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33 votes
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Distribution of square roots mod 1

You can certainly use Vinogradov's method to show that $\sqrt{p}$ is equidistributed $\pmod 1$. I haven't thought about more subtle properties, such as the gap spacing considered by Elkies and ...
Lucia's user avatar
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24 votes
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Anti Arzela-Ascoli

Under the stated conditions, there always exists a subsequence that Cesaro converges almost everywhere. This was a question of Steinhaus, solved by Revesz [1]. More generally, it suffices that the ...
Yuval Peres's user avatar
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18 votes

Distribution of square roots mod 1

Here is an insight on what happens for the bin $[0.5,0.501]$ $n^2+n+\frac14=(n+\frac12)^2$ and $(n+\frac12+\frac3{8n+5})^2=n^2+n+1-\frac{3(8n+7)}{4(8n+5)^2}.$ So, until $\frac3{8n+5} \lt \frac1{1000}...
Aaron Meyerowitz's user avatar
17 votes
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Is the divisor counting function equidistributed mod $p$?

$\newcommand{\Y}{\mathfrak{X}_p(X)}$I haven't checked all the details on the application of Selberg–Delange below, so it's possible something I am saying is nonsense, but even after accounting for the ...
Anurag Sahay's user avatar
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16 votes

Digits in an algebraic irrational number

What is known is that every real irrational has a $0$ in its $g$-ary expansion for infinitely many $g$. WLOG take $0 < x < 1$. Taking an even-numbered convergent of the continued fraction of $...
Robert Israel's user avatar
14 votes
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Equidistribution of $\{\alpha p\}$ for $p$ in an arithmetic progression

I think the sought result follows from Vinogradov's theorem. By Weyl's criterion and the orthogonality of Dirichlet characters, the sought result can be reformulated as follows. For every nonzero ...
GH from MO's user avatar
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14 votes

Behavior of $\sum_{n=1}^{\infty} (\{n \xi \} - \frac{1}{2})$ for irrational number $\xi$

This is studied in detail in Sums of Fractional Parts of Integer Multiples of an Irrational The sum $$C(N)=\sum_{n=1}^{N} \bigl( \{ n \xi \} - \tfrac{1}{2}\bigr)$$ satisfies $|C(N)|>c\log N$ for ...
Carlo Beenakker's user avatar
14 votes
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Is the product of two equidistributed power series equidistributed?

No. Let $f(T)$ be chosen uniformly at random from all power series with constant term nonzero and let $g(T) = 1/ f(T) $. Then $g(T)$ is also chosen uniformly at random from all power series with ...
Will Sawin's user avatar
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13 votes

Uniform distribution of points on Riemannian manifolds

Let $\mu=(\delta_A+\delta_B)/2$. Then the claim of Arnold - Krylov is the weak convergence of the convolutions $\mu^{*n}*\delta_x$ to the rotation invariant probability measure on the sphere (where $\...
R W's user avatar
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13 votes
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Equidistribution of $\{p_n^2α\}$

Yes - this follows from a general theorem of Bergelson, Kolesnik, Madritsch, Son, and Tichy (Theorem 2.1 in https://people.math.osu.edu/bergelson.1/BKMS_PrimePowers.pdf): Let $\xi(x)=\sum_{j=1}^m\...
Thomas Bloom's user avatar
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13 votes
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Continuous variant of the Chinese remainder theorem

Your guess is correct. For $\alpha = (\alpha_1, \alpha_2, \ldots, \alpha_d) \in \mathbb{R}^d$, the values of $m \alpha \bmod 1$ are equidistributed (and in particular dense) in $(\mathbb{R}/\mathbb{Z})...
David E Speyer's user avatar
11 votes
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Upper bound for maximum modulus of polynomial on unit circle in term of the distribution of its roots

Let me first start with the other side: does the maximum being small guarantee that the roots are equidistributed? This is indeed the case, and is a beautiful theorem of Erdos and Turan. For a ...
Lucia's user avatar
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11 votes
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Equidistribution of CM points in the principal genus

This is known, and follows from Theorem 2 in Harcos and Michel's paper The subconvexity problem for Rankin-Selberg $L$-functions and equidistribution of Heegner points. II (Invent. math., vol. 163, ...
Vesselin Dimitrov's user avatar
10 votes

Equidistribution of CM points in the principal genus

Vesselin Dimitrov gave a nice answer, but let me point out that for the OP's question one does not need the result of Harcos-Michel (2006). Instead, the original work of Duke (1988) or alternatively ...
GH from MO's user avatar
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10 votes
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Cancellation in a very rapidly oscillating exponential sum

I doubt that one is able to get as far as $T = \exp(\log^{2-\varepsilon} x)$ with Weyl differencing. Standard Weyl differencing arguments, such as that in Theorem 8.4 of Iwaniec, Henryk; Kowalski, ...
Terry Tao's user avatar
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9 votes
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Let $(a_n)_{n\in N}=(1,2,3,4,6,8,9,12,\cdots)$ list the set$\{2^n3^m\mid m,n\in N\}$. Find $α$ such that $(a_n)\alpha\pmod1$ is not equidistributed

$\alpha =\sum_{n=1}^{\infty} \frac{1}{ 6^{100^n}}$ should do the trick. A positive proportion of numbers on your list are of the form $2^a 3^b$ for $a,b$ within a reasonable constant factor of each ...
Will Sawin's user avatar
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9 votes

Must bounded sequences be well-distributed to most *composite* moduli?

