English

Explicit counting of ideals in number fields of arbitrary degree

Number Theory 2026-04-22 v1

Abstract

We implement methods from the geometry of numbers to give explicit estimates for the number of integral ideals in a number field. We pay particular attention to minimising the effect of the degree nn of the number field on the error term and avoid terms on the order of nn2n^{n^2}. We do this by studying fundamental domains for the action of multiplying with units of infinite order in Minkowski space. With some lattice theory we show that one can make different choices for such a fundamental domain, which yield a smaller error, especially when the degree of the field extension is large. We also adapt Schmidt's partition trick to this generalised setting.

Keywords

Cite

@article{arxiv.2604.19681,
  title  = {Explicit counting of ideals in number fields of arbitrary degree},
  author = {Anton Fehnker},
  journal= {arXiv preprint arXiv:2604.19681},
  year   = {2026}
}