SLAC FPD Experimental Seminar: Cosmology with Large-Scale Structure: Past, Present, and Future

Abstract: Recent advances in astronomical observations have enabled increasingly precise measurements of the growth of large-scale structure (LSS): the cosmic web of galaxy clusters, filaments, and voids on scales larger than 10 Mpc. LSS provides a complementary probe to traditional cosmological observables, such as the primary cosmic microwave background (CMB) and Type Ia supernovae. In this talk, I will first review Stage-III imaging surveys carried out in the 2010s, which used weak gravitational lensing to constrain S8, a cosmological parameter that characterizes the amplitude of matter fluctuations. I will place particular emphasis on results from the Japan-led Subaru Hyper Suprime-Cam Survey and on the possible tension between S8 constraints from weak lensing and those inferred from the primary CMB. I will then introduce upcoming Stage-IV imaging surveys, including the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST), NASA’s Roman Space Telescope, and ESA’s Euclid mission. I will also discuss ongoing spectroscopic surveys, such as the Dark Energy Spectroscopic Instrument (DESI) and the Subaru Prime Focus Spectrograph (PFS), as well as recent indications of time-evolving dark energy. Finally, I will describe how combined medium-band imaging and spectroscopic surveys can enable high-redshift LSS measurements, providing new opportunities to further test the concordance cosmological model and explore physics in the primordial Universe.