English

On non-congruent numbers with $8a\pm1$ type odd prime factors and tame kernels

Number Theory 2021-11-24 v1 K-Theory and Homology

Abstract

Let nn be a positive square-free integer, where every odd prime factor of nn has form 8a±18a\pm 1. We determine when nn is non-congruent with second minimal 22-primary Shafarevich-Tate group, in terms of the 44-ranks of class groups and a Jacobi symbol. In particular, when every odd prime factor of nn has form 8a+18a+1, this condition is equivalent to the vanishing of the 44-rank of the tame kernel of Q(n)\mathbb Q(\sqrt{n}) for odd nn, or Q(n)\mathbb Q(\sqrt{-n}) for even nn. This generalizes previous results.

Keywords

Cite

@article{arxiv.2111.11618,
  title  = {On non-congruent numbers with $8a\pm1$ type odd prime factors and tame kernels},
  author = {Shenxing Zhang},
  journal= {arXiv preprint arXiv:2111.11618},
  year   = {2021}
}

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11 pages