Evolution in the Lyman-alpha forest

Abstract

We reanalyse the spectra used by D.-E. Liebscher (no relation) et al with the same goal -- determining the cosmological parameters -- and basically the same assumptions but with a different statistical method, which does not rely on binning the data. Also, we correct for selection effects. We basically confirm their result, with somewhat larger but still very small (formal) errors. However, all world models within the 99% confidence region are ruled out because a firm lower limit on $Ω_{0}$ is significantly larger. This directly demonstrates for the first time the existence of intrinsic evolution in the Lyman-$α$ forest.