Kavli Affiliate: George Efstathiou | Summary:We investigate the degeneracy between the effects of ultra-light axion dark matter and baryonic feedback in suppressing the matter power spectrum. We forecast that galaxy shear data from the Rubin Observatory’s Legacy Survey of Space and Time (LSST) could limit an axion of mass $m = 10^-25,mathrmeV$ to be $lesssim […]