Cosmological Constraints from Strong Gravitational Lensing in Galaxy Clusters

TL;DR

This study uses strong gravitational lensing in galaxy clusters, specifically Abell 1689, to constrain cosmological parameters and dark energy properties, complementing other observational methods.

Contribution

It introduces a geometric test based on strong lensing in galaxy clusters to simultaneously constrain mass distribution and dark energy equation of state.

Findings

Consistent cosmological parameters with other methods.

Reduces uncertainty in dark energy equation of state.

Provides a new complementary approach to cosmological constraints.

Abstract

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 wx = -0.97 +/- 0.07 which are consistent with results from other methods. Inclusion of our method with all other techniques available brings down the current 2{\sigma} contours on the dark energy equation of state parameter wx by about 30%.