Detectability of large-scale power suppression in the galaxy distribution

Abstract

Suppression in primordial power on the Universe's largest observable scales has been invoked as a possible explanation for large-angle observations in the cosmic microwave background, and is allowed or predicted by some inflationary models. Here we investigate the extent to which such a suppression could be confirmed by the upcoming large-volume redshift surveys. For definiteness, we study a simple parametric model of suppression that improves the fit of the vanilla $\ensuremath{\Lambda}\mathrm{CDM}$ model to the angular correlation function measured by WMAP in cut-sky maps, and at the same time improves the fit to the angular power spectrum inferred from the maximum likelihood analysis presented by the WMAP team. We find that the missing power at large scales, favored by WMAP observations within the context of this model, will be difficult but not impossible to rule out with a galaxy redshift survey with large-volume ($\ensuremath{\sim}100\text{ }\text{ }{\mathrm{Gpc}}^{3}$). A key requirement for success in ruling out power suppression will be having redshifts of most galaxies detected in the imaging survey.