Dark Energy Survey Year 1 Results: A Precise H0 Measurement from DES Y1, BAO, and D/H Data

TL;DR

This paper combines multiple independent cosmological data sets to measure the Hubble constant with high precision, finding a value around 69 km/s/Mpc, consistent across methods and independent of traditional techniques.

Contribution

It provides a new, precise H0 measurement using DES Y1 data combined with BAO and BBN, independent of traditional methods, and compares multiple independent constraints.

Findings

H0 = 67.2^{+1.2}_{-1.0} km/s/Mpc from combined data

Five independent data sets show consistent H0 measurements within 2.1σ

Combined data yields H0 = 69.1^{+0.4}_{-0.6} km/s/Mpc

Abstract

We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) and Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $\Lambda$CDM model with minimal neutrino mass ($\sum m_\nu = 0.06$ eV) we find $H_0=67.2^{+1.2}_{-1.0}$ km/s/Mpc (68% CL). This result is completely independent of Hubble constant measurements based on the distance ladder, Cosmic Microwave Background (CMB) anisotropies (both temperature and polarization), and strong lensing constraints. There are now five data sets that: a) have no shared observational systematics; and b) each constrain the Hubble constant with a few percent level precision. We compare these five independent measurements, and find that, as a set, the differences between them are significant at the $2.1\sigma$ level ($\chi^2/dof=20.1/11$, probability to exceed=4%). This difference is low enough that we consider the data sets statistically consistent with each other. The best fit Hubble constant obtained by combining all five data sets is $H_0 = 69.1^{+0.4}_{-0.6}$ km/s/Mpc.