Skip to main content

New answers tagged

13 votes
Accepted

Difficulty with "A new elementary proof of the Prime Number Theorem" by Richter

The proof of Lemma 3.4 uses the constant $K=[\epsilon^{-3}]$ which should be your clue. After the definition of $K$ the author covers $(8^t,8^{t+\epsilon})$ (which contains at least $\epsilon 8^n/(2n)$...
Conrad's user avatar
  • 2,040
4 votes

How to prove the identity $L(2,(\frac{\cdot}3))=\frac2{15}\sum\limits_{k=1}^\infty\frac{48^k}{k(2k-1)\binom{4k}{2k}\binom{2k}k}$?

To provide an alternative approach, I'll cross-post my answer from MSE, adapted for the series. Similarly to what @Nemo obtained in the comments, we can transform the original series into an ...
Zacky's user avatar
  • 215
7 votes
Accepted

Existence of Finite Amicable Groups

Suppose that $G$ and $H$ are nontrivial finite amicable groups and let $\mathscr{G}$ and $\mathscr{H}$ be the nontrivial proper subgroups of $G$ and $H$, respectively. Then $1 \subsetneq \bigoplus_{S ...
user527492's user avatar
6 votes
Accepted

Clarification and Proof of Inequality (8.11) in Analytic Number Theory by Iwaniec and Kowalski

The assumptions imply $$|S_f(N)|\le\sqrt2\frac N{\sqrt q}+2\sqrt q\log q.$$ Indeed, if $q\le2$, this follows from $|S_f(N)|\le N$; for $q\ge3$, we have $\log q>1$, thus $$\begin{align*} |S_f(N)|^2&...
Emil Jeřábek's user avatar
6 votes

Clarification and Proof of Inequality (8.11) in Analytic Number Theory by Iwaniec and Kowalski

The authors seem to claim that if a real quantity $X$ satisfies $X \le N$ and $$\tag{$*$}\label{483297_star}X^2\le N+\frac{2N^2}{q}+4(N+q)\log q$$ then $$X\le 2\frac{N}{\sqrt{q}}+\sqrt{q}\log q.$$ ...
Ofir Gorodetsky's user avatar
2 votes

Clarification and Proof of Inequality (8.11) in Analytic Number Theory by Iwaniec and Kowalski

After further exploration, I found a related question and discussion on https://mathoverflow.net/questions/208886/iwaniec-kowalski-exponential-sum-for-quadratic-function?rq=1` that addressed my ...
Fatima Majeed's user avatar
2 votes

Possible refinements of the large sieve inequality

Though a bit late -- In general, look at Theorem 2.1 of https://ramare-olivier.github.io/Maths/Eigenvalues-JTNB.pdf This improves a bit on the c in (N+cQ^2). For a generic sifted set, look at Theorem ...
Olivier Ramaré's user avatar
0 votes

Can we balance factors using the set of arithmetic sequence so as to achieve a product quality on both sides?

A necessary condition for an example is that there are positive integers $a,b$ such that $\prod_{i=0}^{2N-1}(a+ib)$ is a square. Differently phrased (divide by $b^{2N}$), we ask for rational solutions ...
Peter Mueller's user avatar
2 votes
Accepted

Bounding a number-theoretic integral

The integral looks something like $$\sum _{n=1}^\infty \frac {\Lambda (n)}{n^c}\int _1^Tt^{1/2-c}\cdot e(t-t\log (X/nt))\cdot dt\hspace {10mm}e(z)=e^{2\pi iz}.$$ The derivative of the phase is ...
tomos's user avatar
  • 1,381
6 votes

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

Here is a more pedestrian version of Fedor Petrov's argument: We set $\lambda=1/\log6$ and claim that $(-1)^n(1/\zeta)^{(n)}(\lambda n)>0$ if $n$ is big enough. With $a_k=\log k/k^\lambda$, we have ...
Peter Mueller's user avatar
12 votes
Accepted

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

In other words, you ask whether the function $f(x):=1-1/\zeta(1+x)$ is completely monotonic on $[0,+\infty)$. We have $f(x)=\sum_{n>1} -\mu(n)/n^{1+x}=\int e^{-xt}d\lambda(t)$, where $\lambda=\sum_{...
Fedor Petrov's user avatar
6 votes
Accepted

Largest prime factors of integer polynomials

te4 is quite right that this is open. A general comment is that asking whether there exists a subsequence whose lim sup is finite is equivalent to asking whether the lim inf of the original sequence ...
Will Sawin's user avatar
  • 148k
-2 votes

