Astro Seminar: Frank Jia Qu

Speaker: Frank Jia Qu, Stanford U.

Title: Mapping the distribution of dark matter using the CMB as a backlight

Abstract: Dark matter not only provides the invisible scaffolding from which the birth of galaxies takes place, but by studying its distribution in our universe we can infer a great deal of information regarding the growth of structure and cosmic expansion. Measuring the gravitational lensing of the Cosmic Microwave Background (CMB) offers a unique and clean way to map all matter to very high redshifts, allowing us to constrain fundamental physics—including the sum of neutrino masses—and test the standard cosmological model.

This talk will present an overview of recent and forthcoming advances in this field, highlighting new CMB lensing results from the Atacama Cosmology Telescope (ACT), South Pole Telescope (SPT), and Planck. I will also describe our ongoing work to produce state-of-the-art lensing maps from ACT's final data release, which combines daytime and nighttime observations with Planck's large-scale measurements. I'll conclude by exploring the transformative potential of the Simons Observatory and the significant implications of these lensing measurements for our understanding of cosmic structure and the property of neutrinos