James Webb Space Telescope Feed Post

Harvard ADS: Can early dark energy be probed by the high-redshift galaxy abundance?

Paper abstract: The analysis of the cosmic microwave background data acquired by the Atacama Cosmology Telescope and the large-scale (\ell <~ 1300) Planck Telescope show a preference for the early dark energy (EDE) theory, which was set to alleviate the Hubble tension of the \Lambda cold dark matter (\LambdaCDM) model by decreasing the sound horizon r_{s}, and gives H_{0} ~ 72 km s^{-1} Mpc^{-1}. However, the EDE model is commonly questioned for exacerbating the \sigma _8 tension on top of the \LambdaCDM model, and its lack of preference from the late-time matter power spectrum observations, e.g. Baryon Oscillation Spectroscopic Survey. In light of the current obscurities, we inspect if the high redshift galaxy abundance, i.e. stellar mass function/density and luminosity function, can independently probe the EDE model. Our result shows that, compared to \LambdaCDM, the EDE model prediction at z\gt 10 displays better consistency with the unexpectedly high results observed by the JWST. At lower redshift, the EDE model only fits the most luminous/massive end, with the majority of the data presenting better consistency with \LambdaCDM, implying that adding an extra luminosity/mass-sensitive suppression mechanism of the galaxy formation is required for EDE to explain all data around z~ 7-10.