Consistency among distance measurements: transparency, BAO scale and
  accelerated expansion
  We explore consistency among different distance measures, including
Supernovae Type Ia data, measurements of the Hubble parameter, and
determination of the Baryon acoustic oscillation scale. We present new
constraints on the cosmic transparency combining $H(z)$ data together with the
latest Supernova Type Ia data compilation. This combination, in the context of
a flat $\Lambda$CDM model, improves current constraints by nearly an order of
magnitude. We re-examine the recently reported tension between the Baryon
acoustic oscillation scale and Supernovae data in light of possible deviations
from transparency, concluding that the source of the discrepancy may most
likely be found among systematic effects of the modelling of the low redshift
data or a simple $\sim 2-\sigma$ statistical fluke, rather than in exotic
physics. Finally, we attempt to draw model-independent conclusions about the
recent accelerated expansion, determining the acceleration redshift to be
$z_{acc}=0.35^{+0.20}_{-0.13}$ (1-$\sigma$).
