Strong Gravitational Lensing and Dark Energy
Abstract
We investigate the statistics of gravitational lenses in flat, low-density cosmological models with different cosmic equations of state w. We compute the lensing probabilities as a function of image separation \theta using a lens population described by the mass function of Jenkins et al. and modeled as singular isothermal spheres on galactic scales and as Navarro, Frenk & White halos on cluster scales. It is found that COBE-normalized models with w > - 0.4 produce too few arcsecond-scale lenses in comparison with the JVAS/CLASS radio survey, a result that is consistent with other observational constraints on w. The wide-separation (\theta > 4'') lensing rate is a particularly sensitive probe of both w and the halo mass concentration. The absence of these systems in the current JVAS/CLASS data excludes highly concentrated halos in w < -0.7 models. The constraints can be improved by ongoing and future lensing surveys of > 10^5 sources.
Cite
@article{arxiv.astro-ph/0110093,
title = {Strong Gravitational Lensing and Dark Energy},
author = {Nick Sarbu and David Rusin and Chung-Pei Ma},
journal= {arXiv preprint arXiv:astro-ph/0110093},
year = {2009}
}
Comments
12 pages, 3 figures. Accepted for publication in ApJ Letters