Diophantine $m$-tuples has full measure?

We say that an $m$-tuple $\omega=(\omega_1,\ldots,\omega_m)$ satisfies the Diophantine condition of order $\nu \geq 0$ if there is a constant $C>0$ such that for all natural $q$ and integer $p_1,\...
demolishka's user avatar
8 votes
1 answer
247 views

Origin of definitions of ramified Hecke operators

Consider a classical space $M_k(N)$ of elliptic modular forms of weight $k$ for $\Gamma_0(N)$. The definition of an unramified Hecke operator $T_{p^m}$ in terms of double cosets is the disjoint union ...
Kimball's user avatar
  • 6,039
1 vote
1 answer
199 views

Simultaneous Diophantine Condition and Growth Rate of Convergents Denominators

Let $\omega=(\omega_1,\ldots,\omega_{m})$ be an $m$-tuple of real numbers. Let $|\omega|_{m}:=\sup\limits_{1 \leq j \leq m}|\omega_j|_{1}$ be a metric on flat torus $\mathbb{T}^{m}=\mathbb{R}^{m}/\...
demolishka's user avatar
4 votes
0 answers
115 views

Relations between an projective variety and galois cohomology

Let $f_1, \cdots, f_k$ be homogeneous polynomials over $\mathbb{Q}[x_0, \cdots, x_n]$. They define an projective variety $X$ over $\mathbb{P}^n(\mathbb{C})$, namely their set of zeros $$X = Z(f_1, \...
HASouza's user avatar
  • 423
3 votes
0 answers
254 views

Looking for Coleman's paper "The Gross-Koblitz formula"

I am looking for a copy of the following paper by Robert Coleman: The Gross-Koblitz formula. Galois representations and arithmetic algebraic geometry (Kyoto, 1985/Tokyo, 1986), 21–52, Adv. Stud. ...
efs's user avatar
  • 3,107
1 vote
0 answers
115 views

Properties of the function $\chi_{s,k}$

Let $\chi_{s,k}$ be the characteristic function of integers $n$ which are expressed as sum of $s$ positive $k$-th powers i.e $\chi_{s,k}(n)=1$ if and only if $n=a_1^k+\cdots+a_s^k.$ Examples of this ...
Khadija Mbarki's user avatar
1 vote
1 answer
241 views

Is it possible to approximate irrational by fractions with denominator and numerator odd? [closed]

Suppose $\alpha$ is a positive irrational, and $\epsilon$ is an arbitrary positive real, are there $m,n$(non-negative integers) such that $$|\alpha-(2m+1)/(2n+1)|<\epsilon/(2n+1)?$$ If they exist, ...
stephenkk's user avatar
  • 201
5 votes
0 answers
317 views

Elliptic curve sequences needed for universal forgery

Elliptic Curve Digital Signature Algorithm (ECDSA) admits universal forgery (UF) if the Attacker can solve the equation $$z=\frac{f_{k-1}(x,y)f_{k+1}(x,y)}{f_{k}(x,y)^2},$$ where $k$ is unknown, $f_{k}...
Alexey Ustinov's user avatar
8 votes
2 answers
564 views

Distribution of primitive roots, as p varies

For a prime number $p$, let $\Phi(p)$ be the subset of $\{ 1, 2, \ldots, p-1 \}$ consisting of primitive roots modulo $p$. (Thus $\# \Phi(p) = \phi(p-1)$, where $\phi$ denotes the totient.) I am ...
Marty's user avatar
  • 13.3k
2 votes
1 answer
217 views

Diagonalising a symmetric matrix with polynomial entries

Suppose I have a symmetric $2$ by $2$ matrix $M$ whose $(i,j)$-th entry $F_{i,j}(\mathbf{x})$ belongs to $\mathbb{R}[x_1, \ldots, x_n]$ for each $i,j$. I know that for each $\mathbf{x} \in \mathbb{R}^...
Johnny T.'s user avatar
  • 3,625
9 votes
2 answers
2k views

Any simple concrete proof of Faltings theorem?

Are there simple proofs of some concrete special cases of Faltings's theorem? Any help would be appreciated.
XL _At_Here_There's user avatar
7 votes
3 answers
926 views

Lefschetz fixed-point theorem for the Frobenius map

Where can one find a proof of Lefschetz fixed-point theorem for the Frobenius map on elliptic curves over algebraic closures of $F_{p}$ ? This could immediately follow if their coholomogies (for the ...
user50311's user avatar
  • 305
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
0 votes
0 answers
257 views

Hercules and the Hydra with time constraints

The game of Hercules vs. the Hydra can be put in terms of a single number in hereditarily-factorized form. For example, if the Hydra is $2^{19^3} \cdot 5^{11^7}$, Hercules must choose between two ...
Dan Brumleve's user avatar
  • 2,302

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