Large scale distribution of total mass versus luminous matter from Baryon Acoustic Oscillations: First search in the SDSS-III BOSS Data Release 10

TL;DR

This study searches for the predicted BAO signature on the relative clustering of total mass versus luminous matter using SDSS-III BOSS data, providing initial evidence that requires further validation with future surveys.

Contribution

It presents the first observational attempt to detect BAO effects on mass versus luminous matter clustering, incorporating CIPs and highlighting potential systematic biases.

Findings

Evidence at 3.2σ for the relative clustering signature when including CIPs

Limits on CIPs amplitude consistent with previous upper bounds

Results are not yet robust due to possible systematic biases

Abstract

Baryon Acoustic Oscillations (BAOs) in the early Universe are predicted to leave an as yet undetected signature on the relative clustering of total mass versus luminous matter. A detection of this effect would provide an important confirmation of the standard cosmological paradigm and constrain alternatives to dark matter as well as non-standard fluctuations such as Compensated Isocurvature Perturbations (CIPs). We conduct the first observational search for this effect, by comparing the number-weighted and luminosity-weighted correlation functions, using the SDSS-III BOSS Data Release 10 CMASS sample. When including CIPs in our model, we formally obtain evidence at $3.2\sigma$ of the relative clustering signature and a limit that matches the existing upper limits on the amplitude of CIPs. However, various tests suggest that these results are not yet robust, perhaps due to systematic biases in the data. The method developed in this Letter, used with more accurate future data such as that from DESI, is likely to confirm or disprove our preliminary evidence.