Questions tagged [nt.number-theory]

Questions in number theory

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Algorithm to check whether a given set is Sidon

We call a set of natural numbers $\mathcal S$ to be a Sidon Set if $a+b=c+d$ for $a,b,c,d\in \mathcal S$ implies $\{a,b\}=\{c,d\}$. In other words, all pairwise sums are distinct. What algorithms do ...
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pq factorization

If I tried to factor a semiprime as the product of the two prime factors given below in the form pq on a home computer would I be successful? p=(2^1024-1)+644 prime factor q=(2^1028-1)+188 prime ...
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Is modular square roots modulo primes in $NC$?

Assume modulus is prime. Is modular square roots then in $NC$? If not then, are there special primes or prime powers or numbers related to these (such as $2^k\pm i$ where $i\in\{-1,0,+1\}$) where it ...
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On the borderline between natural and artificial problems

While there is no formal definition of what constitutes a natural algorithmic problem, in most cases there is pretty good consensus whether a specific problem is natural or artificial. Natural usually ...
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Is the following equitable factoring problem $NP$-hard or in $P$?

Consider the following factoring problem: Given an integer $r$ and another integer $N$ along with all of its $n$ number of prime factors and their corresponding multiplicities $\{p_i,e_i\}_{i=1}^n$, ...
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What is a known sequence for which being constant is not provable?

My question concerns the property of being constant for computable functions ${\mathbb N}\to \{0,1\}$, within any common framework $T$ strong enough to include Heyting arithmetic (and of course not ...
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Decidability of diophantine equations over {=, +, gcd}

