Detectability of large-scale power suppression in the galaxy distribution

TL;DR

This paper examines whether upcoming large-volume galaxy redshift surveys can detect or rule out primordial power suppression on large scales, which could explain anomalies in cosmic microwave background observations.

Contribution

It introduces a simple parametric model of power suppression and assesses its detectability with future galaxy surveys, linking CMB anomalies to large-scale structure observations.

Findings

Suppression could be confirmed or ruled out with ~100 Gpc^3 surveys

Redshift information of galaxies is crucial for detection

Suppression detection is challenging but feasible with large surveys

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 LCDM 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 (~100 Gpc^3). A key requirement for success in ruling out power suppression will be having redshifts of most galaxies detected in the imaging survey.