English

Geometry and Arithmetic of Crystallographic Sphere Packings

Metric Geometry 2017-12-04 v1 Geometric Topology Number Theory

Abstract

We introduce the notion of a "crystallographic sphere packing," defined to be one whose limit set is that of a geometrically finite hyperbolic reflection group in one higher dimension. We exhibit for the first time an infinite family of conformally-inequivalent such with all radii being reciprocals of integers. We then prove a result in the opposite direction: the "superintegral" ones exist only in finitely many "commensurability classes," all in dimensions below 30.

Keywords

Cite

@article{arxiv.1712.00147,
  title  = {Geometry and Arithmetic of Crystallographic Sphere Packings},
  author = {Alex Kontorovich and Kei Nakamura},
  journal= {arXiv preprint arXiv:1712.00147},
  year   = {2017}
}

Comments

Research announcement. 14 pages, 5 figures

R2 v1 2026-06-22T23:03:14.905Z