Session G09: Mini-Symposium: The Cosmic Microwave Background and Fundamental Physics on the Cosmic Frontier

Live

Observations of the cosmic microwave background have been key to our understanding of the early universe. The cosmic microwave background also contains invaluable information about particle physics that can be revealed through precision observations of the polarization anisotropies. In this talk I will review the implications of a detection of primordial gravitational waves from the early Universe and discuss the expected sensitivity for the next generation ground-based CMB experiment CMB-S4.   

Live

CMB-S4 is a major focus of the ground based CMB community. Three key science goals driving the technical requirements for CMB-S4 are: 1) searching for primordial gravitational waves resulting from an early period of accelerated expansion (inflation), 2) searching for new light relic particles in the early universe, and 3) providing a legacy survey of nearly half the sky at centimeter to millimeter wavelengths. Crossing critical thresholds for these science topics requires fielding the largest proposed payload of superconducting detectors on multiple telescopes across different sites. I will provide an overview of the CMB-S4 instrumentation plan with particular focus on its superconducting detector technology.   

Live

The next-generation CMB observations from projects such as CMB-S4 will open up new parameter space for exploring interactions of sub-GeV dark matter particles, in regimes largely inaccessible to present-day lab experiments. I will discuss prospects for dark matter searches with CMB-S4 and highlight its complementarity to other experiments.   

Live

Measurements of the cosmic microwave background (CMB) can constrain the sum of the neutrino masses and the number of relativistic species, expand our understanding of dark energy and dark matter, and set new constraints on cosmological models describing the first moments of the universe. Simons Observatory (SO) will measure the CMB in both temperature and polarization over a wide range of angular scales and frequencies from 27-280 GHz with unprecedented sensitivity. SO will field a set of three small-aperture telescopes that will observe at degree-angular scales and a 6-m large-aperture telescope with arcminute resolution. With over 60,000 detectors, SO's sensitivity represents a leap in performance over current experiments that will advance our understanding of the fundamental physics of the universe. I will give an overview of SO's projected performance and instrument design.   

Live

I will give an overview of the South Pole Telescope (SPT) surveys and experiment. The SPT is a 10-meter diameter telescope at the South Pole designed to measure the cosmic microwave background (CMB). The SPT-3G instrument, first deployed in the 2016-17 Austral summer, is a major upgrade in capabilities over previous generations of SPT cameras, with over 16,000 detectors configured for polarization-sensitive observations in three frequency bands (95, 150, 220 GHz). The SPT-3G maps of the temperature, polarization, and lensing potential of the CMB will have an unprecedented combination of depth (2 $\mu$K-arcmin in temperature at 150 GHz), resolution (1 arcmin), and sky coverage (1500 deg$^2$). This unique data set will enable broad and impactful science, including: sensitive constraints on primordial gravitational waves from a joint analysis with the BICEP/Keck experiment, probe the nature of current tensions on cosmological parameter constraints, improve constraints on the sum of the neutrino masses and additional light relativistic particles, and produce unique catalogs of high-redshift galaxy clusters and early star-forming galaxies.   

Testing Neutrinos with CMB-S4

Neutrinos remain one of the least understood particles in the standard model. I will describe how a future high-resolution CMB experiment such as CMB-S4 can test a variety of neutrino properties: the neutrino mass, interactions, and in combination with laboratory experiments, point towards the Majorana or Dirac nature of neutrinos.   

On Demand

Many well-motivated extensions of the Standard Model of particle physics predict new light degrees of freedom. In many cases, these new light states would have been in thermal equilibrium in the early universe. The extra radiation energy density from such new states would leave a number of imprints in cosmological observables. The temperature and polarization anisotropies of the cosmic microwave background (CMB) on small angular scales are a particularly sensitive probe of the density of light relics. Upcoming CMB experiments will significantly improve sensitivity to the density of light relics, and thereby provide broad and useful constraints on models of new physics. I will discuss the physics of light relics related to the CMB and the sensitivity anticipated from upcoming CMB surveys.