  We present a new model for the full shape of large-scale the power spectrum
based on renormalized perturbation theory. To test the validity of this
prescription, we compare this model against power spectra measured in a suite
of 50 large volume, moderate resolution N-body simulations. Our results
indicate that this simple model provides an accurate description of the full
shape of the power spectrum taking into account the effects of non-linear
evolution, redshift-space distortions and halo bias for scales k < 0.15 h/Mpc,
making it a valuable tool for the analysis of forthcoming galaxy surveys. Even
though its application is restricted to large scales, this prescription can
provide tighter constraints on the dark energy equation of state parameter
w_{DE} than those obtained by modelling the baryonic acoustic oscillations
signal only, where the information of the broad-band shape of the power
spectrum is discarded. Our model is able to provide constraints comparable to
those obtained by applying a similar model to the full shape of the correlation
function, which is affected by different systematics. Hence, with accurate
modelling of the power spectrum, the same cosmological information can be
extracted from both statistics.
