New Constraints on the running-mass inflation model

We evaluate new observational constraints on the two-parameter scale-dependent spectral index predicted by the running-mass inflation model by combining the latest Cosmic Microwave Background (CMB) anisotropy measurements with the recent 2dFGRS data on the matter power spectrum, with Lyman $\alpha $ forest data and finally with theoretical constraints on the reionization redshift. We find that present data still allow significant scale-dependence of $n$, which occurs in a physically reasonable regime of parameter space.