Questions tagged [sieve-theory]
Sieve theory deals with number theoretic sieves, and sifted sets. E.g. the Sieve of Eratosthenes, Brun sieve, and other modern sieves.
315 questions
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Computing the Schirokauer map in Number Field Sieve for Discrete Logarithms
I'm following the Worked Example for the Special Number Field Sieve paper and I got stuck at the Schirokauer Map construction. Could someone verify my map construction logic and help me answer these ...
0 votes
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63 views
Sieve method with primes in the selected range
Is it possible to use the sieve method to solve problems like these? Count a number of $p_1p_2\cdots p_r$, a product of $r\geqslant 1$ primes such that $p_i\in [P,2P]$ for all $i=1,2,\ldots, r$ in ...
4 votes
1 answer
243 views
An inequality in Iwaniec-Kowalski
In the chapter on sieve methods, specifically the $\Lambda^{2}$-sieve, Iwaniec-Kowalski state that $$\sum_{d < \sqrt{D}}^{\flat} h(d) > \prod_{p | q} (1-g(p)) \log \sqrt{D},$$ where $h(d) = \...
5 votes
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Is $S_k(x)$ non-empty for all $k$ for sufficiently large $x$?
Let $x$ be large and $$ A = \{1,3,5,\dots,\le x\} $$ be the odd integers $\le x$. For each odd prime $p \le x$ and for each integer $k$, remove from $A$ all integers $$ n \equiv \frac{p-9}{2} \pmod p \...
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Can two (nonzero) forbidden residues per odd prime $p \ge 3$ ever remove all odd integers $\le x$?
Let $x$ be large and consider the odd integers $$ A = \{1,3,5,\dots,\le x\}. $$ For each odd prime $p \ge 3$ with $p \le x$, choose two residue classes $a_p, b_p \pmod p$. Assume that for every such $...
1 vote
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59 views
A scalable sieve generating long prime streaks
I have been experimenting with a family of Eratosthenes-like sieves that seem to generate long streaks of primes before producing the first composite. I would like to ask if something like this is ...
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49 views
Are bounded prime gaps robust to adversarial residue-class deletion?
Following up on my previous question, suppose we fix parameters $\theta \in (0, 1/2)$ and $\eta > 0$. For each large $X$, an adversary chooses a set $\mathcal{R}(X)$ of residue classes of the form $...
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Simultaneous prime-free short intervals modulo small $q$
Fix a large parameter $X$. For $0<\delta<\theta<\tfrac12$, set $H := X^{\theta}$. Question. Is it true that there exist infinitely many values of $X$ and, for each such $X$, a modulus $q\le X^...
1 vote
0 answers
51 views
Almost-prime lap counts in primitive hexagonal wraps
Consider the equilateral triangular (Eisenstein) lattice $L = \mathbb{Z}\langle a, b \rangle \subset \mathbb{R}^2$ with $a = (1, 0)$ and $b = \left(\frac{1}{2}, \frac{\sqrt{3}}{2}\right)$. A wrap is ...
0 votes
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53 views
Single-AP two-form dispersion beyond $1/2$ on short-interval averages?
Fix an even integer $h \geq 12$ and set $W = \prod_{p < h} p$. Choose a residue class $b \pmod{W}$ with the covering property that for every $s$ in the range $1 \leq s \leq h-1$, there is a prime $...
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Density of prime numbers based on (naive) sieving [duplicate]
By the prime number theorem, we have $\frac{\pi(n)}n \sim \frac1{\log(n)}$. On the other hand, I was wondering whether the asymptotic behavior of $\frac{\pi(n)}n$ can be figured out by a naive sieving,...
1 vote
1 answer
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Substitution inside an integral: an error in Nathanson's proof of the Jurkat-Richert theorem?
I'm studying the Jurkat-Richert theorem from Nathanson's text "Additive Number Theory - the classical bases, 1996" and I think there is an error at a crucial point. The equality from page ...
2 votes
0 answers
76 views
Getting Chebyshev for an interval with sieves
Let $\pi (x+y)-\pi (x)$ be the number of primes in $(x,x+y)$ and define $$A_d=\sum _{x<n\leq x+y\atop {d|n}}1\hspace {10mm}\Psi _z=\sum _{x<n\leq x+y\atop {p|n\implies p>z}}1.$$ The following ...
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49 views
Affine symmetry of a sieved set
Disclaimer: as I'm not sure whether this question is research-level or not, I ask it here rather than on Mathoverflow. In sieve theory, one aims at sieving a set $S$ of integers through modular ...
2 votes
1 answer
70 views
Inequality involving sifting functions
Let $\lambda^{+} : \mathbb{N} \to \mathbb{R}$ be an upper bound sifting function, i.e., $\lambda^+$ satisfy the inequality $$ \sum_{d | n} \lambda^+(d) \geq \sum_{d | n} \mu(d) = \begin{cases} 1 &...