Cosmological constraints on neutrino masses in light of JWST red and massive candidate galaxies

Abstract

The overabundance of the red and massive candidate galaxies observed by the James Webb Space Telescope (JWST) implies efficient structure formation or large star formation efficiency at high redshift $z\sim 10$. In the scenario of a low or moderate star formation efficiency, because massive neutrinos tend to suppress the growth of structure of the universe, the JWST observation tightens the upper bound of the neutrino masses. Assuming $\Lambda$ cold dark matter cosmology and a star formation efficiency $ \in [0.05, 0.3]$ (flat prior), we perform joint analyses of Planck+JWST and Planck+BAO+JWST, and obtain improved constraints $\sum m_\nu < 0.196\,\mathrm{eV}$ and $\sum m_\nu < 0.111\,\mathrm{eV}$ at 95% confidence level, respectively. Based on the above assumptions, the inverted mass ordering, which implies $\sum m_\nu\geq 0.1\mathrm{eV}$, is excluded by Planck+BAO+JWST at 92.7% confidence level.