English

Principal factors and lattice minima

Number Theory 2022-04-26 v1

Abstract

Let k=Q(d3,ζ3)\mathit{k}=\mathbb{Q}(\sqrt[3]{d},\zeta_3), where d>1d>1 is a cube-free positive integer, k0=Q(ζ3)\mathit{k}_0=\mathbb{Q}(\zeta_3) be the cyclotomic field containing a primitive cube root of unity ζ3\zeta_3, and G=Gal(k/k0)G=\operatorname{Gal}(\mathit{k}/\mathit{k}_0). The possible prime factorizations of dd in our main result [2, Thm. 1.1] give rise to new phenomena concerning the chain Θ=(θi)iZ\Theta=(\theta_i)_{i\in\mathbb{Z}} of \textit{lattice minima} in the underlying pure cubic subfield L=Q(d3)L=\mathbb{Q}(\sqrt[3]{d}) of k\mathit{k}. The aims of the present work are to give criteria for the occurrence of generators of primitive ambiguous principal ideals (α)PkG/Pk0(\alpha)\in\mathcal{P}_{\mathit{k}}^G/\mathcal{P}_{\mathit{k}_0} among the lattice minima Θ=(θi)iZ\Theta=(\theta_i)_{i\in\mathbb{Z}} of the underlying pure cubic field L=Q(d3)L=\mathbb{Q}(\sqrt[3]{d}), and to explain exceptional behavior of the chain Θ\Theta for certain radicands dd with impact on determining the principal factorization type of LL and k\mathit{k} by means of Voronoi's algorithm.

Keywords

Cite

@article{arxiv.1907.12158,
  title  = {Principal factors and lattice minima},
  author = {Siham Aouissi and Abdelmalek Azizi and Moulay Chrif Ismaili and Daniel C. Mayer and Mohamed Talbi},
  journal= {arXiv preprint arXiv:1907.12158},
  year   = {2022}
}

Comments

17 pages, 5 Tables