Dark energy and matter evolution from lensing tomography

Reconstructed from lensing tomography, the evolution of the dark matter density field in the well-understood linear regime can provide model-independent constraints on the growth function of structure and the evolution of the dark energy density. We examine this potential in the context that high-redshift cosmology has in the future been fixed by cosmic microwave background measurements. We construct sharp tests for the existence of multiple dark matter components or a dark energy component that is not a cosmological constant. These functional constraints can be transformed into physically motivated model parameters. From the growth function, the fraction of the dark matter in a smooth component, such as a light neutrino, may be constrained to a statistical precision of σ(f)≅0.0006fsky-1/2 by a survey covering a fraction of sky fsky with a redshift resolution Δz=0.1. For the dark energy, a parametrization in terms of the present energy density ΩDE, equation of state w, and its redshift derivative w', the constraints correspond to σ(w)=0.009fsky-1/2 and a degenerate combination of the other two parameters. For a fixed ΩDE, σ(w')=0.046fsky-1/2