The Weak Lensing Hat-Trick: Constraining Cosmology with Galaxy, CMB, and Kinematic Lensing

Abstract

We are entering an exciting decade in which weak gravitational lensing surveys are probing the universe with unparalleled volume and precision. These surveys will produce not only high-quality images of hundreds of millions of galaxies and high-resolution microwave sky maps, but also create challenges in terms of exquisite systematics control. In this thesis, I will present how weak lensing, combined with other probes, can play a crucial role in mitigating systematics and understandingdark energy and the growth of structure in the universe. Specifically, I will introduce “Kinematic Lensing” (KL). This novel technique combines imaging and galaxy kinematics to measure weak lensing with a signal-to-noise (S/N) ratio of approximately one per galaxy. I will demonstrate its potential in constraining cosmology in the context of the Roman Space Telescope and the Dark Energy Spectroscopic Survey (DESI). Furthermore, I will present results on how the combination of galaxy clustering, weak lensing, and cosmic microwave background (CMB) lensing can probe both cosmology and baryonic feedback in our universe using data from the Dark Energy Survey (DES) and the Planck satellite mission.