Questions on the use of the methods of real/complex analysis in the study of number theory.

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1
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1answer
33 views

Show that $\int_{-T}^T |\zeta(\frac{1}{2} + it)|^4 \, dt \sim T \log(T)^4 $

I have been reading about "mean value theorems in number theory" such as $$\int_{-T}^T |\zeta(\frac{1}{2} + it)|^4 \, dt \sim T \log(T)^4 $$ How to prove such a result? One source says it is ...
3
votes
1answer
38 views

Asymptotic for primitive sums of two squares

A positive integer $n$ can be written primitively as the sum of two squares, meaning $n = x^2 + y^2$ with $\gcd(x,y)=1,$ precisely when $n$ is not divisible by $4$ or by any prime $q \equiv 3 \pmod ...
2
votes
2answers
38 views

$\int_2^x\frac{dt}{\log^kt}=O\left(\frac{x}{\log^kx}\right)$

I seek to prove the identity $$\int_2^x\frac{dt}{\log^kt}=O\left(\frac{x}{\log^kx}\right)$$ I was given the following hint: Split the integral into $\int_2^{f(x)}+\int_{f(x)}^x$ for a ...
1
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0answers
75 views

Simple Zero of the Riemann Zeta Function

Let $s=σ+it$. Assume that $ζ(s)-1/(s-1)$ has an analytic continuation to the half plane $σ>0$. Show that if $s = 1 + it$, with $t≠0$, and $ζ(s) = 0$ then $s$ is at most a simple zero of $ζ$. I ...
1
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0answers
65 views

Multiplicity one theorem for GL(n) and SL(n) [closed]

I am reading Dorian Goldfeld's book Automorphic forms and L functions for the groups GL(n,R) ...
0
votes
0answers
59 views

Finite solution of Power Diophantione Equation.

Given an equation $x^2+k=y^3$ where k is a constant and $y=f(x)$,$f(x)$ is differentiable and algebraic. for which- $$\frac{d}{dx}x^{2} \neq\frac{d}{dx} f(x)^3$$ 1. Can I infer that the ...
0
votes
0answers
30 views

Application of Cauchy-Schwartz to an exponential sum involving von Mangoldt function

Let $f(x_1, ..., x_n)$ be a polynomial in $\mathbb{Z}[x_1, x_2, ..., x_n]$. Let $\Lambda$ denote the Von Mangoldt function. Suppose I have an exponential sum of the form $$ S(\alpha) = \sum_{1 \leq ...
0
votes
0answers
27 views

Show that $Q(x)-\frac{6x}{\pi^2}=\Omega_{\pm}(x^{1/4})$

Let $Q(x)$ denote the number of square-free numbers not exceeding $x$. Show that $$Q(x)-\frac{6x}{\pi^2}=\Omega_{\pm}(x^{1/4}).$$
1
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2answers
34 views

non analytic functions

Find two functions, each of which is nowhere analytic, but whose sum is an entire function. I can give examples of functions that are analytic nowhere, but can't find two that add to an entire ...
3
votes
1answer
77 views

Distribution of composite numbers

This question is moved from mathoverflow, there are several excellent answers at mathoverflow which improve my question greatly. For more information, please see the original question posted on ...
1
vote
1answer
31 views

Lower and upper bounds for $\tau(n)$

How to prove the following statement: If $n$ is the product of k powers of primes, i.e. $n=\prod\limits^{k}_{i=1}p_i^{\alpha_i}$ then $\omega (n) = k$ and $\Omega=\sum\limits_{i=1}^{k}\alpha_i$ $$ ...
3
votes
2answers
49 views

How to prove this asymptotic formula?

How to prove this asymptotic formula? $$ \prod\limits_{p\leq x}\left(1+\frac{1}{p}\right) \sim \frac{6 e^C}{\pi^2}\log x $$ Where we multiply over all primes less than or equal to x. I have little ...
4
votes
2answers
50 views

Error term of a Tauberian theorem and lattice points in circles

Suppose $\{a_n\}$ is a sequence of non-negative real numbers, $a_n = O(n^M)$ for a positive number $M$ and it's Dirichlet series $L(s)=\sum \frac{a_n}{n^s}$ has an analytic continuation to a ...
1
vote
1answer
50 views

