Cosmological Constraints from Strong Gravitational Lensing in Clusters of Galaxies

Current efforts in observational cosmology are focused on characterizing the mass-energy content of the Universe. We present results from a geometric test based on strong lensing in galaxy clusters. Based on Hubble Space Tele-scope images and extensive ground-based spectroscopic follow-up of the mas-sive galaxy cluster Abell 1689, we used a parametric model to simultaneously constrain the cluster mass distribution and dark energy equation of state. Combining our cosmological constraints with those from X-ray clusters and the Wilkinson Microwave Anisotropy Probe 5-year data gives Ωm = 0.25 ± 0.05 and wx = −0.97 ± 0.07 which are consistent with results from other methods. 1 a