Baryon oscillations and dark-energy constraints from imaging surveys

Baryonic oscillations in the galaxy power spectrum have been studied as a way of probing dark-energy models. While most studies have focused on spectroscopic surveys at high redshift, large multicolour imaging surveys have already been planned for the near future. In view of this, we study the prospects for measuring baryonic oscillations from angular statistics of galaxies binned using photometric redshifts. We use the galaxy bispectrum in addition to the power spectrum; this allows us to measure and marginalize over possibly complex galaxy bias mechanisms to get robust cosmological constraints. In our parameter estimation, we allow for a weakly non-linear biasing scheme that may evolve with redshift by two bias parameters in each of 10 redshift bins. We find that a multicolour imaging survey that probes redshifts beyond one can give interesting constraints on dark-energy parameters. In addition, the shape of the primordial power spectrum can be measured to better accuracy than with the cosmic microwave background (CMB) alone. We explore the impact of survey depth, area and calibration errors in the photometric redshifts on dark-energy constraints.