Let d be a square free positive integer and O-d the ring of integers in Q(root -d). The main result of this paper is that the groups PSL(2,O-d) are subgroup separable on geometrically finite subgroups.
No takes yet. Share an insight, caveat, or question.
Agol et al. (2001) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: