A Spinning Anti-de Sitter Wormhole
  We construct a 2+1 dimensional spacetime of constant curvature whose spatial topology is that of a torus with one asymptotic region attached. It is also a black hole whose event horizon spins with respect to infinity. An observer entering the hole necessarily ends up at a "singularity"; there are no inner horizons.   In the construction we take the quotient of 2+1 dimensional anti-de Sitter space by a discrete group Gamma. A key part of the analysis proceeds by studying the action of Gamma on the boundary of the spacetime. 
Stefan Aminneborg (1), Ingemar Bengtsson (2) and Soren Holst(2) ((1)   Norra Reals gymnasium, Stockholm, (2) Fysikum, Stockh...