English

Rational points on K3 surfaces of degree 2

Number Theory 2025-10-16 v2 Algebraic Geometry

Abstract

A K3 surface over a number field has infinitely many rational points over a finite field extension. For K3 surfaces of degree 2, arising as double covers of P2\mathbb{P}^2 branched along a smooth sextic curve, we give a bound for the degree of such an extension. Moreover, using ideas of van Luijk and a surface constructed by Elsenhans and Jahnel, we give an explicit family of K3 surfaces of degree 2 defined over Q\mathbb{Q} with geometric Picard number 1 and infinitely many Q\mathbb{Q}-rational points that is Zariski dense in the moduli space of K3 surfaces of degree 2.

Keywords

Cite

@article{arxiv.2505.13262,
  title  = {Rational points on K3 surfaces of degree 2},
  author = {Júlia Martínez-Marín},
  journal= {arXiv preprint arXiv:2505.13262},
  year   = {2025}
}

Comments

10 pages; final version to appear in Acta Arithmetica