A Hubble Constant Determination Through Quasar Time Delays and Type Ia Supernovae

This paper presents a new model-independent constraint on the Hubble constant (H0) by anchoring relative distances from Type Ia supernovae (SNe Ia) observations to absolute distance measurements from time-delay strong Gravitational Lensing (SGL) systems. The approach only uses the validity of the cosmic distance duality relation (CDDR) to derive constraints on H0. By using Gaussian Process (GP) regression to reconstruct the unanchored luminosity distance from the Pantheon+ compilation to match the time-delay angular diameter distance at the redshift of the lenses, one yields a value of H0=75.57±4.415 km/s/Mpc at a 68% confidence level. The result aligns well with the local estimate from Cepheid variables within the 1σ confidence region, indicating consistency with late-universe probes.