The $(4,p)$-arithmetic hyperbolic lattices, $p\geq 2$, in three dimensions

TL;DR

This paper classifies all arithmetic hyperbolic 3-space lattices generated by elements of orders 4 and p (p≥2), detailing their algebraic structures, geometric realizations, and associated number fields, with explicit representations.

Contribution

It provides a complete classification of $(4,p)$-arithmetic hyperbolic lattices in three dimensions, including their presentations, geometric types, and number theoretic properties.

Findings

p can only be 2, 3, 4, 5, 6, or infinity

The invariant trace field degree is at most 4

Explicit faithful representations in PSL(2,C) are constructed

Abstract

We identify the finitely many arithmetic lattices $\Gamma$ in the orientation preserving isometry group of hyperbolic $3$-space $\mathbb{H}^3$ generated by an element of order $4$ and and element of order $p\geq 2$. Thus $\Gamma$ has a presentation of the form $\Gamma\cong\langle f,g: f^4=g^p=w(f,g)=\cdots=1 \rangle$ We find that necessarily $p\in \{2,3,4,5,6,\infty\}$, where $p=\infty$ denotes that $g$ is a parabolic element, the total degree of the invariant trace field $k\Gamma=\mathbb{Q}(\{\tr^2(h):h\in\Gamma\})$ is at most $4$, and each orbifold is either a two bridge link of slope $r/s$ surgered with $(4,0)$, $(p,0)$ Dehn surgery (possibly a two bridge knot if $p=4$) or a Heckoid group with slope $r/s$ and $w(f,g)=(w_{r/s})^r$ with $r\in \{1,2,3,4\}$. We give a discrete and faithful representation in $PSL(2,\mathbb{C})$ for each group and identify the associated number theoretic data.