A question on the Lagrange Inversion Formula

I have to use the L.I.F. for \begin{align*} s\left(x,y\right)=\frac{1}{2}\left(1-x-y-\sqrt{1-2x-2y-2xy+x^2+y^2}\right) \end{align*} to obtain that \begin{align*} s\left(x,y\right) = ...
3
votes
1answer
50 views

$\sum_{n=0}^\infty z^n = \prod_{m=0}^\infty \left(1+z^{2^m}\right)$

When reading Iwaniec and Kowalski's Analytic Number Theory, I came across the following "identity" on page 11 (the Amazon link has a free book preview which includes page 11): $$\sum_{n=0}^\infty z^n ...
2
votes
1answer
114 views

Show that $1/\zeta(2k) = \sum_{m \le K} \mu (m)/m^{2k} + O(1/K)$

Show that $1/\zeta(2k) = \sum_{m \le K} \mu (m)/m^{2k} + O(1/K)$. I have already proved that $1/\zeta(s) = \sum_{m=1}^{\infty} \mu (m)/m^s$. But how do I show that if $k\ge 1$, $1/\zeta (2k) = ...
8
votes
2answers
181 views

Minimizing over partitions $f(\lambda) = \sum \limits_{i = 1}^N |\lambda_i|^4/(\sum \limits_{i = 1}^N |\lambda_i|^2)^2$

I'm trying to characterize the behavior of the the quantity: $$A = \frac{\sum \limits_{i = 1}^N x_i^4}{(\sum \limits_{i = 1}^N x_i^2)^2},$$ subject to the constraints that $$ \sum \limits_{i = 1}^N ...
1
vote
3answers
94 views

Evaluating an integral using Gamma function [closed]

For $r \in (0,2)$, I would like to evaluate the integral $$\frac{2}{r} \int_0^{\infty} \frac{\sin(u)}{u^r} du.$$ The answer should be $$\frac{\pi \cdot \mathrm{cosec}{\frac{r\pi}{2}} ...
2
votes
1answer
66 views

Jacobi Identities

Can anyone guide me how can I prove these two identities? a)$$\prod_{n=1}^{\infty}\frac{1-q^{2n}}{1-q^{2n-1}}=\sum^{\infty}_{n=1}q^{n(n+1)/2}$$ b) ...
4
votes
0answers
34 views

Squarefree products of a class of primes

Numbers which are the sum of two squares are the product of a square and a collection of distinct primes which are 1 or 2 mod 4. Landau proved that there are $\sim kx/\sqrt{\log x}$ such numbers up ...
1
vote
1answer
61 views

Show that $\limsup_{x \to \infty} \frac{\pi(x)}{x/ \log x} \geqslant 1. $

Show that $$\displaystyle\limsup_{x \to \infty} \dfrac{\pi(x)}{x/ \log x} \geqslant 1. $$ I've seen $\displaystyle\lim_{x \to \infty}$ operator, but I haven't seen $\displaystyle\limsup_{x \to ...
5
votes
3answers
76 views

Show that $\sum\limits_{p \leqslant x}1/p = \frac{\pi(x)}{x} + \int_2^x \frac{\pi(u)}{u^2} du.$

Show that $$\displaystyle\sum\limits_{p \leqslant x}1/p = \dfrac{\pi(x)}{x} + \int_2^x \dfrac{\pi(u)}{u^2} du.$$ In the equation above, $\pi(x)$ denotes the prime counting function. To get ...
5
votes
1answer
211 views

Heuristic explanation for oscillatory behavior of first $n$ primes' multiples

Let $A$ be the set of all multiples of the first $n$ primes. The asymptotic density of $A$ should be given by $\mu=1-\prod_{i=1}^n(1-1/p_i)$. Letting $a_k$ be the $k$th element of $A$, the function ...
3
votes
0answers
220 views

An argument for “Brocard's problem has finite solution”

Brocard's problem is a problem in mathematics that asks to find integer values of n for which $$x^{2}-1=n!$$ http://en.wikipedia.org/wiki/Brocard%27s_problem. According to Brocard's problem ...
1
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0answers
27 views

Positive proportion sets of numbers not divisible by twin primes.

