Cusp cross-sections of low-dimensional arithmetic hyperbolic manifolds
Abstract
We study which compact flat manifolds of dimensions 3 ≤ n ≤ 6 occur as cusp cross-sections in commensurability classes of non-compact arithmetic hyperbolic (n+1)-manifolds. Using the classification of low-dimensional flat manifolds together with the relationship between their holonomy representations and rational quadratic forms, we determine the possible arithmetic commensurability classes for every flat manifold in these dimensions. We show that every flat n-manifold for n=3,4,5 occurs as a cusp cross-section in infinitely many distinct arithmetic commensurability classes. In dimension six, the same holds with exactly eight exceptions: eight non-orientable flat $6$-manifolds occur in a unique arithmetic commensurability class. We also show that, for every 3 ≤ n ≤ 6, there is a single commensurability class of arithmetic hyperbolic (n+1)-manifolds containing every flat n-manifold as a cusp cross-section.
Related
- Linking numbers and special differential characters in arithmetic hyperbolic manifolds
- Arithmetic hyperbolic manifolds with bounded rank
- Non-Pseudo-Arithmetic Hyperbolic 4-Manifolds
- Hitchin sections on $3$-dimensional Sasakian manifolds
- Arithmetic purity of strong approximation for toric varieties with constant global sections
BibTeX
@misc{grimbert2026cusp,
title = {{Cusp cross-sections of low-dimensional arithmetic hyperbolic manifolds}},
author = {Marcus Grimbert and Duncan McCoy and Connor Sell},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.08756},
eprint = {2609.08756},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.08756},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Cusp cross-sections of low-dimensional arithmetic hyperbolic manifolds
AU - Marcus Grimbert
AU - Duncan McCoy
AU - Connor Sell
PY - 2026
DA - 2026/09/08
PB - arXiv
DO - 10.48550/arxiv.2609.08756
UR - https://arxiv.org/abs/2609.08756
AB - We study which compact flat manifolds of dimensions 3 ≤ n ≤ 6 occur as cusp cross-sections in commensurability classes of non-compact arithmetic hyperbolic (n+1)-manifolds. Using the classification of low-dimensional flat manifolds together with the relationship between their holonomy representations and rational quadratic forms, we determine the possible arithmetic commensurability classes for every flat manifold in these dimensions. We show that every flat n-manifold for n=3,4,5 occurs as a cusp cross-section in infinitely many distinct arithmetic commensurability classes. In dimension six, the same holds with exactly eight exceptions: eight non-orientable flat $6$-manifolds occur in a unique arithmetic commensurability class. We also show that, for every 3 ≤ n ≤ 6, there is a single commensurability class of arithmetic hyperbolic (n+1)-manifolds containing every flat n-manifold as a cusp cross-section.
ER -