Quotients of anti-de Sitter space
  We study the quotients of n+1-dimensional anti-de Sitter space by one-parameter subgroups of its isometry group SO(2,n) for general n. We classify the different quotients up to conjugation by O(2,n). We find that the majority of the classes exist for all n \geq 2. There are two special classes which appear in higher dimensions: one for n \geq 3 and one for n \geq 4. The description of the quotient in the majority of cases is thus a simple generalisation of the AdS_3 quotients. 
Owen Madden and Simon F. Ross