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Prove or disprove that $|(1/\zeta)^{(n)}(x)| \leq \frac{n!}{(x-\frac{1}{2})}$ for all real $x>1$

$|(1/\zeta)^{(n)}(x)| \leq \frac{n!}{(x-\frac{1}{2})}$ for all real $x>1$. I had this conjecture for a long time. I tried various methods and techniques but they all failed. It might also be wrong ...
Haidara's user avatar
  • 178
5 votes
2 answers
355 views

Can one show that $(-1)^{n-1} {(1/\zeta)}^{(n)}(x) >0$ for all real $x>1$?

Is it true that $(-1)^{n-1} {(1/\zeta)}^{(n)}(x) >0$ for all real $x>1$ ? Or in other words can you show that the higher order derivatives of the reciprocal of the Riemann zeta function ...
Haidara's user avatar
  • 178
0 votes
2 answers
364 views

Can one show $\left|\frac{2(\zeta'(x))^2-\zeta''(x)\zeta(x)}{\zeta^3(x)}\right|\leq \frac{2}{(x-\frac{1}{2})^2}$ for $x\in\mathbb{R}\cap [1,\infty)$?

I have found that $\left|\frac{2(\zeta'(x))^2-\zeta''(x)\zeta(x)}{\zeta^3(x)}\right|\leq \frac{2}{(x-\frac{1}{2})^2}$ for all real $x$ such that $x>1$ seems to be true. I have plotted the ...
Haidara's user avatar
  • 178
6 votes
1 answer
568 views

Can one show that $|\zeta'(x) / \zeta^2(x)| \leq 1/(x-.5)$ for $x\in\mathbb{R}\cap [1,\infty)$?

I have found that $\left|\frac{\zeta'(x)}{\zeta^2(x)}\right|\leq \frac{1}{x-\frac{1}{2}}$ for all real $x$ such that $x>1$ seems to be true. I have plotted the inequality and got this inequality ...
Haidara's user avatar
  • 178
2 votes
0 answers
159 views

Upper bound of a product of sines

Consider the function $$ f_n(t)= \prod_{1 \leq k \leq n-1,\\ \gcd(k,n)=1} \sin\Big(t-\frac{k \pi}{n}\Big),\quad t \in [0,\pi].$$ I wonder whether it is possible to compute some nontrivial upper ...
AgnostMystic's user avatar
8 votes
0 answers
357 views

Bounding a sum of reciprocals of square-free integers

(Cross-posted from MSE, as the question did not get any clear answer) Fix positive integers $k$ and $n$. Let $N_1,\dots,N_r$ be all the integers less than or equal to $n$ that are squarefree and have ...
Juan Moreno's user avatar
4 votes
1 answer
353 views

Inequalities involving binary representation of integers

Let $N\geq 1$ be a positive integer and assume that $N=2^{n_1}+2^{n_2}+\cdots+2^{n_{p}}$, $n_{1}>n_{2}>\cdots>n_{p}\geq 0$, is the binary representation of $N$. I believe that the following ...
aleari1009's user avatar
10 votes
2 answers
849 views

Schur's proof of Hilbert's inequality: streamlining?

TL;DR: Is there a way to make Schur's (elegant) proof of Hilbert's inequality feel like less of a trick/miracle? Longer version: Let me go quickly over Schur's proof to show what I mean. Actually, let ...
H A Helfgott's user avatar
  • 20.2k
10 votes
2 answers
282 views

Non-trivial upper bound for a sum related to $p^{-1}z \pmod q$ and $q^{-1}z \pmod p$

Let $p, q$ be two distinct prime number. I'm trying to provide a non-trivial upper bound for the sum $$S(p, q) = \sum_{1 \leq x < p} \sum_{1 \leq y < q} \frac{1}{\|x / p\| \, \|y / q\| \, \|x/p +...
Seee's user avatar
  • 65
1 vote
0 answers
305 views

About inequalities that involve the sum of divisors, the Euler's totient and the aliquot part $\sigma(n)-n$

In this post, for integers $n\geq 1$, I denote the sum of divisors $\sum_{1\leq d\mid n}d$ as $\sigma(n)$ and the Euler's totient function as $\varphi(n)$. It's easy to check* that if we assume that $...
user142929's user avatar
3 votes
0 answers
151 views

On an inequality for the arithmetic function counting the number of primes $\lfloor n^c\rfloor$ in the spirit of Ramanujan's prime counting inequality

