  We explore the connection between halo concentration and the dark matter
power spectrum using the halo model. We fit halo model parameters to non-linear
power spectra over a large range of cosmological models. We find that the
non-linear evolution of the power spectrum generically prefers the
concentration at non-linear mass scale to decrease with the effective slope of
the linear power spectrum, in agreement with the direct analysis of the halo
structure in different cosmological models. Using these analyses, we compute
the predictions for non-linear power spectrum beyond the current resolution of
N-body simulations. We find that the halo model predictions are generically
below the analytical non-linear models, suggesting that the latter may
overestimate the amount of power on small scales.
