CMB Foregrounds: Problems, Parameterizations, and Progress


Hill, C. (2018). CMB Foregrounds: Problems, Parameterizations, and Progress. Perimeter Institute. https://pirsa.org/18050009


Hill, Colin. CMB Foregrounds: Problems, Parameterizations, and Progress. Perimeter Institute, May. 23, 2018, https://pirsa.org/18050009


          @misc{ pirsa_18050009,
            doi = {},
            url = {https://pirsa.org/18050009},
            author = {Hill, Colin},
            keywords = {Cosmology},
            language = {en},
            title = {CMB Foregrounds: Problems, Parameterizations, and Progress},
            publisher = {Perimeter Institute},
            year = {2018},
            month = {may},
            note = {PIRSA:18050009 see, \url{https://pirsa.org}}


The next frontiers in cosmic microwave background (CMB) science include a detailed mapping of the CMB polarization anisotropy, with goals of detecting the inflationary B-mode signal and reconstructing high-fidelity maps of the matter distribution via CMB lensing, as well as a first detection of CMB spectral distortions.  At this level of precision (~nK), Galactic and extragalactic foregrounds may be the ultimate limiting factor in deriving cosmological constraints.  I will discuss biases due to foregrounds in CMB lensing measurements, including the first calculation of the lensing bias due to the kinematic Sunyaev-Zel’dovich effect, as well as recent progress in developing novel foreground-free CMB lensing estimators.  I will then present methods to extend CMB foreground parameterizations in a systematic, flexible way, with applications to both polarization and spectral distortion measurements.  Using this framework, I will discuss spectral distortion forecasts for CMB spectrometer mission concepts, showing that high-significance measurements of the Compton-y and relativistic thermal Sunyaev-Zel’dovich signals can be expected, as well as a potential detection of the primordial mu-type distortion due to Silk damping of small-scale acoustic modes.