Caltech/IPAC Lunch Seminar

Weak gravitational lensing is one of the best probes we have of the dark Universe. Weak lensing measurements allow us to directly measure the growth of structure over cosmic time, and will be the basis of some of the strongest constraints on the nature of cosmic acceleration coming from the Euclid, Vera Rubin, and Nancy Grace Roman survey programs.

In this talk, I'll outline a new way to measure weak lensing using galaxy kinematics to infer the unlensed shapes of galaxies. This lets us control for almost all of the noise in weak lensing measurements, while largely eliminating the currently dominant sources of systematic error. I'll describe the method, talk about the recent first detection, and outline the current program for carrying out kinematic lensing measurements with the Roman telescope's spectroscopic survey. Even with the small fraction of Roman galaxies for which kinematic measurements will be possible, this method offers a factor of 3 gain in dark energy constraints relative to the primary Roman lensing surveys.