Future Cosmology with CMB Spectral Distortions and Secondaries

Speaker: Alina Sabyr (Columbia) In Person and zoom 

Zoom info: https://stanford.zoom.us/my/sihanyuan?pwd=QnpsUHZWWGJ2ekVYWmZVL3BmM0gzZ…

Spectral distortions – small deviations of the cosmic microwave background (CMB) energy spectrum from that of a perfect blackbody – probe the physical processes that occur in the primordial Universe (\mu-distortion) and at late times (y-distortion). In this talk, I will present a new instrument concept, SPECTER, that we forecast to observe the \mu-distortion at high significance while marginalizing over astrophysical foregrounds. Within the standard cosmological model, the \mu-distortion is sourced primarily by the energy injected via Silk damping and is thus sensitive to the primordial power spectrum at very small scales. Next, I will present a new constraint on the y-distortion from the re-analysis of the COBE/FIRAS archival data. The known source of the y-distortion is the thermal Sunyaev-Zeldovich (tSZ) effect – inverse-Compton scattering of CMB photons off of energetic electrons primarily located in galaxy groups and clusters. Therefore, y-distortion can give tight constraints on the mean ionized gas properties. Finally, upcoming CMB anisotropy experiments will provide high-resolution and low-noise component-separated tSZ maps. I will discuss the cosmological constraining power of several tSZ higher-order statistics. Using a large suite of halo-model-based simulations, we show that there is substantial non-Gaussian information in the tSZ maps that can be extracted in future analyses.