October 24-28, 2016

Abstract

Cosmology with Gravitational Lens Time Delays

Sherry Suyu (Max Planck Institute for Astrophysics)

Gravitational lensing provides powerful means to study dark energy and dark matter in the Universe.  In particular, strong lens systems with measured time delays between the multiple images can be used to determine the "time-delay distance" to the lens, which is primarily sensitive to the Hubble constant. Measuring the Hubble constant is crucial for inferring properties of dark energy, spatial curvature of the Universe and neutrino physics.  I will describe the ingredients and newly developed techniques for measuring accurately time-delay distances with a realistic account of systematic uncertainties.  A program initiated to measure the Hubble constant to <3.5% in precision from gravitational lens time delays is in progress, and I will present the first results and their implications.  An exciting recent discovery of the first strongly lensed supernova has offered a rare opportunity to perform a true blind test of our modeling techniques.  The hundreds of new time-delay lenses that are expected to be discovered in current/upcoming imaging surveys, together with the high-resolution imaging capabilities of JWST for efficient followup, make gravitational lens time delays an independent and competitive cosmological probe.

Invited review