Speaker
Description
Joint analysis of the clustering of Lyman-break galaxies (LBGs) and weak gravitational lensing of the cosmic microwave background (CMB) provides a means of constraining cosmological parameters such as $\sigma_8$ at high redshift. Furthermore, combining these two probes helps to break the degeneracy between $\sigma_8$ and the galaxy bias of the LBG population, offering improved constraints over those obtained via lensing or clustering alone. We exploit the large overlap between the footprints of the most recent data releases from the Hyper-Suprime Cam Subaru Strategic Program (HSC-SSP) and the Atacama Cosmology Telescope (ACT) to cross-correlate the CMB weak lensing measurements from ACT with the clustering of LBGs at $z \sim 4$ and $z \sim 5$ from HSC-SSP, in an effort to push the high-redshift frontier of $\sigma_8$ constraints. I will present the results obtained from the cross-correlation analysis, as well as a discussion of the considerations involved in ensuring unbiased results, such as the LBG sample selection and the treatment of low-redshift interlopers.