Presented By: Leinweber Institute for Theoretical Physics Cosmology Astrophysics Seminars
Cosmo-Astro Seminar | Weak Gravitational Lensing Cosmology with the Roman Space Telescope High Latitude Imaging Survey
Kaili Cao (Ohio State University)
NASA's Nancy Grace Roman Space Telescope is currently scheduled for launch in September 2026. Its High Latitude Imaging Survey (HLIS) will provide powerful tests of cosmological models through sensitive measurements of cosmic shear, galaxy-galaxy lensing (GGL), and galaxy clustering. As a member of the Roman HLIS Cosmology Project Infrastructure Team (PIT), my work spans both Shear & Clustering Measurement (SCM) and Cosmological Parameter Inference Pipeline (CPIP). In this talk, I will mainly talk about our Fisher forecasts of cosmological parameter constraints from combinations of the three probes mentioned above, carried out as part of the HLIS PIT's Data Challenge 1 (DC1). We find good agreement between Fisher analysis and Markov chain Monte Carlo (MCMC) analysis of the DC1 baseline data vector, and we exploit the flexibility of Fisher analysis to investigate varied priors on cosmological parameters and on nuisance parameters describing unknown biases in photometric redshifts or shear measurements. I will also talk about my work on optimal reconstruction of Roman images (which is actually the most essential part of my current research). As an incoming postdoc at UMich, I look forward to learning more about DESI (among other things) in the next few years.