Consistency among distance measurements: transparency, BAO scale and accelerated expansion

TL;DR

This paper assesses the consistency of various cosmic distance measurements, improves constraints on cosmic transparency, and investigates the implications for the universe's accelerated expansion using multiple observational data sets.

Contribution

It provides new constraints on cosmic transparency, re-examines BAO and supernova tension, and offers model-independent insights into the universe's acceleration.

Findings

Improved constraints on cosmic transparency by nearly an order of magnitude.

The tension between BAO scale and supernova data is likely due to systematic effects or statistical fluctuations.

The acceleration redshift is estimated to be approximately 0.35 with uncertainties.

Abstract

We explore consistency among different distance measures, including Supernovae Type Ia data, measurements of the Hubble parameter, and determination of the Baryon acoustic oscillation scale. We present new constraints on the cosmic transparency combining $H(z)$ data together with the latest Supernova Type Ia data compilation. This combination, in the context of a flat $\Lambda$CDM model, improves current constraints by nearly an order of magnitude. We re-examine the recently reported tension between the Baryon acoustic oscillation scale and Supernovae data in light of possible deviations from transparency, concluding that the source of the discrepancy may most likely be found among systematic effects of the modelling of the low redshift data or a simple $\sim 2-\sigma$ statistical fluke, rather than in exotic physics. Finally, we attempt to draw model-independent conclusions about the recent accelerated expansion, determining the acceleration redshift to be $z_{acc}=0.35^{+0.20}_{-0.13}$ (1-$\sigma$).