Exploiting the shift of baryonic acoustic oscillations as a dynamical
  probe for dark interactions
  The baryonic acoustic peak in the correlation function of galaxies and galaxy
clusters provides a standard ruler to probe the space-time geometry of the
Universe, jointly constraining the angular diameter distance and the Hubble
expansion rate. Moreover, non-linear effects can systematically shift the peak
position, giving us the opportunity to exploit this clustering feature also as
a dynamical probe. We investigate the possibility of detecting interactions in
the dark sector through an accurate determination of the baryonic acoustic
scale. Making use of the public halo catalogues extracted from the CoDECS
simulations -- the largest suite of N-body simulations of interacting dark
energy models to date -- we determine the position of the baryonic scale
fitting a band-filtered correlation function, specifically designed to amplify
the signal at the sound horizon. We analyze the shifts due to non-linear
dynamics, redshift-space distortions and Gaussian redshift errors, in the range
0 < z < 2. Since the coupling between dark energy and dark matter affects in a
particular way the clustering properties of haloes and, specifically, the
amplitude and location of the baryonic acoustic oscillations, the cosmic
evolution of the baryonic peak position might provide a direct way to
discriminate interacting dark energy models from the standard \Lambda CDM
framework. To maximize the efficiency of the baryonic peak as a dynamic probe,
the correlation function has to be measured in redshift-space, where the
baryonic acoustic shift due to non-linearities is amplified. The typical
redshift errors of spectroscopic galaxy surveys do not significantly impact
these results.
