Cosmological parameters from lenses distance ratio

TL;DR

This paper introduces an improved method for analyzing strong lensing data to better constrain cosmological parameters, accounting for galaxy structure and model uncertainties, and assesses its accuracy through Fisher matrix analysis.

Contribution

It presents a novel approach to include galaxy structure explicitly in lens modeling and addresses model dependence and nuisance parameters in cosmological inference.

Findings

Enhanced lens modeling method incorporating galaxy structure.

Quantitative assessment of parameter constraints via Fisher matrix.

Insights into the impact of model assumptions on cosmological results.

Abstract

Strong lensing provides popular techniques to investigate the mass distribution of intermediate redshift galaxies, testing galaxy evolution and formation scenarios. It especially probes the background cosmic expansion, hence constraining cosmological parameters. The measurement of Einstein radii and central velocity dispersions indeed allows to trace the ratio D_s/D_ls between the distance D_s from the observer to the source and the distance D_ls from the lens to the source. We present an improved method to explicitly include the two - component structure in the galaxy lens modeling, in order to analyze the role played by the redshift and the model dependence on a nuisance parameter, F_E, which is usually marginalized in the cosmological applications. We show how to deal with these problems and carry on a Fisher matrix analysis to infer the accuracy on cosmological parameters achieved by this method.