Is it possible to explicitly construct a set of integers $S$ which contains a positive proportion of the positive integers and every integer in $S$ is not divisible by any prime $p$ in the set of ...
2
votes
0answers
34 views

Generalization of Dirichlet convolution

The Wikipedia page on the Mobius inversion formula gives the following formula in passing: if $$G(x)=\sum_{k=1}^x \alpha(x)F(x/k)$$ for some arithmetic function $\alpha(n)$ possessing a Dirichlet ...
1
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1answer
57 views

Wrong proof of the functional equation for $ \zeta (s) $ but why is the result correct?

If I introduce the function $ f(x)= |x|^{s-1} $ inside Poisson summatory formula and use the fact that $$ \sum_{n=-\infty}^{\infty}|n|^{s-1}=2\zeta (1-s) $$ If I combine this expression in the ...
7
votes
2answers
174 views

What percentage of numbers is divisible by the set of twin primes?

What percentage of numbers is divisible by the set of twin primes $\{3,5,7,11,13,17,19,29,31\dots\}$ as $N\rightarrow \infty?$ Clarification Taking the first twin prime and creating a set out of its ...
2
votes
0answers
44 views

Titchmarsh S function

SO it is known that Titchmarsh S function $$ S(T)= \pi^{-1} arg\quad \zeta\bigg(\frac{1}{2}+iT\bigg)$$ under the assumption of *riemann hypothesis * gives $$ S(T)=O(\frac{\log T}{\log \log T})$$ can ...
1
vote
1answer
45 views

Group of Dirichlet Characters Modulo $q$ is Isomorphic to $(\mathbb{Z} / q\mathbb{Z})^*$

I'm currently reading a book on analytic number theory, and shortly after defining Dirichlet characters, the author stated that one can prove that for a given $q\in\mathbb{N}$, the group of Dirichlet ...
2
votes
0answers
38 views

Subset of numbers analogous to primitive polynomials over finite fields

It is well known that many problems in number theory have an analogue on the ring of polynomials over finite fields and vice versa, the primes in $\mathbb{F}_q[x]$ being the irreducible polynomials. ...
2
votes
1answer
103 views

Asymptotics for square-free numbers in an arithmetic progression

Set $$Q(s,\chi)=\sum_{n=1}^{\infty}\frac{\mu(n)^2\chi(n)}{n^s},\quad (s=\sigma+i\tau),$$ where $\chi$ is a character $\mod q$, Show that $Q(s,\chi)=L(s,\chi)H(s,\chi)$ where $H(s,\chi)$ is a ...
1
vote
0answers
47 views

Comparative prime number theory with a small tweak

Fix $a, k \in \mathbb{N}$ relatively prime. For $x \in \mathbb{R}$ recall the function $$ \pi(x; k, a) = \sum_{\substack{p \leq x \\ p \equiv a \pmod{k}} } 1 $$ where $p$ denotes the primes. ...
2
votes
1answer
27 views

Logarithm of the n'th prime.

Let $P_n$ denote the n'th prime number. How could we conclude the following from the prime number theorem? $$ \log(P_n)=\log n + \log\log n + o(1) $$ Maybe by showing that $P_n=An\log n $ for a ...
1
vote
2answers
18 views

On estimating a prime related Diophantine equation related to a partition .

A friend gave me the following algebraic combinatorics question which I couldn't solve Let $p$ be a prime number and $f(p)$ the smallest integer for which there exists a partition of the set $\{2,3, ...
4
votes
2answers
51 views

Question from the proof of the Prime Number Theorem

My question is pretty trivial, but I just wanted to ask about something I can't see at all. In the proof of the PNT supplied in these notes, it is asserted that when $|t| \ge 2$ ...
2
votes
1answer
29 views

A question about step in the proof of Selberg's formula

Recently I've found the following paper, discussing and proving Selberg's symmetry formula: http://www.math.uchicago.edu/~may/VIGRE/VIGRE2006/PAPERS/Balady.pdf My question concerns proofs of ...
1
vote
0answers
36 views

Rate of Convergence of $A_{s,k}=\prod_{p}\left(1-p^{-1}\right)^{s-k+1}\sum_{m=0}^{k-1}{s\choose m}\left(1-p^{-1}\right)^{k-1-m}p^{-m}$

I'd like to know how fast the infinite product $$A_{s,k}=\prod_{p}\left(1-p^{-1}\right)^{s-k+1}\sum_{m=0}^{k-1}{s\choose m}\left(1-p^{-1}\right)^{k-1-m}p^{-m}$$ converges, where the product is taken ...
0
votes
1answer
30 views