In page 3 of [1] (please see if you need it the book by Berndt) Axler refers an inequality that involves the prime-counting function $\pi(x)$ and that was deduced by Ramanujan. I'm curious to know if ...
user142929's user avatar
2 votes
0 answers
110 views

On variations of a claim due to Kaneko in terms of Lehmer means

This post is cross posted from Mathematics Stack Exchange, due that there was a mistake from my part (see the excellent partial answer and my thread of edits of my question on MSE) this post on ...
user142929's user avatar
0 votes
1 answer
230 views

Inequality in Iwaniec-Kowalski

I am reading about Dirichlet polynomials in the book Analytic Number Theory by the said authors. Can anyone justify the following inequality? Assume that $a(n),b(m)$ are sequences of non-negative ...
Dr. Pi's user avatar
  • 3,062
5 votes
1 answer
391 views

Proving a specific case of Robin's Inequality

Edit: It turns out that this is equivalent to the RH which gives the idea that this might a a little difficult to show. As such we could consider an even simpler case in which the number $n$ is ...
wjmccann's user avatar
  • 315
0 votes
0 answers
106 views

Variants of Nicholson's inequalities for prime numbers, involving the Lambert $W$ function

The purpose of this post is ask about two closely related/inspired conjectures from inequalities due to Nicholson (see [1]) and Visser [2]. If my reasonings are right should be stronger versions of ...
user142929's user avatar
0 votes
0 answers
219 views

On an inequality involving the Lambert $W$ function and the sum of divisors function

Let $W(n)$ be the principal/main branch of the Lambert $W$ function (this is the Wikipedia related to this special function). I was inspired in Robin equivalence to the Riemann hypothesis (see [1]) ...
user142929's user avatar
2 votes
1 answer
146 views

On an attempt to create interesting variants of Firoozbakht's conjecture, evoking combinations of different generalized means

The idea of this post arises when I've considered simple variants of the known as Firoozbakht's conjecture (see this corresponding Wikipedia or [1]), and comparisons by trial and error with means (if ...
user142929's user avatar
0 votes
0 answers
158 views

Similar problems for the Dedekind psi function than those that are in the literature for the Euler's totient function: reference request or proposals

I know the linked articles from Wikipedia for the Euler's totient function and the Dedekind psi function. I know that are in the literature famous, interesting and difficult problems involving the ...
user142929's user avatar
1 vote
0 answers
315 views

From an inequality for the Euler's totient function to a combination of Firoozbakht's conjecture and Nicolas' criterion for the Riemann hypothesis

In this post we ask about the veracity of an inequality deduced from a combination of Firoozbakht's conjecture (see [1] or [2]) and Nicolas' criterion for the Riemann hypothesis (see for instance [3])....
user142929's user avatar
-3 votes
2 answers
261 views

The inequality $\Pi (1-\frac{1}{a_i})^{x_i} \le \Pi (1-\frac{1}{b_j})^{y_j} $ hold? [closed]

Question: Are the properties as follows holds? Version 1: the answer by Bjørn Kjos-Hanssen Let $P$ be a positive integers. We written: $P=$ $a_1^{x_1}a_2^{x_2}...a_n^{x_n}$ $=b_1^{y_1}b_2^{y_2}......
Đào Thanh Oai's user avatar
4 votes
2 answers
472 views

Sharp estimates for Meissel-Mertens constant

I wondered if it is possible to get a similar inequality like $(1.1)$ of Michael D. Hirschhorn, Approximating Euler's Constant, The Fibonacci Quarterly, Volume 49, Number 3 (August 2011) for the ...
user142929's user avatar
-3 votes
1 answer
281 views

A Bonse's inequality for semiprimes, with a good mathematical content

A semiprime $s$ is a positive integer that is the product of two prime numbers, see Semiprine the encyclopedia Wikipedia. A well-known inequality, with applications, that involves prime numbers is the ...
user142929's user avatar
5 votes
1 answer
268 views

Is it a known property of positive integers $n> 2 $ that one must have $n < \mathrm{rad}(n(n-1)(n-2))$?

Let $P(n)$ be the statement that $$n < \mathrm{rad}(n(n-1)(n-2)),$$ where $\mathrm{rad}$ is the radical of an integer, that is defined as $$\operatorname{rad}(m)=\prod_{\substack{p\mid m\\p\text{ ...
Đào Thanh Oai's user avatar
0 votes
0 answers
83 views

Is it possible to get a conjecture similar to Mandl's conjecture for a different arithmetic function of number theory, mainly related to primes?

