  We study how quantum correlations survive at large scales in spite of their
exposition to stochastic backgrounds of gravitational waves. We consider
Einstein-Podolski-Rosen (EPR) correlations built up on the polarizations of
photon pairs and evaluate how they are affected by the cosmic gravitational
wave background (CGWB). We evaluate the quantum decoherence of the EPR
correlations in terms of a reduction of the violation of the Bell inequality as
written by Clauser, Horne, Shimony and Holt (CHSH). We show that this
decoherence remains small and that EPR correlations can in principle survive up
to the largest cosmic scales.
