English

A refinement of Koblitz's conjecture

Number Theory 2009-09-30 v1

Abstract

Let E be an elliptic curve over the number field Q. In 1988, Koblitz conjectured an asymptotic for the number of primes p for which the cardinality of the group of F_p-points of E is prime. However, the constant occurring in his asymptotic does not take into account that the distributions of the |E(F_p)| need not be independent modulo distinct primes. We shall describe a corrected constant. We also take the opportunity to extend the scope of the original conjecture to ask how often |E(F_p)|/t is prime for a fixed positive integer t, and to consider elliptic curves over arbitrary number fields. Several worked out examples are provided to supply numerical evidence for the new conjecture.

Keywords

Cite

@article{arxiv.0909.5280,
  title  = {A refinement of Koblitz's conjecture},
  author = {David Zywina},
  journal= {arXiv preprint arXiv:0909.5280},
  year   = {2009}
}
R2 v1 2026-06-21T13:51:49.581Z