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The lonely molecule

Suppose $n$ air molecules (infinitesimal points) are bouncing around in a unit $d$-dimensional cube, with perfectly elastic wall collisions. Let $k=n^{\frac{1}{d}}$. For example, in 3D, $d=3$, with $n=...
Joseph O'Rourke's user avatar
11 votes
0 answers
307 views

Entropy, magnitude, diversity of finite metric spaces in number theory

I was reading the article by Tom Leinster, (Maximizing diversity in biology and beyond, arXiv link), and find it very interesting. Since I was searching for entropies of finite metric spaces I found ...
user avatar
8 votes
0 answers
553 views

Hasse-Weil Bound and Chebyshev Inequality

I was reading about the Hasse-Weil bound for the number of points in on a curve over the finite field $\mathbb{F}_q$. $$ \big| |C(\mathbb{F}_q)| - (q+1) \big| \leq 2g \sqrt{q} $$ However, this ...
john mangual's user avatar
  • 22.8k
7 votes
0 answers
134 views

Why does this oddly nice lognormal shape come out of tree?

I was reading this paper and came across the Euclid tree. For a simple version of this tree, consider an infinite binary tree rooted with the triple $(1,2,3)$. Then for each vertex $(x,y,z)$, its left ...
hamburglar's user avatar
7 votes
0 answers
222 views

Projected polar chessboard measure convergence in total variation?

$\newcommand\R{\mathbb R}\newcommand\C{\mathbb C}\newcommand\ga{\gamma}$For natural $n$, let $E_n$ be the set of all points in $\R^2$ with "polar coordinates" $(r,t)$ in the set $$F_n:=\...
Iosif Pinelis's user avatar
7 votes
0 answers
267 views

Can primes be (almost) random sequence in von Mises sense?

Random models for primes (such as Cramer's model) have been extensively used for informal justification of various conjectures involving primes. It is crucial to understand in what sense sequence of ...
Bogdan Grechuk's user avatar
6 votes
0 answers
177 views

Determinant arising in a problem from probability

Consider the determinant: $$\Delta:= \left|\begin{array}{cccc} A_{j_1} & A_{k_1} & A_{j_1}A_{k_1} & 1 \\ A_{j_2} & A_{k_2} & A_{j_2}A_{k_2} & 1 \\ A_{j_3 } & A_{k_3 } &...
Deepti's user avatar
  • 783
6 votes
0 answers
360 views

Examples in which probabilistic heuristic reasoning fails

There are examples of conjectures in which one can use probabilistic heuristic reasoning to show that they are very likely to be true. For instance, Freeman Dyson used probabilistic heuristic ...
Craig Feinstein's user avatar
6 votes
0 answers
671 views

Is there a probabilistic interpretation of Dedekind zeta functions?

Reading the interesting paper Honest Bernoulli excursions by Smith and Diaconis motivated the question whether probabilistic interpretations for general Dedekind zeta functions are known. In the ...
user5831's user avatar
  • 2,029
5 votes
0 answers
614 views

is there a link with the probabilistic model for prime numbers?

Let $x \in \mathbb{R}_+$ and $k \in \mathbb{N}^{*}$. Let : $$\mathcal{A}(x)=\#\{(a_1, a_2, \ldots, a_k) \in \mathbb{P}^k \mid (a_1, a_2, \ldots, a_k \text{ verifying some properties}) \, , a_k \...
Lagrida Yassine's user avatar
4 votes
0 answers
536 views

Is the integer factorization into prime numbers normally distributed?

Edit: Sorry, for the inconvenience: I have edited the question, since there was a misconception in my thinking. Let $P_1(n) := 1$ if $n=1$ and $\max_{q\mid n, \text{ } q\text{ prime}} q$ otherwise, ...
mathoverflowUser's user avatar
4 votes
0 answers
414 views

Explicit formula for tournament sequence

I am looking for an explicit formula for a sequence. The sequence is generated as follows: There is a tournament with $10$ teams. In the beginning, all teams have a 0-0 win-loss record. The teams are ...
Jackson's user avatar
  • 41
4 votes
0 answers
141 views

Local behaviour of fractions with bounded denominator / Was it already studied?