It is well-known that polynomial diophantine equations are undecidable (Hilbert's 10th problem): that is, given a quantifier-free formula over the language $\{=, +, \cdot, 1\}$ (of equality, addition, ...
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Since $e$ is transcendental, the function $f:\mathbb Z_{\geq 0}^{n+1}\to \mathbb R$ is injective, $$f(\underset{\text{Integers}\ \geq\ 0}{\underbrace{a_0,a_1,\ldots, a_n}}) = a_0 + a_1e+a_2e^2+\cdots ... • 1,969 9 votes 1 answer 490 views Formalizing the "no formula for primes" intuition I was trying to formalize the intuition is that there is no formula for primes, and this is my best attempt: Conjecture: There is no O(n^2) expected time randomized algorithm to generate \ge n-... • 3,243 0 votes 0 answers 45 views Is this a proof that diophantine equation solutions can't be bounded by power towers? From this 2017 paper on upper bounds for solutions to diophantine equations: Conjecture 1. If a system of equations S ⊆ Bn has exactly one solution in positive integers x1, . . . , xn , then x1, .... 1 vote 1 answer 232 views Analytic Number theory in TCS [closed] Are there any applications of analytic number theory in TCS? • 31 2 votes 0 answers 83 views is factoring harder than deciding if all prime factors lie in a particular residue class? Let n be a large positive integer. Suppose I want to know if all the prime factors of n are congruent to, say, 3 mod 8. Is this any easier than just factoring n? • 241 20 votes 1 answer 509 views Is prime-counting function #P-complete? Recall \pi(n) the number of primes \le n is the prime-counting function. By "PRIMES in P", computing \pi(n) is in #P. Is the problem #P-complete? Or, perhaps, there is a complexity reason to ... • 812 1 vote 0 answers 103 views Complexity of planted root of a system of quadratic homogeneous polynomials? Given homogeneous degree 2 randomly chosen polynomials f_1,\dots,f_{m} in \mathbb Z[x_1,\dots,x_n,y_1,\dots,y_n] each with only monomials x_iy_j with condition that the system f_1=\dots=f_{m}=... • 12.8k 14 votes 4 answers 624 views Base-k representations of the co-domain of a polynomial - is it context-free? In chapter 4 of Jeffrey Shallit's A Second Course in Automata Theory the following problem is listed as open: Let p(n) be a polynomial with rational coefficients such that p(n) \in \mathbb{N} for ... • 411 5 votes 1 answer 202 views Complexity of counting integer roots of multivariate polynomials in a polyhedron? Deciding integer roots of multivariate polyomials is undecidable. However what is known about counting integer roots of multivariate polynomials in \mathbb Z[x_1,\dots,x_m] with both m and total ... • 12.8k 14 votes 1 answer 1k views Deciding whether an interval contains a prime number What is the complexity of deciding whether an interval of the natural numbers contains a prime? A variant of the Sieve of Eratosthenes gives an \tilde O(L) algorithm, where L is the length of the ... 3 votes 0 answers 271 views Primality in NC hierarchy? AKS primality testing solves whether a given integer is prime in P. AKS algorithm is following: Input: integer n > 1. Check if n is a perfect power: if n = a^b for integers a > 1 and b &... • 12.8k 5 votes 0 answers 147 views How hard is it to generate a set of relatively prime numbers between two given bounds? Informal Question How hard is it to generate a set of relatively prime numbers between two given bounds? Decision Problem Given a, b, and k \in \mathbb{N}. Does there exist a set S \... • 5,127 2 votes 1 answer 160 views Is there any time efficient way of achieving the result of FKS hashing lemma? FKS hashing lemma states. Given a set of n-bit numbers \{x_1,x_2,\dots,x_k\} there exist a prime p of O(\log n + \log k)-bit such that x_i mod p \neq  x_j mod p if x_i \neq x_j... 0 votes 1 answer 91 views Does this pairwise independent random process have expected max load \sqrt{n}? This is an extension to the question about balls into bins: Example of pairwise independent random process with expected max load \sqrt{n} . There the following question is asked and answered in ... • 3,902 1 vote 1 answer 331 views Relation between transcendental numbers and computational complexity? Regarding the relation, there is the Hartmanis-Stearns conjecture, but beyond Turing Machine of the realtime output, there is no further conjecture or theorem. Obviously irrational algebraic number ... • 1,064 6 votes 0 answers 319 views Is there any algorithm outputing e in real time? The Hartmanis-Stearns Conjecture says that a number computed in real time by a Turing Machine is either rational or transcendental. We know that there is some transcendental (Liouville) number that ... • 1,064 10 votes 1 answer 352 views Algorithm to compute distance between powers Given coprime a, b, can you quickly compute$$ \min_{x, y > 0} |a^x - b^y|  Here $x, y$ are integers. Obviously taking $x = y = 0$ gives an uninteresting answer; in general how close can these ...
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The paper "On the computational complexity of algebraic numbers: the Hartmanis--Stearns problem revisited" by Boris Adamczewski, Julien Cassaigne, Marion Le Gonidec https://arxiv.org/abs/1601....
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Equal degree factoring of homogeneous polynomials over $\Bbb Q[x_1,\dots,x_n]$?

Given $f(x_1,\dots,x_n)\in\Bbb Q[x_1,\dots,x_n]$ of form $\prod_{i=1}^df_i(x_1,\dots,x_n)$ where each of $f,f_i$ are homogeneous and each $f_i$ is irreducible what is the best technique to factor such ...
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Algorithms to generate consecutive primes

The prime number theorem, states that the "average length" of the gap between a prime $p$ and the next prime is ln(p). I am looking for (preferably deterministic efficient) an algorithm that generates ...
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Is square removal easier than factoring?

It seems to me that the square removal task can be reduced to the factoring task, but that there is no way to reduce factoring to square removal. Is there a way to make this "feeling" more precise, i....
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Solving a system of sums-of-powers polynomials

What is the complexity of calculating the values of the integers $x_i$, where $0 \leq x_1 < x_2 < \dots < x_k < n$, given only the values $s_m = \sum_{i=1}^k x_i^m$? for $1 \leq m \leq k$? ...
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