English

Locally imprimitive points on elliptic curves

Number Theory 2026-04-22 v1 Algebraic Geometry

Abstract

Under GRH, any element in the multiplicative group of a number field KK that is globally primitive (i.e., not a perfect power in KK^*) is a primitive root modulo a set of primes of KK of positive density. For elliptic curves E/KE/K that are known to have infinitely many primes p\mathfrak p of cyclic reduction, possibly under GRH, a globally primitive point PE(K)P\in E(K) may fail to generate any of the point groups E(kp)E(k_{\mathfrak p}). We describe this phenomenon in terms of an associated Galois representation ρE/K,P:GKGL3(Z^)\rho_{E/K, P}:G_K\to\mathrm{GL}_3(\hat{\mathbf Z}), and use it to construct non-trivial examples of global points on elliptic curves that are locally imprimitive.

Keywords

Cite

@article{arxiv.2304.03964,
  title  = {Locally imprimitive points on elliptic curves},
  author = {Nathan Jones and Francesco Pappalardi and Peter Stevenhagen},
  journal= {arXiv preprint arXiv:2304.03964},
  year   = {2026}
}

Comments

20 pages

R2 v1 2026-06-28T09:55:20.346Z