English

$(G,F)$-points on $\mathbb{Q}$-algebraic varieties

Number Theory 2025-03-12 v1 Algebraic Geometry

Abstract

Let GQ[x,y,z]G\in \mathbb{Q}[x,y,z] be a polynomial, and let V(G)V(G) be the Q\mathbb{Q}-algebraic variety corresponding to GG, i.e., V(G)={PQ3  G(P)=0}V(G)=\{P\in\mathbb{Q}^3~|~G(P)=0\}. Let F:Q3Q3,(x,y,z)(f(x),f(y),f(z))\begin{split} F:\quad &\mathbb{Q}^3\rightarrow \mathbb{Q}^3,\\ &(x,y,z)\mapsto (f(x),f(y),f(z)) \end{split} be a vector function, where fQ[x]f\in \mathbb{Q}[x]. It is easy to know that the function obtained by the composition of GG and FF, denoted as GFG\circ F, is still in Q[x,y,z]\mathbb{Q}[x,y,z]. Moreover, let V(GF)V(G\circ F) be the Q\mathbb{Q}-algebraic variety corresponding to GFG\circ F, i.e., V(GF)={PQ3  GF(P)=0}V(G\circ F)=\{P\in\mathbb{Q}^3~|~G\circ F(P)=0\}. A rational point PP is called a (G,F)(G,F)-point on V(G)V(G) if PP belongs to the intersection of V(G)V(G) and V(GF)V(G\circ F), that is PV(G)V(GF)P\in V(G)\cap V(G\circ F). Denote G,F\langle G,F\rangle as the set consisting of all (G,F)(G,F)-points on V(G)V(G). Obviously, G,F\langle G,F\rangle is a Q\mathbb{Q}-algebraic variety. In this paper, we consider the algebraic variety G,F\langle G,F\rangle for some specific functions GG and FF. For these specific functions GG and FF, we prove that G,F\langle G,F\rangle will be isomorphic to a certain elliptic curve. We also analyze some properties of these elliptic curves.

Cite

@article{arxiv.2503.07615,
  title  = {$(G,F)$-points on $\mathbb{Q}$-algebraic varieties},
  author = {Yangcheng Li and Hongjian Li},
  journal= {arXiv preprint arXiv:2503.07615},
  year   = {2025}
}

Comments

14 pages

R2 v1 2026-06-28T22:14:30.569Z