My question is about a point process that I feel it would be natural to study, but that I have never heard of… This point process would represent, morally, the local behaviour of the set of fractions ...
Rémi Peyre's user avatar
4 votes
0 answers
105 views

On a much weaker version of the Normal conjecture

I would like to ask you about the following question. It is conjectured that every algebraic irrational number is normal (absolutely normal). I know the result by Bugeaud and Adamczewski about the non-...
Jean's user avatar
  • 515
4 votes
0 answers
150 views

Dividing a finite arithmetic progression into two sets of same sum: always the same asymptotics?

This is inspired by the recent question How many solutions $\pm1\pm2\pm3…\pm n=0$. The oeis entries A063865 linked to this question and A292476/A156700 for the related one "How many solutions $\pm1\...
Wolfgang's user avatar
  • 13.4k
4 votes
0 answers
1k views

Matula-Goebel ordering of rooted trees intrinsic?

I was somewhat recently introduced to the Matula-Goebel bijection between rooted trees and natural numbers. (nicely illustrated here http://keithbriggs.info/matula.html) Looking through them, I ...
Zomulgustar's user avatar
3 votes
0 answers
177 views

What is the expected size of the complement of the union of random cosets of the prime ideals of $\mathbb{Z}$?

For each rational prime $p$ let $\mathbf{X}_p$ denote the random variable uniformly distributed in $\{0, 1, ..., p-1\}$, with all the $\mathbf{X}_p$ independent of each other. Define the coset $\...
Daniel Asimov's user avatar
3 votes
0 answers
276 views

Infinitely many $n$ such that $\gcd(\lfloor n\sqrt{2}\rfloor, \lfloor n\sqrt{3}\rfloor)=m$

Is it true that for any positive integer $m$ there are infinitely many positive integers $n$ such that $\gcd(\lfloor n\sqrt{2}\rfloor, \lfloor n\sqrt{3}\rfloor)=m$? $\lfloor x \rfloor$ is the floor ...
jack's user avatar
  • 3,153
3 votes
0 answers
185 views

Lattice points in a rotated product-of-balls

Fix $U$ unitary over $\mathbb{R}^{K},$ take $U_n=I_{n\times n}\otimes U$ and denote the unit ball at 0 in $\mathbb{R}^n$ as $B^n$. For $d_1,\dots,d_K>0$, fix $S_n:=U_n\left(\prod_{k=1}^K d_k B^n\...
Christian Chapman's user avatar
3 votes
0 answers
169 views

Why is the smallest (fractional) absolute central moment of a Gaussian distribution almost at $\sqrt{3}/2$?

Let $X$ be a standard normal random variable. What $\alpha$ minimizes $E|X|^{\alpha}$? Numerically, $\alpha$ turns out to be equal to $\sqrt{3}/2-\varepsilon$ where $\varepsilon$ is of the order $10^...
Philipp Ustinoc's user avatar
3 votes
0 answers
286 views

What is the value of this simple game with primes?

Consider the following game. Alice selects an integer $n$ from $[1,b]$, while Bob selects an integer $m$ from $(a,b]$ (for concreteness, you may choose $a=10^{10}$ and $b=10^{1000}$). Alice wins if $m-...
Bogdan's user avatar
  • 781
3 votes
0 answers
420 views

(Expected) Size of smallest singular value of a Vandermonde matrix associated to roots of polynomial

Let $n,H$ two fixed positive integers. Let $P\in\mathbb{Z}[X]$ a monic integral polynomial of height $H$ and degree $n$ taken uniformly at random (i.e. each of the $n$ free coefficients of $P$ is ...
user70925's user avatar
  • 313
3 votes
0 answers
219 views

Expected period of quadratic generator

I am interested in the mean period of a quadratic congruential generator. Let $X_{n+1} = \sum_{i=0}^2 a_i X_n^i \bmod m$ where the $a_i \in \mathbb{Z_m}$ are chosen uniformly at random and $m$ is a ...
kowalski's user avatar
3 votes
0 answers
173 views

Are numbers $h_{r,s} = \sum_{k} P(r;s;k) \frac{1}{n^{2k}} \bigg(1-\frac{1}{n}\bigg)^{n-2k}$ irrational?

