The extended Baryon Oscillation Spectroscopic Survey: a cosmological forecast
Abstract
We present a science forecast for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) survey. Focusing on discrete tracers, we forecast the expected accuracy of the baryonic acoustic oscillation (BAO), the redshiftspace distortion (RSD) measurements, the f_{NL} parameter quantifying the primordial nonGaussianity, the dark energy and modified gravity parameters. We also use the lineofsight clustering in the Lyman α forest to constrain the total neutrino mass. We find that eBOSS luminous red galaxies, emission line galaxies and clustering quasars can achieve a precision of 1, 2.2 and 1.6 per cent, respectively, for spherically averaged BAO distance measurements. Using the same samples, the constraint on fσ_{8} is expected to be 2.5, 3.3 and 2.8 per cent, respectively. For primordial nonGaussianity, eBOSS alone can reach an accuracy of σ(f_{NL}) ∼ 1015. eBOSS can at most improve the dark energy figure of merit by a factor of 3 for the ChevallierPolarskiLinder parametrization, and can well constrain three eigenmodes for the general equationofstate parameter. eBOSS can also significantly improve constraints on modified gravity parameters by providing the RSD information, which is highly complementary to constraints obtained from weak lensing measurements. A principal component analysis shows that eBOSS can measure the eigenmodes of the effective Newton's constant to 2 per cent precision; this is a factor of 10 improvement over that achievable without eBOSS. Finally, we derive the eBOSS constraint (combined with Planck, Dark Energy Survey and BOSS) on the total neutrino mass, σ(Σm_{ν}) = 0.03 eV (68 per cent CL), which in principle makes it possible to distinguish between the two scenarios of neutrino mass hierarchies.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 April 2016
 DOI:
 10.1093/mnras/stw135
 arXiv:
 arXiv:1510.08216
 Bibcode:
 2016MNRAS.457.2377Z
 Keywords:

 dark energy;
 largescale structure of Universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 15 pages, 9 figures, 6 tables