New galaxy UV luminosity constraints on warm dark matter from JWST

We exploit the recent James Webb Space Telescope (JWST) determination of galaxy UV luminosity functions over the redshift range z=9-14.5 to derive constraints on warm dark matter (WDM) models. The delayed structure formation in WDM universe makes high redshift observations to be a powerful probe to set limits on the particle mass m_x of WDM candidates. By integrating these observations with blank-field surveys conducted by Hubble Space Telescope (HST) at redshifts z=4-8, we impose constraints on both astrophysical and WDM parameters simultaneously. We find a new limit of m_x≥ 3.2 keV for the mass of thermal relic WDM particles at 95% confidence level. This bound is tighter than the most stringent result derived using HST data before. Future JWST observations could further reduce the observation uncertainties and improve this constraint.