Primordial Features from Linear to Nonlinear Scales
  Sharp features in the primordial power spectrum are a powerful window into
the inflationary epoch. To date, the cosmic microwave background (CMB) has
offered the most sensitive avenue to search for these signatures. In this
paper, we demonstrate the power of large-scale structure observations to
surpass the CMB as a probe of primordial features. We show that the signatures
in galaxy surveys can be separated from the broadband power spectrum and are as
robust to the nonlinear evolution of matter as the standard baryon acoustic
oscillations. As a result, analyses can exploit a significant range of scales
beyond the linear regime available in the datasets. We develop a feature search
for large-scale structure, apply it to the final data release of the Baryon
Oscillation Spectroscopic Survey and find new bounds on oscillatory features
that exceed the sensitivity of Planck for a significant range of frequencies.
Moreover, we forecast that the next generation of galaxy surveys, such as DESI
and Euclid, will be able to improve current constraints by up to an order of
magnitude over an expanded frequency range.
