Strong Lensing and $H_0$
Abstract
Time delays from strong gravitational lensing provide a one-step absolute distance measurement. Thus, they measure independently of all other probes. We first review the foundations and history of time-delay cosmography. Then, we illustrate the current state of the art by means of two recent case studies that have been real breakthroughs: i) the quadruply imaged quasar lensed by a galaxy-scale deflector RXJ11311231, for which spatially resolved stellar kinematics is available; ii) the multiply imaged supernova "Refsdal", the first with measured time delays, lensed by cluster MACS1149.52223. We conclude by discussing the exciting future prospects of time-delay cosmography in the coming decade.
Cite
@article{arxiv.2307.05714,
title = {Strong Lensing and $H_0$},
author = {Tommaso Treu and Anowar J. Shajib},
journal= {arXiv preprint arXiv:2307.05714},
year = {2025}
}
Comments
Invited chapter for the book "Hubble Constant Tension" (eds. E. Di Valentino and D. Brout). This version: accepted version