I asked this question on MSE and Mike Spivey gave an insightful answer. I decided to put it here nevertheless in case someone else gets interested. If this violates rules on MO, please let me know, I'...
Alex's user avatar
  • 151
3 votes
0 answers
143 views

finding rank-3 tensors compatible with a rank-2 tensor projection

I am interested in the following problem: Consider a rank-3 symmetric tensor $\boldsymbol{\sigma}$ with $\sigma_{ijk}$ where $\sigma_{ijk}$ can be 0 or 1, and the symmetry is with respect to any ...
Ed Wolf's user avatar
  • 41
2 votes
0 answers
114 views

Echoes of the chord

Just a fun problem I thought of. A man is playing a magical pipe organ - every chord is an integer number of decibals (dB) loud. The softest chord is $0$ dB. Every chord of $N > 0$ dB creates a ...
Nate River's user avatar
  • 6,213
2 votes
0 answers
118 views

the projection distribution induced by integral points on the sphere

Let $A=\{\mathbf{v} \in \mathbb{Z}^{n}: \|\mathbf{v}\|^2= m \}$ and a fixed $\mathbf{y}\in \mathbb{R}^n$, the norm here refers to the Euclidean norm. Suppose $\mathbf{x}$ is a uniform distribution on ...
constantine's user avatar
2 votes
0 answers
215 views

An approach to the prime number theorem with Rademacher variables and a recursive formula for the prime pi function?

Consider the bipartite graphs defined here: Why is this bipartite graph a partial cube, if it is? We do random walks on them with equal propability and since the graphs are finite and connected the ...
mathoverflowUser's user avatar
2 votes
0 answers
98 views

Primes as expected values?

This is a follow-up question, which is related to the answer of this quesiton: Is there a connection of prime numbers and extreme value theory? I will duplicate the answer here, so this question is ...
mathoverflowUser's user avatar
2 votes
0 answers
87 views

The covariance of certain random variable

We define two random variables $X_n,Y_n $ on the sample space $\{1,2,3,\cdots,n\}$ with counting measure. We denote by $C_n$ the covariance of theses two random variables: $C_n=Cov(X_n,Y_n)$. ...
Ali Taghavi's user avatar
2 votes
0 answers
147 views

Is there a way to gain such an estimate?

This problem could be viewed as a polynomial generalization of the Lonely runner conjecture. And $p$, $n$ are taken sufficiently large. Take $n\in \mathbb{N}^*$ fixed, $A_p \subset (\mathbb{Z} / p \...
katago's user avatar
  • 543
2 votes
0 answers
88 views

Example of action of an infinitely countable group that has important ergodic/statistical property?

I work in probability and I am looking for an important example of action of an amenable countable group in other areas of math for which the (pointwise) ergodic theorem is actually quite important. ...
letta's user avatar
  • 21
2 votes
0 answers
299 views

A weighted ergodic average

According to my simulations, it looks like the number of times that the $N$ first iterates $u_0$, $\ldots$, $u_{N-1}$ of the sequence $(u_n)$ defined here meets an interval $I$ is close to $N|I|$ ...
Stéphane Laurent's user avatar
2 votes
0 answers
72 views

Sampling efficiently conditioned on linear constraints modulo both $\mathbb{F}_p$ and $\mathbb{F}_2$

Given a prime $p$ and positive integer $t \ll \log p$ (say $t = \sqrt{\log p}$), is there an algorithm that is polynomial time in $\log p$ to sample uniform $X, Y \in \mathbb{F}_p$ conditioned on the ...
user47772's user avatar
  • 305
2 votes
0 answers
192 views

A question related to metric Diophantine approximation

In metric Diophantine approximation you are often interested in finding conditions on $(\phi(q))_{q \geq 1}$ which guarantee that $$ \left| \alpha - \frac{p}{q} \right| < \frac{\phi(q)}{q} $$ has ...
Kurisuto Asutora's user avatar
2 votes
0 answers
970 views

Is the stationary distribution of this Markov chain uniform?

First, a little bit of background: Since 2012, Canada has decided to phase out the penny for its coinage system. Product prices may still use arbitrary cents, especially since prices do not typically ...
Yann Ponty's user avatar
2 votes
0 answers
146 views

Odds of projections of a point not on the hyperplane

Let $\mathcal{L}=\{\Bbb x\in\Bbb R^n:x_1+x_2+\dots+x_n=0\}$ be a specific hyperplane. Let a projection of $c\in\Bbb R^n$ be $p(c)=[p_1,p_2,\dots,p_n]$ where $p_i\neq c_i\implies p_i=0$. Let $\...
Turbo's user avatar
  • 13.9k
2 votes
0 answers
202 views

