  We propose a possible quantum signature of the early Universe that could lead
to observational imprints of the quantum nature of the inflationary period.
Graviton production in the presence of an inflaton scalar field results in
entangled states in polarization. This is because of a non-trivial effect due
to the derivatives on two scalar fluctuations and it provides a fingerprint
that depends on the polarization of the graviton that Alice and/or Bob measured
in their patch. At horizon crossing, interactions between the gravitons and
inflatons perform the required Bell experiments leading to a definitive
measure. We hint how this signature could be measure in the high-order
correlation function of galaxies, in particular on the halo bias and the
intrinsic alignment.
