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 (f) 0. 0006fₒ₊ₘ^-1/2 by a survey covering a fraction of sky fₒ₊ₘ with a redshift resolution =0. 1. For the dark energy, a parametrization in terms of the present energy density ₃₄, equation of state w, and its redshift derivative w^', the constraints correspond to (w) =0. 009fₒ₊ₘ^-1/2 and a degenerate combination of the other two parameters. For a fixed ₃₄, (w^') =0. 046fₒ₊ₘ^-1/2.