The wilkinson microwave anisotropy probe (WMAP) was a NASA space mission that made sensitive and accurate full-sky maps of the cosmic microwave background (CMB), which is the afterglow radiation…

This is a $400,105 grant awarded by the National Aeronautics and Space Administration (NASA) to The Johns Hopkins University, a private research university, to conduct a detailed analysis of maps and power spectra from the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck missions. The research will focus on three key tasks: 1) developing a novel likelihood method to extract cosmological information while fully propagating foreground uncertainties in CMB polarization data, 2) exploring the origins of a surprising non-zero signal in the Planck 353 GHz temperature/B-mode power spectrum, and 3) assessing the internal consistency and comparing the Planck high-resolution temperature anisotropy measurements to the South Pole Telescope survey data. This work aims to enhance the understanding of current dataset discrepancies and facilitate future cosmic microwave background (CMB) experiments. The grant does not have a set-aside designation and was awarded on February 25, 2019, with a completion date of February 24, 2023.

The wilkinson microwave anisotropy probe (WMAP) was a NASA space mission that made sensitive and accurate full-sky maps of the cosmic microwave background (CMB), which is the afterglow radiation from our infant universe. Planck was an ESA space mission that also made full-sky maps of the CMB, with higher angular resolution than WMAP (but also covering the WMAP resolution range again). The standard cosmological model is derived from these data. The data are characterized by statistical noise, systematic measurement uncertainties, and non-CMB foreground contamination. These must be well-understood to derive accurate and precise cosmological parameters of the model. Currently there are significant tensions and puzzles that prevent full and consistent use of these CMB data and other cosmological data. These tensions have become a major focus of the cosmological community. There are subtle, but important factors that affect the cosmological results that must be better understood. Therefore, we propose a detailed analysis of maps and power spectra from planck and WMAP that will focus on three specific tasks: 1) we propose to make a more rigorous assessment of galactic foreground removal uncertainties than have been made in current determinations of the reionization optical depth using CMB polarization data. We propose to use planck and WMAP polarization data to develop and test a novel general likelihood method to extract cosmological information while fully propagating foreground uncertainties. Not only will this research lead to a clearer understanding of the data at hand, but this work will also pave the way for the analysis of low-multipole polarization data from future CMB experiments, where instrumental noise will be far lower than IT was for WMAP or planck. The methodology we develop will help with robust foreground treatment essential in the future search for gravitational B-modes. 2) there is a surprising non-zero signal in the planck 353 GHZ temperature/B-mode power spectrum. We propose to explore the origins of this signal. Whether this signal is sky-based or instrument-based will have important ramifications for CMB studies, either in terms of polarization calibration practices or foreground characterization. 3) there currently exist tensions between the high resolution and low-resolution planck value for the expansion rate of the universe, as well as between the planck high resolution temperature power spectrum data and planck lensing data. There are also tensions between the planck high resolution data and other cosmological measurements as well. Precise fine-resolution CMB measurements are critical to future cosmological constraints including a cosmological detection of the SUM of the light neutrino masses using CMB lensing, and constraints on additional light species beyond the standard model neutrinos. We propose to explore high-multipole temperature anisotropy measurements from planck to both assess internal consistency and compare with newly released south pole telescope (SPT-SZ) survey maps. This proposed research will enhance our understanding of current dataset dissonances and will facilitate future experiments.