SPT-3G D1: Axion Early Dark Energy with CMB experiments and DESI

Understand

We present the most up-to-date constraints on axion early dark energy (AEDE) from cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) measurements.

• In particular, we assess the impact of data from ground-based CMB experiments, the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT) -- both with and without $Planck$ -- on constraints on AEDE.
• We also highlight the impact that BAO information from the Dark Energy Spectroscopic Instrument (DESI) has on these constraints.
• From CMB data alone, we do not find statistically significant evidence for the presence of AEDE, and we find only moderate reduction in the Hubble tension.