Colin Hill - IAS, Princeton, and CCA, Flatiron Institute

Tue, 02/12/2019 - 11:00am
Pupin Hall Theory Center, 8th Floor


"CMB-TNG: Next-Generation Cosmology and Astrophysics with the Foreground-Cleaned Microwave Background"

The cosmic microwave background (CMB) is the preeminent astrophysical source from which to extract information about fundamental physics, due to its clean, well-understood origin and immense constraining power on many types of new physics.  The next decade of CMB observations will yield answers to at least two fundamental questions: (1) did large-field inflation source the initial density perturbations in our universe? (2) what is the absolute mass scale of the neutrinos?  In this talk, I will explain the methods and data sets with which these answers will be obtained, via the search for primordial gravitational waves in CMB polarization maps and high-precision structure growth measurements through gravitational lensing of the CMB.  I will also highlight complementary constraints that will be extracted from other ``secondary’’ anisotropies in the CMB temperature generated by structure formation.  I will present ongoing work to measure these signals in data from the Atacama Cosmology Telescope (ACT), as well as next-generation forecasts for the Simons Observatory (SO), which will begin observations in less than two years.  Throughout, I will highlight novel foreground mitigation methods that I have developed, which are enabled by CMB observations at multiple frequencies.  Applied to upcoming ACT and SO data, these methods will yield transformative constraints on inflation, neutrino properties, and the growth of structure.  I will conclude with a look ahead to novel early-universe discovery space in measurements of the CMB energy spectrum.

About the speaker

Colin Hill is a postdoctoral fellow at the Institute for Advanced Study and the Center for Computational Astrophysics at the Flatiron Institute.  He obtained his Ph.D. in astrophysics from Princeton, following studies at MIT and Cambridge.  He subsequently worked at Columbia as a Junior Fellow in the Simons Society of Fellows.  He is currently leading data analysis efforts for several major cosmic microwave background experiments, including the Atacama Cosmology Telescope, the Simons Observatory, and CMB-S4, including joint analyses with wide-area galaxy surveys (e.g., the Dark Energy Survey).  His research interests encompass all aspects of physical cosmology, from the early universe to galaxy formation.