Bunimovich stadium bouncing ball

http://terrytao.wordpress.com/2008/07/07/hassells-proof-of-scarring-for-the-bunimovich-stadium/ I cannot relate how the eigenfunctions normalizaed correspond to the probabality distribution of the ...
mayank's user avatar
  • 163
2 votes
0 answers
200 views

Generator density in $\mathbb{Z}^*_p$

Hello, Consider the multiplicative group $(\mathbb{Z}/p)^*$ for a given prime $p$. We know that the number of generators in this group is $\phi(p-1)$ --- the Euleur totient function. The question is, ...
ogn's user avatar
  • 175
1 vote
0 answers
150 views

What are alternative mathematical definitions of observers beyond Bennett and Hoffman's framework?

Motivation: This question is inspired by a talk from Avi Wigderson given on Randomness, where the idea that the randomness is in the eye of the observer is suggested. In the study of information ...
mathoverflowUser's user avatar
1 vote
0 answers
87 views

Equidistribution of Frobenius Classes

Let $G$ be a reductive group over $\mathbb{Q}$. Let $K$ be a maximal compact subgroup of $G(\mathbb{C})$. Let $S$ be a finite set of primes. For each prime $p$ not in $S$, let $Frob_p$ be a conjugacy ...
Kledin Dobi's user avatar
1 vote
0 answers
143 views

Integer points inside the high-dimensional ball (asymptotics)

Let $N(\alpha, n)$ denote the number of integer points inside the origin-centered ball of radius $\alpha \sqrt n$ in $n$ dimensions, where $\alpha \in (0,\infty)$ is some fixed constant. Precisely: $$...
DJA's user avatar
  • 435
1 vote
0 answers
134 views

Number of ways to place 4 kings on nxn chessboard

I have a $n\times n$ chessboard and 4 kings inside it. My goal is to count the number of arrangements where some of them are non-attacking or mutually attacking, for example: In the case where the $4$...
Cardstdani's user avatar
1 vote
0 answers
84 views

Percolative process distribution not equivalent to coupon collector problem distribution

I have a process where; given a $n\times 1$ matrix initially empty, an element is inserted in it at a random position, with the possibility of repeating the insertion at a filled cell. Then, after a ...
Cardstdani's user avatar
1 vote
0 answers
78 views

In the modular exponentiation, as used with the adaptive root problem, how to chose the best base that will yield as few results as possible?

Let $n,m,w\in\Bbb N$ and $\lambda\in\Bbb P$ such that $w^\lambda \mod m = n$, with the requirements: $\lambda$ being a random large prime such as $w^\lambda > 2\times m$ $1 < n < m−1$. m is ...
user2284570's user avatar
1 vote
0 answers
169 views

Normal numbers and law of the iterated logarithm

If I remember correctly, for the binary digits of a real number in $[0,1]$, I was told that satisfying the law of the iterated logarithm (LIL) is stronger than being normal. That is, supposedly, some ...
Vincent Granville's user avatar
1 vote
0 answers
123 views

On probability of coprimality of a list of numbers

We know $r$ randomly chosen integers are coprime with probability $\frac1{\zeta(r)}$. Pick a bound $N$ and pick $k\lceil N^{\alpha}\rceil$ uniformly random integers in $[0,N^{\alpha+\beta}]$ where $\...
Turbo's user avatar
  • 13.9k
1 vote
0 answers
641 views

Some stuff related to the twin prime conjecture

I am making three statements here, and my question is about statement 2, asking if someone can prove or disprove it. A (possibly weaker) version of statement 2 was proved as an answer to a former ...
Vincent Granville's user avatar
1 vote
0 answers
193 views

Theoretical invariant distribution of discrete dynamical systems, including the Riemann Zeta map

Update on 3/10/2021: I added Example 5 in the Appendix. This generic example encompasses the Riemann Zeta dynamical system. A simple version of this post, targeted to engineers, machine learning ...
Vincent Granville's user avatar
1 vote
0 answers
72 views

Question regarding a theorem of Erdos and Renyi on $B_2(g)$ sequence

Let $S \subset \mathbb{N}$. We say $S$ is of type $B_2(g)$ if the number of representation of the form $n = s_1 + s_2 \ (s_1 \leq s_2)$ is bounded by $g$ for every $n \in \mathbb{N}$. Let $S(n)$ be ...
SJY's user avatar
  • 579