Quantum Connectivity of Space-Time and Gravitationally Induced   Decorrelation of Entanglement
  We discuss an alternative formulation of the problem of quantum optical fields in a curved space-time using localized operators. We contrast the new formulation with the standard approach and find observable differences for entangled states. We propose an experiment in which an entangled pair of optical pulses are propagated through non-uniform gravitational fields and find that the new formulation predicts de-correlation of the optical entanglement under experimentally realistic conditions. 
T.C.Ralph, G.J.Milburn and T.Downes