English

Sign choices in the AGM for genus two theta constants

Number Theory 2022-10-11 v2

Abstract

Existing algorithms to compute genus 2 theta constants in quasi-linear time use Borchardt sequences, an analogue of the arithmetic-geometric mean for four complex numbers. In this paper, we show that these Borchardt sequences are given by good choices of square roots only, as in the genus 1 case. This removes the sign indeterminacies in the algorithm without relying on numerical integration.

Keywords

Cite

@article{arxiv.2010.07579,
  title  = {Sign choices in the AGM for genus two theta constants},
  author = {Jean Kieffer},
  journal= {arXiv preprint arXiv:2010.07579},
  year   = {2022}
}