Positive Energy for Asymptotically Anti-de Sitter Schwarzschild   Spacetimes
  Within the general class of Asymptotically Anti-de Sitter spacetimes that are asymptotic to the A-de-S Schwarzschild metric, we give a simple positive mass theorem based on arguments from causal structure. A general result for all asymptotically A-de-S spacetimes will be given elsewhere. 
E. Woolgar