A first model-independent radial BAO constraint from the final BOSS
  sample
  Using almost one million galaxies from the final Data Release 12 of the
SDSS's Baryon Oscillation Spectroscopic Survey, we have obtained, albeit with
low significance, a first model-independent determination of the radial BAO
peak with 9% error: $\Delta z_{\rm BAO}(z_{\rm eff}=0.51)= 0.0456 \pm 0.0042$.
In order to obtain this measurement, the radial correlation function was
computed in 7,700 angular pixels, from which mean correlation function and
covariance matrix were obtained, making the analysis completely model
independent. This novel method of obtaining the covariance matrix was validated
via the comparison with 500 BOSS mock catalogs. This $\Delta z_{\rm BAO}$
determination can be used to constrain the background expansion of exotic
models for which the assumptions adopted in the standard analysis cannot be
satisfied. Future galaxy catalogs from J-PAS, DESI and Euclid are expected to
significantly increase the quality and significance of model-independent
determinations of the BAO peak, possibly determined at various redshift and
angular positions. We stress that it is imperative to test the standard
paradigm in a model-independent way in order to test its foundations, maximize
the extraction of information from the data, and look for clues regarding the
poorly understood dark energy and dark matter.