Vanishing property of logarithmic derivative of zeta function

I was trying to derive the explicit formula for the integrated Chebyshev $\psi$ function, $\psi_1$ defined as \begin{equation}\psi_1(x)=\int_1^x\psi(y)dy\end{equation} But I have stumbled upon one ...
1
vote
2answers
99 views

Number of distinct prime divisors of an integer $n$ is $O(\log n/\log\log n)$

I strongly believe that the claim is true; but I'm neither a mathematician nor speaking French and hope that somebody can confirm it, since related questions (here, here and here) either don't have an ...
1
vote
1answer
38 views

Is there numerical evidence supporting the predicted density of the primes of the form $x^2+1$?

A famous conjecture (due I think to Hardy and Littlewood) states that if $P(x)$ denotes the number of primes of the form $n^2+1$ less than or equal to $x$, then $$P(x)\sim \frac{C\sqrt x}{\log x}$$ ...
0
votes
0answers
22 views

The estimation of $\sum^{K_0+K}_{k=K_0+1} \min\left\{ U, \frac{1}{\left< \alpha k + \beta \right>} \right\}$

I have some difficulty with understanding the proof of the following theorem: Suppose $\alpha$ is a real number which has the form $\alpha = \frac{h}{q} + \frac{\theta}{q^2}$, $(q,h)=1$, $q \geq ...
1
vote
1answer
90 views

Question concerning the Dirichlet density of a subset of the set of primes

I have the following question: I am reading Serre's book "A Course in Arithmetic" (see http://www.math.purdue.edu/~lipman/MA598/Serre-Course%20in%20Arithmetic.pdf). On page 75, it is stated that the ...
9
votes
2answers
134 views

Evaluating $\sum_{\gcd\left(m,n\right)=1}\frac{1}{m^2n^2}$

I was wondering how one would evaluate the sum $$\sum_{\gcd\left(m,n\right)=1}\frac{1}{m^2n^2}.$$ The first thought that came to mind to to try something like this: ...
5
votes
1answer
65 views

Why does Titchmarsh say that we can move the derivative under $\frac{2}{\pi}\int_0^\infty \frac{\Xi(t)}{t^2 + \frac{1}{4}} \cosh(\alpha t) \, dt$

If we define the Riemann-Xi function as $$ \Xi(t) = \xi(\frac{1}{2} + it)$$ where $$\xi(s) = \frac{1}{2}s(s-1)\pi^{-\frac{s}{2}}\Gamma(\frac{s}{2})\zeta(s),$$ then according to Titchmarsh in his ...
0
votes
0answers
35 views

Comparing a primorial $p\#$ to Dusart's upper bound for the $n$th prime

The number of elements of a reduced residue system modulo a primorial $p$ is $\varphi(p\#)$ I thought that it would be interesting to compare each primorial $p_i\#$ to the Dusart's estimate for the ...
0
votes
1answer
46 views

Chebyshev's theorem on the distribution of primes

I a lecture V. Arnold says that Chebyshev had proved that the limit $$\lim_{n\to \infty}\frac{\pi(n)}{n/\mathrm{log}(n)}$$ if exists is equal to one. Where I can find the proof? Thanks!
1
vote
0answers
38 views

Reasoning about Pierre Dusart's estimate of the $n$th prime

Cited here, Pierre Dusart established the following lower bound for $p_n$: $$p_n > n(\ln n + \ln \ln n - 1)$$ Using a spreadsheet and plugging in different values of $n$, I noticed that for an ...
3
votes
1answer
38 views

What is the best estimate known for the upper bound for the difference between consecutive primes?

Bertrand's Postulate gives us that: $$p_n < p_{n+1} < 2p_n$$ So that: $$p_{n+1} - p_n < p_n$$ In this answer, this paper is cited which says in Prop 6.8 that: For $x \ge 396738$ ...
0
votes
1answer
45 views

Writing a Gauss sum as a sum over divisors

Let $\chi$ be a Dirichlet character modulo $q$ induced by a primitive character $\chi^*$ modulo $d$ for some divisor $d$ of $q$. Let $n$ be a positive integer, and consider the generalised Gauss sum ...