Virasoro generators and the dS_3/CFT_2 correspondence
  We discuss the quantization of a scalar field in three-dimensional asymptotic de Sitter space. We obtain explicit expressions for the Noether currents generating the isometry group in terms of the modes of the scalar field and the Liouville gravitational field. We extend the SL(2,C) algebra of the Noether charges to a full Virasoro algebra by introducing non-local conserved charges. The Virasoro algebra has the expected central charge in the weak coupling limit (large central charge c=3l/2G, where l is the dS radius and G is Newton's constant). We derive the action of the Virasoro charges on states in the boundary CFT thus elucidating the dS/CFT correspondence. 
Scott Ness and George Siopsis