Largest prime factors of integer polynomials

Yes, in fact for every non-singular quadratic polynomial such a sequence exists. Actually, something much stronger holds: for every nonn-singular quadratic polynomial $f \in \mathbb{Z}[x]$ and for any ...
Stanley Yao Xiao's user avatar
3 votes

Bounds of zeta function near $\Re(s)=1$

In addition to GH from MO's answer, if one wishes to keep the $(\log|\Im(s)|)^{2/3}$ factor, then there is a very recent improvement due to Bellotti [1]. In particular, Bellotti proved that $$ \zeta(s)...
Daniel Johnston's user avatar
4 votes
Accepted

Bounds of zeta function near $\Re(s)=1$

Heath-Brown (2016) proved that, for any $\varepsilon>0$, $$\zeta(\sigma+it)\ll_\varepsilon t^{\frac{1}{2}(1-\sigma)^{3/2}+\varepsilon},\qquad 0\leq\sigma\leq 1,\qquad t\geq 1.$$ The exponent $1/2$ ...
GH from MO's user avatar
  • 105k
6 votes
Accepted

Primes which are safe and Sophie Germain

This is asking for the density of Cunningham chains of the first kind of length three. Take the integer polynomials $f_1(n) = n$, $f_2(n) = 2n+1$ and $f_3(n) = f_2(f_2(n)) = 4n+3$ and apply the (...
Jesse Elliott's user avatar
3 votes

First occurrence of formula for $\sum_{n\leq x} \mu(n) \log n$ in terms of $\psi(y)-\lfloor y\rfloor$?

I'm willing to give Landau half-marks for section 155 (chapter 41, part 11, vol II) in his Handbuch: he derives $M(x)=o(x)$ from PNT by noting, in effect, that $$\sum_{n\leq x} \mu(n) \log n = - \sum_{...
H A Helfgott's user avatar
  • 20.2k
4 votes
Accepted

Prime number theorem via large sieve type sums

This isn't exactly along the lines you are suggesting, but Hildebrand does have a proof of the Prime Number Theorem which proceeds but estimating $M(x)$ using the large sieve inequality. See: A. ...
Mark Lewko's user avatar
  • 12.9k
5 votes
Accepted

Conjectured error term when counting square-free integers

Your guess is correct! It is indeed conjectured that $a=1/4$. A good recent reference is [1]. In particular, it is known that $$E(x)=\Omega(x^{1/4})$$ and computations have shown $$|E(x)|<1.12543x^{...
Daniel Johnston's user avatar
1 vote

Asymptotic behavior of weighted sums involving the fractional part function

Not an answer but a conjectural answer for the value of $C(m)$ supported by extensive numerical evidence: $$C(m)=\dfrac{1}{m-1}\sum_{2\le k\le m-1}\binom{m-1}{k}\zeta(k)+\sum_{2\le k\le m-2}\dfrac{1}{...
Henri Cohen's user avatar
  • 13.1k
12 votes
Accepted

Are all integers up to $x$ but possibly $O_{\varepsilon}(x^{\varepsilon})$ the sum of $a$ squares and $b$ primes with $a+b\leq 3$?

Linnik (1960) proved that every sufficiently large positive integer is the sum of a prime and two squares, confirming a conjecture of Hardy-Littlewood (1923). Moreover, he gave an asymptotic formula ...
GH from MO's user avatar
  • 105k
7 votes

Residue of Dirichlet series at $s = 1$

Yes, the conclusion follows. Indeed, fix any $\varepsilon>0$. For $t>0$ sufficiently large, the sum $$S(t):=\sum_{n\leq t}a_n$$ satisfies $$|S(t)-Rt|\leq\varepsilon t.$$ Hence for any $s>1$, ...
GH from MO's user avatar
  • 105k
4 votes
Accepted

Residue of Dirichlet series at $s = 1$

I think it's a standard exercise in summation by parts if I didn't make a mistake. We wish to show $$\lim_{\epsilon \to 0^+} \epsilon \sum_{n \ge 1} \frac{a_n}{n^{1+\epsilon}} = R.$$ The sum is the ...
mathworker21's user avatar
  • 1,355
5 votes
Accepted

Mellin transform at $0$

By definition, $\tilde{f}(0)$ exists if and only if $\int_0^\infty f(x)/x\,dx$ exists. As $f(x)$ is smooth and supported on $[0,2]$, we have that that $$|f(x)|=\left|\int_0^x f'(t)\,dt\right|\leq x\...
GH from MO's user avatar
  • 105k

Top 50 recent answers are included