Gravitational lensing by massive clusters offers a unique probe of both dark matter and dark energy. The detailed spatial distribution of dark matter in clusters and the equation of state for dark energy can be simultaneously constrained by combining strong and weak gravitational lensing observations of galaxy clusters.

I will demonstrate the potency of this technique and review the latest results. With constraints from just one lensing cluster folded in with other methods, the current error estimate in the equation of state parameter of dark energy can be brought down by 30%. I will discuss the future prospects of this technique.

Argonne Physics Division Colloquium Schedule