  A quantum communication protocol between harmonic oscillator detectors,
interacting with a quantum field, is developed in a cosmological expanding
background. The aim is to see if the quantum effects arising in an expanding
universe, such as the cosmological particle production, could facilitate the
communication between two distant parts or if they provide an additive noisy
effect. By considering a perfect cosmic fluid, the resulting expansion turns
out to increase the classical capacity of the protocol. This increasing occurs
for all the cosmological expansions unless the latter is sharpened just before
the receiver's detector interacts with the field. Moreover, the classical
capacity turns out to be sensible to the barotropic parameter $w$ of the
perfect fluid and to the coupling between the field and the scalar curvature
$\xi$. As a consequence, by performing this protocol, one can achieve
information about the cosmological dynamics and its coupling with a background
quantum field.