I'm curious to know if are in the literature analogous conjectures to the conjecture due to Mandl, I ask about these analogous conjectures for different sequences playing an important role in number ...
user142929's user avatar
1 vote
1 answer
288 views

Bounding Coefficients of Dirichlet Series

Consider the exponentiated Riemann-Zeta function $\zeta(s)^p$. If it is represented as $$\zeta(s)^p = \sum_{n=1}^\infty\frac{a_n}{n^s}$$ Is there any upper bound we can put on $|a_n|$ in terms of ...
Halbort's user avatar
  • 1,129
1 vote
1 answer
195 views

A simple inequality that arises from the exact form for the prime-counting function and the second Hardy–Littlewood conjecture

The germ of this post arises when I was trying to think what terms of the so-called exact form of the prime-counting function satisfy an inequality of the form $\text{term}(x+y)\leq \text{term}(x)+\...
user142929's user avatar
15 votes
5 answers
2k views

$|L'(1,\chi)/L(1,\chi)|$

Let $\chi$ be a primitive Dirichlet character $\mod q$, $q>1$. Is there a neat, simple way to give a good bound on $L'(1,\chi)/L(1,\chi)$? Assuming no zeroes $s=\sigma+it$ of $L(s,\chi)$ satisfy $\...
H A Helfgott's user avatar
  • 20.2k
2 votes
1 answer
127 views

Effectiveness of the implied constant in an inequality

A result of Heath-Brown states: For $a_1,...,a_n$ be arbitrary complex numbers, $$\sideset{}{^*}\sum_{m\le M} \left|\sideset{}{^*}\sum_{n\le M}a_n\left(\frac{n}{m}\right)\right|^{2} \ll_{\epsilon}(MN)^...
RGM's user avatar
  • 29
13 votes
2 answers
730 views

Show that there exist $k\in\{1,2,\cdots,n\}$ such that $\frac{1}{n}\sum_{i=1}^{n}\left(\{kx_{i}\}-\frac{1}{2}\right)^2>\frac{1}{12}-\frac{1}{6n}$

The following question has post mathsatck :Nice problem, perhaps from a question of expectation.The problem seemed so elementary, but I had tried to solve it for a long time and eventually failed.I 'd ...
math110's user avatar
  • 4,280
1 vote
1 answer
141 views

Compare $\operatorname{rad}(an+b)$ and $\varphi(cn+d)$ in a simple and interesting inequality, for some choice of integers $a,b,c$ and $d$

We denote for an integer $n>1$ its square-free kernel as $$\operatorname{rad}(n)=\prod_{\substack{p\mid n\\p\text{ prime}}}p,$$ with the definition $\operatorname{rad}(1)=1$. You can see this ...
user avatar
0 votes
1 answer
125 views

Polyhedral conditions for quadratic inequalities in fixed dimension

Denote $\mathcal T$ be set of $(T_1,T_2,T_3,T_4)\in\mathbb Z^4$ that satisfy $$0<T_1,T_2,T_3,T_4$$ conditions? Define the level set $$M_{\gamma}(Q,\mathcal T)=\{(T_1,T_2,T_3,T_4)\in\mathcal T:Q(...
Turbo's user avatar
  • 13.9k
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
10 votes
1 answer
1k views

The supremum value of $\int f(t) \log{\frac{1}{|t|}} \, dt$ for normalized Fourier pairs non-negative outside of $[-1,1]$

Observe that for any Schwartz function $f \in \mathcal{S}(\mathbb{R})$ having $$ f(0) = \widehat{f}(0) = 1 $$ and $$ f, \widehat{f} \geq 0 \quad \textrm{outside of} \quad [-1,1], $$ the following ...
Vesselin Dimitrov's user avatar
2 votes
2 answers
1k views

Estimates for Sum of Prime Factors and Number of Prime Factors

Given a positive integer $n$, I've workout out a formula which involves the expression "sum of distinct primes dividing n" minus "number of distinct prime factors of n." Are there any known ...
The Substitute's user avatar
1 vote
2 answers
209 views

What is the upper bound for $\int \limits_{2}^{x} \frac{e^{-0.3\sqrt{\ln(t)}}}{\ln^2(t)} dt$?

For start, is $\int \limits_{2}^{x} \frac{e^{-0.3\sqrt{\ln(t)}}}{\ln^2(t)} dt \leq x\ln(\ln(x)) \frac{e^{-0.3\sqrt{\ln(x)}}}{\ln^2(x)}$ ? If the above is true, what is a better bound for the integral ...
Ahmad's user avatar
  • 185
5 votes
1 answer
436 views

Even sharper upper bound for prime product?

