Cosmology-independent Estimate of the Hubble Constant and Spatial Curvature Using Time-delay Lenses and Quasars

Understand

With the distance sum rule in the Friedmann-Lema\^{\i}tre-Robertson-Walker metric, model-independent constraints on both the Hubble constant $H_0$ and spatial curvature $\Omega_{K}$ can be obtained using strong lensing time-delay data and Type Ia supernova (SN Ia) luminosity distances.

• This method is limited by the relative low redshifts of SNe Ia, however.
• Here, we propose using quasars as distance indicators, extending the coverage to encompass the redshift range of strong lensing systems.
• We provide a novel and improved method of determining $H_0$ and $\Omega_{K}$ simultaneously.