English

Deterministic methods to find primes

Number Theory 2012-05-29 v4

Abstract

Given a large positive integer NN, how quickly can one construct a prime number larger than NN (or between NN and 2N)? Using probabilistic methods, one can obtain a prime number in time at most logO(1)N\log^{O(1)} N with high probability by selecting numbers between NN and 2N at random and testing each one in turn for primality until a prime is discovered. However, if one seeks a deterministic method, then the problem is much more difficult, unless one assumes some unproven conjectures in number theory; brute force methods give a O(N1+o(1))O(N^{1+o(1)}) algorithm, and the best unconditional algorithm, due to Odlyzko, has a run time of O(N1/2+o(1))O(N^{1/2 + o(1)}). In this paper we discuss an approach that may improve upon the O(N1/2+o(1))O(N^{1/2+o(1)}) bound, by suggesting a strategy to determine in time O(N1/2c)O(N^{1/2-c}) for some c>0c>0 whether a given interval in [N,2N][N,2N] contains a prime. While this strategy has not been fully implemented, it can be used to establish partial results, such as being able to determine the \emph{parity} of the number of primes in a given interval in [N,2N][N,2N] in time O(N1/2c)O(N^{1/2-c}).

Keywords

Cite

@article{arxiv.1009.3956,
  title  = {Deterministic methods to find primes},
  author = {D. H. J. Polymath},
  journal= {arXiv preprint arXiv:1009.3956},
  year   = {2012}
}

Comments

15 pages, no figures. A reference added. (Note also that the published version lists the main contributors to the project as authors, at the insistence of the journal.)

R2 v1 2026-06-21T16:16:33.035Z