Gaussian Bianchi group
= Gaussian Bianchi group
{c}
{title2=$PSL_2(\mathbb Z[i])$}
The Gaussian Bianchi group is the <Kleinian group> of determinant-one two-by-two matrices over the <Gaussian integers>, modulo $\{\pm I\}$. Its matrix entries lie in a discrete subring of $\mathbb C$, so it is a discrete subgroup of $PSL_2(\mathbb C)$. The <Borromean link group> is a torsion-free subgroup of index 24.