• Corpus ID: 227227595

# Space vectors forming rational angles.

@article{Kedlaya2020SpaceVF,
title={Space vectors forming rational angles.},
author={Kiran S. Kedlaya and Alexander Kolpakov and Bjorn Poonen and Michael O. Rubinstein},
journal={arXiv: Metric Geometry},
year={2020}
}
• Published 28 November 2020
• Mathematics
• arXiv: Metric Geometry
We classify all sets of nonzero vectors in $\mathbb{R}^3$ such that the angle formed by each pair is a rational multiple of $\pi$. The special case of four-element subsets lets us classify all tetrahedra whose dihedral angles are multiples of $\pi$, solving a 1976 problem of Conway and Jones: there are $2$ one-parameter families and $59$ sporadic tetrahedra, all but three of which are related to either the icosidodecahedron or the $B_3$ root lattice. The proof requires the solution in roots of…
5 Citations

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