Questions tagged [multiplicative-number-theory]
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20
questions
0
votes
0answers
70 views
Strange lacunary Lambert series related to the Liouville function
Although I have my own interest for the Liouville function, I will suppress it here as the question seems to be interesting in its own right.
It occurred to me when I saw an answer by GH from MO to ...
4
votes
1answer
289 views
On a sharp version of Halasz's theorem
I am trying to read the following paper by Granville-Harper-Soundararajan and I had a few questions regarding the paper. They prove, for $S(x):=\sum_{n\leq x}f(n)$ and $F_x(s):=\prod_{p\leq x}\left(1+\...
4
votes
0answers
92 views
Consecutive integers which are products of Fibonacci numbers
Let $F_1, F_2, \dots$ be the sequence of Fibonacci numbers, and let $\mathcal{M}$ be the set of positive integers expressible as a product of Fibonacci numbers (OEIS A065108).
One can prove that
$$F_{...
2
votes
0answers
108 views
Question regarding proof of Mertens' estimates in Montgomery-Vaughan's “Multiplicative number theory”
I have been trying to read Theorem 2.7 of Montgomery-Vaughan's "Multiplicative number theory" volume 1, and there is an issue I have run into: in the proof of subpart (e), when they write
$$\...
4
votes
1answer
238 views
Average of sums of $r_2(n^2+d^2)$
Let $r_2(n)$ denote the number of ways in which a positive integer $n$ is expressed as the sum of two squares (integers). I would like to know if there is a result that gives the exact behavior of (as ...
2
votes
2answers
256 views
Convergence of Euler product and Dirichlet series in the same half-plane?
I'm crossposting this from math.stackexchange because I think it might be inappropriately research-level for the community over there.
Suppose we have an Euler product over the primes
$$F(s) = \prod_{...
8
votes
0answers
211 views
Does every multiplicative function have a logarithmic average?
Is it true that for every completely multiplicative function $f:\mathbb N\to\mathbb C$
with $|f(n)|=1$ for all $n$, the logarithmic average
$$\lim_{N\to\infty}\frac1{\log N}\sum_{n=1}^N\frac1nf(n)\...
8
votes
0answers
160 views
Strong uniqueness of Euler's totient function
Let $f:\mathbb N\to \mathbb C$ be some arithmetical function. Define $\varphi_f(n)$ by the following formula:
$$
\varphi_f(n)=\sum_{\substack{k\leq n \\ (k,n)=1}}f(k).
$$
In other words, $\varphi_f(...
2
votes
0answers
124 views
Well-known estimate for $L(s,\chi)$ for $\sigma=\text{Re}s\geq 1/2$
This is a very short question.
Let $s=\sigma+it$ be a complex number with $\sigma \geq 1/2$.
In the paper 'Jutila, Matti. "On the Mean Value of $L(1/2, \chi)$ FW Real Characters." Analysis 1.2 (...
2
votes
1answer
143 views
Questions about a certain set of primes
Let $A$ be a set of prime numbers, generated by the following procedure. Let $A_0 = \{2\}$. Let $A_n$ be generated by setting $x_n = (\prod_{p_i \in A_{n-1}}p_i) + 1$, and adding all the prime factors ...
3
votes
0answers
77 views
Uniformity in Wirsing's Mean Value Theorems
In two important papers of Wirsing, namely "Das asymptotische Verhalten von Summen über multiplikative Funktionen" (1961) and its follow up (1967), several results on mean values of multiplicative ...
1
vote
0answers
89 views
Existence of equation about the product of the divisor sum function
Let $\sigma_k(n)$ be the sum of the $k$-th powers of the positive divisors of $n$ and $\mu(n)$ be the Möbius function.
As Arithmetic function - Wikipedia mentioned, there is an equation that $$\...
4
votes
0answers
151 views
Math software / language for analytic / multiplicative number theory
What software/languages are the most used to do computations in analytic / multiplicative number theory?
I use Python, Maple, etc., but each time I want to compute expressions like, for $n$ with an ...
1
vote
1answer
306 views
Is it possible to find all integer functions which satisfy $f(m!+n!)\mid f(m!)+f(n!)$ and $m+n \mid f(m)+f(n)$?
I'm interesting to know more about multiplicative property of integer functions then I'd like to ask this humble question:
Question:
Is it possible to find all integer functions which satisfy $f(m!+...
6
votes
1answer
291 views
A question about $(0,1]$-valued multiplicative functions
Suppose $f:\mathbb{N}\to [0,1]$ is a multiplicative function (i.e. $f(nm)=f(n)f(m)$ whenever $m$ and $n$ are coprime). Suppose $f$ has non-zero mean, which means
$$
\lim_{N\to\infty}\frac{1}{N} \sum_{...
10
votes
0answers
192 views
The multiplicative group generated by shifted primes
I am asking for references about the following problem.
In particular, it is still open? If not, what is the state of the art result?
Problem 1. Let $\Gamma$ be the multiplicative subgroup of $\...
1
vote
0answers
71 views
All all hypo-multiplicative functions linear combinations of quasi-multiplicative functions?
A function is called quasi-multiplicative by many authors if $f(m)f(n)=f(1)f(mn)$, a slight generalization of multiplicativity. (Basically a multiplicative function times a constant is a quasi-...
16
votes
1answer
1k views
Least prime in an arithmetic progression and the Selberg sieve
My question concerns a technical step in the proof of Linnik's theorem on the least prime in an arithmetic progression, as presented in Chapter 18 of Iwaniec-Kowalski: Analytic number theory.
The ...
3
votes
0answers
300 views
Linear combination of multiplicative functions
Carlitz showed necessary and sufficient conditions for an arithmetic function to be a linear combination of two multiplicative functions. He mentions the possibility of generalizing to $k$ ...
0
votes
0answers
184 views
Number of biquadrates mod n
Is there an explicit formula for the number of fourth powers mod n?
Finch & Sebah [1] give theorems, partially folklore, for squares and cubes mod n, but I don't know of a similar formula for ...
