English

The Lang-Trotter conjecture on average for genus-$2$ curves with Klein-$4$ reduced automorphism group

Number Theory 2025-09-01 v2

Abstract

For an elliptic curve EE over Q\mathbb{Q} without complex multiplication, Lang and Trotter conjecture #{p<XE has a supersingular reduction at p}cXlogX \# \{ p<X \mid E \text{ has a supersingular reduction at } p \} \sim \frac{c\sqrt{X}}{\log X} as XX \rightarrow \infty, where c>0c>0 is a constant depending only on EE. Fourvy and Murty obtained an average estimation related to the Lang-Trotter conjecture, called the Lang-Trotter conjecture on average. We considered the Lang-Trotter conjecture for curves of genus 2, and obtained a similar result to the Lang-Trotter conjecture on average for the family of curves Cλ:y2=x(x1)(x+1)(xλ)(x1/λ)C_{\lambda}:y^2=x(x-1)(x+1)(x-{\lambda})(x-1/ \lambda). Such curves are characterized as curves of genus two with reduced automorphism group containing the Klein 44-group.

Keywords

Cite

@article{arxiv.2408.13695,
  title  = {The Lang-Trotter conjecture on average for genus-$2$ curves with Klein-$4$ reduced automorphism group},
  author = {Chihiro Ando},
  journal= {arXiv preprint arXiv:2408.13695},
  year   = {2025}
}

Comments

24pages. To appear in Research in Number Theory