Time Delay Cosmology

Eric Linder

Co-Director, Institute for Nuclear and Particle Astrophysics, Lawrence Berkeley National Laboratory
Director (LBL campus), Berkeley Center for Cosmological Physics

Thousands of strong gravitational lenses will be found by time domain surveys such as DES and LSST. Time delays between multiple images can be used to form a geometric time delay distance, a cosmological probe with some unique sensitivities and complementarities. In addition to the cosmology impact, I discuss the statistics challenge of accurate estimation of time delays between noisy, gappy lightcurves and recent results from the blind mock data Time Delay Challenge. I will also present new concepts and calculations for redshift drift, a direct probe of cosmic acceleration with a Hubble time delay, with synergy with galaxy surveys such as DESI.