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 Telescope images and extensive ground-based spectroscopic follow-up of the massive 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 Omega(m) = 0.25 +/- 0.05 and w(x) = -0.97 +/- 0.07, which are consistent with results from other methods. Inclusion of our method with all other available techniques brings down the current 2sigma contours on the dark energy equation-of-state parameter w(x) by approximately 30%.
Jullo
Eric
E
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
Natarajan
Priyamvada
P
Kneib
Jean-Paul
JP
D'Aloisio
Anson
A
Limousin
Marceau
M
Richard
Johan
J
Schimd
Carlo
C