Cosmology with the lyman-alpha forest in the WMAP era

In the WMAP era of high precision cosmology an accurate determination of the matter power spectrum from lyman-alpha forest data becomes crucial. When combining the matter power spectrum derived from CMB experiments with that inferred from lyman-alpha absorption an evidence for a running spectral index and a primordial index n < 1 arises (Verde et al. 2003). In this talk, I will describe some results obtained from a sample of 27 high resolution and high signal-to-noise quasar spectra (the LUQAS sample) and I will address possible systematic errors that can affect the estimate of the flux power spectrum.