James Webb Space Telescope Feed Post

Harvard ADS: Explanation of high redshift luminous galaxies from JWST by early dark energy model

Paper abstract: Recent observations from the James Webb Space Telescope (JWST) have uncovered massive galaxies at high redshifts, with their abundance significantly surpassing expectations. This finding poses a substantial challenge to both galaxy formation models and our understanding of cosmology. Additionally, discrepancies between the Hubble parameter inferred from high-redshift cosmic microwave background (CMB) observations and those derived from low-redshift distance ladder methods have led to what is known as the ``Hubble tension''. Among the most promising solutions to this tension are Early Dark Energy (EDE) models. In this study, we employ an axion-like EDE model in conjunction with a universal Salpeter initial mass function to fit the luminosity function derived from JWST data, as well as other cosmological probes, including the CMB, baryon acoustic oscillations (BAO), and the SH0ES local distance ladder. Our findings indicate that JWST observations favor a high energy fraction of EDE, f_\text{EDE} ~ 0.2 \pm 0.03 , and a high Hubble constant value of H_0 ~ 74.6 \pm 1.2 km/s/Mpc, even in the absence of SH0ES data. This suggests that EDE not only addresses the H_0 tension but also provides a compelling explanation for the observed abundance of massive galaxies identified by JWST.