3:30–4:30 pm ERC 401
Host: Chihway Chang
Qianjun Hang (University College London) "Measuring the growth of structures of the universe"
The large scale structures (LSS) of the universe encode rich cosmological information. In this talk, I will mainly focus on three different measurements of the LSS. In the first part, I will talk about the angular cross-correlation between the Cosmic Microwave Background (CMB) and the local LSS. Two main features come from the spatial and temporal perturbations of the CMB photon trajectory due to LSS: weak lensing and the Integrated Sachs-Wolfe effect. I will talk about the measurements using DESI Legacy Imaging Survey and the Planck 2018 CMB maps, and briefly on the ‘lensing-is-low’ tension. In the second part, I will focus on the large peaks and troughs, or “superstructures”, in the galaxy density field, and the imprints on the CMB. In the last part, I will briefly mention Redshift Space Distortion (RSD) as an important probe for the growth rate of LSS. Using the groups and galaxies from the GAMA survey, I will show that despite the variation due to different galaxy properties and group masses, the growth rate can be robustly extracted down to small scales. Finally, I will also mention some of my on-going projects, especially the infrastructure work in LSST DESC.
