EPR effect in gravitational field: nature of non-locality
  The realization of the Einstein-Podolsky-Rosen effect by the correlation of spin projections of two particles created in the decay of a single scalar particle is considered for particles propagating in gravitational field. The absence of a global definition of spatial directions makes it unclear whether the correlation may exist in this case and, if yes, what directions in distant regions must be correlated. It is shown that in a gravitational field an approximate correlation may exist and the correlated directions are connected with each other by the parallel transport along the world lines of the particles. The reason for this is that the actual origin of the quantum non-locality is founded in local processes. 
Horst von Borzeszkowski (Institut fuer Theoretische Physik, Technische   Universitaet Berlin, Berlin, Germany) and Michael B...