This question is related to the results in Bergelson, Vitaly; Richter, Florian K., Dynamical generalizations of the prime number theorem and disjointness of additive and multiplicative semigroup ...
Terry Tao's user avatar
  • 114k
8 votes

Distribution of square roots mod 1

For the spikes, note that in your picture, the predicted number of points in the bin around 0 is 100, but there are 300 squares in your range. Similarly, there are 75 quarter-squares (where by quarter ...
Igor Rivin's user avatar
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8 votes
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$\{(\log n)^\alpha\}$ not equidistributed if $0<\alpha\leq 1$, so how is it distributed?

There is no limit distribution at all for $a:=\alpha\in(0,1)$: for each $x\in(0,1)$, the relative frequency \begin{equation*} f_n:=f_n(x):=\frac1n\,\sum_{j=1}^{n-1}1(x_j<x) \end{equation*} will ...
Iosif Pinelis's user avatar
8 votes

Reference request - Pillai-Selberg Theorem

The original references are: S. Selberg [Math. Z. 44 (1939), 306–318; zbMATH:0019.39308] S. S. Pillai [Proc. Indian Acad. Sci. Sect. A. 11 (1940), 13–20; zbMATH:66.0168.01, MR0001761]. Interestingly ...
Anurag Sahay's user avatar
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8 votes
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Equidistribution on $\mathrm{SU}_2$

In the article "On the spectral gap for finitely-generated subgroups of SU(2)" by Jean Bourgain and Alex Gamburd (Invent. Math. 171, No. 1, 83-121 (2008)), they show that free subgroups of $...
Lucas Kaufmann's user avatar
6 votes
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Sequences similar to $\{n\alpha\}$ that are both equidistributed and truly random-like

For any $p>0$ the sequence of fractional parts $x_n=\{n^p\alpha\}$ cannot be random-like in the sense defined in the appendix. The case of integer $p$ was already discussed in the comment by ...
Yuval Peres's user avatar
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6 votes

Elementary proof of the equidistribution theorem

An elementary proof was given by Alberto Zorzi in An Elementary Proof for the Equidistribution Theorem The Mathematical Intelligencer September 2015, Volume 37, Issue 3, pp 1–2 Unfortunately the ...
coudy's user avatar
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6 votes
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Convolution sum of divisor functions

Too long for a comment Maybe this helps though it has $\sigma(n)=\sigma_1(n)$ not $\sigma_0(n)$. It may be that a similar identity may hold for $\sigma_0(n).$ In a long paper available here we find ...
kodlu's user avatar
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6 votes

for which $A\subset \mathbb{N}$ does there exist irrational $\alpha$ for which $\alpha\cdot A \pmod 1$ is not uniformly distributed?

Consider a random set $A$ where $n\in A$ with probability $f(n)/n$ for $f$ a function going to $\infty$ arbitrarily slowly. Then I think $A$ has $\alpha \cdot A$ uniformly distributed for all nonzero $...
Will Sawin's user avatar
  • 148k
6 votes

Must bounded sequences be well-distributed to most *composite* moduli?

The answer to both questions is negative. I will now try to be careful about constants. Let $\omega(n)$ be the number of prime factors of $n$, let $$a_n = \begin{cases} 1 & \omega(n) < \log \...
Will Sawin's user avatar
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5 votes
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The lonely runner conjecture and equidistribution on tori

A corrected version of this argument is contained in Section 4 of Six Lonely Runners by Bohman, Holzman, and Kleitman. Their argument shows, using equidistribution, that the case of the lonely runner ...
Will Sawin's user avatar
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5 votes
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Duke and Schulze-Pillot condition for equidistribution

I recommend that you study the paper by Duke and Schulze-Pillot, Representation of integers by positive ternary quadratic forms and equidistribution of lattice points on ellipsoids (Inventiones, 1990)....
GH from MO's user avatar
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5 votes
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Equidistribution of distances of integer points to a circle

Yes. What you are looking for follows from the known error bounds in the Gauss Circle Problem. In particular, in the notation of that Wiki article, $\text{card}(A_r\cap [a,b])=N(r+b)-N(r+a^-)$, while $...
Anthony Quas's user avatar
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4 votes
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Is this a criterion for uniform distribution modulo one?

I provide a sequence $(x_k)_k$ that is not uniformly distributed but satisfies $\frac{1}{N}\sum_{k \le N} a_k^m e^{2\pi i x_k m} \to 0$ as $N \to \infty$ for each $m \ge 1$, where $a_k = 1$ if $k$ is ...
mathworker21's user avatar
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