n-dimensional anti de Sitter space is the geometry with Lorentzian signature with the automorphism group SO(n,2) (possibly with reflections), according to the Erlanger program.

It is also a cosmological model for the universe.

A coordinate patch covering part of the space gives the half-space coordinatization of anti de Sitter space. The metric is now

See also de Sitter space, AdS/CFT.

This article is a stub. You can help Wikipedia by fixing it.