In Dusart papers he proves that $\prod \limits_{p \leq x} \frac{p_i}{p_i-1} \leq e^\gamma \ln (x) \left(1+\frac{0.2}{\ln ^2 (x)} \right)$ for large numbers. What I am asking is could we make the ...
user avatar
0 votes
1 answer
437 views

Mertens' 3rd theorem, upper bound

Is it true that $$\prod_{p\le x}\frac p{p-1}\le e^\gamma\ln x\left(1-\frac{0{.}011}{\ln x}+\frac{0.2}{(\ln x)^2}\right)$$ for all $x>25\,000$, where the product is over prime $p$?
user avatar
-1 votes
1 answer
199 views

Find the values of $n$ that satisfy this inequality involving a product over prime numbers [closed]

Inequality What values of $n$ satisfy the following inequality? $$2(n-2) < Ap_n\prod_{i=3}^n \left(\frac{p_i-2}{p_i}\right)$$ $p$ are prime numbers and the notation $p_i$ indicates the $i$th ...
Brad Graham's user avatar
4 votes
1 answer
419 views

The values of $n$ which satisfy an inequality about prime numbers

For which values of $n$ does the following inequality hold for? $$2(n-2) < Ap_n\prod_{i=3}^n \left(\frac{p_i-1}{p_i}\right)$$ $p$ are prime numbers and the notation $p_i$ indicates the $i$-th ...
Brad Graham's user avatar
2 votes
1 answer
222 views

trigonometric sum and inequalities

let $x\in\mathbb{R}-\mathbb{Z}$ and $e(x)=e^{2\pi ix}$. If we have this sum $$\left|\overset{q}{\underset{h=1}{\sum}^{*}}e\left(h\, x\right)\underset{\underset{p\equiv h\,\textrm{mod}\, q}{p\leq N}}{\...
peppo's user avatar
  • 45
4 votes
2 answers
366 views

Inequality for an integral involving $ \exp $, $ \sin $ and $ \cos $

Let $ t > 0 $ and $ k \in \{ 0,1,2,\ldots \} $. Does the following inequality hold? $$ \int_{k + 1/2}^{k + 3/2} \frac{x \sin(2 \pi x)}{1 + 2 e^{2 \pi t} \cos(2 \pi x) + e^{4 \pi t}} ...
Fancier of Mathematica's user avatar
3 votes
1 answer
921 views

Number of solutions in a sum of squares Diophantine equation

Let $n$ be an integer. I'm interested in upper bounding the number of integer solutions of \begin{equation*} x_1^2+x_2^2+\ldots+x_p^2=y_1^2+y_2^2+\ldots+y_p^2, \end{equation*} where for all $i\in\{1,...
mohi's user avatar
  • 859
10 votes
1 answer
1k views

Can the Brun-Titchmarsh theorem be improved when the modulus is smooth?

For $q,a$ relatively prime, let $\pi(x,q,a)$ denote the number of primes less than $x$ which are congruent to $a$ modulo $q$. The Brun-Titchmarsh theorem states that $$\pi(x,q,a)\leq \frac{(2+o(1))x}{\...
Eric Naslund's user avatar
  • 11.4k
3 votes
0 answers
947 views

Inequalities in paper by Jean Bourgain

The question refers to the following paper by Jean Bourgain: http://arxiv.org/abs/math-ph/0011053 Specifically, I can't derive the following inequality in (1.20): \begin{equation} \left|\sum_{|k|\...
Eduard Tetzlaff's user avatar
11 votes
1 answer
1k views

The Bombieri Vinogradov Theorem restricted to moduli divisible by $k$

The Bombieri-Vinogradov Theorem states that given $A>0$, there exists $B>0$ such that for $Q=\sqrt{x}\left(\log x\right)^{-B},$ we have $$\sum_{q\leq Q}\max_{y\leq x}\max_{\begin{array}{c} a\...
Eric Naslund's user avatar
  • 11.4k
3 votes
4 answers
678 views

Equidistribution Theorem: distance between solutions

Can please someone help me with the following problem. Say we have a sequence $nx \; \mathrm{mod} \; 1$, where $n$ is a whole number and $x$ is irrational. Now I need to solve the inequality $nx \; \...
Sasha's user avatar
  • 33
3 votes
2 answers
597 views

lower bound for $\Re\zeta(1+it)$

Hi is there any lower bound for $\Re\zeta(1+it)$. I did try with computer until some ordinate and I saw $\Re\zeta(1+it)>0$. If it is true, is there any reference to prove it. thanks
asd's user avatar
  • 163