Time delays between multiple images of lensed sources can probe the geometry of the universe. We propose a novel method based on free-form modelling of gravitational lenses to estimate time delay distances and, in turn, cosmological parameters. This approach does not suffer from the degeneracy between the steepness of the profile and the cosmological parameters. We apply the method to 18 systems having time delay measurements and find H0 = 69 ± 6(stat.) ± 4(syst.) km s-1Mpc-1. In combination with Wilkinson Microwave Anisotropy Probe 9, the constraints on dark energy are Omegaw = 0.68 ± 0.05 and w = -0.86 ± 0.17 in a flat model with constant equation of state.
M. Sereno, D. Paraficz (2014). Hubble constant and dark energy inferred from free-form determined time delay distances. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 437(1), 600-605 [10.1093/mnras/stt1938].
Hubble constant and dark energy inferred from free-form determined time delay distances
SERENO, MAURO;
2014
Abstract
Time delays between multiple images of lensed sources can probe the geometry of the universe. We propose a novel method based on free-form modelling of gravitational lenses to estimate time delay distances and, in turn, cosmological parameters. This approach does not suffer from the degeneracy between the steepness of the profile and the cosmological parameters. We apply the method to 18 systems having time delay measurements and find H0 = 69 ± 6(stat.) ± 4(syst.) km s-1Mpc-1. In combination with Wilkinson Microwave Anisotropy Probe 9, the constraints on dark energy are Omegaw = 0.68 ± 0.05 and w = -0.86 ± 0.17 in a flat model with constant equation of state.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
