Revisiting the effect of lens mass models in cosmological applications of strong gravitational lensing

Understand

Strong gravitational lens system catalogues are typically used to constrain a combination of cosmological and empirical power-law lens mass model parameters, often introducing additional empirical parameters and constraints from high resolution imagery.

• We investigate these lens models using Bayesian methods through a novel alternative that treats spatial curvature via the non-FLRW timescape cosmology.
• We apply Markov Chain Monte Carlo methods using the catalogue of 161 lens systems of Chen et al (arXiv:1809.09845) in order to constrain both lens and cosmological parameters for: (i) the standard $\Lambda$CDM model with zero spatial curvature; and (ii) the timescape model.
• We then generate large mock data sets to further investigate the choice of cosmology on fitting simple power-law lens models.