Supernova H0pe is a multiply-imaged Type Ia supernova (SN~Ia) and the second lensed SN to yield a measurement of the Hubble constant by the time-delay cosmography method, finding H0=75.4−5.5+8.1km s−1Mpc−1 (Pascale et. al 2025). We investigate the seven lens modeling approaches used to derive H0, assessing their agreement with ΛCDM constraints from SN~Ia surveys through a purely observational comparison. \textbf{We test each lens model by combining its predicted magnifications with the observed time delays to reconstruct the intrinsic SN~Ia luminosity and corresponding distance modulus.} While photometrically derived magnifications yield distance moduli in line with ΛCDM expectations, our comparison reveals that lens model predictions, even the most precise ones, \textbf{consistently overestimate the magnification, with an offset >1~mag}. This known bias, already appreciated by modeling teams, is independently confirmed through our analysis and highlights the value of lensed SNe as a tool to test model accuracy. If unaccounted for, such magnification biases can propagate into uncertainties in derived cosmological parameters, including H0, a critical challenge for precision cosmology using strongly lensed transients.
@article{arxiv.2510.07637,
title = {Testing Lens Models of PLCK G165.7+67.0 Using Lensed SN H0pe},
author = {Aadya Agrawal and J. D. R. Pierel and Gautham Narayan and B. L. Frye and Jose M. Diego and Nikhil Garuda and Matthew Grayling and Anton M. Koekemoer and Kaisey S. Mandel and M. Pascale and David Vizgan and Rogier A. Windhorst},
journal= {arXiv preprint arXiv:2510.07637},
year = {2026}
}
Comments
18 pages, 7 figures. Published in ApJ on May 6, 2026