Institute for Advanced Study/Princeton University Early Universe/Cosmology Lunch Discussion

Over the past two decades, cosmological spectroscopic and photometric surveys have substantially advanced our understanding of galaxy formation and cosmology. Nevertheless, these two types of surveys possess unique advantages and disadvantages, often aligned with distinct scientific objectives. Combining them can yield a wealth of information. I present a series of my investigations utilizing both spectroscopic and photometric surveys to deliver novel measurements and results across various areas. These include precise measurements of the galaxy stellar mass function down to 10^5.0 Msun using our Photometric object Around Cosmic webs (PAC) method, the first measurement of baryon acoustic oscillations from galaxy-ellipticity correlations, and the use of magnification for measuring gravitational lensing as an independent and complementary method to shear. With the forthcoming Stage-IV cosmological surveys, these measurements can be significantly enhanced, addressing fundamental questions about the nature of dark matter and dark energy, as well as the physics of galaxy formation.