Cosmology Seminar - Precision Weak Gravitational Lensing: From Image Analysis to Cosmology Inference

Speaker: Xiangchong Li (Carnegie Mellon University)

Title: Precision Weak Gravitational Lensing: From Image Analysis to Cosmology Inference

Abstract:
Weak gravitational lensing shear introduces a subtle yet consistent distortion in the images of distant galaxies, caused by the mass that lies in between, making it an indispensable tool for mapping dark matter distribution and understanding the universe's expansion. The Stage-IV weak-lensing surveys will measure the weak-lensing shear across billions of galaxies with unprecedented precision, necessitating our measurement techniques to be refined to achieve less than one percent systematic error. This presentation will kick off with a concise overview of weak-lensing cosmology analysis using data from the Hyper Suprime-Cam (HSC) survey. Following this, I will present a newly developed analytical approach designed for the rapid and accurate measurement of shear distortion in galaxy images. Additionally, I will discuss potential advancements and applications of this approach for future explorations.