Constraining the dark energy equation of state with double-source plane strong lenses

• Published in: Monthly notices of the Royal Astronomical Society Vol. 424; no. 4; pp. 2864 - 2875
• Main Authors: Collett, T. E., Auger, M. W., Belokurov, V., Marshall, P. J., Hall, A. C.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 21.08.2012; Oxford University Press
• Subjects: Astrophysics; Catalogues; Constraining; Cosmic microwave background; cosmological parameters; Dark energy; Equations of state; gravitational lensing: strong; Lenses; Planes; Stars & galaxies; dark energy; cosmological parameters; gravitational lensing: strong
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2012.21424.x

ABSTRACT We investigate the possibility of constraining the dark energy equation of state by measuring the ratio of Einstein radii in a strong gravitational lens system with two source planes. This quantity is independent of the Hubble parameter and directly measures the growth of angular diameter distances as a function of redshift. We investigate the prospects for a single double-source plane system and for a forecast population of systems discovered by re-observing a population of single-source lenses already known from a photometrically selected catalogue such as Cambridge and Sloan survey of wide arcs in the sky or from a spectroscopically selected catalogue such as Sloan Lens ACS survey. We find that constraints comparable to current data sets (σ(w) ∼ 15 per cent) are possible with a handful of double-source plane systems. We also find that the method's degeneracy between ΩM and w is almost orthogonal to that of cosmic microwave background and Baryon Acoustic Oscillations measurements, making this method highly complimentary to current probes.