High accuracy Power Spectra at high redshift in Dynamical Dark Energy simulations

Accurate predictions on non–linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes. We need then high precision simulations, exploring the functional space of w(a) DE state equations, for the admitted cosmological parameter ranges. A procedure was however suggested, making recourse to suitable w=const. auxiliary models, and yielding a ∼1% precision at z=0. The precision of this procedure, however, worsens at higher z. Here we follow a different criterion for high z. Our N–body gravitational simulations then show that auxiliary w=const. models still meet given w(a) model spectra within 1% at z=0, but are much better at higher redshift, where they approach a permil precision.